Solar water heating uses the sun's rays to heat water, which is then stored in an insulated hot water tank. On a less sunny day, the system may need back-up heating, usually provided by electricity or gas.
How solar water heaters work in Barbados
Solar water heating systems use solar panels, called collectors, fitted to your roof. These collect heat from the sun and use it to heat up water which is stored in a hot water cylinder.
A flat plate collector is installed on the roof below the storage tank. The flat-plate collectors is an insulated, weatherproofed box that contains a dark absorber plate under one or more glass or plastic (polymer) covers. The system works using the process of Thermosyphon which is based on the principle that hot water rises while cold water sinks. At the beginning of the process, cold water in the storage tank falls to the bottom of the storage panels, where it is heated by the sun. Heated water will then rise through the copper absorber tubes, continuing to be heated until it leaves the collector panel, where it is stored in the tank until ready for the household needs.T
The main benefit of a Solar Water Heating System is to have the use of hot water without having to continually pay for electricity or gas to heat the water.
Barbados Solar Water Heater Industry
“Barbados’s efforts to encourage the widespread adoption of SWH technology has been a success. The island’s 200,000 inhabitants now boast more than 50,000 SWH installations and save over 100,000 MWh of energy per year.”
The SWH industry in Barbados emerged in the early 1970s in response to the major oil shock, where prices increased threefold in the space of one year. Like many SIDS in the Caribbean, Barbados relied heavily on imported fossil fuels providing 95% of the country’s energy needs.
In 1973 Canon Andrew Hatch of Christian Action for Development made a SWH out of an old oil drum and fixed it to the roof of his church. Recognising the potential of the technology, James Husbands founded Solar Dynamics, the first SWH company on the island, in 1973 and soon had the opportunity to demonstrate the technology at the highest levels of government. “The Prime Minister, Tom Adams, wanted a water heater. We installed one of our units at his house and he was very pleased with it.” Having the country’s leader see his annual gas consumption drop by 70% was a new business owner’s dream.
Government incentives brought competition in the business of manufacturing and supplying SWHs, with SunPower and AquaSol setting up shop. The market grew, with solar installations peaking in 1989 at over 2800 units. By 2009 there were around 45,000 installed SWH systems, representing two in five households.
Written by Will Bugler of Acclimatise Climate and Development Knowledge Network (CDKN) September,2012.