Solar Concentrator PV Systems use some optical system to focus Sunlight onto a PV Array. There are various techniques for focussing:



And various best places in the world to deploy:



Examples shown below:

The idea is to essentially take a large collecting area and focus it on a smaller area, thus concentrating the incoming sunlight and therefore increasing the incident energy on the PV. This means that less PV material will be required to produce a given amount of energy and this, potentially, saves expenses. However, current projects are not proving to be cost effective: Ideally the LCOE (levelized cost of electricity) should be 5-8 cents per kwh for competitiveness with other sources of electicity generation.



However, levelized costs for this technology remain high and future cost reductions may be overly optimistic. This is from a 2009 report: (its now 2018 by the way)



From 2011:



Very recently we have tried to bring some large scale solar nameplate on line - this has not yet worked out very well (see question 5 in Homework 1).



And some of the proposed facilities which we will evaluate again on Wednesday



While the trajectory of the world looks relativley good - with the key point that 2016 saw 10 times more installed capacity than 2009 - the total installed is about 300 GW which, out a world electric nameplate of now about 6 TW - is only 0.5%.



And then along came Trump

And This is an example of a stupid, style over substance project

CSP plant attached to NG facility so as to use solar power to help heat the water and therefore produce less GHG emissions, and so us Canadians are now green . Great idea in principle but what did they actually do?

• NG nameplate is 200 MW
• CSP nameplate is 1 MW = 1/200 = 0.5%
• CSP facility cost $9 US million 9$ per watt
• WTF?

On the other hand the Austrailans have sort of done it right or at least tried to with the Kogan Creek Solar Boost facility

• Coal Fired nameplate is 750 MW
• CSP nameplate is 44 MW = 44/750 = 6%
• CSP facility costs $120 US million $3 per watt (but some government subsidy)
• But sensible ideas often Die

Long term outlook, however, is that CSP will always be significantly more expensive than PV.



But still, the future roadmap is quite optimistic --



In that real world, the issue then becomes the reliability of the CPV components over time. Also CPV systems function best under clear sky, direct-sun conditions. Early installations were made in Saudi Arabia, Arizona and at Alice Springs, Australia.

Costs are a strong function of DNI (Direct Normal Irradiance):



The primary potential problem here for any CSP system is heat load and subsquent failure of either the PV material itself or one of the components in the optical path. Within CPV systems, the concentration rato can have high variance. If light that falls on 100 sq. cm of reflector surface is focussed onto a 1 sq. cm surface of PV material, then the concentration ratio is 100. Current commercial design concentration ratios are in the range 200-300 suns. Concentration ratios of more than 1000 have been produced by start up companies that have claimed to "solve" the energy problem but those companies, like their components, quickly melted.




Various Designs for CSP systems are shown below:

Linear Fresnel Lens:

Advantage = simplest system and light weight. Focus is "horizontal" and not parabolic. Can be made Large or small

Linear Array for Power Tower



In this case a network of mirrors (heliostats) mostly surrounds a central tower. That reflected and focussed sunlight heats up some kind of receiver at the top of the tower. That hot liquid, usually molten salts, then mixes with water to make steam and hence electricity. This process is shown below.