In the short time since President Obama’s alternative energy plan was announced, already the prospects look good for clean energy that is cost-competitive with fossil fuel. That’s without even factoring in the avoidable health costs that that the public currently absorbs from high risk, antiquated fuels. The latest case in point is a new high efficiency solar power system out of the National Renewable Energy Laboratory. Designed with the help of some centuries-old technology, it produces electricity at a competitive rate with natural gas in at least six states.
NREL Multi-Junction Solar Cells
The key to the new system is a high-efficiency solar cell based on “multi-junction” technology. As reported recently on this site, multi-junction solar cells are far more efficient than conventional silicon solar cells. In the recent past they were not particularly cost effective, but that is changing as the technology improves. NREL has been working with the solar company Amonix to integrate multi-junction solar cells with its existing concentrated solar system, the Amonix 7700, which was originally designed for conventional silicon cells.
Super-Efficient Concentrated Solar Power
In the lab, NREL’s cells can convert 41.6 percent of the sunlight they collect to usable energy. NREL notes that production cells always under-achieve lab cells, and the ones produced for the Amonix 7700 are achieving 31 percent per module and 27 percent for the system overall. That’s quite a bit lower but it’s still a respectable figure; in fact, NREL states that it is the highest ever recorded for concentrated solar.
New Tech + Old Tech = Cheap Solar Power
Aside from using multi-junction solar cells, NREL and Amonix used a few tricks to keep the cost of the Amonix 7700 down. One factor was the pairing of each cell with an inexpensive lens called a Fresnel lens, which was first conceived and developed in the 1700’s. For less than $2.00 per lens, each cell got a whopping 500-power amplification. As with another modular solar power system new to the market, Amonix also focused on keeping the cost of installation at rock bottom. The 7700 requires only a few subassemblies that can be hauled to the site on just two flatbed trucks, and put together in several hours.
Solar Competes with Natural Gas in Six States
According to NREL, the 7700 produces electricity at or near the same price as a new state-of-the-art gas-powered plant in six states: Arizona, Colorado, Nevada, New Mexico, Utah, and Texas (based on CMRP). No wonder the fossil fuel industry is pulling out all the stops in its efforts to roadblock the President’s energy policies. Like firewood, fossil fuels will probably always have a place in the energy picture, but the time is fast approaching when they will no longer dominate.
Image: Pennies by jayhay312 on flickr.com.