Time Is Energy

Solar reaching GW scale

One of my favorite aspects of solar technology is that the more we make/use/buy the cheaper it gets.

There are several reasons for this from the trivial--buying any product in bulk is cheaper than buying one, two or three at a time--to the more profound like the experience curve: you get better at making any widget the more widgets you make. Also as the solar industry grows it continues to improve the efficiency of the cells that go into the panels as well as how efficiently it makes the panels (yield).

Semi-related to the experience curve is that scale brings certain advantages--I'm alternately annoyed/amused when people compare the "high" cost of solar for a home (3-5 kw system) to the "low" cost of electricity from a GW sized coal power plant and reach the conclusion that solar is simply a bad investment. This is like comparing the cost of transporting an item from NYC to LA by bicycle to the cost of doing so by freight train and then deciding that a bicycle is simply a bad investment. It is clearly comparing apples and oranges...you would need to compare the cost of electricity from a GW solar plant (and preferably the cost from the nth GW solar plant not the first one) to the cost of electricity from a GW coal plant to reach a meaningful comparison. Or you would need to build a house sized (3-5kw) coal fired power system and compare that to the home solar system.

Several recent news items appear to show that we will soon have GW (or near GW) scale solar plants to compare with the coal variety...from a 1 GW solar thermal plant to multiple 0.25 GW solar plants (PV and CSP) under review out in CA. Although this won't yet be a perfect comparison it will at least become a meaningful comparison.

Just as you would organize the installation plan and procedure for installing 1.6 MW of solar PV differently from installing 2-3kw of solar, so I expect another similar leap going from 1-2MW to ~250MW of PV. It was only 4 years ago that Google's 1.6MW planned solar installation at their headquarters (completed by mid 2007) made headlines around the country/world, and now we are clearly well along on plants that are two to three orders of magnitude larger.

One thing that comes to my mind is...why not automate the assembly of the panels into blocks (at or near the site) just as solar panel manufacturing has become automated? Each solar panel is basically the same as the next one--just as each cell in the panel is equivalent to the next, and that is very automated. A 1 MW install consists of ~4,000 panels (250kW ea), while a 250MW install consists of 1 million panels (250kW ea)...maybe the assembly is not 100% fully automated, but there will be at least a dozen "activities" in the installation porcess that could be individually, or partly automated, saving a million person iterations of the same procedure (and likely improving consistency).

At the moment this belongs to the realm of science-fiction, but one could certainly imagine a room-sized machine that travels along one row of (ground mount) panels with a fully automated sequence of actions to locate, one panel next to the prior panel, mount it (i.e. screw it in place) mechanically and then make the electrical connection and perform a quick test to ensure a minimum mechanical stability and electrical performance is achieved, and then rinse and repeat...

posted by Daniel @ 11:33 AM