Solar water heating technology — also referred to as solar thermal technology — has been around for ages. But its effectiveness hasn’t lead to broad adoption in the United States. Why you ask?
As a brief review, solar hot water systems don’t generate electricity like a photovoltaic (PV) system does. Instead, they use the sun’s thermal energy to directly heat water, bypassing the step of electricity generation. This has important implications for building energy efficiency. Solar thermal technology can be used for water heating, space heating and space cooling. Solar water heaters, however, are the most common application of solar thermal technology. In a word, they can be great investments: compared to PV panels, solar hot water systems have relatively low up-front costs and often offer shorter payback periods.
Image courtesy of WikiComons
Solar hot water systems were incredibly popular in the 1970s and early 1980s, a time that saw the energy crisis of 1973. Partly as a response to rising oil prices, President Carter’s administration established rebates and other incentives to encourage the adoption of renewable energy systems. During this time, there were as many as 500 U.S. manufacturers of solar water heating equipment. This number dwindled to a mere five, however, after the federal government curtailed the incentive programs.
The government wasn’t the only factor behind solar water heaters’ rapid decline. The industry grew quickly and without much oversight, a combination that resulted in a spate of low-quality installations and under-performing systems. As a result, solar water heating got a bad rap for being ineffective. Understandably, a technology that suddenly got less affordable (due to the axed incentives), and was perceived to be less reliable, quickly fell out of favor.
As a result, new systems were rare in the United States until the 2000s, when renewable energy saw increased interest from both consumers and politicians. The few companies who have been in the solar thermal business for the long haul have focused on solar heating for swimming pools, a smaller market that allowed them to weather their industry’s long downturn. Today’s market looks more promising, though, so we’re hoping this great renewable energy option can regain some of its former popularity.
subsidy on conventional energy sources and use fullness of SWH in 4 months a year have killed. Abolish conventional evergy subsidy and make such SWH which can do say cooking in summers.