We are getting asked a lot more about batteries to support your home through a power cut.
This is a reply to a customer who wanted to know if she could prewire for a battery system when she was building the house. Note: They already have an Enphase Micro-Inverter System installed which can only be integrated with a battery inverter with our Stand Alone Management System (The SAM).
Here are a few things to consider for wiring for batteries in the Future:
- You will need a battery inverter/charger. This will measure approximately 1 M high by 500mm deep and wide (maximum) and should be mounted near the distribution board if possible. If not then run cables between the distribution board and the inverter location: 2 runs of 2 core 16mm, 2 runs of 6mm Earth Conduit Wire, 2 Cat6 Data Cables.
- Batteries: Depending on the type of battery, there is a small chance that you may use lead acid but I would recommend Lithium or a newer technology at the time. If you are going to disconnect completely or you need to survive long periods with no power then Lead Acid may be slightly better but that is a discussion for later. You should allow for 1M2 or area on the floor for batteries and also have them on an outside wall so that they can be easily ventilated if needed. Lithium Iron Phosphate is best for on grid (at this point in the evolution of battery development). Typically the batteries should be mounted very close to the inverter - if this is not possible then you'll need to run battery cables between the two locations. For a run <10M then run 50mm2 Cable for runs from 10 up to 20M run 120mm2 Cable. 2 runs (+ve and -Ve) PLUS a Cat6 Data Cable.
- Generator backup for long power outages: Run 1 x 16mm2 2c Neutral TPS, 1 x CAT6 Data Cable and 1 x 2c 1.5mm TPS between the Inverter location and an outdoor area for the generator and allow for the generator to be as far away from the house as you like (on the neighbor's property?? ;) ) and if you are thinking of sheltering it in a shed then allow for an exhaust flu up through the roof or wall.