The Tables Are Turning, two very experienced and canny bloggers – Callimachus and Reader_Iam - debate, among other things, the question raised above. Here’s my answer.
What kind of wimps are you? Robert Heinlein must be turning in his grave!
Sofirst Callimachus says
“Manhattan Project came along when the new energy source had been discovered and described and defined, and all that left was a massive motivation of money and manpower to bring it to fruition. That's the point at which a government push can be helpful. That's not where we stand with alternative energies.”
Declining manufacturing costs (dropping at 3 to 5% a year in recent years) are expanding the range of cost-effective uses. The average lowest retail cost of a large photovoltaic array declined from $7.50 to $4 per watt between 1990 and 2005. With many jurisdictions now giving tax and rebate incentives, solar electric power can now pay for itself in five to ten years in many places. "Grid-connected" systems - that is, systems with no battery that connect to the utility grid through a special inverter - now make up the largest part of the market. In 2004 the worldwide production of solar cells increased by 60%. 2005 is expected to see large growth again, but shortages of refined silicon have been hampering production worldwide since late 2004."
And before you ask, yes, silicon can be derived from sand and yes, sand is found in deserts just like the oil but let's not be childish about this.
Solar cells can presently convert around 15% of the energy of incident sunlight to electrical energy. If built out as solar collectors, 1% of the land today used for crops and pasture could supply the world's total energy consumption. A similar area is used today for hydropower, as the electricity yield per unit area of a solar collector is 50-100 times that of an average hydro scheme. Solar cells can also be placed on top of existing urban infrastructure and does then not require re-purposing of cropland or parkland. The German government currently has a huge photovoltaic energy initiative, which is being watched with interest by other countries."