Short answer: a typical NZ bach running a fridge, water pump, lights, wifi and phone/laptop charging needs roughly 2–3kW of solar and 3–4kWh of battery storage – which is exactly what our OffGrid Plug’N’Play Solar Pack is built around. Add a chest freezer or power tools and you’ll want to size up from there.
Start with what you’re actually running, not the roof space
The most common mistake is sizing a system around how many panels will fit, rather than what the bach actually draws power for. Work backwards from your appliances instead:
| Appliance | Typical daily draw |
|---|---|
| Fridge/freezer (energy efficient) | ~1–1.5 kWh |
| Water pump | ~0.3–0.5 kWh |
| Lighting (LED) | ~0.2–0.4 kWh |
| Wifi router + chargers | ~0.2 kWh |
| Chest freezer (on timer) | ~0.8–1.2 kWh |
| TV, evening use | ~0.3 kWh |
Add those up and most baches running the basics – fridge, pump, lights, wifi – land around 2–3kWh of daily use. That’s the number that actually determines system size, not roof area.
Why our kit is sized the way it is
Our Plug’N’Play kit is built around a 3,328Wh battery bank (a 130Ah main battery plus a 100Ah auxiliary) and two 320W panels, prewired to a 1.5kW inverter. That covers the appliance list above with margin for a run of cloudy days, and it’s designed to be simple to install rather than custom-engineered for every property – which is also why it’s priced as a fixed $4,650 kit rather than a quote.
If you’re running heavier loads – power tools, a washing machine most days, more than one fridge – that’s when it’s worth talking to us about sizing up rather than assuming the standard kit will stretch to cover it.
Don’t forget sunshine hours where the bach actually is
System sizing also depends on how much sun the bach gets. A bach in Northland, averaging around 2,200 sunshine hours a year, will produce more from the same panels than one in Waikato at around 2,050 hours – not a huge gap, but worth factoring in if you’re on the margin between kit sizes.
Frequently asked questions
Will 2 solar panels really run a bach?
For the basics – fridge, pump, lights, wifi – yes, when paired with enough battery capacity to smooth out cloudy days, which is exactly how our kit is built. It’s not enough for heavy continuous loads like a spa pool or several power tools running at once.
What if I only use the bach on weekends?
That actually helps – the battery gets a full week to recharge between visits, so a smaller system can comfortably cover weekend-only use than one running a bach full time.
Can I add more panels later if I need more power?
Yes, though it depends on the inverter and controller having spare capacity – worth checking with us before you buy if you think you’ll want to expand.