backtop


Print 105 comment(s) - last by DaleCoz7.. on Sep 16 at 11:26 PM


Germanium multi-junction solar cells have the highest potential for efficiency, surpassing solar cells' theoretical efficiency by more than 250 percent. However, germanium wafers, like the one pictured, is much more costly than a wafer of silicon. Now, a new machining method may help to slash its costs and reduce waste.  (Source: Eberhard Bamberg, University of Utah)

University of Utah mechanical engineers Dinesh Rakwal and Eberhard Bamberg have developed a new method using an electrified molybdenum wire to help reduce germanium solar cell costs by more than 10 percent.  (Source: Sumet Heamawatanachai, University of Utah)
New solar cell slicing method promises more streamlined mass production, less breakage

The most efficient solar cells currently on the market today are also the most expensive.  Unlike traditional silicon cells commonly used in photovoltaic consumer power setups, NASA relies on multijunction germanium, gallium-indium-arsenide, and gallium-indium-phosphide cells due to their much higher efficiencies.  Unfortunately germanium, a semiconductor like silicon, is far scarcer than silicon, with costs of about $680 per pound.  Further, the traditional cutting processes for the germanium cells brass-coated, steel-wire saws typically waste much of the wafer due to cracking, as germanium is a hundred times weaker than silicon.

A new cutting method has been devised by University of Utah engineers that promises to cut costs.  In the new approach, researchers used an electrified molybdenum wire 75 to 100 microns thick, often used in machining tools, to cut the cells (in contrast the typical saw is 170 to 180 microns thick).  The result was that they were able to cut cells with virtually no cracking and even cut thinner cells, previously infeasible to process, with little to no cracking.

Eberhard "Ebbe" Bamberg, an assistant professor of mechanical engineering, describes, "The idea is to make germanium-based, high-efficiency solar cells for uses where cost now is a factor.  You want to do it on your roof."

Currently, the 4-inch wafers in germanium solar cells cost $80 to $100 each.  Grant Fines, chief technology officer for germanium wafer-maker Sylarus Technologies in St. George, Utah says the new processing method may reduce costs at his company by more than 10 percent.  He states, "Anything that can be done to lower this cost ultimately will lower the cost of solar power per kilowatt-hour, which is beneficial.  That's why this technology Ebbe has come up with is very intriguing. (It will) reduce the amount we have to recycle and increase the yield.  It has the potential to give good savings, which helps enable this technology here on Earth."

The new method has been extended to a patent pending multiwire approach which Professor Bamberg compares to an egg slicer.  This approach should help make the method ready for mass production.

Germanium cells have a maximum theoretical efficiency of over 50 percent.  Using concentrators, efficiencies as high as 40 percent can be achieved.  With traditional silicon solar cells, 20 percent conversion of sunlight to electricity is about the theoretical maximum. 

Using current 300 micron thick wafers, the production yield was increased 30 percent.  With thinner 100 micron wafers, production was up a whopping 57 percent.  Perhaps most importantly, "kerf", or wasted germanium, was reduced by almost 22 percent.

The one remaining piece of the puzzle is to reduce the time of the cuts.  Currently the method takes 14 hours, while traditional cutting takes 6 hours.  While the new approach offers the possibility of crack free cutting, it currently has to be done a more ginger speed to avoid such cracking.  However, Professor Bamberg and his fellow researcher Dinesh Rakwal, a doctoral student in mechanical engineering, are confident they can reduce the time to 6 hours before long.  If this prediction holds true, this would be a very significant development to the solar power industry.

The new research appears in the Journal of Materials Processing Technology.



Comments     Threshold


This article is over a month old, voting and posting comments is disabled

Going the wrong way...
By mmcdonalataocdotgov on 9/15/2008 11:09:57 AM , Rating: 2
"Germanium cells have a maximum theoretical efficiency of over 50 percent. Using concentrators, efficiencies as high as 40 percent can be achieved."

So why do the conecntrators lower the efficiency of the cells, and as a follow on, why would anyone therefore use concentrators?





RE: Going the wrong way...
By 306maxi on 9/15/2008 11:15:25 AM , Rating: 2
They have a theoretical efficiency of 50% but the highest achieved is 40% using concentrators.

That's how I read it.


RE: Going the wrong way...
By Gzus666 on 9/15/2008 11:17:41 AM , Rating: 2
Theoretical being the key word here. In theory, you can get a maximum of 50% out of them. With concentrators, they have achieved 40%, close to the theoretical maximum that they can ever produce. Reading comprehension, it isn't just a phrase you heard once in school.


By mmcdonalataocdotgov on 9/15/2008 11:20:32 AM , Rating: 2
Okay, that makes more sense.


RE: Going the wrong way...
By eyebeeemmpawn on 9/15/2008 12:19:30 PM , Rating: 3
FYI

quote:
Most steel engines have a thermodynamic limit of 37%. Even when aided with turbochargers and stock efficiency aids, most engines retain an average efficiency of about 18%-20%


-wikipedia


RE: Going the wrong way...
By Spuke on 9/16/2008 11:52:10 AM , Rating: 2
What's a steel engine?


What are all the variables...
By mmcdonalataocdotgov on 9/15/2008 11:19:03 AM , Rating: 2
Okay, less breakage, and less kerf, but slower, but more wafers per slice, amortizing cost of new machinery...

I still don't know if this is a good thing. I think reducing the cost of a wafer from $680 per to $612 per might not get these on my roof even given the gained effeciency. How much more will this reduce my energy bills, and what is the break even range over conventional solar panels? I think this article should have been subtitled: For NASA administrators only.




By masher2 (blog) on 9/15/2008 11:24:40 AM , Rating: 4
> "How much more will this reduce my energy bills"

None at all. These cells are not used for residential power generation. Germanium multijunction cells are primarily used for satellites and other ultra-high yield applications. They have twice the efficiency, but can cost 10X as much.


RE: What are all the variables...
By Keeir on 9/15/2008 11:47:01 AM , Rating: 2
http://www.bp.com/solarsavings.do?categoryId=90195...

Calculator from a major player in the Solar Market.

Note: If you install the panels yourself, or buy wholesale panels/labor you costs will be significantly less than the reflected total. But reasonably, I doubt you can install a quality system for less than 75% of the BP Retail Total.


RE: What are all the variables...
By theapparition on 9/16/2008 9:56:20 AM , Rating: 1
Wow. Just wow.

If I act now, it would only take me around 50 years to pay off a system at current energy prices. Even if prices were to significantly increase, there's no way I'd get a return on investment before the panels had to be replaced.

And some want taxpayers to subsidize this crap?


RE: What are all the variables...
By Spuke on 9/16/2008 12:51:57 PM , Rating: 2
Yeah, my wife and I were thinking about getting a solar system when we move but after learning that solar panels maybe need to be replaced after 10 years, we're not doing that.

How about a solar powered HVAC system? How much does a typical HVAC system draw?


By theapparition on 9/16/2008 3:31:15 PM , Rating: 2
So many factors. How big's your house. Where is it. How energy efficient. How many windows have southern exposure. How many people, etc, etc. And then, what kind of HVAC. Assume heat pump since that's fully electric.

Depending on your climate, HVAC usage can be as high as 50-60%. For my area, it runs about 40%. Considering that BP's largest solar array can only power 25% of my home's usage (on sunny days) it falls short. And then, what do you do when the sun goes down?

I'm all for solar research, and hope one day it will be feasible. But it's not now, won't be for another 10-20years (that's if we had a signifigant breakthrough today) and anyone who suggests otherwise is burying thier head in the sand.


Kerf
By austinag on 9/15/2008 10:39:12 AM , Rating: 3
Can anyone tell me why wasted germanium is called "kerf"?




RE: Kerf
By omnicronx on 9/15/2008 10:52:30 AM , Rating: 2
Its not, kerf is the term used usually when using a blade to cut something. It measures the the width of the blade at its widest spot. The bigger the kerf, the more material that gets used up by the blade when cutting. 22% less kerf although impressive, is not that big of a difference, i.e the blade now makes 8mm cuts instead of 10mm cuts.


RE: Kerf
By Gzus666 on 9/15/2008 11:05:12 AM , Rating: 2
True about percentage not being that great on one unit, but if you are cutting millions, the gains are there, clearly.


Want!
By shin0bi272 on 9/15/2008 4:45:08 PM , Rating: 2
I know that this isnt a solution for global power usage or anything but I'd still love to get a few (maybe 6 or 8) panels with this stuff on them. Not to save the planet or some BS like that (since we really would have to work hard to hurt the planet in the first place it would be almost impossible to stop a planet from getting warmer or colder) but to cut my power bill. I live in North Carolina USA where we didnt have much rain last year for almost 9 months. Thats a LOT of sunshine. I could cut my power bill out either completely or at least cut it drastically with solar panels with these wafers on them. Or leave my lights and pc's and AC on constantly and still pay about the same Im paying now... though it would be hard to sleep with the lights on LOL!




Where is Oliver?
By Oregonian2 on 9/15/2008 6:34:19 PM , Rating: 2
Anybody remember Oliver Germanium? Hasn't been around for a while, but lasted long into the Silicon age. He's baaaaaaaaaaaaaack!

Or at least by proxy. :-)




The point is!!!
By bobny1 on 9/16/2008 8:25:39 AM , Rating: 2
Storage is going to be the real issue for decades to come. The power companies will switch to cheaper solar, wind, etc. But the average electric bill will be higher and higher and the average Joe will continue to get screwed. Their profit will triple but unless the majority of people can control their own production , the big boys will continue the "power game" for ever.




Stop the daily updates on solar "advancement"
By Lord 666 on 9/15/08, Rating: -1
By thepalinator on 9/15/2008 1:36:33 PM , Rating: 1
He'll grow up. I was just as optimistic about solar when I was a kid. I was so excited when Solar One was built and cheap solar power seemed just around the corner. That was a quarter-century ago though and we're really not any closer now than we were then.


By phxfreddy on 9/15/2008 3:58:54 PM , Rating: 2
Developments in nanotechnology could put solar into the running for producing unsubsidized power as little as 5 years from now.

The point is we have to get to 2013 somehow. Just stomping your feet and holding your breath until you turn blue does not make "alternative energy" get here any more quickly.

In fact one can argue that a healthy capitalist economy is what will bring the alternatives on quicker.

Thus I say DRILL DRILL DRILL ... and nuclear too!


RE: Stop the daily updates on solar "advancement"
By KC7SWH on 9/15/2008 7:38:52 PM , Rating: 1
How else are we to get our daily Mick vs. Masher?
I quite liked the article (I'm biased as the lab work was done in Utah).
I think that only through advances like this one will the efficiencies get high enough that it will reduce the cost per watt that it can truly become an (non government funded (read incentives, rebates etc.)) alternative power source.


By DaleCoz7 on 9/15/2008 10:42:57 PM , Rating: 2
Yeah, solar cells were oversold 25-30 years ago. Material science is hard . A lot of companies went bankrupt finding out that it often (usually) takes decades and tens of millions of dollars to move laboratory breakthroughs into reliable mass-production, and even then it doesn't always happen.

On the other hand, several companies have spent the decades and tens of millions to get it right. For example, First Solar is in mass production (on track for at least 420 megawatts production in 2008) and they claim that their current production cost is $1.14 per peak watt. Anybody can toss figures around, but when something is actually in large-scale production those figures actually mean something. Based on their production, revenue, and gross income figures the $1.14 is about right. The company formed in 1999, but the research base they are using goes back decades.

Rule of thumb: When somebody announces a lab breakthrough, on solar cells, figure you may or may not see something in ten to twenty years, depending on whether or not they find investors with deep pockets and a lot of patience. When somebody announces that they have something in production and have the capital in hand to expand into the half a gigawatt or more range, then take that seriously. At that point add a year to their schedule and you should be about right.

Based on that rule of thumb, solar cells will hit the moderately big time around 2011, with maybe half a dozen US companies doing more than a billion in sales, and global production in the 20 gigawatt per year range, approximately 5 times what it is now.

Will they be cheap then? Probably 30-40% less than they are now unless demand keeps outpacing supply.

Is that cheap enough? Depends on a lot of things: Location, what your application is, what the cost of competitors is over the 20-plus years, how much the various governments subsidize solar versus how much they subsidize other alternatives.

If solar cells do get competitive with traditional fossil fuel it won't be like flipping a light switch. Competitive in California or Hawaii is a lot easier than competitive in Washington state. A lot more sun and higher utility costs. Large hunks of Africa and some parts of South America are competitive now. The grid is miles away and gas for a generator has to come over a lot of miles of bad road. If those areas ever move up they'll probably go directly to solar without ever going the traditional utility route.


Cue comment from Masher
By 306maxi on 9/15/08, Rating: -1
RE: Cue comment from Masher
By omnicronx on 9/15/2008 10:56:59 AM , Rating: 5
Ever heard of listening to both sides of the argument? Between Masher and Mick, regardless of of who you think is correct, we really do get a good perspective from both sides.


RE: Cue comment from Masher
By 306maxi on 9/15/08, Rating: -1
RE: Cue comment from Masher
By CryptoQuick on 9/15/08, Rating: -1
RE: Cue comment from Masher
By BladeVenom on 9/15/2008 1:07:56 PM , Rating: 3
Yet another story about the coming of cheap solar. I've been hearing these stories since I was a little kid, and there still aren't any real cheap solar panels available. More people have seen bigfoot than dirt cheap solar panels.


RE: Cue comment from Masher
By thepalinator on 9/15/2008 1:33:50 PM , Rating: 4
Yeah, I can still hear Jimmy Carter telling us that solar power was the solution, not nuclear. That was like 30 years ago.


RE: Cue comment from Masher
By JasonMick (blog) on 9/15/2008 1:44:06 PM , Rating: 4
Except you couldn't be more wrong -- solar costs have dropped, and dramatically.

In Japan, PV system prices in Yen/W from 3750 to around 750 in just 1993-2002

Source:
http://www.solarbuzz.com/statsCosts.htm

In the U.S. costs have fallen from
$50 per peak watt in 1980 to $3 per peak watt today.

http://www1.eere.energy.gov/solar/myths.html
(U.S. Gov)

Sure its still expensive compared to coal power and its arguable whether this tech is at a point now where widespread adoption is justifiable from a pure financial perspective (from the mindset that broader adoption will help to drop costs quicker), but its pure foolishness to shut your eyes to the fact that costs have dropped dramatically.

Maybe you'll never see them "dirt cheap" (fossil fuel power isn't "dirt cheap", you pay $80-100 a month or more for it), but if current trends continue, it will become cost competitive with fossil fuel technologies in a couple decades.


RE: Cue comment from Masher
By masher2 (blog) on 9/15/2008 3:32:16 PM , Rating: 5
> "but if current trends continue, it will become cost competitive with fossil fuel technologies in a couple decades"

In sunny, low-latitude locations-- when the sun is up. You're forgetting that solar cell cost is only one of the three major problems preventing widescale solar implementation. Energy storage and transmission are the other two legs.

In a couple decades, I think it highly likely that solar can find widespread use in a peak shaving role. However, if electric-powered vehicles take off in a big way, peak electricity consumption may no longer come during the afternoon, but late evening, when the sun isn't available.

As I've said on countless occasions, I am adamantly for the continuation of solar power research. However, misleading people into the belief that powering the country from solar is "just around the corner" is very dangerous. Even by the most optimistic scenario, solar power won't even be able to supply just the *growth* in electricty demand over the next three decades. Yet we're already blocking the construction of new coal and nuclear plants. That's not a sane energy policy. If not corrected, it will have serious consequences within a generation.


RE: Cue comment from Masher
By McDragon on 9/15/2008 5:16:52 PM , Rating: 3
Actually low-latitude locations do not make much difference on PV - if the incident angle matches the latitude, the 'thicker' atmosphere is mostly offset by higher efficiency in colder climates

And there are some solutions available to those problems you mention.

You could use the energy to produce Hydrogen fuel (although you'd waste most of the energy doing so).
If your location supports it, you could pump water into a mountain lake with an efficiency (electrical to potential) of nearly 90%. Back down through a turbine is quite efficient as well.
If electric cars take off, you could charge them while people are at work, and drain a predefined percentage during peak hours in early evening - using the collective car park as a massive short term storage.

I would agree to blocking coal power, but nuclear power has only one shortcoming IMO - That people fear that which they don't understand.


RE: Cue comment from Masher
By Myg on 9/16/2008 6:55:39 AM , Rating: 1
"That people fear that which they don't understand."

Sterlity and genetic alterations are quite well understood.


RE: Cue comment from Masher
By theapparition on 9/16/2008 8:42:30 AM , Rating: 4
Please list one instance in the US where someone was mutated or rendered sterile from the local nuclear power plant.

Just one.

Until then, just go away.


RE: Cue comment from Masher
By Spuke on 9/16/2008 3:03:36 PM , Rating: 2
quote:
Sterlity and genetic alterations are quite well understood.
This comment wasn't generated from irrational and ignorant fear at all.


RE: Cue comment from Masher
By randomly on 9/16/2008 9:36:38 AM , Rating: 3
One of the interesting side effects of widespread electric powered vehicles use though is all the worn out battery packs. Worn out means down to 80% capacity. Surplus used battery packs out of vehicles could become a major resource for distributed power storage from the shear volume of supply.

A few old battery packs hooked up to your roof solar panels and your house becomes the equivalent of a hybrid car. You draw power from the grid when you need it, and don't when you can supply yourself locally.

You can also charge off the grid when grid supply is available and/or cheap even if you have no solar panels. Charge your car off the packs when you get home, etc. Distributed load leveling/matching.


RE: Cue comment from Masher
By BladeVenom on 9/15/2008 4:00:14 PM , Rating: 2
quote:
Except you couldn't be more wrong -- solar costs have dropped, and dramatically.

I said they aren't cheap, and they aren't. I never said they haven't come down in price. Old predictions were that everyone would have them by now, and they wouldn't cost much more than shingles.

quote:
it will become cost competitive with fossil fuel technologies in a couple decades.

I heard that over 30 years ago, and it hasn't happened yet.


RE: Cue comment from Masher
By Spuke on 9/16/2008 3:08:04 PM , Rating: 2
quote:
I heard that over 30 years ago, and it hasn't happened yet.
Come on Blade, you know that lessons from the past are just voodoo and hookeyslark. Besides, today's modern man (child) is just SO much more informed and educated than those rusty old bastards of yore. They're just old and ignorant.


RE: Cue comment from Masher
By porkpie on 9/15/2008 11:20:54 AM , Rating: 3
quote:
to disregard renewables as being part of the solution
Because they aren't. They all suck right now. They can generate enough power to give enviros a warm and fuzzy, but not nearly enough to actually solve any problems.

We used to be smart enough to pick the best solution for the problem. Guess that's considered old fashioned nowadays.


RE: Cue comment from Masher
By spuddyt on 9/15/2008 2:30:50 PM , Rating: 2
the most effective method RIGHT NOW is hydrocarbons, both renewable and nuclear are ideas for the future


RE: Cue comment from Masher
By Gzus666 on 9/15/2008 2:44:26 PM , Rating: 2
Nuclear is an idea for the future, even though it has been actively generating power across the world, more efficiently than anything else we have for what, the better part of a half century? People have been ravenously anti-nuclear for years, cause of unfounded fears and a silly dogma placed on it.


RE: Cue comment from Masher
By Chernobyl68 on 9/15/2008 3:34:25 PM , Rating: 2
I wouldn't say their fears about nuclear are unfounded, Chernobyl and Three Mile Island are enough to give anybody pause. However, new designs drastically reduce the possibilities of accidents, and should be pursued. The problem is, the majority will never think of anything but those accidents.


RE: Cue comment from Masher
By masher2 (blog) on 9/15/2008 3:40:34 PM , Rating: 5
> "Chernobyl and Three Mile Island are enough to give anybody pause"

Not anyone with common sense. TMI in particular demonstrated just how safe reactors are -- a meltdown occurred, and yet no one was killed or harmed in any way. Even those workers inside the plant received less radiation than they would have from taking a vacation in Denver.

As for Chernobyl, that was simply an object lesson in how not to build a reactor. As you well know, no Western nation has ever built a positive-void RBMK-type reactor, because they are inherently unsafe. . . especially when built without any sort of containment dome at all, as Chernobyl was.


RE: Cue comment from Masher
By Gzus666 on 9/15/2008 5:21:42 PM , Rating: 2
DING DING DING, get this man a prize. I would be willing to bet more people have died mining coal, or in a coal plant then have died in nuclear accidents.


RE: Cue comment from Masher
By randomly on 9/16/2008 9:24:01 AM , Rating: 2
Unfortunately there is a very large portion of the population that doesn't have a realistic view of nuclear power. They just think it's scary and that's about as much as they know. It's going to take years of marketing to change people mindset on that one.


RE: Cue comment from Masher
By Spuke on 9/16/2008 3:12:50 PM , Rating: 2
quote:
It's going to take years of marketing to change people mindset on that one.
Forget waiting! Just shove it down peoples throats like solar, wind, and CFL's are doing.


RE: Cue comment from Masher
By sigilscience on 9/16/2008 10:02:27 PM , Rating: 2
quote:
Forget waiting! Just shove it down peoples throats like solar, wind, and CFL's are doing.
Actually there was a Zogby poll a few months ago that showed more people wanted nuclear power than wind or solar.


RE: Cue comment from Masher
By masher2 (blog) on 9/15/2008 11:27:31 AM , Rating: 5
> "but it's not the be all and end all when it comes to power generation "

If and when the day ever comes that solar power is even close to as practical and cost-effective as nuclear, you'll hear me shouting its praises from the rooftops.

But until then, it belongs in the lab, not the marketplace.


RE: Cue comment from Masher
By JasonMick (blog) on 9/15/2008 11:37:25 AM , Rating: 5
The research that this article sites was done in the lab ;)

And as to the original op, I agree with the responding op that states that its good that both Michael and I get a chance to share our perspective. The world is seldom black or white, but usually gray.

I'm sure Mike would admit, I raise some good points, as would I admit that he raises some valid points as well.

I feel passionate about developing alternative energy to its full potential and continuing to support this kind of research, which is why it really makes me excited to write about this stuff. If you feel the same way, I'm glad we're on the same page, but if you disagree that's fine too, share your perspective, either in comments here, or in your own blogs, like Michael does.


RE: Cue comment from Masher
By Mitch101 on 9/15/2008 2:04:56 PM , Rating: 2
I do agree that solar is not ready for prime time but is on its way or alternatives are coming in the foreseeable future that are more green and have the reliability and lifespan that would make them worth while options.

But would it be so bad to say nuclear is a good alternative currently as compared to our coal systems at least until we can effectively create better green technologies? Why is it so bad if we build a few reactors until we find a better way?

I see gasoline today as many would see the steam engine of yesterday. We obviously can create a viable alternative to petroleum based fuels we just need to do this in bulk. I'm sure we will get even more efficient as time goes on. But alternative fuels are a viable solution today where solar panels are not there yet.

I certainly don't see building a few nuclear reactors as threatening the development of green technologies.

I also in a way think people would be more green is everyone selling green items didn't impose a guilt cost making the items have a X years to recover the cost attached to them. A lot of green items I have seen should cost less than their counterparts which means to go green means to guilt people out of their money instead of doing the right thing and offering them at a fair price to save the planet.


RE: Cue comment from Masher
By dl429 on 9/15/08, Rating: 0
RE: Cue comment from Masher
By Creig on 9/15/08, Rating: 0
RE: Cue comment from Masher
By masher2 (blog) on 9/15/2008 1:09:58 PM , Rating: 3
I have solar cells on my cellboat also. However, we're discussing commercial power generation. Excluding a few remote and vacation areas, nearly every home in US and Canada is already connected to the existing power grid.

I'm sure your friend has a very nice system. It comes at a per-KWh cost probably ten times higher than commercial power..and at night or during cloudy weather, will provide nothing whatsoever. Those "battery banks" will be exhausted almost immediately if they're trying to supply anything above the level of a light bulb or two.


RE: Cue comment from Masher
By Creig on 9/15/2008 3:01:38 PM , Rating: 1
masher, you're making deliberately misleading remarks again.

1) His system still puts out juice during cloudy weather, although at a reduced rate. Your "during cloudy weather will provide nothing whatsoever" claim is completely false.

2) And about your "those battery banks will be exhausted almost immediately trying to supply anything above the level of a light bulb" statement? We were there for a three day weekend and never ran out of juice despite have three women and two guys in the A-frame and my in-laws two friends living in the main cabin. We ran the lights when we wanted, the TV, the microwave, laptops, hair dryers, etc. It was all completely transparent to us and we never had to do anything except plug in our appliances.

So despite the initial cost, I think he's done very well equipping himself with useful amount of electricity while living in a remote area. Heck, I wasn't even without the internet for the weekend because he had a satellite internet service provider and a wireless router.

So please, stop trying to downplay those scenarios where solar power makes sense. It just makes you look desperate for any excuse to completely dismiss all solar technology.


RE: Cue comment from Masher
By masher2 (blog) on 9/15/2008 3:24:33 PM , Rating: 3
> "So please, stop trying to downplay those scenarios where solar power makes sense"

I've already said solar can make sense for the ~0.1% of locations which lack grid availability. However, in the case of your friend, I strongly suspect a small natural gas generator would have filled his needs for probably 1/10 the cost, especially given the high latitude, and the fact he likely has to bring in natural gas or some similar fuel anyway for winter heating.

No one is disputing that solar *can* work. With enough money and resources, he could power his entire cabin with hamster wheels. But that's besides the point, isn't it?


RE: Cue comment from Masher
By Gzus666 on 9/15/2008 3:30:57 PM , Rating: 2
Hamster Wheel Technology, it is the wave of the future. This had me rolling, seriously.


RE: Cue comment from Masher
By Creig on 9/15/2008 4:04:56 PM , Rating: 2
He does have a large gas generator in a shed near the A-frame. He originally bought it because he was unsure how well the solar system would work and if it would provide enough juice to meet demand plus keep the batteries charged.

He's putting it up for sale because it hasn't been used in 10 years.

And "my point" is that you keep making disparaging remarks about solar when obviously it works quite well depending on the situation. He wanted a low-maintenance system that basically ran itself and that's what he has. And he did it on a budget.


RE: Cue comment from Masher
By masher2 (blog) on 9/15/2008 4:22:26 PM , Rating: 3
> "And he did it on a budget"

No he didn't. Not if you're running high-amp devices off battery packs. A typical residential battery pack uses 12V RV batteries. These are about $5K for 10, when bundled with inverter and control electronics. That'll give you around 1000 A-h of current. After inversion losses, that's about 9.6 KW-h of stored juice. Ontario is going to see up to 16 hours of darkness during the winter -- that only works out to about 600 watts/hour. That's only 1/5 of what your average household uses. We'll be kind, though, and assume you're not running refrigerators, dryers, A/C, or any of the truly high-load pulls. So one pack will be sufficient...but you have to replace it every 5 years or so.

Next, we turn to the solar panel itself. Even Phoenix has only an AF of about 33% -- Ontario is probably lucky to get 30 in the summer, and 15% in the winter. That means to keep those batteries charged, you need an array with a peak capacity of about 80 KW * coloumetric charging losses in the batteries (70%) = 100KW. At $5/watts, that's $100K just for the panels.

Throw in $10K to install the whole system, and you're at $115K ...plus another $5K every few years.

Or, he could have simply paid $4,000 for an auto-start natural-gas powered generator.

Yes, you're right-- he was really on a budget.


RE: Cue comment from Masher
By Fiendish on 9/15/2008 8:55:45 PM , Rating: 3
Can someone please do the math on hamster wheel power for this house? I'm beginning to think it may be the cost efficient way to go.


RE: Cue comment from Masher
By DaleCoz7 on 9/15/2008 10:12:05 PM , Rating: 2
Ummm. Twenty thousand peak watts of solar panels to power a cabin in the woods? Might want to check the math on that one. The BP solar calculator mentioned elsewhere on the thread considers a 10k installation for a house a large installation. It doesn't even go any higher than that.

Move the decimal point to the left one place and you might be in the ballpark. That puts you in the BP small system category, which makes sense, not at double what they recommend for a large house.


RE: Cue comment from Masher
By masher2 (blog) on 9/15/2008 10:22:42 PM , Rating: 2
> "Move the decimal point to the left one place and you might be in the ballpark"

The math is correct; I invite you to do the calculations yourself. The reason the 'BP solar calculator' doesn't rise that high is few people are silly enough to buy an installation large enough to keep batteries charged throughout 16 hour Northern-latitude winter nights.

If you just want an installation primarily for peak shaving during prime daylight hours, you obviously need far less.


RE: Cue comment from Masher
By DaleCoz7 on 9/16/2008 11:18:57 AM , Rating: 2
Masher says: The math is correct; I invite you to do the calculations yourself.

Okay. 20k watt peak * 8hrs = 160k watts. Divide by two for various inefficiencies and losses gets you your 80k watt/hours. How many watt/hours per month is that? Multiply by 30. That gives 2400k watt/hours per month.

The estimates of monthly household usage I've seen are in the 600-900k watt hours per month range. That's for a house with all the trimmings. So you have to be off by a factor of at least 3. You are probably off by a factor of 10. This is a cabin without the big ticket energy users like electric space heating and (at least in the winter) air conditioning. They probably don't use more than 200k watt hours per month.


RE: Cue comment from Masher
By masher2 (blog) on 9/16/2008 12:07:04 PM , Rating: 2
> "Okay. 20k watt peak * 8hrs = 160k watts"

First mistake. A system with a 20KW peak will only generate 1/3 that amount (a 33% Capacity Factor) in a location like Phoenix. In Ontario, 20% is an optimistic figure-- the weather is cloudier, and the latitude higher:

http://en.wikipedia.org/wiki/Capacity_factor

So the true amount of power generated is closer to 1440 Kw-h/month, not 2400.

> "The estimates of monthly household usage I've seen are in the 600-900k watt hours per month range."

Second mistake. Canada averages 15,645 Kwh per year per capita:

http://www.nationmaster.com/graph/ene_ele_con_perc...

Convert to months and assume a household size of two and you get a value of 2600 KW-h. That's for a normal household. I assumed a value of nearly half that, since this is a small cabin.

My figures were correct. If anything, they understated the size of the system needed.


RE: Cue comment from Masher
By DaleCoz7 on 9/16/2008 1:06:24 PM , Rating: 2
Masher says:

"So the true amount of power generated is closer to 1440 Kw-h/month, not 2400."

Wouldn't mind seeing the math on that. I come up with 2880 Kw-h/month using your figures:

20k * 24 hours * .2 (20 percent) to get the number of watt/hours per day, then times 30 to get watt/hours per month. Granted you don't get 24 hours of sun shine, but that's why you have to divide the capacity factor by five (or multiply by .2).

As to getting the average power consumption for a household by looking at per capita power use, that makes no sense. Per capita power use is not just household use. It also includes manufacturing, retail, etc. It's total electricity use by the country divided by the number of people in the country.

Unless the guy's cabin is generating part of the electricity for the WalMart next town over and part of the power for the nearby snowmobile factory, and part of the electricity for Alberta's street lights and government building, your numbers are way high--again, probably by a factor of close to 10. If you want to look at household electricity use without all of the stuff that doesn't apply, you have to look at household electricity. Period.

Another way of figuring this out: You're using 9.6 kwhs in your calcs. How much solar panel does it take to generate 9.6 kwhs in a day? Use your 20% of peak watts figure:

(9600/24) * .2 = 2000 peak watts

Your 9.6 kwh battery couldn't store anywhere near the juice generated by a 20,000 watt/peak panel, so there would be no point in having anywhere near that large of a solar array.

Add in another 1000 peak watts for daytime usage and you get maybe 3000 peak watts total. Add in various conversion losses and you might bump that to 4000, though I doubt it. Not cheap, but a small fraction of your initial figure.


RE: Cue comment from Masher
By masher2 (blog) on 9/16/2008 1:45:07 PM , Rating: 2
> "Wouldn't mind seeing the math on that. I come up with 2880 Kw-h/month using your figures:"

You forgot your original divisor of two, to allow for, as you put it "various inefficiencies and losses". I left it alone, as with the actual coulometric charging losses (30%), inverter conversion losses (20%) and a few other factors, its fairly close.

> "Per capita power use is not just household use. It also includes manufacturing, retail, etc"

True. However, I used the per-capita figure of barely over one person. The average household size in Canada is 2.5 people. So my figures are still fairly close to inline with actual household energy usage.

> "9600/24) * .2 = 2000 peak watts"

Again you've forgotten coulometric and inversion losses, as well as the direct usage during the day. But much more importantly, you forgot that my 10 battery array example was just for illustrative purposes. An array that size isn't sufficient to run a residence through a lengthy night. The OP himself claims this site uses a total of 60 batteries, not 10.


RE: Cue comment from Masher
By DaleCoz7 on 9/16/2008 2:50:35 PM , Rating: 2
Masher:
quote:
You forgot your original divisor of two, to allow for, as you put it "various inefficiencies and losses". I left it alone, as with the actual coulometric charging losses (30%), inverter conversion losses (20%) and a few other factors, its fairly close.


Actually, I put that in to (a)simulate the factors that you claim would reduce actual power from 33% to 20% of peak, and (b)To take into account conversion losses. So you're actually double counting if you use 20% and still cut the figure in half.

Masher says: "Again you've forgotten coulometric and inversion losses, as well as the direct usage during the day."

Really? And here I thought I covered that when I said:

"Add in another 1000 peak watts for daytime usage and you get maybe 3000 peak watts total. Add in various conversion losses and you might bump that to 4000, though I doubt it."

Masher says: "> "Per capita power use is not just household use. It also includes manufacturing, retail, etc"

True. However, I used the per-capita figure of barely over one person. The average household size in Canada is 2.5 people. So my figures are still fairly close to inline with actual household energy usage."

Really? Earlier you said you were assuming two people per household. More importantly, your calculation from per capita figures have Canadians using approximately 3 times as much electricity per household as us extremely wasteful Americans. That is almost certainly much too high. Even if it wasn't, you still have a cabin in the woods sucking down nearly twice as many watt/hours per month as an average US house. (1300 watt/hours versus 600 to 900). Half to a third of the average US household electricity budget would be a much more reasonable top-end estimate.

Masher says: "more importantly, you forgot that my 10 battery array example was just for illustrative purposes. An array that size isn't sufficient to run a residence through a lengthy night."

I don't think it's a matter of me forgetting it as of you not saying that in the first place. As a matter of fact you say:

"So one pack will be sufficient...but you have to replace it every 5 years or so."

You don't specify any other batteries. You just go on to price the panels. Okay, just so we're clear on this: early on in your post you talk about a barebones system based on minimal batteries. Later on you give us solar cell numbers for a much larger (actually rather opulent)system. I didn't catch that, and I doubt that anyone else would unless they ran the numbers and (like me) said "this doesn't add up".

More importantly, your numbers hinge on a cabin requiring much more electricity than a US house. Not going to happen. You are still off by a factor of close to ten.


RE: Cue comment from Masher
By masher2 (blog) on 9/16/2008 3:08:30 PM , Rating: 2
> "Actually, I put that in to (a)simulate the factors that you claim would reduce actual power from 33% to 20% of peak"

I'm not sure if you're intentionally being obtuse or not, but the two are in no way related. See the links I provided. A 20% CF for a solar site in Ontario is actually very optimistic.

That factor, though, relates *only* to the power exiting the PV cells themselves. To store that power into batteries involves further coulometric charging losses. Removing that power and inverting it into AC current incurs stil further loss.

This really shouldn't be that difficult for anyone to understand.

> "Really? Earlier you said you were assuming two people per household"

Again, you seem to be struggling with a language barrier. What I said was this:
quote:
assume a household size of two and you get a value of 2600 KW-h. That's for a normal household. I assumed a value of nearly half that , since this is a small cabin.
To anyone who comprehends plain English, it's clear I used a figure of just over half the usage of two people. That's to compensate for this being a small cabin, and *not* a full-sized house.

> "early on in your post you talk about a barebones system based on minimal batteries"

Once again-- read the posts. The system discussed has not changed. The OP claimed this cabin was sufficient to run whatever he wanted, whenever he wanted -- laptops, TVs, hair dryers, microwaves. He was visiting a couple, so we should assume at least three people in this cabin at once. The location is Ontario, which means long periods without sunlight. The rest devolves from that.

His claim is a fraud. A PV system capable of such would cost easily $100K, if not significantly more.


RE: Cue comment from Masher
By DaleCoz7 on 9/16/2008 6:53:09 PM , Rating: 2
Masher: I'm going to ignore the comments that appear to be intended as personal attacks and simply reiterate: For your numbers to work a cabin in the woods would have to take more electricity to run than the average US household uses. That makes no sense because many of those US households use electric heat and air conditioners. Your numbers are simply wrong. They are too high by at least five and probably ten times.

To illustrate that, lets use your calculations so there is no quibbling about methodology. You say:

"20 kilowatts x 0.2 (Capacity Factor) x 0.7 (Coulometric Charging Efficiency) x 0.8 (Inverter Efficiency) x 720 hours/month = 1612 Kw-h per month."

Let's provisionally accept that. That means that your system for this cabin gives approximately twice the watt/hours of electricity that an average US household uses.

Here's a reality check: My monthly electric usage in a recent month was 1183 kwh, a bit above the average US household. That bill is for a huge old house with a mother-in-law apartment which is on the same bill, four desktop computers plus two laptops that we leave on 24/7, room air conditioners, baseboard electric heaters in some rooms, two outdoor lights that stay on all night, freezer, two old and inefficient refrigerators, dishwasher, electric cooking stove, two microwaves, three TVs (often on at the same time) teenage daughter that leaves lights on and uses a hair dryer a lot, and to add to the fun I have an electric lawn mower which I use weekly to mow a large lawn. Common sense. A cabin in the woods CANNOT take close to 500 kilowatt hours per month more electricity than my house does. Anybody reading this can do their own reality checks. How many of you have monthly electric bills that show 2600 kwh/month of usage? How many of you even have 1300 kwh/month of usage?

Here is another reality check: How on earth could you have to use 1600+ kilowatt hours/month in a cabin? You would have to average 1612 divided by 720 = 2238 watts per hour. If each of your 3 people has a CFL lightbulb on constantly that gives you maybe 45 watts each hour. If each of them is watching a separate HDTV 24/7 that's maybe 150 watts apiece times 3 = 450 watts each hour. The microwave might take a thousand watts, but probably not for more than an hour in a day at the very most. How on earth could you use that much electricity? Granted you have to be able to get through a 16 hour night, but you're going to be sleeping 7 or 8 hours of that. How are you going to use 2238 watts of electricity in an hour while you're asleep in a cabin? Makes no sense.

Masher: Common sense. On the one hand we have actual numbers on US household energy consumption. You can do a Google search and find them. We have my electric bill and bills of anybody else who wants to look. That says you are 5 to 10 times too high on how much electricity is needed.

On the other hand we have you doing a back of the envelope calc derived from per capita income. You apparently have no idea how much of that per capita electricity use is household use versus manufacturing, retail, etc, not even order of magnitude.

I'll help you out on that. The only number I've been able to come up with says that households are only 40% of total electric consumption, (http://www.npr.org/news/graphics/2008/july/househo... which would account for a goodly hunk of the difference between your numbers and mine. Multiply your 2640 kilowatt hours by .4 and you get 1056 kilowatt hours/month for an average Canadian house. Divide that in half and you end up with 528 kilowatt hours/month for the cabin.

So let's tentatively use your numbers with that correction. Plug them into your solar cell cost calculation and you are at $44,000 for the system. That's assuming that the cabin really does require half the electricity of a full-scale house. I very much doubt that, but even if you were right on that, the cost would still be less than half your initial figure.


RE: Cue comment from Masher
By masher2 (blog) on 9/16/2008 8:21:24 PM , Rating: 2
> "Here's a reality check: My monthly electric usage in a recent month was 1183 kwh"

Here's one for you. My usage last month was 4074 Kwh, for a four-person household in a very large, but very-well insulated home (substantially above local construction standards, with low-e argon-filled windows, R-19 walls, R-38 ceilings, and energy-star appliances.

Use a little commmon sense yourself. The figure I gave is one third of the electricity usage in my own home. Could a cabin use that much, especially with 2-4 people in it? Of course.

I'm glad to see you're no longer attempting to dispute my figures for total power generated. You can dispute the total usage all you wish, but the fact remains I chose a value only slightly above the per-capita usage for **one** person.

Worse, even if you pick a value only half that, the cost is still well in excess of $50K... a figure still far and away above doing it "on a budget", and ten times what a good natural gas generator would cost.

The OP's claims were tripe. There is no "budget" solar system that will supply any sort of residence with solar 100%...cabin or not.



RE: Cue comment from Masher
By DaleCoz7 on 9/16/2008 11:26:54 PM , Rating: 2
Masher says
quote:
Here's one for you. My usage last month was 4074 Kwh, for a four-person household in a very large, but very-well insulated home (substantially above local construction standards, with low-e argon-filled windows, R-19 walls, R-38 ceilings, and energy-star appliances.


Wow. Really? You've got to be paying $300-400/month for electricity. (Out of debate mode for a minute) If that's true you might want to get some things checked out. That's way out of line. Even if you're in a hot climate and keep your air conditioner cranked there is something wrong there. That's got to be eating you alive. (back to debate mode)

I've often found that in one of these on-line arguments it's useful to step back and see what we agree and disagree on. We disagreed on how much power would get generated from a given amount of solar array, but we're close enough that the difference is not worth quibbling over.

We disagree on on how much electricity a cabin is going to need. There are two issues here (1)Your estimate of the average household electric use is between 2.5 and 4 times higher than mine. (2)You estimate that a cabin would take half as much electricity as an average full-scale house. I doubt that it would take more than a third and think it would probably take quite a bit less unless you set it up in a really stupid way.

Start with the second point because it's less contentious: Comparing the cabin to a house. First, we may not have as much to disagree about on this as we seem to. There are some things about this cabin that the OP didn't specify but that are vitally important. (1)How is it heated? (2)What kind of water heater does it have? If the answer to both of those questions is "Electric", then I would say half of the electric use of an average home is reasonable.

I would also say that whoever built the cabin was stupid if they did it that way. Space heating and water heating is about 2/3rds of the electricity used in homes that heat that way. It would be stupid to use expensive electricity just to generate heat, and I'm not aware of any remote solar installations that use electric heat. If the cabin uses propane or some other non-electrical source of energy for space and water heating, then the electric usage drops by two-thirds, to about one-sixth of what it would take to power an average house. So the key point here is 'how do they heat the cabin?' Almost certainly not with electricity, but if they do you are much closer to right--only off by two to three times rather than ten or more.

Now the contentious part: Your numbers for an average household are approximately 2.5 to 4 times as high as mine. I got my figures from, among others, the US Department of Energy (http://www.eia.doe.gov/cneaf/electricity/esr/table... The estimates were for the US and ranged from 600 to 920 kilowatt hours per month. That's roughly one-fourth to one-third what you got.

Why the difference? Canada may have slightly higher electricity usage than the US--10-15%. The big difference though is that you use per capita electricity use to estimate average household demand. Per capita electric use is just total electricity used in a country divided by the number of people in that country. That's not the right way to get average household usage. As you agreed, per capita use includes industrial and commercial uses. That's 60% of the total. To get the household part of per capita you have to get rid of the 60% that's used outside of the household. You don't. If you did take the 60% out of your numbers, your numbers would be a little higher than mine, but within 10-20%. Close enough for these kinds of back-of-the-envelope calculations. That glitch in your calculation inflates your figures for the cost of the solar array by around 2.5 times.

Bottom line: If the OP's friend was dumb enough to try to heat his cabin and his water with electricity, then yes, it would be very expensive--under half your estimate, but still very expensive. If he heated with some other energy source, then my estimate of 2k to 3k peak watts is reasonable, and the cost of the panels themselves would be $10,000-15,000. That doesn't include batteries or inverters or installation, but overall the system should fit within the income of the people the OP talked about.



RE: Cue comment from Masher
By masher2 (blog) on 9/16/2008 3:35:40 PM , Rating: 2
Here it is, all in one easy-to-understand calculation:

20 kilowatts x 0.2 (Capacity Factor) x 0.7 (Coulometric Charging Efficiency) x 0.8 (Inverter Efficiency) x 720 hours/month = 1612 Kw-h per month. That's just over the per-capita consumption of *one* Canadian citizen. The average household is 2.5 people. Given per-capita usage incorporates industrial and commercial usage, these two terms should balance.

The 20% CF is an average (and for Canada, an optimistic one). For summer days, they'll see 25%+. But a winter day is going to dip below 15%. Meaning during those months, the system is really going to be supplying more like 1100 Kh-h. On a fully overcast winter day, still less.

The Coulometric charge efficiency is based on lead-acid batteries. Li-Ion would nearly eliminate that term...it'd also quintuple the price of the battery array.

My figure of $115K is, if anything, optimistic. Given the OP has already admitted the system contains $15,000 in battery costs alone, I'm surprised you're still trying to argue such a system would be much cheaper.


RE: Cue comment from Masher
By porkpie on 9/16/2008 2:06:31 PM , Rating: 2
quote:
Add in another 1000 peak watts for daytime usage and you get maybe 3000 peak watts total. Add in various conversion losses and you might bump that to 4000, though I doubt it.
This may not be rocket science but its sure more complex than pulling a few numbers out of your *** and trying to make them work. You can't just add a few random figures and hope for the best.

My wife's parents have a solar system. They're in CA (a lot sunnier place than Canada) and they paid almost $20K for it. If they're not using air-con, it'll run their house maybe 30 minutes after sundown, that's it. With the air on at night, the system shuts down entirely and they're back on city power (batteries can't handle the load). Installing something that will run a house all night is hella expensive.


RE: Cue comment from Masher
By DaleCoz7 on 9/16/2008 4:55:11 PM , Rating: 2
If you have a specific problem with the numbers of mine that you quote please join in with that. Not much to respond to respond to at this point.

Thanks
Dale C.


RE: Cue comment from Masher
By porkpie on 9/16/2008 5:21:04 PM , Rating: 2
quote:
If you have a specific problem with the numbers of mine that you quote please join in with that
My specific problem is that your numbers don't add up. Anyone with the sense God gave a peanut knows you can't power your whole house with a cheap solar system. Your "a thousand here, a thousand there" calculation doesn't compare to real figures from real sources, like other people here have given you. Learn or stay stupid. Your choice.


RE: Cue comment from Masher
By DaleCoz7 on 9/16/2008 9:39:07 PM , Rating: 2
Personal attacks without content bore me. Been there, got tired of that when I was about 12.

Thanks

Dale C.


RE: Cue comment from Masher
By sigilscience on 9/16/2008 10:09:19 PM , Rating: 2
quote:
Anyone with the sense God gave a peanut knows you can't power your whole house with a cheap solar system.
I priced one for my last house. For a $32,000 package, the dealer would only guarantee a 10% drop in my utility bills. I can't even imagine what it would cost to run the whole house at night.


RE: Cue comment from Masher
By Creig on 9/16/2008 8:13:46 AM , Rating: 1
masher, has anybody ever told you that sometimes you come off as an ass? First was your "won't charge on cloudy days" comment, then came "can't run two light bulbs without sucking the system dry", and finally somehow coming up with $115,000 as your assumed cost. And all without having ever seen the system or had it described to you.

I understand that you don't like solar. We ALL understand it by now. But just because you're on some personal anti-solar vendetta doesn't mean that other people can't find solar to be useful and affordable.

Just for the record, there is no way this couple spent $115,000 on their solar system. None at all. They are retired teachers from Michigan who spent their weekends driving to the land to clear it, turn the felled trees into lumber and use that lumber to build the A-frame cabin. Bob then constructed an on-site woodworking shop and proceeded to make chairs, tables, doors, trim... Just about everything in both houses was personally built by him. And these are beautiful pieces of furniture. He even built a water tower above the wood working shop so that there would be sufficient water pressure for indoor plumbing in both houses.

He also designed, constructed and installed both solar systems. One of panels was built using components from an old satellite dish system so that it will automatically track the sun.

Do these sounds like the sorts of people to either have that amount of money to spend on solar or who will be WILLING to spend that much? No. Now, I don't know the exact cost but I do know the people. Perhaps the next time I talk with them I'll ask if they know exactly how many square feet of panels they have and what they paid for them. But if he had to shell out $115 grand for everything, he would have simply used the large generator he already owned instead.

From what I remember after looking at his system, he's using 24 batteries at the A-frame and 36 at the main house. The 24 batteries are currently 12 years old and I think the 36 batteries are only 8 years old. He was thinking of replacing the 24 bank just to be safe and I think he was looking at batteries around $250 each, not $500 as you're quoting. And obviously they're lasting FAR beyond your five year estimate.

Both battery and solar systems are interlinked so that he can shunt power as needed. They don't usually have guests so both systems are normally used to power the main house. Now, I'm not sure how long he's had the entire system, but I think the 24 batteries at the A-frame are the original ones he bought when he installed the solar system. So he's gotten at LEAST 12 years of use out of it so far and I'm sure he intends to keep on using it in the future. So every year he keeps on using it lowers his average overall cost per year that much more.

I'm sure you'll read my post and have yet another smartass answer. You seem to have an endless supply. I just wanted to share with other readers the fact that in some cases, solar can be the best choice for supply electricity and that it can be affordable as well.


RE: Cue comment from Masher
By masher2 (blog) on 9/16/2008 9:14:15 AM , Rating: 2
> "And all without having ever seen the system or had it described to you"

I'm not the one making wild claims without a shred of proof. Unless your "friend" has access to alien technology, he didn't build a cheap solar system capable of powering his cabin through the night. Period.

You're welcome to continue ignoring the laws of physics. But if you bring wild claims to a public forum, expect to see them challenged.

For the record, my cost estimate was actually very conservative. I size the system large enough to charge through a 16-hour winter night...but only if the previous day was clear. Assume a system large enough to operate through a day or two of cloudy water, and the cost is easily double that $115K figure.

> "and I think he was looking at batteries around $250 each"

By your own admission, he has 24+36=60 batteries. At $250 each, that's $15,000 right there, without a penny for solar cells or inverters. Ah, but he did it all on the budget, right? Did you not stop to think before you posted?

And for the record, yes, batteries will last longer than 5 years. If you use them rarely. If you're deep-discharging them every night, then


RE: Cue comment from Masher
By Creig on 9/16/2008 9:47:05 AM , Rating: 2
Whatever, masher. As I'd expected, you posted more smartass remarks instead of politely asking questions. I could care less what your "expert-on-every-subject" opinion is. They're retired teachers who built a system that works for them and did it using whatever money they had left over from their salaries after paying their normal living expenses and building the cabin and house.

You really need to get a life.


RE: Cue comment from Masher
By masher2 (blog) on 9/16/2008 12:13:41 PM , Rating: 2
quote:
As I'd expected, you posted more smartass remarks instead of politely asking questions
You mean, instead of politely accepting a fictitious system that quite obviously cannot exist? For an encore, will you berate us for not believing your friends also built a perpetual motion machine?

In the Canadian climate, it's utterly impossible to build a PV system capable of powering the average residence through nights and cloudy days without spending in excess of $100K. No amount of shouting and foot-stamping is going to change that.


RE: Cue comment from Masher
By Spuke on 9/16/2008 5:07:45 PM , Rating: 2
quote:
You really need to get a life.
Masher needs to get a life because he shredded (with facts no less) your fantasy solar power system? Actually, he provided good info that the rest of us can use in figuring out solar systems. All you did was show us that snake oil salesman still exist. Buyer beware a$$hole.


RE: Cue comment from Masher
By omnicronx on 9/15/2008 1:36:28 PM , Rating: 2
quote:
I recently went to Canada with my in-laws to visit some friends of theirs who own a couple cabins on a lake.
quote:
I was very shocked when we arrived and I saw that both the guest cabin (a very nice A-frame) and the main house were equipped with banks of solar panels, microwaves and indoor plumbing. .
Well if I had 3-4 million to spend per cabin on a lake then I would have installed all of that too. I know Tom Hanks did... (Saw his cottage last week)

If you are talking about cottage country in Ontario, just the land will cost you close to a million to be on the lake.

So yes, if you are a millionaire, solar can be a great solution. That is until your power goes out for 7 days because of one of the many bad storms they receive, and their solar power only lasts them about a day..


RE: Cue comment from Masher
By Creig on 9/15/2008 3:53:05 PM , Rating: 2
No, they're not millionaires. Not even close. In fact, they're both retired teachers from Michigan. They picked up the land from the Crown back in the 70s when they were selling lots in a few locations on the lake. They spent their weekends driving up to the lot in order to clear the land and build the cabins themselves. Took them a number of years to do it. These aren't mansions, just a nicely constructed A-frame cabin and a small single-level house.

They said that on occasional they've had to limit their electrical usage due to low sunlight, but they've never completely run out. And they've been living there for years. They constructed their system with both enough panels and enough battery storage to allow for occasional times of low sunlight.


RE: Cue comment from Masher
By Spuke on 9/16/2008 5:09:47 PM , Rating: 2
Can I have your fantasy solar installer come down to the States and install that system on my house? I sure would like a system that can power my house (I'm not on a lake) on the cheap.


RE: Cue comment from Masher
By randomly on 9/16/2008 9:46:42 AM , Rating: 2
quote:
But until then, it belongs in the lab, not the marketplace.


I disagree with this statement. I do agree that solar should not be oversold as a panacea because of the economic costs and power availability issues. However I think it has definitely reached the point where there is much to be learned by building large scale solar systems.

Cost effective solar power isn't just cheap solar cells but the cost of an entire power generating system include maintenance and infrastructure aging.

Although solar is not cost competitive with other large scale energy supplies yet, it's getting much closer than it ever has been before. Building some large scale solar facilities should be an invaluable learning resource to continue to push the costs down and solve the real world problems of large scale systems.

Should we set arbritrary goals like 30% solar power by 2020? No, that's an emotional decision without enough real information on costs, impacts, and results to make an informed decision. Solar development has a was to go yet, but I think it's time it started coming out of the lab.


RE: Cue comment from Masher
By omnicronx on 9/15/2008 11:28:36 AM , Rating: 2
You are absolutely correct, renewables will be part of the solution, in 20 years.. While masher does usually take it too far, efficient, cheap and pretty much clean energy is already available in the here and now.

For example: http://www.cbc.ca/technology/story/2007/04/26/tech... Wow the largest solar farm in North America, for a ground shaking 40MW! Now compare this too a 30 year old Nuclear power plant outside of toronto (there are really two that are combined), 3.5GW... that's 88 times the amount of power with 30 year old technology..

This is also a small plant, Ontario's largest produces 6.3 GW. For for fun I would also like to point out that using technology available for mass use right now, that areas further north would require a space about half the size of New York to generate as much power as a mid sized nuclear power plant.


RE: Cue comment from Masher
By Gzus666 on 9/15/2008 11:35:58 AM , Rating: 2
Agreed, while I agree with a lot of what I have seen from Masher, some of his stuff is a little dismal of the future of these technologies. But, in his defense, he does tend to say that he thinks they will be viable for supplements, which I have to say I agree with as well.

Nuclear just makes so much power for the area it takes up, resources input, and cost. This should be the number one power technology, then follow that with hydroelectric, and geothermal. Wind is kind of a joke, solar will get there, and eventually have it's time in the sun (solar pun, I win).


RE: Cue comment from Masher
By 306maxi on 9/15/2008 11:38:40 AM , Rating: 1
Valid points. But how are renewables going to be a part of the solution in 20 years time without large scale commercial trials and also government subsidies?

Here in the UK there has been some trouble building new Nuclear reactors and it's going to cause serious problems in the future. In Australia precisely 0% of energy comes from nuclear power. These countries definitely need to pick up their act or we'll be seeing brownouts and rolling blackouts and that would suck.


RE: Cue comment from Masher
By Gzus666 on 9/15/2008 11:48:50 AM , Rating: 3
I don't think anyone advocates stopping research towards these things. In fact, I believe I have seen Masher specifically state he is all for this research. It is just a matter of randomly jumping into these technologies as infrastructure, without doing the research, testing, and improvement first. We aren't toying with something like a game, or something that won't affect everyone if it isn't a success the first time. If they fail at implementing power, the problem hits everyone in the world financially.


RE: Cue comment from Masher
By Keeir on 9/15/2008 11:52:39 AM , Rating: 2
quote:
Valid points. But how are renewables going to be a part of the solution in 20 years time without large scale commercial trials and also government subsidies?


The problem is that many current alternative energies fail the requirements of being ready for large scale commercial trials. IE, I don't know many companies that would really attempt to roll-out large tests of technologies that are as much as 5 times more expensive than current solutions. Lets do more R&D (such as this article) until the technology has a reasonable shot of being compeditive before spending millions to billions on inefficient technology.


RE: Cue comment from Masher
By omnicronx on 9/15/2008 11:54:04 AM , Rating: 2
quote:
Valid points. But how are renewables going to be a part of the solution in 20 years time without large scale commercial trials and also government subsidies?
I am not saying do not fund Solar energy products, I am saying there is no reason to put all of our eggs in one basket when a viable and cheaper solution is already here. If Solar, an unproven, inefficient and costly source of power is receiving a large amount of funding, Nuclear, a proven, safe, and efficient source of energy should also be receiving a large chunk of this money, at least half in my books.

And Lets face it, even with 100% efficiency, we will one day have to figure out another way of collecting solar energy (perhaps similar to what they are doing in the Sahara, or that MIT project), because it is just not going to stack up very well versus other types of energy unless this can be done, especially when you consider that a solar farm is a huge waste of space, effects the wildlife around it, and can be effected by weather conditions.


RE: Cue comment from Masher
By nah on 9/15/2008 12:33:16 PM , Rating: 2
http://www.ez2c.de/ml/solar_land_area/

90 % of humanity live in areas where the solar irradiance is at least above 150 W/m2 .Even the northernmost areas have solar irradiance of atleast 100 W/m2. Total nuclear capacity now is around 365 GW .

quote:
Photovoltaic systems installed in the areas indicated by the dark disks on the map would produce an average electric output of 18 TWe, i.e. 3 TWe each when assuming a conversion efficiency from incident sunlight to electricity of 8 %. This corresponds to an energy output of 13,567 Mtoe per year (world total primary energy supply (TPES) in 2003: 10,579 Mtoe [4]). The following table lists the locations in the map to give an idea of land area requirements and availability, although the particular scenario shown is suboptimal for many political and technical reasons. Location / Desert Desert Size / km2 [5] Irradiation / W m-2 Area required / km2
Africa, Sahara 9,064,960 260 144,231 Australia, Great Sandy 388,500 265 141,509 China, Takla Makan 271,950 210 178,571 Middle-East, Arabian 2,589,910 270 138,889 South America, Atacama 139,860 275 136,364 U.S.A., Great Basin 492,100 220 170,455


The total area required is around 910019 km2--of largely barren wasteland--now for transmission-

quote:
Long-distance transmission of electricity (thousands of miles) is cheap and efficient, with costs of US$ 0.005 to 0.02 per kilowatt-hour (compared to annual averaged large producer costs of US$ 0.01 to US$ 0.025 per kilowatt-hour, retail rates upwards of US$ 0.10 per kilowatt-hour, and multiples of retail for instantaneous suppliers at unpredicted highest demand moments).[5] Thus distant suppliers can be cheaper than local sources (e.g. New York City buys a lot of electricity from Canada). Multiple local sources (even if more expensive and infrequently used) can make the transmission grid more fault tolerant to weather and other disasters that can disconnect distant suppliers.


RE: Cue comment from Masher
By masher2 (blog) on 9/15/2008 1:16:35 PM , Rating: 2
> "90 % of humanity live in areas where the solar irradiance is at least above 150 W/m2 .."

100% of humanity lives in an area where sunlight is unavailable for an average of 12 hours per day, and in a society that lacks the means to cheaply concentrate solar energy into a productive form.

Until we have a few quantum advances in energy storage and transmission technology, and similar ones in reducing the construction costs of solar cells, this technology will remain wholly unsuitable for widescale deployment. All the foot-stamping in the world won't change that.


RE: Cue comment from Masher
By nah on 9/15/2008 1:40:04 PM , Rating: 2
quote:
Until we have a few quantum advances in energy storage

Battery storage capacity has been increasing at a rate of over 1 % per annum for the past 100 years--it's not inconceivable that homes could have storage which would last them thru the hours when neither solar/wind supplies anything--since both don't work in the same time--since strongest winds blow at nights and sunlight is concentrated during the day--it would be a challenge to power large buildings-but not impossible

quote:
and transmission technology,


This already exists---look up my above post

I didn't mean for this to be a solution for the developed countries but for underdeveloped ones--governments there are riddled with corruption and don't have the inclination or energy ( no pun intended) to get the capital to build nuclear--that's why solar is having a tremendous impact-- NOW in the lives of citizens in such countries--they don't have to wait for their governments to supply them their meager power requirements --they can simply use solar--immediately --at prices lower than the mount they spend for kerosene, cow dung, leaves etc--at a saving of time and health as well--If a couple of million families can take charge of their energy needs immediately--without waiting for apathetic governments to supply them with power--whats so wrong about it ? Measuring solar energy in terms of cents/Kwh doesn't work in all the situations,all the time


RE: Cue comment from Masher
By masher2 (blog) on 9/15/2008 1:50:36 PM , Rating: 2
> "it's not inconceivable that homes could have storage which would last them thru the hours when neither solar/wind supplies anything"

In several decades, perhaps. Not now. That's the point. Solar is impractical at present for commercial power generation, and will remain so until technology advances substantially in several different areas.

> "This already exists---look up my above post"

Technology to cheaply transmit power long distances does not exist. HVDC will lose a substantial portion of the energy over continental distances, and superconducting lines can cost tens of millions of dollars per mile.

> " Measuring solar energy in terms of cents/Kwh doesn't work in all the situations"

It only works in the real world, yes. In fantasy-land where "money" is a fuzzily-defined quantity that the government possesses unlimited quantities of, its' no problem at all.


RE: Cue comment from Masher
By nah on 9/15/2008 2:11:14 PM , Rating: 2
quote:
In several decades, perhaps. Not now


I didn't say they'd have to be NOW

quote:
echnology to cheaply transmit power long distances does not exist. HVDC will lose a substantial portion of the energy over continental distances, and superconducting lines can cost tens of millions of dollars per mile.


quote:
HVDC links are sometimes used to stabilize against control problems with the AC electricity flow. In other words, to transmit AC power as AC when needed in either direction between Seattle and Boston would require the (highly challenging) continuous real-time adjustment of the relative phase of the two electrical grids. With HVDC instead the interconnection would: (1) Convert AC in Seattle into HVDC. (2) Use HVDC for the three thousand miles of cross country transmission. Then (3) convert the HVDC to locally synchronized AC in Boston, and optionally in other cooperating cities along the transmission route. One prominent example of such a transmission line is the Pacific DC Intertie located in the Western United States. [edit] Grid exit


quote:
It only works in the real world, yes. In fantasy-land where "money" is a fuzzily-defined quantity that the government possesses unlimited quantities of, its' no problem at all.


Meant this in the context of the US and other Western countries only--in a 3rd World country--the cost of using the kerosene, leaves, cow dung is far outweighed by the savings in costs,time and health--let's face it--no one will provide energy for them--a point about which you are silent--

If a couple of hundred million people can get cheap decentralized, safer, energy NOW, why should you complain--I don't see any government doing anything about it--least of all theirs--any argument to avoid this is hypocrisy


RE: Cue comment from Masher
By nah on 9/15/2008 2:00:48 PM , Rating: 2
Also, energy density has increased by a factor of 5-7 in the last year alone--in terms of Energy density by mass (MJ/kg)
Lithium ion battery with nanowires 2.54-2.72
Lithium ion battery 0.54–0.72
compared to older tech--
Lead acid battery 0.09–0.11
NiCd Battery .14-0.22

Also, if you can provide a comprehensive site which can replace wiki and be even half as reliable--I'll be more than glad to include links from it for my future posts


RE: Cue comment from Masher
By randomly on 9/16/2008 9:18:02 AM , Rating: 2
The lithium ion battery with nanowires number is unfortunately bogus.

Silicon nanowires increase the energy density of the Anode material but it's the Cathode material that has the low energy density and is the weak link. The potential improvement of an actual cell is relatively small with silicon nanowires.

Should a breakthrough come in a high energy density Cathode material then we'd have something.


RE: Cue comment from Masher
By nah on 9/15/2008 12:37:36 PM , Rating: 2
Also,
quote:
In the Phoenix, Arizona area, for example, the average annual solar radiation is 5.7 kWh/m²/day,[38] or 2080.5 kWh/m²/year. Electricity demand in the continental U.S. is 3.7*1012 kW•h per year. Thus, at 100% efficiency, an area of 1.8x10^9 sq. m (around 700 square miles) would need to be covered with solar panels to replace all current electricity production in the US with solar power, and at 20% efficiency, an area of approximately 3500 square miles (3% of Arizona's land area). The average solar radiation in the United States is 4.8 kwh/m²/day,[39] but reaches 8–9 kWh/m²/day in parts of Southwest.


RE: Cue comment from Masher
By masher2 (blog) on 9/15/2008 1:24:36 PM , Rating: 2
> "Thus, at 100% efficiency..."

Unfortunately, cells of even 50% efficiency don't exist, and using ones that are ony 20% efficient results in costs far in excess of anything feasible. Solar alone runs about 4X conventional costs. Solar plus energy storage runs anywhere from 15-40X as costly. Add in superconducting power lines to transport power from the AZ desert to the entire nation, and you're talking costs easily 200X as high. Does anyone really want their $150 power bill to rise to $30,000/month?

Your figures also ignore angle of incidence and several other factors (the dangers of quoting Wikipedia-- their source is a broken link to 'Northwest Indian College'), but let's ignore that for now. The larger problems of energy transport and storage are the real issues here.


RE: Cue comment from Masher
By nah on 9/15/2008 1:49:54 PM , Rating: 2
quote:
Unfortunately, cells of even 50% efficiency don't exist,


I know--I didn't say this was economically feasible--only technologically

quote:
Your figures also ignore angle of incidence and several other factors (the dangers of quoting Wikipedia


The desert figures are from the german site--which has links in wiki


RE: Cue comment from Masher
By DeepBlue1975 on 9/15/2008 3:16:55 PM , Rating: 2
Quite so.

I personally like the idea of solar power, but I also think it is not quite ready for massive use as some countries are trying it to be.
Great for personal initiatives like putting solar panels in your roof to shave off some electricity bucks while helping the industry to continue to develop, but not much more than that.


RE: Cue comment from Masher
By CryptoQuick on 9/15/2008 11:15:20 AM , Rating: 2
Nuclear is a very attractive alternative, regardless of who it comes from. Solar power is just not concentrated enough to be as useful for the generation of electricity. I'd rather be producing biofuels with that same sunlit area, perhaps with algae. Biofuels are worth much more per joule than electricity.

Of course there's no point in using biofuels for energy production, due to inefficiencies in photosynthesis.

We're set if we can get reasonable legislation/regulation passed for fast-neutron/breeder reactors, and it may be possible to build cleaner, safer, sustainable reactors.


RE: Cue comment from Masher
By phxfreddy on 9/15/2008 3:54:16 PM , Rating: 2
Yes do cue that. Its quite applicable. You should cue it since you already cued the pie-in-the-sky dreamy eyed boy with a crush on Obama drivel.

Time to put away your Barbie Dolls and get on with business. The empire is crumbling waiting on these super-gay-green ideas. ( gay as in stupid, effeminate as in left wing )


RE: Cue comment from Masher
By Oregonian2 on 9/15/2008 6:30:11 PM , Rating: 2
That statement makes no sense. Instead of deploying something go and develop something else (replacing building with designing) ? IOW - current oil and coal is best for us in the next twenty-thirty years? I suspect not. Nuke is better than what's available NOW at the scale needed. Continue making others better and more cost efficient then turn off the nukes AFTER the new stuff is deployed in sufficient quantity to produce the power the nukes are. Developed stuff, no matter how great, generates no power. Only after paid for and built (often taking a lot of both) are they of any use. Even just the goals of many green leaders (who usually are optimistic) expect wind to make it to only 20% of that used 22-years from now.


"We basically took a look at this situation and said, this is bullshit." -- Newegg Chief Legal Officer Lee Cheng's take on patent troll Soverain














botimage
Copyright 2014 DailyTech LLC. - RSS Feed | Advertise | About Us | Ethics | FAQ | Terms, Conditions & Privacy Information | Kristopher Kubicki