March 16, 2009
1366 Technologies Aims For Cheap Silicon Photovoltaics
MIT mechanical engineering prof Emanuel Sachs thinks his solar photovoltaics (PV) start-up 1366 Technologies can bring down the costs of silicon polycrystal-based PV below the current cost of thin film PV. His company's goal is to bring the cost down even below coal electric in 3 years. 1366 Technologies is pursuing at least 4 technological improvements in order to beat coal electric.
1366 Technologies' first idea, called a "light-capturing ribbon," is to manufacture so-called interconnect wires with V-shaped grooves. Normally, light hits those interconnect wires, which are under the solar cell, and bounces straight out. By contrast, the grooved wires reflect light at an angle so that it can bounce onto a solar panel's glass covering and back down onto the cell. That "internal reflection" squeezes a bit more electricity from the incoming light without having to reinvent the production process.
The second idea is to redesign the wires that carry current on a solar panel to be smaller and less expensive. There are two other improvements on the drawing board, including one that uses reflective wires to trap more light onto cells, but the company is cagey on the exact details.
PV below the cost of coal electric would simultaneously lower the prices we pay for electricity, reduce conventional pollutants such as particulates and mercury, and also reduce greenhouse gas CO2 emissions.
I would like to see polysilicon PV beat the current low cost leader FirstSolar's Cadmium Telluride thin films. For a few reasons. First off, silicon-based PV achieves higher conversion efficiencies. Higher conversion efficiencies mean you can get more electric power out of the same rooftop area. This raises the potential energy output for electric power generation for homes and commercial buildings. Second, whether Tellurium (Te) production can scale up is uncertain. Third, silicon PV is probably easier to deal with in terms of disposal at the end of life (though I'm not certain on that point).
I still see any of the major PV technologies as such big net pluses that making any of them very cheaply will be a big win for all of us.
3 big problems with photovoltaics that you are not addressing:
1. The sun doesn't provide energy everywhere 24 hours a day (more like 6 hours a day at best, usable)
2. There is no good utility scale storage technology that can be implemented around the world
3. You have to build PV to 3 to 4 times the capacity of a coal or nuclear plant to make up for the inconstant sun, assuming useful storage which doesn't exist.
PV is great for rich folks and for off the grid apps.
It doesn't matter how efficient the panels are, you have to address
We've discussed the pros and cons of solar power extensively in the comments sections of previous posts. See my Energy Solar category archive for lots of previous posts on solar. A few points:
1) PV tracks approximately with peak demand. Electricity demand is not constant. It is much higher in the day than night. In the US it is much higher in the summer than winter. PV produces power when demand is higher. It is not a perfect fit with demand since demand peaks in the afternoon and early evening. But during the summer the fit is close enough to be highly useful.
2) Current peaking electricity comes mostly from natural gas and plants that have low capital cost and low efficiency. Solar has to compete with peaking natural gas electric at much higher price points than the cost of coal or nuclear.
3) Concentrating solar (as distinct from PV) lends itself to fairly easy storage as intense heat with cheap salts. This allows the heat to be used in the evening to generate electricity. Some plants do this.
4) PV cost versus nuclear: Nuclear power is a baseload power source. Solar won't compete with it much due to the solar storage problem - especially for short winter days.
5) Dynamic pricing can shift demand around. If solar panels become very cheap some demand will shift to when solar produces the most power. For example, run water pumps during the day more than the night. The cost of fuel to pump water on farms far exceeds pump costs.
A few other points:
1) the sun is always shining somewhere. The more long-distance transmission you have, the more you can take advantage of this. For instance, the US has several time zones, which smooth out overall US insolation over time.
2) PV is likely to be mostly on the consumer side, where it competes with retail prices after taxes. It's also likely to be on rooftops, which eliminates land costs, transmission losses and some mounting costs.
3) "Dynamic pricing can shift demand around." You said it! There's enormous potential with charging of electric vehicles (plug-ins, EVs), and refrigeration and A/C. Keep in mind that much I/C night time demand (smelting, manufacturing) is only there because of low prices: if daytime electricity prices fall, some demand will come back to the daytime.
The "sun is always shining somewheres" argument helps the US East Coast more than the US West Coast. The West Coast can send its noon time solar electric surplus eastward. But the West Coast has nowhere to get the electricity from.
Eurasia is in a far better position to ship electric power across time zones. But I'm guessing Europe and China won't want to become dependent on Russia and the Stans.
The only kind of solar power that truly scales up is orbital SPS. The argument that insolation matches electrical demand is bogus. 9 PM on a winter's night. Obama has banned coal, gas, oil, shale, nuclear and sands. The wind isn't blowing and the sun sure as hell isn't shining. You gonna freeze in the dark, sucka.
"The "sun is always shining somewheres" argument helps the US East Coast more than the US West Coast."
Sure, but 4 time zones are better than one. Every little bit helps.
" I'm guessing Europe and China won't want to become dependent on Russia and the Stans."
You would think so, wouldn't you? And yet, Europe is badly dependent on Russian/FSU oil & gas, and China is working hard to become so. It's odd.
Building a better grid, which would be a high voltage DC design, is much more important than worrying about the solar power itself for the moment.
It is true that the West can not import solar power in the evening. But the East has the same constraint in the morning. Power lines work in both directions.
The grid is more important because both sides of the country have a huge idle capacity from dusk until dawn which could help the other region.
In summer the Southwest uses plenty of air conditioning before noon. The load does not magically awake at noon. So morning solar power from the East could be useful in the West. Alas, not all geography is equal, so large-scale solar farming should first be funded for the better sites in the Southwest and West.
The West doesn't need as much power in the morning. Peak is in the afternoon and evening. Sure, morning power has some value. But demand and wholesale prices are higher in the afternoon.
"The West doesn't need as much power in the morning."
No, but it needs a place to put it's morning and noonish production, so it would be handy to have East Coast demand.
Again, not an overwhelming improvement, but it helps a bit.