Solar Futures – Power Plant Generation

One of the aspects of solar power generation that I have been interested in is whether there are any real economies of scale. For example having hundreds of thousands of 4kwh household units has advantages to those householders but what if solar was used to build an actual power plant ? And what difference in pricing would that make.

Also there is transmission loss of about 7% (as I understand it) so local generation does provide an efficiency gain by minimising that loss.

Given the numbers of panels that might be involved to get up to mw scale (1000kw=1mw) and electricity power plants tend to be 100mw and above. In say a desert area like the Middle East or large parts of Australia using extra land area might not be such an issue but if there is a way to concentrate PV produced power then that would also be very useful for locations where space is at a premium.

Following on that logic a greater amount of energy being produced from a smaller amount of PV installed would also improve the payback for all users of that power; and make solar power plants more cost effective on a larger scale.

In Australia the largest solar power plant is under construction now in Mildura.

The Mildura Solar Concentrator Power Station is a proposed photovoltaic (PV) heliostat solar concentrator power station

Planned capacity is 154mw and once complete that will make it Australia’s largest solar plant. There have been other large scale solar power plants planned in Australia but so far this one will be the biggest.

According to a summary over on wikipedia there has been a more than 10 fold increase in installed solar power there in the past 3 years. Australia has an estimated 1.74GW of installed photovoltaic (PV) power as at August 2012. To put that in context NZ has 600mw of windpower – so Australia has about triple that in solar PV generation capacity now.

According to Silex Systems, the technology used in the Mildura plant is at the forefront of utility-scale solar power generation. By employing triple-junction solar cells which are able to track the sun during the day, the Mildura site will be capable of operating at over 40% conversion efficiency claims the company – roughly double the efficiency of today’s best silicon-based cells.

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The technology being used concentrates power and so needs cooling as PV performance falls by about 1.7% for every 10degrees C rise in temperature. Most interesting is that this technology is already working and more efficient than most PV systems out there plus the PV cells themselves can be upgraded as that tech improves.

This system looks great but in looking around I came across a project by Otto Ng who is an architect and technologist concerned with ecological consciousness. He developed plans for the Powerscape — landscape architecture that produces renewable energy — as his research thesis at MIT. This was presented at the TED talent search last year.

Otto’s talk titled : Canopying the desert for solar energy (5mins) shows that solar PV generation has plenty of room for innovation. Incredibly the cash rich Middle East could/should be very interested in his research as a way to reduce their dependency on fossil fuel and it looks like there are other benefits that include cooling and possibly agriculture.