I'm considering purchasing several 5kW solar kits that come with 12x 410W panels and a 4k inverter for €1,200 each. My goal is to install three of these systems for a total of 15 kW of solar power and a 12 kW inverter, with plans to switch to three-phase power for my workshop later on. Since the opportunity to export to the grid is limited in my area, I intend to set everything up for zero export and plan to add batteries in the future. I wonder if there are any downsides to oversizing my solar setup that I might be overlooking? Just to clarify, all the equipment is brand new, nothing used.
3 Answers
The main consideration could be the cost-effectiveness of investing in such a large system now. You might spend a bit more upfront, but if you plan to eventually add batteries, then it could be worth it in the long run.
Keep in mind that if there's no export or battery charging happening, a lot of the energy generated may just sit there, only covering your daytime usage. You might not save as much as you'd expect when the sun goes down, as you'll revert back to paying for energy. I'd definitely recommend adding batteries sooner rather than later to store excess energy for later use.
One downside to be aware of is higher inverter idle losses since an oversized inverter isn't running optimally. However, you could counter that by adding more panels, which might help balance things out. It sounds like you’re not planning to make a lot from exporting anyway, so that could ease your mind.