Energy storage: is it worth it for me?
Storage is not a fashion item. It pays when you have midday surplus and would otherwise buy that energy back in the evening at retail. Under gross metering that spread is wider than the old net-metering world.
If someone is home all day, panels are eaten on the spot — a small battery may suffice, or the array should be designed first.
When it usually pays
It pays less if daytime load is already high, or the array is so small there is almost no leftover kWh. Size the field first, then the battery.
- Evening and night loads (cooking, cooling, EV after 17:00)
- A heat pump you want to run on your own kWh after sunset
- Short outages — a backup sub-board is value by itself
- Gross metering with a low export price
What capacity to start with
Start from the winter–spring evening block you want to cover, not from July peaks. Many homes begin at 5–10 kWh usable; with EV or heat pump, 10–15 kWh is common.
Nameplate kWh is not always usable kWh. Check depth of discharge, cycle life and the 10-year capacity warranty. Two “10 kWh” packs can differ 15–20% in energy you can actually pull.
Safety and matching
Modern LFP is more stable than older NMC, but it still wants a dry, coolable, non-bedroom space. Hybrid inverter and battery voltage/comms should be one family — mixed brands hurt.
If a PlugZone-ready DC or smart AC charger is in the plan, battery and charger share the same load control. We design them as one system.
- Ask for usable kWh, not only the label
- 10 years or cycle count — whichever comes first
- Indoor / outdoor IP rating for the real location
- Agree backup circuits (fridge, internet, gate, one lighting ring)