PowerSwitch

http://www.treehugger.com/files/2011/07 ... awatts.php

'2625 Feet Tall! Solar towers, which are kind of big funnels that generate electricity by using the fact that hot air rises, are too often forgotten when we discuss solar energy. Solar PV and CSP get all the press, but solar towers have attractive power-generating characteristics and I wish more companies were working on perfecting them. EnviroMission is an Australian company working on that very thing, and they've announced that they want to build a gigantic 2625 feet/800 meters solar tower in the Arizona desert that would produce about 200 MW, enough to power 150,000 US homes.

[...] Currently undergoing site-specific engineering and land acquisition, EnviroMission estimates the tower will cost around US$750 million to build. It will generate a peak of 200 megawatts, and run at an efficiency of around 60% - vastly more efficient and reliable than other renewable energy sources.

The output has already been pre-sold - the Southern California Public Power Authority recently signed a 30-year power purchase agreement with EnviroMission that will effectively allow the tower to provide enough energy for an estimated 150,000 US homes. Financial modelling projects that the tower will pay off its purchase price in just 11 years - and the engineering team are shooting for a structure that will stand for 80 years or more'.

Jon

Talking about "Payback" when the buyer is the government is always tricky.
What price are they paying?

Spot Price?
Long Term forward contracts?
Subsidy price to make any renewable viable?
Interesting concept, which should continue even through winter should it not?

Lets hope that it isnt just greeny fantasy

Yes, as always, price is a big factor, though I can't help thinking that we will have to start thinking further than just money at some point...

The design of this solar tower is a new one to me. I was only aware of the type found in Spain, where curved mirrors in a large array around the tower focus sun energy on water in the tower, boil it and drive turbines with steam. This Arizona one uses a massive draft of warm air up the tower to drive turbines. The air is heated by the sun in a large cavity under massive dark coloured panels set out around the tower, then drawn up the tower by convection. I'm very interested to see if they build it and how reliable and powerful it turns out to be.

Jon

[quote="ujoni08"]

RGR wrote:...now if we could just find a way to limit the abundance of fossil fuels to give them a decent economic head start.

As you have often told us, RGR, there is one and it's called "price". The reducing output from the North Sea will mean that the UK can increasingly not afford to purchase what it wants from abroad. Increasing demand from Chindia will ensure a rising world price. We will have an incentive to diversify even if the US doesn't.

RGR wrote:Took everyone long enough to notice, what is it with how long it takes for the rest of the world to learn stuff?

We took notice alright: of the problems with water supplies and pollution that seem to accompany fracking. Our politicians aren't so corrupt as your lot and they are more concerned to get re-elected by the people who would suffer from the pollution than they are with the oil companies that pay US politicians.

The electors in Europe are more concerned than in the US with the environment that they live in as we are a bit more crowded than you are. In the US you might not give a sh*t about a few hill billies in the boon docks having gas and carcinogens in their water supplies. We're all a bit closer to that water supply than you might be (with the exception of New York) so we want you to make all the mistakes first. If there's anything to learn we want to learn it. What price money if you can't get water to drink.