The shape of a good system.

01The bill before the roof

It's tempting to start with the roof and ask how many panels fit. We start with the bill and ask what the home needs.

A bill tells us how much electricity you use. A bill with time-of-use detail tells us when. Those two things decide what a system should do: cover a busy middle of the day, carry a long evening, or get ready for the electric car that's a year away.

02Reading the roof

Then the roof. From above we can see each face, which way it points, how steep it is, and what stands near it.

In Melbourne a north face makes the most over a year. East faces do their work in the morning and west faces in the afternoon and early evening, which is when many households use the most. So a west face is often worth more to the people living under it than its yearly total suggests. A south face makes the least, and we'll usually leave it alone.

The best system for a roof isn't always the best system for the people under it.

03Shade is a design problem

A chimney, a tree, the neighbour's second storey. Shade moves through the day and through the year, and a panel that's clear in January can be shaded for half of June.

There are two ways to deal with it. The first is to put panels somewhere else, which is often the right answer. The second is to use equipment that lets each panel work on its own, so one in shade doesn't hold back the rest. Which one suits depends on the roof, and it's decided at the design stage, not on the day.

04The connection sets the limits

Your home connects to the grid through your electricity distributor, and the distributor sets how large a system you may connect and how much you may send back. A home on single-phase power has a lower ceiling than one on three-phase.

That's why we ask about your power phase early, and why we offer to look at a photo of your switchboard. It's far better to know the limits before a system is designed than to find them at the approval stage.

05A battery sized for your nights

A battery should be sized to what your home uses after dark, not to what fits on the wall. Too small and you're buying from the grid by nine. Too large and part of it sits idle most of the year.

Most of the batteries we install are built in layers, so the sensible approach is to start with what your nights need now and add a layer when your life adds more.

06What you'll see on the wall

The last part of a design is the part you'll look at for years. Where the inverter and battery go matters: out of the afternoon sun, easy to reach, and within the safety standards that govern where a battery may be placed. In a garage that can mean a bollard in front of it.

Then the details nobody notices when they're done well. Panels lined up with the roof's edges. Cable runs kept short and out of sight. It costs very little to get these right on paper.

07Then it's built

You're assigned a project manager, who designs your system. Accredited installation partners install it.

Nothing is fixed until your design review, where we walk through the design together and you can change it. The proposal comes after that.