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SunPower's SunTile solar energy collectors lie flush with the home's roof line.
Buyers of new solar-powered homes could see their energy bills cut in half, builders say

One of the nation's biggest home builders has plans to go solar. Miami-based Lennar Homes said its homebuilding division in San Ramon, California, will install solar panel power systems in all of its new homes in the San Francisco Bay Area.

Lennar made the announcement during the opening of a new all-solar housing development in the Bay Are suburb of Danville. The "Milano at Monterosso" community is the first of three solar-powered housing projects that Lennar plans to open in the Bay Area this year. Lennar representatives said the company will also construct 650 solar homes in the California town of Roseville, north of Sacramento.

The "standard" solar package for homes in the Danville development is based on a roof-mounted solar electric system from PowerLight, a subsidiary of SunPower Corp. In its promotional video and related materials, SunPower boasts that homeowners will experience savings of 40% to 50% on their energy bills as a result of installing its PowerLight Sun Tile solar energy system. The company also notes that homes such as those in the Milano community employ a variety of energy-saving technologies, as well. These include double-pane windows, high-performance insulation, low-wattage lighting systems and other features.

Lennar and SunPower are participants in the California Energy Commission's New Solar Homes Partnership, a 10-year, $350 million initiative to promote solar power in new residential construction projects. The program is part of a statewide plan to install 400 megawatts of solar power in the next decade. Homebuilders are being offered incentives of $2.60 per watt for systems they install, while home buyer are eligible for a one-time credit of $2,000 off their federal taxes.

Lennar is not the only Bay Area builder emphasizing solar homes. Home builders such as Centex have also integrated solar power into new residential developments there, but Lennar is the first to promise installation of solar systems in all of its new homes in the region. 





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Its too soon for solar...
By daftrok on 2/27/2007 2:21:24 AM , Rating: 1
Its too soon for solar to be available to households. They need to mass produce it for business and manufacturing companies first. The benefits will be more if used there. For now there are 4 things people can do for their homes: Buy CFL light bulbs, get double pane windows or get the special laminate that keeps heat from escaping the home and heat entering, wrap your water heater with the special blankets during winter, and insulate your home (get special filters, etc.). These four things can cut down your home electricity usage by 15-20 percent and are a lot cheaper. Another thing you can do is to get energy efficient air conditioners and even garage door thresholds: http://www.skymall.com/shopping/detail.htm?pid=102... At this time solar energy for the household is too expensive for most people. Mass producing them for manufacturers and other major structures (Wal-Mart, Fast food restaurants, malls, movie theatres) would benefit much more.




RE: Its too soon for solar...
By Marlowe on 2/27/2007 3:16:14 AM , Rating: 5
I absolutely disagree! Someone should have done this years ago! The sooner it gets wide adoption the better! When it first starts to get mass produced the prices will fall and even more contractors would hopefully follow. This is as good a start as any.

You know, our family has a small, old cabin up in the mountains with no connection to the power grid. A couple of years ago we installed a system with a small solar panel (about 1x2 feet) hooked up to a controller and a couple of car batteries in paralell. We also put up 12-volt lighting in the cabin, so now we have lights all day and night the whole year.

If this is possible here in above-the-polar-circle Norway I really don't understand why a similar system couldn't be installed in normal houses! And no, the cost is really not a good excuse :) Firstly, its initial cost would just be a tiny percentage of the entire houses, and second you would save on, eliminate or invert your electricity bills :)


RE: Its too soon for solar...
By daftrok on 2/27/2007 4:37:48 PM , Rating: 2
I would rather have major companies invest in using this first to bring the price down before bringing it to the masses. Businesses use much more energy than households and the benefits of solar will be greater there. And you stated a tiny percentage? Solar panels cost roughly 30-40 thousand dollars (to fully power your house a la solar would reach the near 80 thousand) making this a VERY significant percentage. At this time it would be easier (and cheaper) to just use the energy tips and let the businesses use solar to bring down the cost for households.


RE: Its too soon for solar...
By Thrasherlife on 2/27/2007 5:32:36 PM , Rating: 1
$30-40k is around 5% of the price of a home in these areas of California so I'd say its a small percentage.


RE: Its too soon for solar...
By hubajube on 2/27/07, Rating: 0
RE: Its too soon for solar...
By Justin Case on 2/27/2007 8:46:48 PM , Rating: 2
What kind of business has enough roof area to power all its production line? If there's one segment where solar really isn't an option, that's industry. Industry will always need external power supplies. As will large cities. Homes are the prime candidates for full solar power (large roof area, low power consumption).

And since when does the use of anything by businesses bring down the cost for consumers? If anything, it's always been the other way around. Look at pro graphics cards, for example. Did they get cheaper? No, it was the consumer cards that got faster, simply because there was a much bigger volume and more competition.


RE: Its too soon for solar...
By Calin on 2/28/2007 2:46:21 AM , Rating: 2
Industries use a lot more energy - but they have also a lot less area where they could install solar panels. Homes would use much less electricity, and have available a higher surface for electricity generation.
As an example, a huge office building, 10-stories tall, will have a tenth of its floor surface available for solar panels. In moderate latitudes (45 North, let's say), the angle of the sun reduces the effectiveness to some 70%. Meanwhile, a house (single story) would have a higher proportionate area of solar panels per usable space, and the roof would be better directed to sun.
Even so, the cheapest way to use solar energy would be solar water heaters (but not necessarily so useful all year long)


RE: Its too soon for solar...
By Grast on 2/28/2007 10:59:42 AM , Rating: 2
daftrok,

The economics of solar power for homes is a complex issue. In California, the price of solar is expensive due to state rebates (acctually raised the price), mandated state licensed installers (in order to qualify for electrical rebates and on-the-grid systems), and price gougeing.

I think installing solar on every house especially in regions which have the weather to support is a great idea. Just to give you an example: A 8K solar system on your house will typcially generate enought power to remove from your bill all the components of the house except the air conditioner. I have personal friends which in the middle of summer are paying $13-20 a month for electricity. In the winter, they are paying nothing and sometimes depending on the weather getting money back.

The issue is your point of the large cost of solar systems, 30-40K. You are correct that is too much. I believe since the state is messing with the free market already by offering 12-15K rebates which by the way simple raize the price not lower. The state should mandate the profit margin for state licensed installers. The would lower the cost with the exception of hard physical cost and hopefully make solar more economical for home owners. However, I have a better idea.

Regardless of the economics in california if a system was to cost 15-18K for a 6-8k solar system, the owner could recoup their costs in 10 years. Plus take pride (equal smug alert, hheehehe) in knowing their helping the environment.

In regards to Lennar, the solar systems are only 2.5K systems. Absolutely worthless and just a marketing gymic to get home owners in due to slowing new home sales.

Later...


RE: Its too soon for solar...
By StevoLincolnite on 2/27/2007 7:47:46 AM , Rating: 3
To soon? I think not, luckily Australians know the benefit of Solar, And Wind Power (At least in South Australia) Alot of public places like toilets etc. Are becoming self cleaning, And are solar powered, I know at one time there was some talk about solar panels on every street light, A multi million (Billion?) dollar wind farm was built here as well, Solar Panels aren't actually that expensive, For a 12v Car Battery charger (It charges car battery's ;)) Costs about 20 bucks. It gives the car enough charge to jump start.
I know people who have solar Power on they're homes and sometimes they actually get paid money, As the solar panels energy goes back into the grid, Mind you they are very energy conscious, Now It may become compulsory to have energy efficient globes here in Australia.


RE: Its too soon for solar...
By TomZ on 2/27/2007 10:24:31 AM , Rating: 2
Solar and wind are fine for generating small amounts of electricity. But to power a home requires a $30-40K investment in solar cells and related equipment, which is quite a bit different than your $20 example. I think this illustrates the real problem - it's not a question of will or desire on the part of consumers, but it is a problem of economics. Most families simply cannot afford such an investment.


RE: Its too soon for solar...
By qualme on 2/27/2007 10:58:37 AM , Rating: 2
This is California right? Average house costs $500,000 right? $30-40k is a mere drop compared to that.


RE: Its too soon for solar...
By TomZ on 2/27/2007 11:02:38 AM , Rating: 3
The relative cost has nothing to do with its acceptance. The acceptance is tied to the number of years to "break even" from the investment. After all, even folks buying $500K homes can probably think of other things to do with that money.


RE: Its too soon for solar...
By qualme on 2/27/2007 11:55:26 AM , Rating: 3
maybe use the $10k wallpaper instead of the $15k wallpaper or the $20k faucets instead of the $30k ones. value is subjective and who can say if solor panels will raise the value of a house more than the current faucet fad.

all i'm trying to say is that acceptance has nothing to do with cost, it has everything to do with what is currently "fashionable".


RE: Its too soon for solar...
By masher2 (blog) on 2/27/2007 1:02:05 PM , Rating: 2
But a $40K solar system won't power your home entirely, not even close to it. It'll simply allow you reduce your utility bill somewhat. And that $40K isn't a one-time cost either. Solar systems also require maintenance and, for solar cells, degeneration and total replacement every 15-20 years.


RE: Its too soon for solar...
By RogueSpear on 2/27/2007 2:18:13 PM , Rating: 3
quote:
But a $40K solar system won't power your home entirely, not even close to it.

I'm not certain how you arrive at this conclusion, but some folks I've known for years in Florida spent $30K - before rebates and incentives - and for most of the year they are actually generating a surplus of electricity. This is with air conditioning and all of the other common conveniences. Additionally they do heat their water with a seperate solar system that is specifically made for that purpose.

I don't know the brand name of panels they purchased or the contractor that performed the installation, but the setup is pretty impressive. And when the power goes out they usually don't even realize it.


RE: Its too soon for solar...
By TomZ on 2/27/2007 2:36:21 PM , Rating: 2
Most existing homes don't use electricity for heat and hot water - most use natural gas or heating oil (especially in the North). So that makes an upgrade to an existing home even more costly if you want to convert entirely to solar.

If you are building a new home, then you can design it to be all-electric; however, in that case it pushes out your break-even time since, e.g., natural gas is cheaper per BTU than electricity.


RE: Its too soon for solar...
By RogueSpear on 2/27/2007 2:38:58 PM , Rating: 2
Where I live in the northeast, yes we use natural gas for heating, hot water, oven, etc. Where my Mom and this couple with the solar installation live in Florida, natural gas is not an option. The closest thing would be propane I believe.


RE: Its too soon for solar...
By ttowntom on 2/27/2007 2:36:49 PM , Rating: 3
Sorry, but I call BS on this. There's no way in the world that's true, not even with a system costing twice as much. The batteries alone for a system large enough to power a house during the night would cost more than $30K.

Here's a link to a solar system estimator. A 5kW system costs, before rebates and incentives, $35,000. The estimated savings is $423/year. That's $35/month off a $200/month power bill.

http://www.srpnet.com/environment/solar/home/calcu...

5KW might sound like a lot...but thats peak power production. Evening, mornings, and during storms/cloudy weather, it'll be considerably less. At nighttime, it'll be zero, of course.

With a $30K system, your friends might generate a small amount of surplus power for a couple hours a day, during part of the year. The rest of the time, they'll be sucking deeply from the grid.


RE: Its too soon for solar...
By RogueSpear on 2/27/2007 2:45:06 PM , Rating: 2
Admittedly they are not a typical couple with a typical home. The house was designed from the beginning at being "green". It isn't quite 1100 sq. feet which is generally rule #1 when designing an efficient home. I can't possibly begin to get into the technical specifications of their system either, because I simply don't know them. However if you do some looking around on the internet you'll find there is quite a market of extremely efficient appliances and lighting.

If I were to put this system on my house (even if it were in Florida and not New York), there's no way it would supply me fully. But my house is also very much a "before" picture.


RE: Its too soon for solar...
By masher2 (blog) on 2/27/07, Rating: 0
RE: Its too soon for solar...
By evildorf on 2/27/2007 5:41:29 PM , Rating: 2
quote:
1000 sq. ft? That's the size of a couple dorm rooms


That's a pretty sweet couple of dorm rooms! :)

quote:
Look in the library, under "fantay and science fiction".


No need to be unpleasant. Mr. RogueSpear's figures are likely in error, but it's not like a solar home can't be done...it's just it can't be done (to my knowledge) for $30k.
In reply to the OP, you're correct, most homeowners cannot afford solar panels, but this doesn't make it "too soon" to offer panels to those who want and can pay for them. If PV is going to continue improving efficiency and/or cost, they need every market segment they can get.


RE: Its too soon for solar...
By RogueSpear on 2/27/2007 8:04:15 PM , Rating: 2
You'd be surprised at how nice their house is even though it is rather small. It's just the two of them as they're retired and their kids are on their own.

I have relayed what was told to me. I did not demand to see receipts. These people are close friends of my mother, not me. When I was told that the solar system itself was $30K I was actually shocked at how high it was.

You can call BS or whatever you like. It's no skin off my back.


RE: Its too soon for solar...
By masher2 (blog) on 2/27/2007 9:18:49 PM , Rating: 1
> "You'd be surprised at how nice their house is."

What does "nice" have to do with the power output of their system? The fact remains that there are NO systems for sale for $30K that will power even a tiny home like that and regularly generate a surplus. They might show a surplus around the noon hours on bright days...but the rest of the time they'll be drawing power from the grid.


RE: Its too soon for solar...
By Grast on 2/28/2007 11:19:53 AM , Rating: 2
Masher,

These systems are not generating power and storing it. They are generating the power and applying any surplus to the local grid during peak usage times (mid of day). The home owner gets credit for power generated at the peak rate.

The home owner then later uses electricty after work at a typicall the lowest rate after 5:00 Pm and thus they save a lot of money.

Since most families in California are dual income folks, the house is empty during the day.

Later..


RE: Its too soon for solar...
By Grast on 2/28/2007 11:15:16 AM , Rating: 2
Ttowntom,

These systems are not off-the-grid systems. They are on-the-grid systems. The inverter applies the power back to the grid when a surplus of power is generated.

The home owner then gets top KW credit for every KW generated. Later when the home owner gets back to the house after work, they use more power than generated. However, they are using power which is at a lower rate due to no longer being peak rates.

That is how the systems work and people do only pay 15-30 dollars a month during summer while still using the air conditioner.

later...


RE: Its too soon for solar...
By Farfignewton on 2/28/2007 10:03:55 AM , Rating: 2
Cost, return on investment, and other considerations aside, I imagine the "sunshine" state gets more sunshine than the Bay Area. But it's Lennar, they've probably never even heard of fog.


RE: Its too soon for solar...
By daftrok on 2/27/2007 4:41:59 PM , Rating: 2
1/2 true. The methods that I said above will cut your energy bill by 20% easily (give or take 5% depending on where you live, weather makes a difference). A 30-40 thousand dollar investment will cut down your energy bill by another 40-50 percent (80 thousand for complete solar dependency). And of course Solar power requires much more maintenance and at this time too expensive to be economically beneficial to the households.


RE: Its too soon for solar...
By Grast on 2/28/2007 11:10:57 AM , Rating: 2
Masher,

While I normally agree with you. You have a few misconceptions.

1. A typical 6k-8k system in California will run at peak power generation 8 months out of the year.
2. Most people in California are two working adult families which means that most if not the entire day; the house is empty and thus not using a lot of electricity.
3. These are on-the-grid systems which means if your system is generating 6k of power every hour for 8 hours a day. That is 48K worth of power back on the grid. This equals to 48K at peak value rate being applied as a credit to the home owners account
4. The power being generated is running the home owners meter backwards.
5. The cost of electricity is less after peak hours.

Thus once the system is installed, the average home owner will pay around 20-25 dollars a month for electricity even using the air conditioner because they are generating power and getting credit equal to the highest pay rates. While using the majority of their power at the lowest rates.

Thus the home owner will save money hands down. The only issue is ROI is 20 years at 30-40K. I think the cost of solar is the only down side. If the systems where 15-20K, I think we would see greater adoption.

Please also install the high effeciant solar panels and not the panels which look like concrete tiles. Those systems are 50% less effecient than a standard solar panel.

As to Maintenance:
1. DC/AC inverterts are rated at 30 years before replacement. Personal friend systems has a 15 year warranty.
2. Solar Panels have a 20 year life span and 15 year warranty.
3. Maintenance is simply washing at least once every three months in the summer and less during the winter due to normal rain fall.

Later....


RE: Its too soon for solar...
By hubajube on 2/27/2007 3:02:07 PM , Rating: 2
I live in CA and the problem is the cost even on $500K+ homes. We aren't rich, most of us are middle class, two income households (the only way we can afford to live here). Also, everything is more expensive not just housing so the money doesn't go as far as you might think. Yes, some people just plain got a lot of disposable income and those are the people you see with solar and windmills on their homes or maybe they had their homes custom built. But most of us like to be able to send our kids to college not to mention be able to pay for all the school activities (friggin expensive) so that $30K can be used for other stuff. Also, some neighborhoods don't allow either to be installed because of the "eye sore" factor. And then there's still people that simply don't know it can be done.


RE: Its too soon for solar...
By hubajube on 2/27/2007 3:14:40 PM , Rating: 2
Another thing. I live in an area where it gets pretty windy and my wife and I have wanted to do a windmill for years. Those work VERY well here but the cost is just too much. It's really only worth it if you have one built while you're building a house. Or if you're lucky enough to not need a new car for about 15 years.


RE: Its too soon for solar...
By NaughtyGeek on 2/27/2007 11:48:20 AM , Rating: 2
Understand, the largest amount of investment capital available in the good ol US of A is in the hands of individuals/corporations who make quite a bit of money off our dependence on the oil they control. There are quite a few independent investors out there who fund small projects to further "clean" energy, but until a huge cash investment is made, these technologies will remain expensive compared to conventional energy production. We need someone like Microsoft or GE to get out of the oil industries back pocket and start funding projects to further develop these green technologies as a viable means for us "average Joes" to utilize. Look at what the US government spent over the last 10 years on research and funding for alternative energy projects. We spent more last year on "foreign relations." This is why it is, and will remain, prohibitively expensive to use alternate energy.


RE: Its too soon for solar...
By jabber on 2/28/2007 6:09:33 AM , Rating: 2
"We spent more last year on "foreign relations." This is why it is, and will remain, prohibitively expensive to use alternate energy"

Good grief that is bad. Must have been just a few bucks!

Seriously though I think your point on getting corps/organisations that are not party to the hydrocarbon purse, into alternative energy projects is important.


RE: Its too soon for solar...
By TomZ on 2/27/2007 10:20:21 AM , Rating: 1
I agree! The problem with solar panels is clearly the cost. Adding a reasonable amount of solar generation capability to a house adds $30-40K in up-front cost. Assuming you add that into your mortgage, as most consumers would, that increases the cost even more, plus any maintenance costs along the way.

Then if you take that total cost and divide it by the cost savings per year, you'll probably end up with a break-even in the 20-30 year range. Most people simply aren't going to make a large up-front investment for a return that is so many years out. Tax incentives (government handouts) are the only way to make it economically viable until solar panel prices fall considerably.


RE: Its too soon for solar...
By MightyAA on 2/27/2007 11:04:48 AM , Rating: 2
Totally disagree. Business' and commercial buildings use a ton more energy than homes. The average home is typically unoccupied during the day.
A big point is missed. I haven't seen it mentioned, but besides the tax incentive, the power company must buy the energy to put into the grid; the power you create does not power your house, it powers the electrical grid of your region. It was a huge win for the clean energy guys because now you don't have to deal with energy storage (expensive battery racks)... you just feed the grid like your own little power plant.
So, when you go home tonight, look out the window at the sea of roofs in massive suburban areas. Now envision all those homes putting clean energy back into the grid to power those office buildings and commerce during the day... this means less power plants (mostly coal and pretty dirty things).


RE: Its too soon for solar...
By masher2 (blog) on 2/27/2007 1:09:32 PM , Rating: 2
> "The average home is typically unoccupied during the day..."

Agreed. And Lennar Homes (this builder) could probably save far more energy by simply installing a smart thermostat in each home, preprogrammed to turn down the HVAC and water heater during the day. But "going green" is generates positive publicity for a company.

I do wonder about the construction details on these homes. Are they all being built with Low-e windows, SEER-20+ heat pumps, superinsulated walls and ceilings, etc? Or are they scrimping on these features to sell an "energy-saving" solar home at a reasonable price?


RE: Its too soon for solar...
By MightyAA on 2/27/2007 2:17:42 PM , Rating: 2
Most buildings are required to have programable thermostats now and these days. Issue I have is folks set them too low. Just know that it takes a lot more energy to heat things up than to maintain a constant temperature.
Current energy codes also require substantial insulation, performance glazing, etc... Building Code requires tight construction. Also note that Codes are a lot more restrictive for commercial (lighting controls are required, as is vestibules, etc.)....

But my beef is these newer "greener" codes are also causing substantial problems (they also don't give energy credits for things like solar). Molds and sick buildings can be the result of too tight construction & residential doesn't require outside air (commercial codes require 20%). I've witnessed structures literally raining inside because there is no way for humidity buildup to excape. Structures need to breathe, but that's not energy efficient (unfortunately, most construction is poor and it leaks air anyway). Pick your evil. Personally, I'd pick clean solar & wind to a sealed up box. You should also be aware that Codes are just like any "big political" document. Developers, suppliers and manufacturing pay big money to sway the codes adopted; hence the difficulty in getting things like solar adopted into codes & standards.

Kudo's for the developer and for those willing to pay the additional premium to incorporate the technology.


RE: Its too soon for solar...
By RogueSpear on 2/27/2007 2:24:26 PM , Rating: 2
You can build a house that is as air tight as possible and make it substantially healthier than a house which is poorly insulated. Most folks have an air to air heat exchanger installed to keep the interior air healthy and fresh. The downside to these is that for a very high efficiency model you're going to pay. Depending on the square footage of the house anywhere from $5K to $10K.


RE: Its too soon for solar...
By MightyAA on 2/27/2007 6:05:22 PM , Rating: 2
Air-exchange units.. that was exactly what I looked at (I'm a expert witness for construction). Because there is no outside air component, you can't shed humidity in a sealed unit. But, you are still adding humidity from showers, cooking, and just breathing. You can get humid enough to condensate on cooler walls. We did a 12 month study on this.. unoccupied units had no issues.
Biological growth needs heat, food, and water.. you have it all unless you take away a component. Remove the humidity, and you won't have growth. Food is anything that can deteriote (in other words, the majority of "green friendly" products), so you can't get rid of the food easily. And you need heat...
The code relies on owners opening windows for ventilation, but with AC, security concerns, etc.. that just isn't happening that much anymore.


RE: Its too soon for solar...
By MightyAA on 2/27/2007 6:47:45 PM , Rating: 2
Forgot to also mention the sick building syndrom. Basically, products used off-gas. Plastics are the worst and used in things like glues, carpets, vinyl floors, etc. If you aren't bringing in outside air, those gasses just recycle through the system and keep building up.
An air exchange is closed loop, meaning is salvages or sheds heat from an outside source; usually the hot water heater(like a car radiator transfers fluid heat to air passing through it).. no air is actually exchanged.


RE: Its too soon for solar...
By masher2 (blog) on 2/27/2007 7:35:02 PM , Rating: 2
> "An air exchange is closed loop... no air is actually exchanged."

I'm not sure what you've been installing, but its not an air exchanger. These systems do exchange air from inside to outside, and vice versa. Otherwise, there'd be no purpose to them. Here's a link to a diagram on how they work:

http://www.airexchangers.info/air_exchanger_basics...

Also, for the previous poster who claimed "most people" have them...I have to express disbelief. They are, at least in my part of the country, quite rare in residential construction.


RE: Its too soon for solar...
By TomZ on 2/27/2007 7:48:06 PM , Rating: 2
I agree. Here in Southeast Michigan, air exchangers are rare or even unheard of. Heck, new homes here still have 80% efficient furnaces as standard issue. How dumb is that?


RE: Its too soon for solar...
By RogueSpear on 2/27/2007 8:19:11 PM , Rating: 2
When I said "most", I was referring to "most" homes that are constructed to be practically air tight. Most homes around me are not made this way. A couple of years back a local developer put in a single road (cul de sac) development where the marketing spin was that the homes were incredibly eco-friendly. My wife and I went to see the model. I wasn't really that impressed. The basic selling point they were running on was that the house was very well insulated, top of the line windows and doors, and it wasn't your standard timber frame construction. The "shell" was basically sheets of plywood sandwiching Styrofoam. Thus their claim is that the house was nearly airtight. So each house was outfitted with a Trane air to air heat exchanger.


RE: Its too soon for solar...
By MightyAA on 2/28/2007 10:26:33 AM , Rating: 2
Learned something new. Never seen a system like that. Around here, what they call an "air exchanger" is basically the hot water pipe feeding a radiator box. A fan unit blows air across this radiator to warm the air and distribute. There is no outside air component.


RE: Its too soon for solar...
By TomZ on 2/27/2007 2:41:03 PM , Rating: 2
quote:
Just know that it takes a lot more energy to heat things up than to maintain a constant temperature.

Why is that? It seems to me that the energy loss would be related to the indoor-outdoor temperature differential, times the number of hours that the differential is maintained. So if you reduce this differential for a period of time, you would have energy savings.


RE: Its too soon for solar...
By MightyAA on 2/27/2007 6:40:30 PM , Rating: 2
Yes... differential makes a huge difference because of the heat loss through the shell. All I'm saying is don't drop it down to 50degrees then bring it up to 74 twice a day.. You'll spend more money having that furnace run full blast a long time to keep up with the temperature swings then you would to just let it maintain a temperature or deal with smaller swings.


RE: Its too soon for solar...
By TomZ on 2/27/2007 7:46:46 PM , Rating: 2
Why is that? Running the furnace full blast compared to intermittantly doesn't waste more energy, does it? Apart from furnace inefficiency loss, all loss is through the shell, right? Therefore, I don't understand why running the furnace full blast to increase the temperature wastes energy. Can you please explain that?

I have to admit, I think this belief is a myth, but I'd like to understand it better from someone who is knowledgeable in the field.


RE: Its too soon for solar...
By masher2 (blog) on 2/27/2007 8:35:22 PM , Rating: 2
I have to agree its a myth. A basic furnace will have roughly constant efficiency across a temperature range, while a heat pump actually increases in efficiency as the temperature differential decreases. So allowing a house to cool down during the day is going to save energy regardless.


RE: Its too soon for solar...
By masher2 (blog) on 2/27/2007 3:54:45 PM , Rating: 2
> "Most buildings are required to have programable thermostats now and these days..."

In some states, perhaps...not in mine. And no state requires them to be pre-programmed to assume an empty home during the day.


RE: Its too soon for solar...
By MightyAA on 2/27/2007 5:56:19 PM , Rating: 2
National Energy Code. If they've adopted the latest code (2006?), then it's required. That code is federal and referenced by the International Building Code. CA is the only state I can think of that balked at the international codes..


RE: Its too soon for solar...
By Kuroyama on 2/27/2007 5:35:57 PM , Rating: 2
Agreed, but I would be curious to know the value to business consumers of having this extra power pumped back into the grid during the peak daytime hours. This means the electric company has to buy less power has to be bought at the very expensive peak hours, and fewer new power plants have to be built to meet demand at those peak hours. On top of that, CA electricity prices are quite high, so the power from the panels is worth much more to a homeowner in CA than in say GA.

Anyways, I don't doubt that the subsidy is more than the benefit provided to consumers of the state, but I would be curious if anyone knows of a study trying to quantify the full $$ benefit of putting solar panels on a house in CA.


RE: Its too soon for solar...
By daftrok on 2/27/2007 4:34:37 PM , Rating: 2
My point EXACTLY. Solar would be more beneficial if used for businesses because THEY USE MORE ENERGY THAN HOMES. At this point in time energy companies should really invest in wind power and inform people how to be energy conscious. If you can afford to be solar that is fine, but don't make it a requirement for homes, adding tens of thousands of dollars (which is equivalent to at least two extra years of mortgage payments) when you can save 20% if you just do the energy tips I showed above (WAY above, i didn't know i sparked such a debate :)


RE: Its too soon for solar...
By TheWizardofOz on 2/27/2007 2:47:07 PM , Rating: 2
Isn't it sad that all the things you have mentioned have been done and still been doing in the 90% of Europe.

US is wasting energy like I've never seen...


RE: Its too soon for solar...
By TomZ on 2/27/2007 2:51:03 PM , Rating: 2
That's funny - when I was in Germany, France, and Italy last, I don't recall seeing even a single house with solar panels.

What "90%" of Europe do you mean, exactly?


RE: Its too soon for solar...
By hubajube on 2/27/2007 4:41:43 PM , Rating: 2
I'd like to see that 90% as well. I don't remember seeing ANY solar panels NOR did I see windmills. I've been to France, Italy, UK, Spain and even Monaco.


RE: Its too soon for solar...
By daftrok on 2/27/2007 4:44:54 PM , Rating: 2
PAY ATTENTION. He wasn't talking about solar panels, he was talking about the energy methods I entered WAY the fuck above in the beginning. And what do you mean you didn't see any windmills? Nearly 10% of Germany's energy is run on wind farms and a whopping 30% for Denmark.


RE: Its too soon for solar...
By masher2 (blog) on 2/27/2007 4:55:08 PM , Rating: 2
> "Nearly 10% of Germany's energy is run on wind farms ..."

According to the links below, solar, wind, and geothermal combined only contribute 5.6% of Germany's power. That compares with 2.3% for the US...so its not exactly a huge difference.

Denmark, by the second link, generates 18% from solar/wind/geothermal/biomass combined. That's a far cry from a claim of 30% from wind alone.

http://encarta.msn.com/media_461547119_761576917_-...

http://www.cslforum.org/denmark.htm


RE: Its too soon for solar...
By RogueSpear on 2/27/2007 8:23:57 PM , Rating: 2
I remember reading somewhere that Denmark plans or wants to have 30% by 2010 or somewhere close to that, but that they don't currently have 30%.


RE: Its too soon for solar...
By daftrok on 2/27/2007 11:52:49 PM , Rating: 2
http://en.wikipedia.org/wiki/Renewable_energy_in_G...

My bad, 5% was wind, however 11.9% was renewable energy. And the Denmark number was near 20% for wind and not 30%. Still quite a huge number.


RE: Its too soon for solar...
By TomZ on 2/27/2007 5:12:09 PM , Rating: 2
You're right - my bad - I misunderstood the poster's comment.

I seriously doubt the 90% figure anyway. 90% of Europe has CFL bulbs? 90% wrap their hot water heaters? 90% use double-pane class? 90% use house-wrap? I doubt it.


RE: Its too soon for solar...
By Kuroyama on 2/27/2007 5:22:08 PM , Rating: 2
In many countries you cannot buy a standard Thomas Edison type bulb, as in the US. Don't know about Europe, but in Japan it is pretty much all fluorescent lighting.


RE: Its too soon for solar...
By Pandamonium on 2/27/2007 5:57:04 PM , Rating: 2
Businesses will adopt solar power when solar actually saves them money in the long run. This is a technology that consumers will have to support through infancy.... because we care about "being green" whereas businesses care about staying in the black.


RE: Its too soon for solar...
By Grast on 2/28/2007 10:48:44 AM , Rating: 2
Everyone,

READ THE FINE PRINT.....

My wife and I recently went to a Lennar home in the Sacramento area. The solar systems being installed are a joke and a marketing ploy nothing more. The total system capability for all their homes are 2.5 Kwatts. That is barely enought too off-set the lights in a home much less any other appliances.

I am all for requiring solar to be included in new homes. However, the system needs to be at least a 6Kwatts system to impact the local electrical grid.

Lennar is simply using solar as a marketing ploy nothing more.

Later...


Federal tax incentive
By ksherman on 2/27/2007 1:44:32 AM , Rating: 2
Call me crazy, but a $2000 one time tax deduction seems weak. If the gov't really wanted to give potential buyers an incentive, they need to try a lot hard. How about grants to help with the down payment or similar. It's not like they get $2000 back at the end of the year in tax rebates. Same thing with the hybrid rebate back in the day.




RE: Federal tax incentive
By Ringold on 2/27/2007 2:23:32 AM , Rating: 2
Or how about the government keeping the money, lowering our taxes, and make the multi-billion dollar companies looking for 'green' creds among the environmentalist movement use some of their vast financial resources to simply improve the technology to the point where it's profitable to be bought and installed without the rest of America subsidizing it? That's what I'd say, but call me crazy too. :)


RE: Federal tax incentive
By KristopherKubicki (blog) on 2/27/2007 2:30:21 AM , Rating: 4
Shh... Listen, you can hear it in the wind. Somewhere, a young Masher got it's wings.


RE: Federal tax incentive
By Marlowe on 2/27/2007 2:56:15 AM , Rating: 2
Hehehe oh Kristopher you're killing me :D
I just wanted to comment the link to the promotional video seems to be broke.


RE: Federal tax incentive
By SmokeRngs on 2/27/2007 2:03:31 PM , Rating: 2
I'm sure as hell no young masher2 (or would that be masher3?) but I would have said the same thing. Sometimes great minds think alike.


RE: Federal tax incentive
By therealnickdanger on 2/27/2007 9:19:27 AM , Rating: 1
I agree with your view, however, the consumersare too unmotivated as a whole to believe it's worth doing without a big orange carrot dangling in front of them. The fact that their own tax dollars are paying for such a "rebate" doesn't seem to phase the masses. They just think "free money". I think that any price we pay to advance solar energy is worth it. The government should skip the Prius (Pious) "rebate" and stick to endorsing real solutions like photovoltaics.

If anything, the expansion of solar power might help Algore maintain his facade of "being green".
http://www.fairviewobserver.com/apps/pbcs.dll/arti...


RE: Federal tax incentive
By masher2 (blog) on 2/27/2007 1:20:04 PM , Rating: 2
> "might help Algore maintain his facade of "being green"..."

A $1200/month average power bill and $1000/month natural gas bill...all for just *one* of Al Gore's three homes. Sounds like he's seriously concerned about global warming, alright.


RE: Federal tax incentive
By RogueSpear on 2/27/2007 2:36:35 PM , Rating: 3
Well you are consistent with mentioning only part of the story. I'm sure it won't matter to any of the ideologues out there, but all of his electrical use comes from renewable sources and he does purchase carbon credits.


RE: Federal tax incentive
By masher2 (blog) on 2/27/2007 2:42:36 PM , Rating: 3
> "all of his electrical use comes from renewable sources and he does purchase carbon credits..."

Oops, wrong again. Let me quote from USAToday, which ran a similar story on Gore a few months ago:
quote:
But according to public records, there is no evidence that Gore has signed up to use green energy in either of his large residences . When contacted Wednesday, Gore's office confirmed as much but said the Gores were looking into making the switch...
http://www.usatoday.com/news/opinion/editorials/20...


RE: Federal tax incentive
By dever on 2/27/2007 2:58:33 PM , Rating: 2
Don't be fooled, this is proof not just that Al Gore somehow exempts himself from his own preaching, but rather does not even believe it! If he truly believed the dire and immediate consequences he spouts, there's no way he could justify using 20x the average energy for just one of his houses. If he believes his own rhetoric, then he must also believe that his energy consumption is putting himself and his family in jeopardy.

What is infinitely more likely, is that he is an intelligent person who uses climate change rhetoric for self-gain. Socialists use fear to control.


RE: Federal tax incentive
By doctor sam adams on 2/27/2007 10:29:29 PM , Rating: 2
Is there any political group which does not use fear to control? Why are you maligning the socialists? That's like saying socialists use money for bribes. It's just the easiest thing to use. Try controlling people with rational arguments. Start with yourself, see how it works!


RE: Federal tax incentive
By RogueSpear on 2/27/2007 3:00:45 PM , Rating: 2
http://thinkprogress.org/?tag=Global+Warming

quote:
Gore’s family has taken numerous steps to reduce the carbon footprint of their private residence, including signing up for 100 percent green power through Green Power Switch, installing solar panels, and using compact fluorescent bulbs and other energy saving technology.


I did look at your link which I had not seen prior to you posting it. If in fact he is not with this Green Power Switch utility, then indeed I am quite disappointed. However it won't change my feelings about the issue or all that he has done to bring it out in the open.


RE: Federal tax incentive
By masher2 (blog) on 2/27/2007 3:51:06 PM , Rating: 2
If he is, then he made the switch after the uproar from the first story...which shows he was motivated by his image, not any real concern for the environment. And even if he has, it doesn't change the fact he's using $1000/month in natural gas in just one of his three mansions.

Personally, I doubt he's using many "compact fluorescents and other power-savings measures" in his homes. Else his bill wouldn't be nearly so large. My home is half the size of his, and my total utility bills are less than 1/5 of his $2200/month.


RE: Federal tax incentive
By hubajube on 2/27/2007 4:58:40 PM , Rating: 2
When you put it that way it puts a different perspective on just how much energy he uses. Wow! There's obviously no emphasis placed on energy efficiency in his home (I would assume his other homes are run in the same manner). That cost seems rather high even for a large home such as his. My home is about half the size of yours and I am no where near even a 1/5 of his energy costs.


RE: Federal tax incentive
By masher2 (blog) on 2/27/2007 5:30:58 PM , Rating: 2
> "When you put it that way it puts a different perspective on just how much energy he uses. Wow!"

Don't forget those figures are just for one of his three homes...and it doesn't include anything from his largest energy expenditure-- incessant travel.


RE: Federal tax incentive
By RogueSpear on 2/27/2007 8:28:21 PM , Rating: 2
I have to say that while this story does not look good in any way for Gore, the numbers are bothering me. When you look at those numbers, do they even seem possible? I think I'm going to reserve judgement until facts are a little more fleshed out.


RE: Federal tax incentive
By masher2 (blog) on 2/27/2007 8:45:38 PM , Rating: 2
> "I think I'm going to reserve judgement until facts are a little more fleshed out..."

This story was first reported months ago, by a large number of reputable sources. It hit the press again a cople days ago, with the news that his usage has actually increased in the past year. Furthermore, for Gore's main home, utility records are a matter of public record. Gore's had plenty of time to deny the figures, which he hasn't done.

I understand how painful this may be to you, but facts are facts. Sometimes we just have to face them.


RE: Federal tax incentive
By TomZ on 2/27/2007 2:48:02 PM , Rating: 2
It's still "wasted" energy, isn't it? I mean, if a person is such a strong advocate of environmentalism, why would they choose a lifestyle that consumes so many resources unnecessarily? After all, it's much easier to tell others they have to sacrifice, than to actually make a sacrifice yourself.

Bottom Line: I don't care how Al Gore chooses to live his life, just so long as he isn't telling me how I should live mine.


RE: Federal tax incentive
By RogueSpear on 2/27/2007 3:10:01 PM , Rating: 2
quote:
It's still "wasted" energy, isn't it?

I would agree it is. I personally think that all of these 4000+ sq. ft. homes going up in my neck of the words are a tad excessive. I wouldn't go so far as to say someone shouldn't be allowed to build or buy one. But I would at least hope with the amount of money going into a house that size that there would at least be some kind of efficiency built into it.

This is an issue I have been dealing with for a while now myself. I've been trying to convince my wife that we should consider a home a bit smaller (about 1100) than what we're in now (about 2300). It's just the two of us and it seems extremely wasteful for us to be in a house that size. I don't want to get too personal here, but when we purchased the house we bought it with the plan of having two children. That isn't going to happen however so it to me it seems to make sense to downsize.


RE: Federal tax incentive
By dever on 2/27/2007 2:50:16 PM , Rating: 2
WARNING: COMMUNIST ALERT
quote:
...however, the consumers are too unmotivated as a whole... ...I think that any price we pay to advance solar energy is worth it.
In other words, everyone else is stupid. A few high-minded individuals should make all of our decisions for us, like, as he mentioned, Al Gore.


RE: Federal tax incentive
By gerf on 2/27/2007 9:28:51 AM , Rating: 1
quote:
Or how about the government keeping the money
Oh, but they will. The increase value of the house will increase the property taxes collected on it, offsetting the energy cost savings.

Someone needs to do an in depth study here..


RE: Federal tax incentive
By Steve Guilliot on 2/27/2007 4:14:50 AM , Rating: 2
The article says "credit" not deduction. Do you know the difference between the two?


RE: Federal tax incentive
By KillerNoodle on 2/27/2007 10:04:32 AM , Rating: 1
I do I do....Credit = Money back if you don't owe the feds.
While a deduction = no Money back even if you don't owe the feds.

It is a huge difference IMHO.


RE: Federal tax incentive
By TomZ on 2/27/2007 10:13:39 AM , Rating: 2
No, I think the difference is that a deduction is multiplied by your tax rate to calculate your tax savings. A credit is a direct savings.

For example, if your tax rate is 28%, then a deduction of $2000 is worth only $560. A $2000 credit is worth $2000.


RE: Federal tax incentive
By Mitch101 on 2/27/2007 11:42:30 AM , Rating: 3
The problem is the INSTALLERS know this and jack up the costs a few grand and tell you about the tax break instead of it just costing $2K less.

The sad part is I know if I commit to it that will be the year they decide to cancel the incentive.

The did that the year I donated a VAN worth several thousand in excellent running condition then to have them limit my deduction to $500.00. I could have easily sold it for $5k instantly and donated the cash instead.


lighter color roof alternative
By feelingshorter on 2/27/2007 1:44:39 AM , Rating: 2
In California, there are many houses that have some sort of light brown (or any other light color) tile roofing, instead of black roofs that are common everywhere else. Just by changing your roof color, you will save a lot also on your electric bill. Annoyingly, people just don't care enough. Also, due to building rules, you cannot just change your roof color. Kind of like how every one in your neightborhood has to have the same style of mailboxes (such as bricks, metal, or at the door). Certain cities/neighborhood have more strict building codes but I believe solar power is not a good way to "save energy," at our current state of technology.

Just like hybrid cars, it "costs" a lot energy to to mine for the precious metals required for solar panels. More energy than you would save in the lifetime of the house. Plus, if half the house is on solar panels, its added 1/2+ more to the costs of the house. Last time I herd, buying enough solar panels to power a house will usually cost more than the house itself.

Lighter color roof. Start the initiative first. Its also something more affordable.




RE: lighter color roof alternative
By derdon on 2/27/2007 1:57:07 AM , Rating: 2
Most of the solar panels installed on roofs are not producing electricity, but are there to heat water. They are rather simple and inexpensive to construct. You then save a lot of the electricity that you'd otherwise spend to heat the water. This is quite an effective and cheap way to save energy.


RE: lighter color roof alternative
By Kuroyama on 2/27/2007 3:04:19 AM , Rating: 3
For those unfamiliar with this, the solar heating to which he refers does not use solar panels in the conventional sense, but works instead via the property we all know of that metal gets very hot in the sunshine (and hence can heat water). This is a very cost effective way of saving energy at a low cost in places with a lot of sunshine.

There's also geothermal A/C where water is cooled by pumping it underground (the ground is cooler than the air in the summer, and hotter in the winter), and then used to cool the air (or something like that). This is also supposed to be cost effective, although over a longer period like 10 years or so, but still that's perhaps a shorter time horizon than what unsubsidized solar panels on a roof would cost.


RE: lighter color roof alternative
By RogueSpear on 2/27/2007 9:46:14 AM , Rating: 2
quote:
it "costs" a lot energy to to mine for the precious metals required for solar panels.

What precious metals are you referring to? How much does it cost? How does the cost relate to the cost of mining for coal?

Someone else suggested that we should not have any incentives on solar at all. Fine, then do away with the billions in tax payer funded subsidies to the oil industry.

A couple who are friends of my family in Florida actually had a surplus of electric last year from their solar installation.


RE: lighter color roof alternative
By qualme on 2/27/2007 12:18:53 PM , Rating: 2
I think the precious metals he's referring to are: amorphous silicon, poly-crystalline silicon, micro-crystalline silicon, cadmium telluride, copper indium selenide/sulfide.

yes, i'm joking since none of those are rare and are all the current latest generation materials for solar cells.

fact is solar will be "cost effective" only when the "sheep" hear the "media" say its so


By RogueSpear on 2/27/2007 2:28:13 PM , Rating: 2
I was actually being a little sarcastic when I asked the question ;)

I wanted to see if he'd actually answer.


RE: lighter color roof alternative
By masher2 (blog) on 2/27/2007 3:58:17 PM , Rating: 2
> "Fine, then do away with the billions in tax payer funded subsidies to the oil industry...."

What subsidies are you referring to? I suggest you research the subject a bit; you'll find the reality is quite a bit less dramatic than what you've been led to believe.


RE: lighter color roof alternative
RE: lighter color roof alternative
By masher2 (blog) on 2/27/2007 9:13:54 PM , Rating: 2
Ah, our unbiased media labels them "subsidies", and few people read further than the first paragraph or two to find out exactly what they are. How far did you read?

There are no "subsidies" being rolled back. Here's whats changing. The government leased certain sites (primarily in the Gulf of Mexico) to oil companies at a fixed rate, and now wants to make those leases contingent upon oil prices (the government says it mistakenly forgot to ask for that rate structure originally). So, any company that refuses to voluntarily pay the new rates (retroactively, no less) will be barred from seeking any new leases.

Two. A tax deduction (not a subsidy) for drilling and development costs was removed. Of course, these are real costs of doing business which any other company would be able to deduct..but oil companies are very unpopular at the moment, so we're specifically targetting deductions only they use.

Three. A tax deduction for depleting wells was removed. This means that companies will have to pay taxes on the well's original basis (value), even as it slowly gets emptied. Again, this is contrary to normal accounting principles...but what do we care, if it increases the taxes "Big Oil" must pay?

Four. Some incentives for drilling in the Gulf of Mexico were removed. I support this actually...but again, these are in no way, shape, or form "subsidies". They merely reduced (very slightly) the tax burden of a company which choose to drill otherwise unproductive wells in US waters.

Five. Some technical changes to the timing of reporting of income from foreign oil and gas sources, and the reporting of foreign tax credits.

Six. Some other technical changes, none of which relate to subsidies in the least.

Here's a link to the actual bill. Read it and learn the truth. Don't merely accept what you're spoon-fed.

http://thomas.loc.gov/cgi-bin/query/D?c110:2:./tem...


RE: lighter color roof alternative
By hubajube on 2/28/2007 1:48:09 PM , Rating: 2
That link died.


RE: lighter color roof alternative
By TomZ on 2/27/2007 9:55:21 AM , Rating: 2
quote:
Lighter color roof. Start the initiative first. Its also something more affordable.

Many houses have attics that are designed to be well-ventilated to the outdoors. In other words, the temperature inside the attic is about the same as the outdoors. In houses like this where the attic is properly ventilated, the roof color isn't going to make much difference. The degree of ventilation is going to dominate.

Even if you don't, in many parts of the country, we spend as much of time heating as cooling. Obviously in the winter, a darker colored roof is a benefit for heating. In addition, a darker roof clears ice and snow quicker.


Pollution
By Ringold on 2/27/2007 1:33:22 AM , Rating: 3
Out of curiosity, I wonder how reflective these pv tiles are?

I ask because I just had a daydream of flying a plane over Northern California, relishing the beauty of the landscape, then flying over a giant parabolic reflector and having my retina burst in to flames. An exaggeration, but considering it's the most busy airspace in the world just ahead of Central Florida, and I know how bad central FL's airspace is, any additional distractions would be.. most annoying, to say the least.

The promotional video doesn't really do much to confirm or deny my fears there. Indeed.. the first 50sec or so have an animation that makes me even more paranoid.




RE: Pollution
By derdon on 2/27/2007 1:51:47 AM , Rating: 1
Flying planes causes a lot of noise and air pollution themselves, it's not a bad thing if there were less flights.


RE: Pollution
By Ringold on 2/27/2007 2:15:23 AM , Rating: 2
Except for, of course, the far-ranging economic impacts of such a thing, which airport detractors always skim over. With so much commerce going on in CA, and flight training (#2 flight training destination in the world), it would indeed be a bad thing if in the long run there were less flights. At least, for Californian's. Business would carry on elsewhere without them in the long run obviously


RE: Pollution
By dever on 2/27/2007 3:03:07 PM , Rating: 1
We wouldn't want to limit Al Gore's additional energy consumption. What we aren't told is that Gore's energy use from travel far exceeds his home energy use which far exceeds our home energy use. I'm guessing his energy use is thousands of times higher than the average Americans.


RE: Pollution
By TomZ on 2/27/2007 3:25:42 PM , Rating: 2
Sounds like Al Gore's carbon footprint is actually a crater. :o)


RE: Pollution
By lennylim on 2/27/2007 2:31:01 AM , Rating: 2
quote:
Out of curiosity, I wonder how reflective these pv tiles are?

They wouldn't be very efficient if they are highly reflective. Unless, of course, this is another one of the military's new high tech weapons in disguise.


RE: Pollution
By MrTeal on 2/27/2007 8:32:05 AM , Rating: 3
How ironic would it be if the military not only installed a giant death ray reflector gun on the homes of hundreds of San Fransisco hippies, but got them to pay extra for the option.

That makes me smile a little, inside.


RE: Pollution
By FITCamaro on 2/27/2007 8:38:23 AM , Rating: 2
LMAO! That comment made my morning. I didn't hide my smile inside though but let out a nice Dr. Evil laugh.

Awesome.


RE: Pollution
By rickmannow on 2/27/2007 9:08:20 AM , Rating: 2
But solar cells are *not* very efficient. The expensive ones are only 20-24% efficient and the low cost ones are around 12% efficient. They are pretty much all reflective since they are typically covered by glass to prevent damage.

The danger to pilots would be about the same as flying over a lake or ocean. So I don't think it will show up on the "radar" of air transportation. :^)


RE: Pollution
By codeThug on 2/27/2007 11:47:16 AM , Rating: 2
http://www.boeing.com/ids/news/2006/q4/061206b_nr....

Boeing Spectrolab has the efficiency up to around 40%. Not in production yet sadly.


RE: Pollution
By masher2 (blog) on 2/27/2007 1:12:48 PM , Rating: 1
Those Spectrolab cells use a concentrator much larger than the cell itself, focusing light upon the cell. Also, that efficiency figure is calculated from light impinging at a normal angle (90 degrees) which, for a static house-mounted system, only happens for a few minutes per day, if then.


Joules
By ted61 on 2/27/2007 10:29:06 AM , Rating: 2
I don't understand how they calculate effeciency for solar power.

If 1 watt-hour=3600 joules and 1 joule=the energy from the sun covering 1 square foot at sea level, how can you get kilowatt hours from 1000 square feet of solar panels?

Masher and Kris, I am counting on you.




RE: Joules
By TomZ on 2/27/2007 10:52:23 AM , Rating: 4
In North America the average insolation at ground level over an entire year (including nights and periods of cloudy weather) lies between 125 and 375 W/m² (3 to 9 kWh/m²/day). This represents the available power, and not the delivered power. At present, photovoltaic panels typically convert about 15% of incident sunlight into electricity; therefore, a solar panel in the contiguous United States on average delivers 19 to 56 W/m² or 0.45 - 1.35 (kW·h/m²)/day.
http://en.wikipedia.org/wiki/Solar_energy

Based on this, 1000 square feet = 93 m² produces 41 - 126 kW·h/day.


RE: Joules
By daftrok on 2/27/2007 4:50:21 PM , Rating: 2
If I could, I would click "Worth Reading" in a heartbeat Tom.


RE: Joules
By ted61 on 2/27/2007 5:38:55 PM , Rating: 2
I love the link. It is nice to see how things are calculated and how they work.

Thanks Tom


It all adds up!
By jabber on 2/27/2007 9:00:28 AM , Rating: 4
I'd love to build a home that was as self sufficient as possible but living in the UK thats a bit of a pipedream. Plus the solar can get a little dissapointing but we do have a lot of wind.

However, doing all the little things really helps. Been running the same low power lightbulbs for 11 years, (they just keep going) got plenty of insulation and double glazing (never had to use the gasfire or adjust the thermostat after fitting that even during winter).

This year alone I decided to replace my 20 year old hot water/heating boiler. Had a gas combi boiler fitted and we got the last quarters energy bill in, we were really pleased. For the previous old boiler quarter (June to September)for which we only used the old boiler for two 1 hour sessions to heat the hot water the bill came to about £50. From October to January using the new boiler for all our winter heating, new power shower and hot water the gas bill came to £45.

So we can now fully heat our home and run all the hot water we want for less cost than the old system could do just heating water for two hours a day.

Nice!




The Big Picture
By Grast on 2/28/2007 11:35:41 AM , Rating: 2
Everyone seems to have the incorrect idea that solar in homes is generating and storing the power for later. THAT IS WRONG. The homes are generating power and supplying any excess power to the grid. The home owner gets credit for the power generated.

As to solar for home not good enough since businesses use more energy, the idea is to remove the home from using any electricy during the day and hopefully turning an entire development into a large power generator.

If every home had solar, entire developments would be putting power on the grid. This would translate in a lower demand and regular power generators (gas turbine, coal, and other fossil fuel generation plants) would not have to operate at peak times of the day.

The idea is to use solar on a massive scale to reduce the amount of power needing to be generated during the day. An example is this: 42000 homes with a 6k system can generate a peak power equal to 1 large scale gas turbine power plant (250 Mega watts). In a city the size of Sacramento, the theoretical power generation could be 4 gas turbine power plants. 165000 homes based on 2006 demographics. That is 1 terawatt of power with no emmissions or harm to the environment.

As you can see, the amount of power which could be generated is significant. The only issue is cost. If we can lower the cost of solar systems, mandate inclusion of at least 6K systems in all new home sales; we could elliminate the need for hundreds of megawatts of new power generation plants to be built.

We have the technology. We only need the education and will to use it.

later..




RE: The Big Picture
By BillionDollarRhino on 2/28/2007 1:15:58 PM , Rating: 2
Bingo thats it. If 165,000 homes could turn off 4 gas turbines then that is a big improvement on emissions. Now imagine that on a greater scale (where possible, of course).


Finally!!!
By jondevelops on 2/27/2007 1:22:34 AM , Rating: 2
Can I get one of these build here in NYC?




RE: Finally!!!
By Ringold on 2/27/2007 1:38:58 AM , Rating: 1
Sure, if you want to save $5 off your light bill that far north. ;)

There's very few regions of the country where these are worth the investment. NY is most definitely not among them. Even here in FL the rather frequent afternoon clouds I would think would hurt it.

Not to mention, shingles getting blown in to the streets by hurricanes I can deal with. Shattered PV pannels installed by illegal mexican's using duct tape I can't.


Business use for solar
By SiSiX on 2/27/2007 10:47:01 PM , Rating: 2
Businesses, especially large warehouse style buildings (large roof area, 2 or 3 stories high) would benefit tremdously by installing solar in the roof. Lighting is one of the major energy draws along with AC. These buildings are typically light most brightly during the daylight hours when the solar flux is at is maximum. Additionally, if the solar panels are mounted on the roof in a manor that they are not in direct contact with the roof (ie, mounted on stands at an angle), the will reflect a significant portion of the sunlight hitting them, thereby reducing the amount of thermal energy absorbed by the roof and radiated into the building.

It might not be enough to power everything, but it would help to jumpstart the solar panel industry from a mass production standpoint, thereby reducing prices.

I think that you've got to look at it as a way to help reduce the overall load on the utilities, thereby reducing the need for additionaly power generation capabilities and a reduction in fuel consumption for those power generation systems already on the grid.




I dont care
By Sharky974 on 2/27/07, Rating: -1
RE: I dont care
By bplewis24 on 2/27/2007 11:05:10 AM , Rating: 2
Solar power makes people happier too :)

Brandon


RE: I dont care
By Fanon on 2/27/2007 11:43:27 AM , Rating: 2
This isn't a social issue, although some may make it out to be with "clean energy" and whatnot.

I am a staunch conservative, and solar panels appeal to me. Why? Because I live in West Texas where the sun shines 98% of the time; where we have really only one provider of electricity (there are a few companies, but they all basically charge the same). If I can save any money from my $600/month summer electricity bill, I'm interested.


"So, I think the same thing of the music industry. They can't say that they're losing money, you know what I'm saying. They just probably don't have the same surplus that they had." -- Wu-Tang Clan founder RZA










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