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Students Show Off Super-Efficient Solar Homes
mmol_6453 writes "An article at voanews.com describes the 'first-ever solar decathalon,' where the students show off effecient solar-powered homes." As a former Airstream resident, tiny efficient homes have a special place in my heart. Anyone in the D.C. area who can get out there and take pictures, links to photos would be much appreciated in comments.
Well.. I doubt that you would need to cover 1/2 of southern california to provide all the energy needs... but even taking that as a fact... Consider what would happen if everyone, or even a significant number of people (thousands to millions) put a couple of panels on their roof. You are talking about a serious amount of energy production, and just as important, a serious amount of energy production when it is needed most, during the hottest part of the day when everyone has their air conditioners on high. The point of the student's exercise was not to turn people's houses into Multi-Megawatt power plants, but to make homes more self sufficient, energy efficient, and able to produce in aggregate large amounts of energy in a pollutionless manner. After tax incentives and rebates in my area (LI,NY) the cost for solar power is about $3/ watt as I recall (which is considered by the industry to be a magic price point, ala the $1000 PC). So you say everyone spends $3000 on a system, or all new houses incorporate a system, and produces 3kW of power during the day. Times 1000 homes is 3 megawatts, without all the impending doom problems that lurk with nuclear power (dont peg me as some tree hugger though- nuclear is my preferred method of power after hydroelectric and solar). Nice added benefits: reduced reliance on fossil fuels and thus the middle east. Also... power outages are less problematic. I dont think any of the students or even any solar energy zealots really believe that solar is the answer to all of our energy problems, but solar can make a huge dent in our energy needs.
Throwing about hyperbole does not help
.01 = .031 KWh/m2/day
.031 = 343 x 10^6 Kwh/day
Doing a quick calculation and using the sq mileage for San Diego County of 4281 sq miles and the nominal energy density of solar at that latitude of 3.1 KWh/m^s/day and a 1% conversion factor gives:
3.1 KWh/m^2/day *
4281 Sq Miles * 2.58 x 10^6 Sq Meters/ Sq Miles = 11 x 10^9
11 x 10^9 x
Or 343,000 Megawatts-Hours for a small California county.
Not that I am proposing to cover an entire county with PV panels but if you are going to "tell it like it is" then do.
BTW, can we bury the Nuclear afterproducts in your backyard?
> but at least I will tell it like it is
Or at least how right-wing kooks want you to believe it is.
You're overlooking two things. First, solar thermal. Most of our power demands are for thermal applications, which are cheap and easy to do with solar. Photovoltaics get all the press because they're "sexy", even though they don't collect much power.
Second, demand. It's very, very easy to lower demand without changing lifestyle, because we currently waste enormous amounts of energy. California demonstrated that during the last manufactured energy crisis. Basically, if *any* effort is made to lower energy use, demand drops dramatically. In particular, it's easier, cheaper, and affects our lifestyle less to lower demand, rather than pouring more money into centralized power generation so we can turn around and waste it again.
Yes, to made crystalline PV cells requires the same sort of chemicals and plant processes used in making semiconductor chips. It isn't necessarily dirty but very power intensive. Amorphous silicon PVs are also dirty to produce because of the amount of power needed and the chemicals used. Even if the chemicals are handled responsibly by the manufacturer there is no guarantee that the chemical's manufacturer handled the chemicals safely.
Calling PV power generation clean is an absurd falsehood by those promoting it, not to insult you but instead to point out the people who convinced you PV was the clean wave of the future. To generate power you need to spend power, on the whole it is a zero sum process, you don't get moreo ut of what was put in.
The reason oil is cheap easy and popular is because the energy it contains has been put there over the course of millions of years by microbes decomposing organic matter. The energy required to tap fossil fuels is much less than all of the energy contained in fossil fuels. The same goes for fisson power, the energy in the uranium was put there by a supernova billions of years ago. All we have to do is spend a little energy to tap that. Water, wind, and solar power sources are clean on the level they don't produce emissions themselves but the processes constructing them sure as hell do.
PV is clean in the same way electric cars are clean. Sure the eletric car doesn't produce emissions itself but it did take quite a bit of power to construct. There there is the fact that 55% of the nation's power comes from coal power plants, so for every kilowatt an eletric car uses you need to chalk up the fossil fuel emissions that generated that kilowatt. ULEV cars are cleaner overall than electric ones.
Hydroelectric and geothermic power generation is typically the cleanest IIRC all things considered. They are both just redirecting energy being emitted naturally and require a minimum amount of dirty processing to construct. They also last much longer than PV or wind generators and produce most power.
The only real way to clean up power usage is to make things more efficient and work with what you already have. PV cells require too much material alteration to be long term efficient. Lower power electronics, higher efficiency lighting, better industrial resource planning, solar heating, and efficient building design are all measures that can clean up power generation simply because less power is required. PVs can help lighten loads of the power grid by they are far from being a clean power source or an effective alternative to fossil fuels.
I'm a loner Dottie, a Rebel.