Solar Hot Water

Discussion

Solar hot water systems are a cost-effective way of reducing energy demand by households, industry, and other hot water users, by incorporating energy direct from the sun.

A national roll out of solar hot water heaters across all houses would cause minimal disruption and pay for itself quickly, even on current (low) energy prices.

Resulting reduced demand for gas, and especially for electricity from coal fired plants, would make a significant difference to Australia's greenhouse gas output.

Readings

Solar Hot Water

Solar Hot Water. Your Home Technical Manual. Australian Greenhouse Office

Using solar energy to heat water produces no harmful greenhouse gas emissions. A solar water heater can provide between 50 percent and 90 percent of your total hot water requirements, depending on the climate and the model of heater.

Solar Hot Water

Solar Hot Water. Sustainable Energy Authority. Victoria

Using the sun's energy to heat water will save you energy, lower your hot water bills, and reduce greenhouse pollution.

Each year about 135 000 water heaters are replaced in Victorian households. Less than 1% of these replacements are solar hot water heaters.

Why Choose Solar Hot Water

Using the sun’s energy to heat water can reduce your household hot water bills by more than 60% each year; that’s a saving of around $200–$300 each year for the average family. This could add up to thousands of dollars saved over the lifetime of the system.

Hot Water Systems - Comparison

Hot Water Systems. Australian Consumers Association

Your water heater can account for a large part of your household energy consumption and the related emission of the greenhouse gas carbon dioxide (CO2). Modern solar and heat-pump water heaters use mainly the sun and air to provide you with hot water, producing much less CO2.

In most locations, the systems can produce up to several tonnes less CO2 per year than conventional electric water heaters. However, compared to conventional gas systems, only the best solar performers can save substantial amounts of CO2. Most models can also save you money in the long run. However, depending on the model and where you live, you may not be able to get a fast payback time for installing one of these systems. This is because they're considerably more expensive to buy than conventional systems.

Getting the Right Size

As a general rule, one person uses about 50 L of hot water each day. If you take very long showers, have a dishwasher or often wash clothes in warm or hot water, you may use more than that (not to mention if you have a spa bath you use frequently).

Based on a consumption of 50 L, for solar heaters an average four-person household needs about four square metres of solar collector area (two panels) and a 300–360 L tank, to allow for days with lower radiation or higher demand (for example, if you have visitors). If your panels can't be installed in an ideal location, their efficiency may drop and you'll need a larger collector area. An additional panel is usually available.

Heat pumps don't rely on the sun, so a slightly smaller system is sufficient (270–315 L tank for four people).

Water Heating Costs

Water Heater Cost Calculator. Energy Smart

Calculate the real cost of your hot water, taking into account purchase, installation and running costs. Compare a solar and an electric heater over 5, 10 and 15 years and see the impact of running costs on the total cost of the water heater.

2006.5.16