Current State of Solar Power August 2, 2006Posted by Unreasonable in Energy Matters, Matters Architectural.
Key points (from memory, so I may be off a little):
- Sunpower and Sanyo make the most efficient solar cells at 23%. Most manufacturers are in the 15-20% range.
- Theoretical maximum efficiency is 33%.
- This year the photovoltaic industry passed the computer chip industry in use of silicon.
- Like all commodities, there’s currently a shortage raw silicon because the silicon “refineries” haven’t kept pace with the growth of the PV industry. However, they are currently building more capacity.
- In 1979 PV cost was $30/watt
- Now cost is $3/watt
- Cost has had a linear relationship with the number of cells produced. Every time we double the number of cells produced, the cost drops by 18% (I think – the important thing is: its linear).
- That projects $1/watt in 2012, which makes photovoltaics located on a roof used to power a house cost competitive (without any govt subsidies) with traditional fossil fuel generated electicity from the grid.
- At $0.67/watt PV will be cost competitive in megawatt scale solar farms to replace fossil fuel fired power plants.
- The embedded energy also falls in the same linear relationship. It currently takes 3 years for a solar panel to generate the amount of energy that it took to get the silicon and make the solar panel.
- The largest PV markets are currently Germany (#1) and Japan (#2).
- Sunpower sells panels to Japan’s largest home builder, who offers solar as an upgrade. Last year 1/2 of the houses they built p had solar power.
- As with everything else, China will be a huge market pretty soon.
- When we get to the point that somewhere between 3 and 30% of power on the grid is from solar, storage will be a big problem to deal with.
- Solar cells don’t fail. The soldering that connects the individual silicon wafers does. Most solar panels have 25 year warranties.
- In solar systems, the inverter that converts the power from DC to AC is what fails 95% of the time (because they have electrolytic capacitors in them). The mean failure rate has been 5 years. Newer versions should be around 10 years.