Reality Check: Installing solar power

Whether you want to be clean, green and energy conscious, or hope to save money on power bills, solar powered water heating is an increasingly affordable option.

Solar power is one of the cleanest methods of energy production. Solar panels convert the energy of the sun into energy people can use, so there are no harmful by-products.

Solar water heating works alongside electricity so you need not worry about those rainy days.

Sola 60 sales and marketing director Dave Catley says a Sola 60 system can provide up to 75 per cent of an average family's hot water needs.

In winter solar will not do the lot, but considerable savings can still be made with electrical backup on hand to pick up the heating on days with little or no sunshine.

Catley says in summer, many solar hot water users turn the electricity component off and receive 100 per cent hot water savings.

Liz and Don MacColl, of Te Awamutu, are newcomers to solar heating and admit they are still coming to grips with it.

A year ago they moved into their new home complete with solar panels to provide hot water and underfloor heating.

"We wanted to use renewable energy. We've got five children. I thought solar power would be us doing our bit to help the environment," says Liz.

The family loves the underfloor heating, which keeps the house warm and dry. Liz says she thought they would miss the open fire but the clean, dry house is "like having summer all year round".

They looked at solar systems at home shows, talked to friends who had already installed a solar hot water system and also instructed their architect to include as many "sun or energy friendly" features as possible in the design of the house.

Their house had a "pretty good test this summer with six people at home - all needing showers" and it coped on solar only. During the winter months they have switched over to solar with electricity backup.

Liz says it is not as simple as turning a switch on and off to get both sufficient hot water and heating for the floor; it has taken trial and error to get the timing and balance right for the winter.

The cost for both hot water and under floor heating worked out at about $45/sq m for the 310sq m house. Sola 60 quotes a four-person family hot water system at around $3900 to $4400 , installed to the existing hot water cylinder.

Solar water heating panels heat water directly whereas solar electric panels convert sunlight into electricity with an efficiency of about 13 per cent. The earth's surface receives close to 1000 watts per sq m of energy from the sun. Solar panels can convert these 1000 watts into about 130 watts of electricity per sq m of solar panel.

Since solar panels are usually fixed on a roof, they must be angled to maximise the amount of sunlight striking them.

"The ideal panel angle is latitude 37 degrees for Auckland or 43 degrees for Christchurch, and facing north or, better still, nor nor west to capture the sun at its most intense," says Catley.

While there is a lot of interest in the new technology of solar electrics, producing electricity from the sun is expensive technology. Generally this is a viable option only if you are building in a remote area and it is going to cost you thousands of dollars to run power lines to the site. Solar water heating, on the other hand, is about a tenth of the cost, and is a viable option in most homes.

Sola 60 dealer network ph 0800 100 849.