Solar panels are becoming common sights in many parts of the USA, and even more capacity is on roofs out of sight and mind. After 5 years of explosive growth, solar capacity exceeds now 8,000 megawatts or about enough power for 1.3 to 1.6 million homes.
The revolution in solar is real but still in its earliest days, as is brought home by the fact that all the solar systems today in the US produce less power than the two closed California nuclear plants at San Onofre. The 2 California nukes total 2,254 megawatts but produce considerably more power than the 8,000 megawatts of solar across the USA. Why?
Nuclear plants operate typically around the clock and at more than 90% capacity factors for an entire year.
A general rule of thumb is that 1 megawatt of nuclear produces as much electricity as 5 to 6 megawatts of solar. As a result, solar capacity in the USA will have to reach at least 11,270 megawatts before it will produce as much power as the 2 closed nuclear units at the San Onofre plant. US solar capacity, however, will do that by the end of this year.
After recently announced nuclear closures, the US will still have about 100 nuclear units operating in the USA. And by the end of this year, US solar capacity will produce annually power equal to about 2 of the nuclear fleet's big units or 4 small nukes. Just to build enough solar to replace the equivalent of the US nuclear fleet will take decades.
These facts should be kept in mind when judging claims that solar or wind can replace nuclear or coal or gas power plants by certain dates. By 2050, just about anything is possible.
But by 2020, California will be leading the nation in getting to 30% renewable energy for electric power production, while 70% will be still coming from mainly natural gas. And to reach even 30% renewable energy power production by 2020, California will rely on massive amounts of electricity to be generated by big hydro, biomass, and geothermal power plants, in addition to solar and wind.