I'm in the process of setting up a small off-grid solar system for my flower farm in Surrey, UK, and could use some guidance. I previously worked on a van conversion project and have a few components left over. Here's what I've got so far:
- 2 x 275w solar panels
- 200ah 12v lithium battery
- 3000w Renology PSW inverter
- Victron SmartSolar MPPT 100/30 controller
While I have an idea of some basic uses like lights and phone chargers running off 12v, I'm not exactly sure what my total daily usage would be, particularly for AC power, as I plan on possibly adding a fridge and power tools down the line.
What else do I need to purchase? Specifically, what sizes of cables should I use? Is there a way I can enhance the system without having to buy everything new? The panels will be fully exposed to sunlight; should I consider adding more panels or an additional battery?
Also, is there anyone in the Surrey area who could help with the installation? Thanks a lot for any advice!
2 Answers
Just a heads up, if you're considering a fridge, go for a DC-powered one. AC fridges can really drain your system, as they require the inverter to be on constantly, which adds to the load. If you do need an inverter for certain loads, try to pick one that can be switched on and off as needed to save power.
It sounds like you're on the right track! For your setup, here are a few things you'd need:
- Wiring from the panels to the breaker should be 10AWG wire.
- You'll need a DC-rated breaker/disconnect too, mainly for safety. It's not just about overcurrent, it's for disconnecting purposes.
- For the wires from the breaker to your Victron controller, stick with 10AWG solar wire.
- Then from the Victron to the battery, use another 10AWG wire.
- Don't forget a fuse between the battery and inverter (300A), and a 40A fuse from the battery to the controller.
- Finally, you'll want 2AWG wire connecting from the battery to the inverter.
As for boosting your system, adding a second battery in parallel can definitely help. More solar panels would require another charge controller, but you can run multiple controllers on one battery. The 200AH battery's BMS will probably trip around 2500W, so keep that in mind!
Great suggestions! Just to add, make sure also to get a disconnect switch between your panels and controller, plus fuses between each component for safety. If you're wiring everything directly to the battery terminals, some fuses can be combined to simplify your setup.