You may think that solar power systems are a completely modern idea: they're not. In fact, people have used solar power since prehistoric times and we only think it's a new invention because it's so frequently coupled with electricity. In fact, electricity nearly caused the death of the solar thermal industry.
Before the 1930s, most solar thermal systems were simple batch, flat-plate or closed loop systems. They used the sun's energy to heat a tank of water, either directly or in a separate location, and stored it for later use, again either directly in the heated tank itself or in an insulated tank fed from the heating location. In the few years before the US joined World War II, from 1935-41, about 60,000 solar thermal systems built by William Bailey's company were installed on around 80% of new homes built in Florida and California. Unfortunately, the US's entrance into the war dealt three killing blows to solar.
First, the war effort froze all non-military uses of copper, which was a major component in manufacturing Bailey's systems. Second, the appearance of automatic washing machines, dishwashers and other appliances increased the demand for hot water beyond what small solar thermal systems could provide. Third, a massive drop in electricity prices and a push by electric water heater manufacturers encouraged most home owners to install these new, cheaper systems than to repair their ageing, leaky solar setups.Things stayed that way until the energy crisis of the 1970s. Americans believed they had more than enough energy for everything and it wasn't until the rude awakening of the Arabian oil embargo (1973) that anyone really thought about power consumption. The long lines of cars waiting for gas and the tripling energy prices for heating scared the entire country.
President Carter took the first significant step back towards alternative, renewable sources by putting on a sweater and installing a solar thermal system on the roof of the White House. This was followed by massive investment in renewable sources by both the private sector and the government (who spent 400 times more in R&D).Throughout the late '70s and into the '80s, solar thermal system installation was patriotic: it reduced the US's dependence on foreign imports. Of course, the tax credits and incentives didn't hurt, since they could reduce the cost of installation by half!
Unfortunately, the good times ended when President Reagan took office. He repealed the credits, reduced funding for research by 90%, took the solar thermal system off the White House roof and discredited renewable energy in a massive campaign that gutted the industry. Why? The cynics would say it was because his presidential campaign – the most expensive ever seen at that time – was partly funded by oil interests.
Throughout the 1990s, solar almost disappeared in the US. Everywhere else in the world, usage increased but at home, Americans were switching back to fossil fuels and only the more environmentally aware stuck with alternatives. Thankfully, the green movement did not die under the pressure of the oil barons (or anyone else) and has regained its