Getting Started With Solar Power At Home

There are numerous benefits to making your home solar powered — and more than a few pitfalls. Here's what you need to know about solar powering your home in Australia.

Image: Oregon Department Of Transportation

What Do I Need For Solar Power?

The very basics of a solar power system rely on just a few key components.

  • The Sun. Unlikely to go out for a few million more years, but it's worthwhile considering the positioning of your home relative to the big ol' ball of nuclear fire, because it can and will affect how much power you can generate.
  • Solar Panels. If you're looking for a whole of home solution, you'll need more than one, but for a small property only looking to handle hot water duties, you may be able to get by with just one or two panels using a solar thermal solution.
  • An Inverter. This converts the DC power produced by your solar panels into the AC current used by devices in your home.
  • A bidirectional electricity meter — if you're going to feed power back into the grid, you'll need to be able to quantify it, which means in almost every instance, you'll need a new electricity meter to go with it.
  • Batteries for power storage — this is an optional step, unless you plan to go fully off-grid or minimise your need for grid power in the medium term

How does it all work?

The solar cells in a typical system collect energy using the photovoltaic effect, which is why you'll sometimes see solar systems referred to as "PV" systems.

During the day, the sunlight is collected through the panels, converted via the inverter into AC current for whatever electrical need you might have and also fed outwards to the wider electricity grid if you're on-grid, or stored in batteries if you've opted to go entirely off-grid.

What Does On-Grid/Off-Grid Mean?

If you're connected to your electricity supply via a cable that runs from a pole, or underground, you're on the Australian electricity grid, and thus on-grid.

The advantages for solar systems in an on-grid setup is that your power generation can be fed back into the grid. Instead of generating power for you to use, you generate an income based on the feed in tariff paid in your state by your provider. The advantage for an off-grid system is that by using storage batteries, you save all the power generated by your system during the day, so that once the sun has gone to bed at night, you've still got power to use when it's dark.

Off-grid arguably makes the most sense for genuinely remote areas, however, as the cost of batteries does add considerable load to a solar system if you're setting up from scratch. This is an area where costs are improving — Tesla's Powerwall systems are being touted as challenging the existing price of storage batteries, although it remains to be seen how genuinely economical they may be — but it's undeniable that adding batteries and the necessary infrastructure around them can significantly increase the cost of setting up a new solar system.

Can I turn a profit on my solar setup?

The lure of feed-in tariffs can tempt many towards solar systems, figuring they'll never pay a power bill again, and instead start raking in cold, hard cash from their power company.

The reality is, as it so inconveniently is, rather more complicated than that.

At one point in time, many solar systems benefited from being paid a gross tariff for the power they generated, at reasonably high rates, which meant that whether you were using power or feeding it back into the grid, you got paid by the power company for that production.

That's no longer the case except in the Northern Territory, which means that you only get paid for net feed into the grid — that's the amount you feed in less the amount you're using — at relatively low rates, typically under 10c per kWh.

You've got to balance that rate against the likely production of a solar system and costs of installation and any maintenance issues. At a practical level, at current price structures, it's unlikely that a new solar system would pay for itself simply from net feed tariffs in most states.

Which isn't to say that a solar system is simply a green dream that can never pay off, because the other side of the equation lies in reducing your power bills. You might only be getting 10c per kWh from your provider for the power you feed in, but if you're reducing your draw from the grid substantially, where your per-kWh prices will be quite a bit higher, you're saving money — and in essence, paying for your solar system as long as it's running for a sufficient number of years.

One huge caveat here is ensuring that your electricity provider in your state provides any kind of feed-in tariff at all. Not all do, and the rates that they pay vary quite considerably. This is an area where it pays to do your research and, where feasible, switch providers to maximise your solar investment.

How much solar capacity do I need?

This is one of those "how long is a piece of string" questions, because it's complicated by not only your total overall power usage — which you should be able to find from any power bill — but also when you're actually using that power.

Why does that matter? Unless you're going entirely off-grid, the best savings for an all-solar system are made when you're using the power yourself and saving that margin on the power usage versus taking it from the grid, rather than feeding it directly to the grid and getting the meagre feed-in rate.

Bear in mind that the sun only shines during daytime, which depending on the season and your exact location could be anywhere from 6am to 9pm, but is probably better averaged out to around 7-6 daily, with your peak production around midday under direct sunlight.

If your power draw is considerable during the day, you'll make much larger savings on that power usage than if you're out of your home during the day and using most of your power at night, where you'd be likely slugged with full power grid prices. This can be mitigated with a hybrid on-grid and battery system to an extent, but again you've got to weigh the infrastructure costs against the likely return.

Positioning of your solar system will affect overall efficiency of the system, but so will the size of the system that you're able to install on your property. This isn't always a direct linear effect of the size of the system, as some panels and systems can be more efficient than others.

Should I just buy the cheapest solar system?

Probably not. Again, this can be complex to state as an absolute, but it's clear that the Australian solar industry has had more than its fair share of dodgy traders and installers making wild claims, claiming rebates on behalf of customers in an unfair manner and installing sub-standard panels with limited lifespans.

As such, given the general cost of installing a solar system, it's wise to get as many quotes as feasible, and ensure that you're happy with the professional standard of an installer and the goods they're selling to you. Australian consumer law will cover you in any case, but that's not going to be much use if your installer closes up shop or you find that a system with a ten year "warranty" only has a two year warranty on the inverter or panels.

How do rebates work?

At the federal level, rebates are available for solar systems for the creation of renewable energy certificates (RECs). At the home level, what you're doing is creating a Small-scale Technology Certificate (STC) — this is, in essence, your home solar system, for which you receive a rebate on installation costs. However, this isn't a cash-in-hand payment to you, but instead applied as a general discount to the cost of installing the system.

It was also possible to get financial investment help with solar systems through the Clean Energy Finance corporation, but recent moves by the Abbott Government has blocked that particular financial avenue for installations under 100kW. This has been widely condemned by the solar industry, to the surprise of absolutely nobody; the current government genuinely doesn't seem that interested in solar or wind power options at this point in time.

Can I install it myself?

Technically you can install parts of a solar system yourself, but in most cases it's not going to be your best move on both safety — because electricity isn't a casual thing to muck around with unless you're properly trained — and financial grounds. If you want the rebates on a panel, they have to be installed by a properly CEC accredited electrician, and not self-installed.

Equally, there's a number of electrical regulations that apply to hooking up any kind of device to the power grid. If you happen to be an electrician with the necessary training and certification, go for it, but for everyone else, it is a job best left to the professionals.

This all seems very complex

That's because it is. While absolute prices for solar systems have come down considerably over recent years, the decisions around the installation of solar systems rely on a number of variables. Some of them can be calculated, while others may end up being best guess estimates to provide a general picture of your power usage and needs. As such, this is intended to be a broad outline only. It absolutely will pay dividends to do your proper research before signing on any dotted lines. Ensure you're happy with your installer, their choice of brands when it comes to every part of your solar system — not just the panels, but also the inverter and its features, wiring and switching boxes and so on — and the rates you'll get for feeding into the system or costs for installation of batteries if you go down the hybrid or off-grid pathways.

Originally published on Lifehacker Australia

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