Architecture and Building | Michael Green

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Switching to solar

As electricity prices increase, more people are turning to solar power to reduce their reliance on the electricity grid. For those who want to make the switch, here are the basics of solar PV.

THERE’S a basic fact that a surprisingly large number of people haven’t yet grasped about solar energy. “We still get queries from people who get solar photovoltaics mixed up with solar water heating,” says Mick Harris, managing director of eco-retailer EnviroGroup. “It’s really a matter of understanding what you want.”

It’s a simple point, but it underscores the most important thing prospective panel purchasers need to do – research well.

Your deliberations will be detailed, from the technology and rebates to installation issues and variable electricity charges. But don’t be put off – once the panels are in place, maintenance is minimal. For at least 20 years, you’ll be able to sit back and enjoy the sunshine.

Technology

There are three common types of solar PV panels: monocrystalline, polycrystalline and thin film. Most of the panels sold in Australia are of the mono and poly kind. Thin film is much less efficient – it needs nearly double the roof space of other panels – but requires far less silicon to make and has less embodied energy. Lance Turner of the Alternative Technology Association adds that there is also a hybrid panel made by Sanyo which is a combination of crystalline and thin film technologies. “These perform particularly well,” he says, “but at a price premium.”

As well as the panels on the roof your system will need an inverter, which converts the DC (direct current) electricity produced by the panels to AC (alternating current) and feeds any excess electricity into the grid.

‘Building-integrated’ photovoltaic systems such as tiles, facades or glazing are uncommon. Susan Neill, from engineering consultancy Global Sustainable Energy Solutions, says those systems are much more expensive: “It tends to be driven by airports or iconic buildings that want to make a statement by putting it in.”

Rebate madness

For the solar PV industry in Australia and for households it’s been the best of times and the worst of times. Let’s start with the worst: changes to government rebates.

The Federal Government’s cash-back rebate is based on the trading value of ‘small-scale technology certificates’ (STCs, formerly known as RECs), which are created when renewable energy systems are installed. Right now, eligible householders receive a credit of three times the certificate price, which fluctuates according to market demand. From July 1, the credit will be reduced to two, meaning the rebate for householders will fall by one-third.

Most of the incentives offered by state governments have also been cut. These feed-in tariff schemes pay people according to how much energy a household supplies to the grid. Queensland’s feed-in tariff is the last one intact – elsewhere they’ve been reduced, phased out or abolished overnight.

Tim Sonnreich, policy manager at the Clean Energy Council, says that despite these cuts there is good news for household solar PV that shouldn’t be overlooked. Overall the price hasn’t increased significantly, thanks to lower production costs and the high Australian dollar. A 1.5kW grid-connect system can cost from $1500 to $6000 installed (including the federal rebate).

“The price of solar technology has come down dramatically over the last few years,” he says. “Even five years ago, buying solar was a major financial decision, like buying a car. But now it’s in the ballpark of $2000, people put it on their credit card and get on with their lives. The market has changed dramatically.”

What size system should I get?

The answer to the all-important question of size, says Mick Harris, will become clear when you ask three additional questions. “Firstly, how much room have you got? That’s going to limit how much you can put on your house,” he explains. “Secondly, how much of your energy bill do you want to get rid of? And thirdly, what is your budget?”

Shade is death for solar panels, especially the mono and polycrystalline kind. Even a small amount of shading significantly reduces the efficiency of the whole system, so there’s no point buying one if you have a mighty big tree blocking the sun. Ideally, for a small system, you’ll need at least 10 square metres of roof space facing north.

Next, take a good look at your electricity bill and make note of how much you use. The average Australian household consumes 18 kilowatt-hours (kWh) a day, according to the Clean Energy Council. The output of panels varies throughout the country, but a 1.5kW system will offset roughly a third of the average daily consumption.

At this point in the research process, it’s wise to think more broadly about where you use the electricity you consume. If you have an electric hot water service, it probably accounts for about a quarter of your bill, Sonnreich says. “Hot water is a major expense, so if you don’t have much rooftop space, solar hot water might give you a better return than PV.”

Installation

Up to half the cost of your solar electricity system will go towards its installation, and as with any job around the house, you’ll want to make sure it’s done well.

The output of your panels will vary significantly according to their orientation, access to full sun, and whether they’re angled appropriately for your latitude. With that in mind, quiz your solar company about all these requirements, and about their installers’ experience.

To be eligible for the rebates and feed-in tariffs, you must use an installer accredited by the Clean Energy Council. “You must use an accredited installer in order to be able to access the upfront discount provided by the Small Technology Certificates (STCs) that are traded back through the renewable energy market,” says Damien Moyse from the ATA. He adds that when choosing a system and an installer, it’s best not to just choose the cheapest one. “Solar, like any other technology, depends on quality for performance, and you want a system that will generate for at least 20 to 30 years. Consider the warranties closely and be prepared to pay a little more upfront for a good-quality system that will provide you plenty of savings on your electricity bill over time.”

Susan Neill suggests that before buying you should request an indication of the panels’ performance. “Ask for a performance guarantee that the system will produce a certain number of kilowatt-hours per year, on average, for your location,” she says. “Then you’ll have the knowledge to check it yourself.” Likewise, seek a long-term warranty (up to 25 years) and make sure you keep hold of the documentation.

Energy retailers and distributors

You need to let your energy retailer know if you’re going to install a solar PV system. Many retailers will offer you a premium for the electricity you export to the electricity grid, but don’t be bamboozled by that rate alone: make sure you find out what your new tariff and fee structure will be.

“You have to ask the whole question – how much is it really going to change your bill?” Sonnreich says. “You might get a better rate for the power you export, but you might pay more for the power you import. Do the sums on everything.”

And while you’re speaking to the energy companies, ask them about your new meter – who will supply it, how will it work and how much will it cost?

Off-grid systems

Stand-alone renewable energy systems are much more expensive upfront than grid-connected systems. As well as the panels, you’ll need batteries, a regulator to manage the way they charge and possibly a backup generator.

After the Victorian bushfires in 2010, the ATA commissioned research into the cost of off-grid systems compared to grid infrastructure.

“The capital cost is high compared with grid connect,” says Damien Moyse, “but if you have an efficiently operating house, then you can set up one of these systems for $20,000 to $30,000 and it’s going to generate electricity for at least 20 years and longer.”

Is there any cause to go off-grid in the city? Smart meters now allow retailers to set time-of-use tariffs that incorporate high rates for peak time energy use. “If you are a household that cannot avoid consuming energy during these peak times, the long-term cost of installing batteries and electricity backup may become an attractive option,” Moyse says. “However, in most circumstances this will not yet be the case and a grid-connect system will still offer plenty of opportunity to avoid peak rates.”

Ask lots of questions

Some local councils or community sustainability groups still coordinate bulk purchases, though they’re less common than they once were. If you haven’t the time or the head for research, these schemes are a good source of information.

Even so, start your research with the Clean Energy Council’s consumer guide to buying solar panels. It contains a comprehensive list of questions to ask, but the legwork is up to you. “Shop around. Don’t make a snap decision,” Sonnreich suggests. “Find a company that is prepared to talk the issues through with you.”

Mick Harris also recommends some sleuthing. “There’s a mixture of players out there in the market – some of them are good and some are not so good,” he says.

If you google a solar retailer, together with the words 'problems' or complaints, you'll soon find out which is which. It's also worth checking the popular forums on the Whirlpool and ATA websites. "You can protect yourself from the worst of the companies by doing some homework online," Harris says.

This article was published in Sanctuary Magazine.

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