PV Gap

Tonya Said:

what are the advantages and dis advantages of solar power?

We Answered:

Advantages:
The 89 petawatts of sunlight reaching the earth's surface is plentiful compared to the 15 terawatts of average power consumed by humans. Additionally, solar electric generation has the highest power density (global mean of 170 W/m2) among renewable energies.
Solar power is pollution free during use. Production end wastes and emissions are manageable using existing pollution controls. End-of-use recycling technologies are under development.
Facilities can operate with little maintenance or intervention after initial setup.
Solar electric generation is economically competitive where grid connection or fuel transport is difficult, costly or impossible. Examples include satellites, island communities, remote locations and ocean vessels.
When grid connected, solar electric generation can displace the highest cost electricity during times of peak demand (in most climatic regions), can reduce grid loading, and can eliminate the need for local battery power for use in times of darkness and high local demand; such application is encouraged by net metering. Time-of-use net metering can be highly favorable to small photovoltaic systems.
Grid connected solar electricity can be used locally thus minimizing transmission/distribution losses (approximately 7.2%).
Once the initial capital cost of building a solar power plant has been spent, operating costs are low compared to existing power technologies

Disadvantages:
Solar electricity is expensive compared to grid electricity.
Limited power density: Average daily insolation in the contiguous U.S. is 3-9 kW·h/m2 usable by 7-19.7% efficient solar panels.
Like electricity from nuclear or fossil fuel plants, it can only realistically be used to power transport vehicles by converting light energy into another form of stored energy (e.g. battery stored electricity or by electrolysing water to produce hydrogen) suitable for transport.
Solar cells produce DC which must be converted to AC when used in currently existing distribution grids. This incurs an energy loss of 4-12%.

Mary Said:

information on solar powered city?

We Answered:

http://www.energybulletin.net/648.html
This url links to a news article about Gardner, Massachussetts, a small city that has been running on solar for 20 years. As an experiment, it had a mixed success record of being reliable and economical. I can't copy the article here, because it is copyrighted.

Kay Said:

Has anyone ever heard of solar powered safety signs or know where I could get more information?

We Answered:

I actually have worked with a company that specializes in solar safety signs - check them out: http://www.starcomsolar.com. Good luck!

Ramon Said:

solar powered cars... anyone have information?

We Answered:

Dear Ilove,
I don't know of any good websites, but
I know a little about solar cars. A car that
runs strictly on solar power won't work because
there is not enough energy in the sunlight
that hits the car. A better idea is a battery
powered car that recharges from solar cells on
the roof. Drive it to work or school and it sits
there all day and recharges. Then drive it home
and plug it in. The solar cells on your barn roof
keeps your house's battery charged so you
always have some electricity. For long range
you are mucked, but for forty miles or so you
are fine.