Solar water heater/heat pump

A solar water heater uses energy from the sun to heat water. Water is heated by the sun as it passes through collectors located on the roof of a house. The main solar collector types are flat plate, evacuated tube and heat pumps.

Heat pumps use the reverse of a refrigeration process, transferring heat from the air to the water stored inside the hot water tank. The heated water is stored for use in an insulated storage tank just like a conventional hot water system.

Greenhouse gas savings

One megawatt hour of solar-derived electricity avoids approximately one tonne of CO2.

Water heating accounts for one quarter of the energy used in the average Australian home and is responsible for 23 percent of total household greenhouse gas emissions.

The installation of a solar water heater will reduce the greenhouse pollution associated with water heating in the average Australian home by between 60 and 90 per cent (depending on the location).

In Australia

According to the Australian Bureau of Statistics, 7 per cent of Australian households used solar energy for heating water in 2008, an estimated 600,000 homes. This represents a 61 per cent increase on 2005, when only 4 per cent of households had solar hot water and the installed solar water heater capacity was just 429 megawatts. By the end of 2007, the International Energy Agency measured solar water heater capacity at around 1300 megawatts.

Major manufacturers include Aquamax, Beasley/Rinnai, Dux Hot Water, Rheem, Solahart/Edwards, Solar- Mio, Solco Industries, Conergy, Stiebel Eltron Pty Ltd and Everlast Hydro Systems.

Potential

With only 7 percent of Australian homes currently fitted with solar water heaters, there is considerable potential for market growth. As awareness towards the benefits of installing solar water heating and heat pumps increases, so too will the proportion of Australians adopting the technology.Government policy and grants are expected to provide a considerable boost to sales over the next few years.

Global view

Solar hot water heating technologies are becoming widespread and contribute significantly to the water heating markets in countries like China,Turkey, Israel and parts of Europe. Dozens of other countries have smaller markets. Globally solar heating capacity was 145 gigawatts at the end of 2008, double the capacity in 2004.

Current Issues

In 2007 the government committed to ensuring that 20 percent of Australia's electricity supply would come from renewable energy sources by 2020 by establishing the expanded national Renewable Energy Target (RET) scheme. Draft legislation on the design of the expanded RET was released in December 2008 and the final legislation was passed in August 2009. Solar water heaters and heat pumps are an important part of this expanded target.

In early 2010, the Australian Government announced its Renewable Energy Bonus Scheme to assist households to reduce their carbon emissions. Part of this includes a rebate which provides existing homes with $1000 for a solar hot water system or $600 for a heat pump hot water system. The Australian Government as part of its National Strategy for Energy Efficiency has also announced a phase out of greenhouse intensive electric hot water systems from new buildings from 2011.