PV Gap

Arlene Said:

Sources for the benefits (economic and social) of wind and solar energy?

We Answered:

Benefits of Wind Power

Cup wind anemometer for measuring wind speed. (NREL photo)A wind energy system can provide a cushion against electric power price increases. Wind energy systems help reduce U.S. dependence on fossil fuels; and they are nonpolluting. If you live in a remote location, a small wind energy system could help you avoid the high costs of having utility power lines extended to your site.

Although wind energy systems involve a significant initial investment, they can be competitive with conventional energy sources when you account for a lifetime of reduced or altogether avoided utility costs. The length of the payback period – the time before the savings resulting from your system equal the cost of the system itself – depends on the system you choose, the wind resource on your site, electricity costs in your area, and how you use your wind system.

http://www.montanagreenpower.com/wind/in…
Solar energy - please see this link.
http://www.solarenergycompany.co.uk/bene…

Gladys Said:

Good essay topic for Solar Energy?

We Answered:

Maybe you could run with the fact that our entire planet runs on solar energy already - it provides us heat and light, grows our crops with photosynthesis, causes evaporation, clouds and rain and is therefore also responsible for giving us water. It even gave us oil, coal and gas because the dinosaurs wouldn't have been here and the ancient trees wouldn't have grown if the sun wasn't shining! So there's a few benefits. Now for the costs ....

Rafael Said:

what are the risks and benefits of solar energy?

We Answered:

Solar exists in two forms, photovoltiac and heat related. The problems with photovoltiac are cost of materials, fragile cells, cells "wear out" and need replacement after about 10 years. Of course, power is only made during the day. With heat plants, the sunlight is reflected with a mirror array to a central tower where a heat exchanger is located. The piping contains a salt which is liquid when hot enough. Heat is stored in the liquid salt in insulated tanks underground. The hot salt is used as the heat source to boil water to turn a turbine generator. Heat stored in the tanks can be used after sunset much like a car battery stores electricity when the car is not being driven. The disadvantage is the salt is highly corrosive and difficult to handle. And, if allowed to cool, becomes a solid. The only bad thing for the environment with the photovoltiac array is the amount of land covered by the array and the exotic chemical processes used for manufacture of the cells. For the heat plant, the bad thing is the salt used, which is corrosive and hard to handle because it is SO hot. After all, salt is a form of rock, and liquid rock salt is a close relative to volcanic lava. Otherwise, the heat plant has the same thermal footprint as any other heat power plant such as coal, gas or nuclear. All steam cycle plants exhibit the same thermal effects, using heat to boil water, and needing cooling from water nearby to condense the steam back into water so it can be fed back into the boiler, which heats the environment where the cooling water comes from. Unlike oil, coal and gas fired power plants which rely on combustion, there are no stack gases from the solar heated power plant. Both types of solar power plant are considered to be GREEN because thermal footprints are not a majority contributor to damage to the environment, as the problems are very local in nature. The major problem why solar is not more widely used is simple economics, the cost of installation is huge compared to other types of power plants. Both types require huge areas of land to collect enough light to make them practical as a utility serving many customers. The solar photovoltiac array on a roof powers only one house, think how much area you need to power 10,000 houses. Houses can also use the sun to heat water and use the heated water in insulated tanks to heat the house on cloudy days. Solar water heating just takes a really big tank per house. Water is cheap and the technology exists to make durable system which will last almost forever. Except for cost again, single house solar heating is practical. A friend back in the years before Y2K, went off the grid. He firmly believed Y2K would be a total meltdown of society, so he had a house built way far away from Seattle in the Olympic Mountians on the coast of Washington. He spent roughly $40,000 on the solar heating and electricity and pays no utility bills except for water. He has a well, but it is metered by the county where he lives. The problem he has is age. The systems are now over 10 years old and he needs a total replacement of the storage batteries and solar cells, to the tune of about $10,000. With the initial cost plus the replacement cost, he has spent $50,000 for 10 years of services, which works out to about $400/month. If he lasts another 10 year and spends another $10,000, his monthly cost will be about $250 per month. The problem is this: his old utility bills rarely ran over at most $200/month in winter and as low as $70 in summer, averaging about $120/month per year. As you can see, the systems he has have not paid for themselves and even after over 20 years, will STILL be costing him more than if he had used the community utility systems to power his lifestyle. The real problem is initial installation and then periodic maintenance and replacement costs. Maybe after 30 years, the systems will equal out and "break even". A utility company is NOT going to invest in such a bad deal to generate power. Utilities need a return on investment much sooner than 30 years. I would love to go solar. I really like the idea of not relying on a power company for lights and heat. It IS the most environmentally friendly source of energy to power things for us... I just can't afford to do it...

Billie Said:

If you had to argue the benefits of solar energy, what would they be? What are the risks? ?

We Answered:

The benefits are obvious whilst the sun shine one produces energy for free without the production of green house gases. The risk are low but there are downsides.
1 storage of energy for nite use is messy at best
2 takes up valuable space that could be use for agriculture
3 takes a lot of energy to produce photovoltaic cells
4 units have a finite life 10 to 20 yrs