Date: Thu Mar 29, 2007 1:20 am. By: Fran
On Mar 29, 1:22 pm, maur...@tpg.com.au (Mauried) wrote:
On Thu, 29 Mar 2007 02:39:24 +0100, Eeyore
rabbitsfriendsandrelati...@hotmail.com> wrote:
Fran wrote:
On Mar 29, 4:30 am, xnich...@hotmail.com wrote: This story appeard today in the International Herald Tribune: -
LISBON, Portugal: The world's largest solar power plant was inaugurated Wednesday in Portugal.(see link below) quote> "The 11-megawatt ,61 million (US$78.5 million) plant, a joint project of U.S energy companies GE Energy Financial Services, PowerLight Corporation, and Portuguese renewable energy company Catavento, spreads across a 60-hectare (150-acre) hillside in Serpa, 200 kilometers (124 miles) southeast of Lisbon Southern Portugal, one of the sunniest places in Europe, has as much as 3,300 hours of sunlight a year. The new plant will produce enough power to supply 8,000 homes and will also prevent the emission of 30,000 tons of greenhouse gases a year when compared to fossil fuels." <endquote
This is a rapid brainstorm and I haven't double-checked the calculations, but using the data supplied it would seem that: -
* This solar power station can produce electricity for 8,000 homes on 150 acres. * So one square mile would produce electricity for about 34,000 homes at a cost of $334 million * Population of Portugal July 2006 estimate 10,605,870 * Assuming 4 people per home = 2,651,467.5 homes * This means you could produce all the domestic electricity in Portugal on roughly 78 square miles (say 8*10 miles) at a cost of $ 26,052, million (not including economies of scale and neglecting displaced economic activities and compensation to farmers) * Portugal's GDP = $183,619 million = 14.2% of Portugal's annual GDP
Spread out over 10 years, that would be achievable at roughly 1.4% of annual GDP Saving in Greenhouse gases = roughly 10 million tons
There's plenty of unproductive land in Southern Spain, North Africa and the South Western USA/Mexico
Why not build more of these?
link to main article:http://www.iht.com/articles/ap/2007/03/28/news/EU-GEN-Portugal-Solar-...
I suppose you'd have to look at the initial capital and recurrent cost to work out the total cost over the effective lifetime of the plant, and the useable energy that it could generate to work out cost benefit. There's also the question of how they get all that silica.
Yes, the sun doesn't always shine, but these days there are ways of "storing" the energy using pumped storage or heated water stored below ground. Luckily, peak load tends to be during the day and especially during the summer months.
Not in Norhern Europe. Can't speak for Southern Europe. Air conditioning isn't so widely used here.
Graham
You might also wish to have a look at the civil engineering works and the costs of building dams for storage. It makes the cost of the actual solar plant look like small change. As a simple exercise , Australia consumes 574 million Kwh per dayhttps://www.cia.gov/cia/publications/factbook/geos/as.html. If solar power was used to provide the entire power solution then storage of at least 2/3s of a day would be needed, and allowing for pumping losses and re generating losses you would need at least 1 days storage. Calculate how many dams and what capacity water wise , would be needed. Its a good exercise , and you will quickly learn that pumped hydro doesnt work for very large amounts of electricity storage
We've been down this road before, Mauried.
Yes, dams are expensive to construct, but if their primary purpose is to supply water, and there is no more cost effective way to supply water in the volumes, at the quality and pressure needed, one must choose between abandoning those human activities dependent on it, or pay whatever it costs.
Once you do that, it's the cost of pumped storage *at the margin*, rather than *ab initio* that is relevant.
Of course, one can also use the electricity to run sewage treatment plants. That's now done with fossil-fuel energy most of the time. If you use your solar to run that and divert the energy you would have used to do that someplace else, or reduce output by that amount, then effectively, you have "stored" it. In many places in the country side, remote from the sources of power on the grid, but near sites for solar, one can get the advantages associated with local power supply. At the ends of the grid, power losses in transmission can be as high as 10%. Avoid losing most of 10% and you need less power.
Of course, I strongly favour the construction of seabord pumped storage. Why not use whatever renewable energy you have to pump seawater into a high catchment. Then, as you release the water, you get hydro, and desal. Double benefit. So the cost of the system can be spread across two pressing needs -- potable water and power.
Fran
Fran