Harness power of the sun

Rotorua's Paul Sterrenburg has had a solar power system for about a year. PHOTO/STEPHEN PARKER

If you dream of slashing your power bill, some Bay of Plenty residents say: go solar. Renewable energy experts say a drop in the price of solar panels in the past five years, plus fast-rising power prices, are swelling the ranks of households harnessing sunshine. 48 Hours reporter Dawn Picken visited homeowners who are minimising dependence on the grid, including some who are getting solar panels for free.

ROTORUA'S PAUL Sterrenburg says he started looking at a solar-powered hot water system for his Hamurana home, but decided a full array would be more cost-effective.

He researched online and chose S4Solar to install his grid-connected photovoltaic (PV) solar panel system at a cost of $25,000 (S4Solar amalgamated with Auckland-based Sky Solar in August).

Sterrenburg says it was a wise investment for their 350sqm home with two wings.

"If we had $25,000 sitting in the bank, the power savings we make pay us way more than interest. We started looking at it because the house we bought was so expensive to run on power. We've gone from over $300amonth with two [people]... down to about 100 bucks. Every four months I send my supplier a bill. It works out to about $400."

That's a net gain of about $300amonth, he says.

Utility companies, in the past year, have cut the price at which they buy excess power from solar producers such as the Sterrenburgs, from 25c (or more) per unit, to 7c (or less) per unit. That means solar households must use energy as they produce it.

"My wife's at home during the day, anyway. She uses the dishwasher during the day, does a hot wash during the day... In winter on sunny days rather than use the wood burner, we use the heat pump to get the house up to 23 or 24 degrees. In summer, we run air conditioning for nothing. It's just a change of mindset."

A new battery due out soon (see sidebar) will allow households generating solar energy to store power for later use. It's a product Sterrenburg and other solar users say will change everything.

"If we were building a new house, we wouldn't even be on the grid. We're doing about $3500 a year back to us on a $25,000 investment. That's a 10 per cent return. We've seen how fast power prices go up. I'm not a greenie by any stretch of the imagination; I don't wear long socks and sandals, but there's so much exciting technology out there."

Brad Dixon and his two daughters, Stella, 5, and Eva, 7, greet 48 Hours at their Mount Maunganui home, which includes about 120sqm of living space and a ranch slider leading to a sunny deck. We get a peep of ocean view in one direction, and in the other, a glimpse of solar panels atop a low roof.

Dixon says, "People used to be put off by the look of them, but these, you can barely see."

The seven panels were free, thanks to a new programme offered by a company called solarcity. Dixon leases seven solar panels for $50 per month. He paid $150 upfront. He says the panels provide up to 12 kilowatt hours of power per day, saving his family $70 to $90 each month on their utility bill.

"Even if I had to pay a little more, I would've done it. The biggest drawcard for us was that we could tap into a renewable energy source. New Zealand prides itself on its clean, green image and it's absurd that not more people are making use of solar power."

Under solarcity's solarZero programme, customers pay nothing upfront, with a fixed monthly fee starting around $50 a month for low energy users to more than $200 per month for farms or businesses.

Newly-built home has solar power system. Bradley Dixon with his daughters Eva Dixon, 7, and Stella Dixon, 5,. Photo/George Novak

Solarcity's online calculator indicates someone with a typical monthly power bill of $250 could save up to $14,000 over 20 years. Dixon says solar works for them, because he or his wife are home during part of most days.

He's looking forward to getting a battery so the family can store power for later use and hopes the lease-to-own option gains popularity.

"When you've got kids, you want to make sure you're leaving the planet in a good state and this is one small thing we can do and it's not costing us anything."

Anthony Sarafa moved into his new, 211sq mhome in Pyes Pa a year ago.

The software engineer and former Aucklander said going solar was an easy choice.

"I think new homes all should put in some solar. The system doesn't require any maintenance [beyond occasional cleaning] and systems have come down further since I got mine. There's a lot of sunlight in New Zealand."

Sarafa says he spent $14,000 for 15 panels and an inverter (converts solar energy to current which can be fed into a commercial electrical grid), all sourced through solarcity.

"It's obviously a significant expense upfront, but will get paid off over time." Sarafa has calculated each cent he's saved and earned on solar power.

He says Contact Energy has paid him $614.14 since last September, bringing his total savings and earnings to $1521 over 14 months. "At this rate the system will be paid off in 11 years."

Sarafa, too, is considering a battery storage system, scheduled for release in New Zealand within the next year.

When 48 Hours visited, Sarafa's array was operating at a maximum 4000 watts. His advice to potential converts: consider more than return on investment. "They should just do it. There's a bigger objective, because as electric cars get more common, we can all charge from the sun, which eliminates the need for foreign oil."

Sarafa plans to buy an electric car (Nissan Leaf) next year, which will make his solar panels pay off even sooner.

A recent report from the New Zealand Institute of Economic Research (NZIER) said consumers without solar power would pay about 10 per cent more for energy in the next 10 years because of high consumption charges and "accelerated investment in solar photovoltaics.' The report also estimates rate of return for solar photovoltaics at around 6 per cent.

According to NZIER, "This means consumers, on average, will be better off saving the cost of solar photovoltaics installation and continuing to use grid-supplied energy for all their electricity supply."

Solarcity NZ chief executive Andrew Booth says the Bay of Plenty is one of the top three markets nationally for solar energy use, though just .2 per cent of Kiwi households use solar. A recent Deutsche Bank report mentions New Zealand as one country where solar energy costs the same or less than retail power.

Auckland-based SkySolar managing director Nick Freeman says his company's three kilowatt system costs roughly $10,000 installed. He says the company has 50 customers in the Bay of Plenty and will soon open its first Tauranga office.

He tells people thinking about going solar to buy the right-sized system.

"Never put a system on with the aim of selling it [power] back."

Freeman suggests ensuring any new solar system has the ability to grow and add batteries as they drop in price over the next two years.

"For most scenarios now, a storage system is more expensive than people want to spend."

Mysolarquotes.com founder Kristy Hoare says about 40 companies nationwide provide home solar installations, including several that service customers in the Bay of Plenty. Her website provides information about solar power, choosing an installer, equipment, operation and maintenance.

Hoare says the popularity of solar is steadily growing.

"Most people just want to be more independent from the big retail providers. They're sick of their bills going up and want to takeback a bit of that control."

Waikato University senior science and engineering lecturer Dr Mike Duke has researched photovoltaic (PV) systems and says while the industry used to be about innovation and the environment, today's focus is cost.

"It's gone from green, let's put on solar because we're saving the planet...that's been overtaken by the drive to get cost down. It's about return on investment. If you put money in the bank, you earn 4 or 5 per cent [interest]. If you install solar panels, you're looking at a rate of return of up to 10 per cent."