PV Gap

Stephen Said:

Solar power how much does it cost per watt to install today and?

We Answered:

Solar panels by themselves are about US$4.50 per watt. You might get a 'deal' at slightly over $4.00 per watt if you buy a large quantity. So, if you want a 3 kW system, that's between $12,000 and $13,000 just gor panels.

Installation costs go up from there. A proper inverter could run $1000, and batteries are about $50 - $100 each for deep-cycle types (you will want at least 10 of those).

Labor for installing everything from a licensed electrician could also run in the $1000 range and up.

There is good news, though -- there are still major tax credits from the US government and probably from your state gov., as well. Your electric utility company might also have incentives to offer. These can all add up to 30% of the panel costs, which is definitely worth it.

For the future... 'they' have been talking amorphous silicon for a decade now, and not much has been done about that. Triple layer and quad-layer panels are super efficient, but they also cost more. The latest out of Colorado State University (IIRC) is a process to mass produce copper-oxide based solar cells at a target price (eventually) of $1.00 per watt. I think this might be the best 'hope' for cheaper panels in the next 5 years.

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Steve Said:

When / how is solar power going to be cost-competitive with today's common energy sources?

We Answered:

Actually this depends on where you live, and how much electricity you use.
obviously if you live in an area that has a lot of mostly sunny days, the Solar panels are more cost effective than where I live.
where I live we get 80 to 100 inches of rain a year, so we only get about 75 non-rainy or cloudy, or foggy days a year.
also our utility company is a Co=op, so our energy bills are reasonably low.

however if you live in say Ca. either central or southern, with rebates and incentives, you should be able to recoup the cost of you solar panels in 15 years or less.

This site should give you insight into cost and other related benefits.

http://www.treehugger.com/files/2006/10/…

Elmer Said:

How much would it cost to run the entire united states on solar power?

We Answered:

Georock is correct that storage would be required. Pumped hydro is the most efficient way of storing power at this level - surplus power is used to pump water to an elevated reservoir, then reclaimed by draining the water through a turbine. The need for storage can be decreased also by carrying the electric grid through multiple time zones so the time that there is no sunlight on the grid is decreased.
CIA figures show U.S. electrical consumption at just over 4 trillion KwHr per year. At about 2000 hours sunlight per panel per year (conservative estimate) that means about 2 trillion watts of solar panel. Retail prices right now are about $3.50/watt, so a one-time cost of $7 trillion would give us fossil-fuel electricity in the states. There isn't that much solar panel fabrication capability in the world yet. Seems like a better investment than a lot of others we've been making at that scale, though.
The area is a bit tricky - the newer thin-film photovoltaic panels will be lots cheaper when the bcome available in bulk (that's production capacity limited right now) but the take up to 10x the area of the silicon photovoltaics. Figuring in silicon, at around 10 watts/square foot, it's 200 billion square ft. or about 7200 Square miles. That's the size of the eastern 1/3 of San Bernadino county, which is mostly Mojave desert.
Another possibility is solar thermal, which uses mirrors to focus sunlight on a boiler. This is a powerplant-sized solution with about the same efficiency as the photovoltaic. Some designs incorporate enough thermal storage to allow overnight continuous operation.