Solar hot water in Australia
From Wikipedia, the free encyclopedia
Solar hot water refers to water heated by solar energy, a renewable energy source derived from the sun. This process involves thermal collectors, often called solar panels, which absorb solar energy to increase the temperature of the water. The heated water is then stored in a reservoir tank for future use. Solar hot water systems are utilised for a variety of purposes, including domestic and commercial water heating, contributing to heating and cooling systems, and providing process heat for industrial applications.
In residential settings, solar hot water systems are typically installed in one of two configurations. The "close-coupled" or "thermosiphon" setup integrates the thermal collectors with the hot water storage tank on a rooftop, allowing heated water to rise naturally into the tank. Alternatively, the "split system" separates the thermal collectors from the storage tank, requiring a pump to circulate water between the collectors and the tank. This configuration provides more flexibility in system placement and is often used when roof strength or aesthetics are considerations.[1]
Solar hot water systems are designed to reduce energy consumption, a significant source of greenhouse gas and carbon emissions; If the state of Victoria switched from electric to solar hot water, Australia's total greenhouse gas emissions would be cut by 20%.[2]
The penetration of solar water heaters in the Australian domestic market is at about 4% or 5%, with new dwellings accounting for most of the sales.[3][4]
During the 1950s, Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO) carried out world leading research into flat plate solar water heaters.[5] A solar water heater manufacturing industry was subsequently established in Australia and a large proportion of the manufactured product was exported. Four of the original companies are still in business and the manufacturing base has now expanded to 24 companies.
Heating of water is the largest single source of greenhouse gas emissions from the average Australian home, accounting for around 28% of home energy use (excluding private vehicles). The Australian government estimates that installing a climate-friendly solar-powered hot water system could help households save $300 to $700 of electricity bills each year.[6]
The solar hot water rebate program[7] for financial year 2009 offered a $1,600 rebate for the installation of solar powered hot water systems.
The rebate can be collected once the installation has been finished, if the household meets the necessary requirements stated below:
- The solar hot water system is a substitute for a previous electric heating system.
- The application and the installation process has taken place within the dates the rebate is offered.
- The household is a principal place of residence.
- The solar or heat pump hot water system is eligible for minimum 20 Renewable Energy Certificates (RECs).
- A licensed plumber or electrician is consulted for the installation.
Once the system is installed, the applicant has up to six months to submit the application form with the purchase receipt attached to it.
The mandatory renewable energy target[8] scheme was created by the Australian government to mandate energy retailers to the usage of renewables. Each solar heating system is given a certain number of RECs depending on how effective it is and in which of the four climate zones[9] one resides. Each zone is associated with a number of postcodes ranging across the whole continent.
Once issued, the RECs can be sold to energy retailers. While the market value of RECs is subject to variation, even residential-sized installations—depending on the current market conditions and the performance of the installed unit—often amount to payments of $900 or more.[10]
