Solar water heating has quite a long history. In the United States alone, the industry has boomed and busted 3 times in the last 130 years – each time displaced by cheap energy. Many are surprised to know that the first US patent for a residential solar water heater was issued in 1891 to Clarence Kemp, a Baltimore inventor. That’s right, 1891. In the 1920’s, 30% of the homes in Pasadena, CA had solar water heaters. With the discovery of natural gas resources in the region, the industry evaporated almost overnight. Solar thermal technology is mature and efficient; the problem lies with allowing our commitment to solar to dissolve in favor of decreasing natural gas prices.
In these previous industry “busts”, energy became cheap and we were lulled into a false expectation of stable prices. Each time, not long after the industry was dismantled, energy prices began to creep back up, making us long for that clean and cheap solar energy again. So today Solar Water Heating is on the rise again. Will it be different in the 21st century or are we doomed to repeat the same cycle? What was it that Winston Churchill said about failing to learn from history….?
The recent surge in US solar water heating deployments began in 2008. This resurgence, especially at the commercial scale, has helped to drive up adoption rates while scaling down installation costs. Several factors are converging in recent years to bring about this renaissance:
- Engineers, architects, and contractors are becoming increasingly familiar with this mature technology – improving costs with increasing experience
- Regional incentives are bolstering the existing federal incentives to reduce the capital investment.
- The federal government has mandated that a minimum of 30% of water heating must come from solar for new construction or major renovations on federal buildings.
- Project Developers like Skyline Innovations (http://www.nextility.com/) have introduced new business models to help deploy these systems for those without available capital.
- Property owners increasingly want to have more control over their energy budget
- Various societal pressures continue to reward solar adoption
- An improving economy has allowed property owners finally to reinvest in their buildings
Remarkably, much of this has occurred despite a backdrop of rapidly falling natural gas prices (the primary heating fuel for commercial water heating), decreasing drastically from 2008 to 2012. However, in the last 18 months, natural gas prices are climbing again in a trend that is likely to continue: gas exportation; deployment of energy intensive manufacturing in the US; diversion of more natural gas to transportation (locomotives, trucks, fleet vehicles and eventually automobiles); conversion of more power plants and residential heating to natural gas.In light of these trends, property owners are rapidly moving forward to install solar water heating systems before the financial incentives expire. Business owners with substantial hot water loads in Washington DC and Maryland are able to achieve simple ROIs of 2-7 years. This approach requires them to take a slightly longer perspective, recognizing that they are buying 30+ years of energy up front for a fixed price (with generous subsidies). Whether financed independently or through the bank, building owners are able to lock in their energy prices and hedge the inevitable increase in fuel costs while leveraging all of the other benefits of renewable energy.
If you have any doubts about this trend, visit our commercial solar water heating page and take a look at the photos of just a subset of the projects we’ve been deploying in the region (https://solarsaves.net/commercial-solar-water-heating/).
If you want to know more about the history of solar water heating, check out this excellent book: The Golden Thread: 2500 Years of Solar Architecture and Technology, coauthored by Ken Butti and John Perlin.