- You should fit your build with the maximum solar capacity allowed on a single phase home (in most parts of Australia). This is 6.6kW of solar with a 5kW inverter, and is usually the best value per kW due to the way the rebate works.
- If you want more than this (up to 20kW) then you need to ask your builder to install a 3 phase power supply. You should get it installed at the outset as it will be quite expensive to put in after.
- A solar system can generate about 150W per m² of roof. So for 6.6kW you want about 50m² of roof space. Ideally North facing, but East and West can work too.
- Check your local Distributed Network Service Provider (DNSP) to see if 3 phase is available in your area and if you have any export limits.
Discussions with your architect/home builder
- Solar inverter placement. Will there be room for a switchboard next to it, and is it shaded from the sun? You could place it in your garage. In the garage consider you may need a fire proof wall for wall mount batteries. But as long as the battery is sited 30cm away from any wall adjoining a habitable room you should be OK.
- Think also about a good place to add future batteries. It should be in a shaded spot near the switchboard and inverter.
- TV aerial and internet transceiver (rooftop wireless) should be out of the way of any solar. Preferably a south facing roof.
- Pre-install the conduit for your solar system during the build. An electrician can easily put the conduit for solar in the before the walls are in place. Also consider a 2nd conduit if you are planning on expanding the amount of panels down the track.
- Pre-wiring is especially useful for small roof spaces.
- If the inverter is far from the switchboard pre-wire the main cable between them.
- Plan for installation of EV charger including space in switchboard / sub board.
- Also you should put in a data cable from the switchboard to the inverter, and a data cable from the house modem/router to the inverter. This gives you a hard wire to the data communications of the inverter which is much more reliable than wi-fi.
When speaking with your electrician you could say:
“So we want to put the inverter in the garage. Can you put in a conduit from there to the roof? Also can you run AC from the main switchboard to where the inverter is? Also run a data cable from the inverter to the smart meter as well as between the modem/router and the inverter.”
- Make sure to future proof with a bigger switchboard with lots of room for extra breakers. Sometimes you can have a 2nd switchboard.
- Thinking about the future again you will want to prepare for your electric vehicle requirements. It will be much cheaper to put in 3 phase cabling in your switchboard now, capable of having at least an 11kW connection or even more!
- You will want to have a solar-ready electricity meter installed from the outset.
- If building a multi-storey house definitely put your solar panels on the roof before the scaffolding comes down. Otherwise you’ll be paying twice for the scaffolding! Also consider and plan for Work-safe requirements as scaffolding will most likely need to go up to the top gutter. (not just to the first floor wall access). Guardrails can be employed at rooftop level with scaffold for 1st floor access.
- Make sure every roof face can support being filled with solar panels as some new homes (cheaper builds) cannot support a good sized solar system.