Solar FAQ’s

Solar FAQs  –  Gavin Gilchrist, June 26, 2018.

What should be installed first, the solar meter or the panels and inverter?

Your holy grail is to have a solar-compatible digital meter in place by the time your solar panels and inverter are installed so that your solar installer can turn on the new system as soon as it’s completed.

But for a range of reasons, it’s not always possible to time things to perfection. Most residents in the Inner West still have old-style rotary meters – the ones with the shiny metal disk spinning in the middle – so if you have made a decision to go solar, first decide whether you are staying with your existing power. Some companies, such as Powershop, currently provide a free solar meter for all customers with no strings attached.

Once you’ve decided who will be your electricity company, tell them you’re going solar and that you want a “solar-compatible meter”. Then you can hope it’ll be installed by the time your solar system goes in.

Some households who have been changed to a digital meter in the past year have found they still need a new meter to go solar. Talk to your electricity company.

What are the steps to getting a solar system, from inquiry to electricity generation?

These are the steps if you use Inner West Community Energy for help and advice. First, we will send you our Customer Data Form, which asks you about your household, contact details, your energy use, and if you have any firm requests for the type of solar PV system you want. This gets all the information together in one place to save everyone time.

You send that to us. If something’s not clear, we’ll ring and ask you. Then we will send it to one of our preferred solar installers. He’ll review it and ring you to set up a time for a visit to your house. We insist on our installers always looking at the house before quoting; some solar companies don’t bother. Then, the installer will email you and us his quote. We’ll read it and speak to the installer if we have questions. We’ll email you our thoughts on his quote.

You then decide if you want to proceed. Note that the contract is between you and the installer, not us. If you agree to go ahead, the installer will be on site typically in 4-6 weeks. Some installers ask for a deposit upon acceptance of the proposal but our current installer invoices in full upon completion.

If you have the right electricity meter (see: What should be installed first, the solar meter or panels and inverter?, above), you can be generating your own power the next day. We also will give you a hand ensuring your system joins the Inner West Community Energy fleet on Solar Analytics, which we recommend.

What resources should an installer have?

The installer is a qualified electrician. We only work with solar installers who are accredited with the Clean Energy Council’s solar accreditation process (http://www.solaraccreditation.com.au). Our installer heads a team of three: him, another electrician and an apprentice. Sometimes there’s a fourth member of the team.

What is a realistic timeframe to get a solar system installed?

As you can read from our answer above (What are the steps to getting a solar system from inquiry to electricity generation?) there are quite a few steps involved, and some of the timing will be dependent on your availability and speed of decision making. But from the time our installer is invited on to the roof of your house to system completion is typically one to three months.

How long does installation take?

Again, there are variables involved in answering this question. Assuming perfect weather (no dew on the roof in the morning, no rain all day, no strong winds) normally a good sized system can be installed from start to finish in one day. Sometimes our installers will install a small system in the morning and make a start on another system in the afternoon, then return the next day to complete it.

How many panels for a 5kw system?

It depends on what type of panels are used, but typically it will be about 18. A 5kw system is quite a big system for the Inner West.

Can you access two storey houses?

Yes. Our installer has long ladders and safety equipment.

What are micro inverters?

Inverters convert the DC electricity of solar panels into the AC electricity that matches the power of the electricity grid that we all use. In a conventional system, one inverter is used to convert all the output of the PV cells into AC power but one shortcoming of these inverters is that if one or two panels are shaded by, say, a tree, the output of the whole system will be affected. With microinverters this does not happen. On the other hand, microinverters are more expensive. At Inner West Community Energy most customers have used conventional inverters but a few have paid more for microinverters because their roof is at times shaded by trees and/or chimneys.

What is Inner West Community Energy’s financial relationship to its preferred installers.

Our installers pay us a “Finder’s Fee” of four per cent of the full price paid by the customer. Three quarters of that payment is invested by us in building our group, and the rest is put in a trust fund to build community solar systems in the Inner West.

Can we run the house just on solar without batteries? We want to be able to run the house on solar when the grid goes down

No, you can’t run the system without batteries. The inverter needs the grid to stay active.  Batteries are needed to ensure power supply matches demand if you’re not on the grid.

Is it better to oversize the PV system, to have one bigger than you currently need?

Yes. Always install as much PV as you can afford because in a few years you’ll have batteries, you may disconnect all gas appliances, and you may have an electric car. In our experience, nobody ever regrets putting in too big a system, only that they installed too small a one.

It’s best to more-or-less match the PV system size to the inverter, although some people put in more PV than the inverter can manage. This is called oversizing and because of the efficiency performance of most inverters when running below 100% capacity, we think this makes a lot of sense. Most of the time your inverter will not be at capacity so oversizing will cut your annual efficiency losses a little. Discuss it with your installer.

Is it better to have the panels flat or tilted?

If you consider the ideal tilt for solar in the Inner West is 30 degrees to the north, then having them flat on a flat roof will cut their performance to 87%; that is, if the tilted panels produced 100 kilowatt-hours a year, the flat ones will only produce 87kWh. While tilt frames do cost a little more, perhaps $250 to $500, having panels tilted not only improves performance, it does mean the panels will be kept cleaner when it rains, as the rain will wash them. This won’t happen if they are flat, and you will need to get on the roof and clean them more often. As well, tilted panels will also stay cooler because even a slight breeze on the roof will help keep them cooler. Panel performance declines when they get hot. We also think having panels tilted to the sun looks cooler too!

Do you deal with batteries?

Yes, we can help with battery storage advice. Generally, our members haven’t installed  batteries yet because they seem too expensive and people would prefer to invest as much money as they have solar for now. We agree with this approach, in principle, but look forward to helping anyone who wants to do solar and batteries.

Is there an opportunity for community purchase ie bulk buying?

For now, Inner West Community Energy is not able to generate enough sales volume to drive down prices through bulk buying, as the volumes required for this are huge. However, when we compare the prices our members are paying for solar compared with industry benchmarks, we feel we are already delivering top-quality systems for a competitive price. So we’d like to do bulk buys, but are not able to do that just yet.

Is the structure of a regular roof strong enough to support a solar system?

Yes. But quite a few Inner West metal roofs are old and rusty so in those cases we would not attempt to install solar until the roof is replaced. Almost certainly we won’t install solar on a heritage slate roof either  as there’s too much risk of expensive damage to the slate. But often Inner West houses with slate roofs on the original building have a modern extension on the back of the original house with a Colorbond roof that’s just perfect.

On a sunny day in Sydney how much electricity can I expect to generate?

You can Google this to get lots of typical general figures, but here are some real numbers from our monitoring through Solar Analytics. One of Annandale households has a 3.3kw system and on January 1, 2018, a sunny mid-summer day, his system generated 16.4 kilowatts. On June 23, 2018, a sunny mid-winter day, it generated 8.8kw.

What are the heritage issues to consider when designing a solar system?

Generally, Inner West Council has no problem with solar as long as you do not install a system facing the street if you live in a heritage or conservation area. We are seeking some standard advice on this but if you have any doubts, call the council planning department. They are very helpful, in our experience.