Could solar power save you money?

Demand for solar power in New Zealand is surging, says SolarKing general manager Roy Maddox. Photo / Getty Images.

Element Advertising Promotion: During a sunny summer day, Philippa Johnson's home on the North Shore in Auckland makes more than enough power to cover her and her husband's electricity needs.

In the six months since installing a three kilowatt solar power system in June 2013, on the shortest day of the year, the couple generated almost 2440 kilowatt hours of electricity. About half of that they use themselves; the other half is exported to the national grid to offset their power bill. "My monthly bills are down to $30 at the moment," Johnson says. "How good is that?"

She's not the only one catching on to solar power in New Zealand. According to SolarKing general manager Roy Maddox, there's been a surge in demand in the last twelve months. "We've gone from a system per week to three to four per day," he says.

SolarKing, based in Takapuna, is a specialist provider of solar power systems. The company is owned and operated by certified electricians and works across New Zealand, installing everything from a small two kilowatt system to a ten kilowatt array on a roof in Mount Eden.

"The products we're bringing in are the top-selling products in Australia, where literally hundreds of thousands of homes are using them with great success and no failure rates," Maddox says.

Using the latest technology from Germany and China helps ensure efficiency even on cloudy or rainy days, he adds, which makes SolarKing's panels particularly suited to weather in New Zealand.

SolarKing's experts design a personalised system for each customer. Johnson initially wanted a larger system but was advised it wouldn't be the best fit for her and her husband's electricity needs. "They talked me down a size and they were completely right," she says. "I really appreciated it."

So why go solar? With favourable returns on investment of up to 12 per cent per year, tax-free, it's usually a financial decision. It's also a handy way to hedge against future rises in power costs.

"My husband is nearing retirement and I'm trying to get my overheads down," Johnson agrees. "For overheads like rates, you have no control - but for power, you can do something about it."

How does photovoltaic solar power work?

Photovoltaic solar power systems turn the sun's powerful energy into electricity. Each cell in a panel contains a sandwich of semi-conducting material, usually silicon. When sunlight hits a cell, it knocks electrons free and sends them moving, which generates electricity. Photovoltaic panels work differently to solar thermal panels, which use heat rather than light.

What's your ROI?

It's easy to calculate the return on investment (ROI) from a solar panel system.

Step 1: Figure out how much your power company charges you for electricity - this is usually between $0.25 and $0.27 per kilowatt hour.

Step 2: Ask your solar provider how many kilowatt hours your system will generate in a year. Multiply this by the cost of your power to figure out your savings per year.

Step 3: Divide the total cost of your system by your savings per year to get your ROI. For example, a 3kw system that costs less than $10,000 should knock about $1100-1200 off your power bill each year, which works out to an 11-12 per cent ROI - or under ten years to pay for the cost of the system.

The SolarKing Buyers' Checklist

• Do I have a decent roof space? Does it get a decent amount of sun?
• Are my panels manufactured by a Tier-1 solar supplier so they'll last long enough to get a decent return on investment?
• Does the company I'm dealing with employ master electricians and belong to an association such as ECANZ, so I get an independent workmanship warrantee for my installation?
• Does the company I'm dealing with offer ongoing service and assistance?
• Does it offer a long-term guarantee for my panels and their performance?

Make the most of summer! Register your interest at 0508 SOLAR NZ (0508 7652 76) before the end of January 2014 and you'll be guaranteed SolarKing's special summer price of $9660 including GST for a top-end 3kw solar power system. You'll also get six months interest-free deferred payment terms.