Hey everyone! I'm a first-timer diving into solar energy and I need some help with my calculations. I've got a basic setup I'm working on:
- My total load is 430 watts.
- I plan to use it for about 8 hours each day, so I calculated my total energy consumption as 430 x 8 = 3,440 watt-hours (Wh).
- I'm looking to run a 24V system from my batteries, which gives me 3,440 Wh / 24V = 143.33 amp-hours (Ah).
Considering I only have about 4 hours of direct sunlight daily, I've figured I would need 3,440 Wh / 4 hours = 860 watts of solar panels. So I'm looking at buying five 200-watt panels.
As for storage, I'm thinking of using two 200Ah LiFePO4 batteries connected in series to achieve 24V. I found a decent deal on some 200W panels from Dokio on Amazon for 98 each, but there's no VOC information available, which has me a bit concerned.
The charge controller is where I'm really unsure. The Dokio panels supposedly have a VOC of around 19.2V. If I wire the panels in parallel, I'll keep the 19.2V but increase the total wattage to 1000W.
If I go for an MPPT charge controller like the Victron 100/30, I'm confused about the actual voltage and amp ratings. Isn't the first number usually low when dealing with DC systems? So I've been trying to decode if I actually need something like a 30/100. Am I missing something? Any guidance would really help! Thanks in advance!
3 Answers
Switching to a series setup for your panels is definitely a smart idea! If you're planning to add more panels down the line, just make sure your charge controller can accommodate it. Also, considering a larger model than the 100/30 might save you some trouble later. Good luck with your project!
Just a heads up, when you calculate your load, make sure you're using average consumption rates, not just the max values on devices. Solar panels usually produce about 80% of their stated wattage, especially under less-than-perfect sun conditions. You’ll also want to balance your batteries if you connect them in series, to keep everything running smoothly. Avoid panels that are vague about their specs—those usually lead to future headaches. And looking at brands with solid reputations is totally the way to go!
Hey there! For your solar panels, if you wire them in series, you can increase the voltage significantly, which lowers the amps. This approach minimizes voltage loss, making it easier on your wiring. So with your setup, you’ll have around 96V at 1000W, which means you really need to ensure your charge controller can handle that voltage! Just keep in mind, the VOC (voltage open circuit) is temperature-dependent and can vary. Most controllers can handle higher wattages but often have a strict limit on voltage. So tweaking your config to series is a solid move.