The 5 Most Common Mistakes When Buying a Solar System (and How to Avoid Them)

When buying a solar system, there’s a lot you can mess up. Comparing solar providers? Well, some people buy a massive system that’s completely oversized – or the opposite, a tiny one that barely produces any electricity. Then there are the bargain hunters who go for cheap components and are surprised when everything falls apart […]
  • Posted: 28.10.2025
  • Reading time: 3 minutes
The 5 Most Common Mistakes When Buying a Solar System (and How to Avoid Them)
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When buying a solar system, there’s a lot you can mess up. Comparing solar providers? Well, some people buy a massive system that’s completely oversized – or the opposite, a tiny one that barely produces any electricity. Then there are the bargain hunters who go for cheap components and are surprised when everything falls apart after just two winters.

Many don’t even properly inspect their roof – and a crooked or rotting roof can be a real dealbreaker. And don’t even get me started on battery storage: if it’s not properly integrated, you’ll regret it later. Oh, and most people forget about maintenance too.

So how do you avoid making these mistakes when buying a solar system? Easy: get the pros involved. Let a professional solar company check your roof and your energy needs thoroughly. Go for quality brands, not cheap knock-offs. Plan for a battery, otherwise, it won’t do much good. And most importantly – check (or have someone check) every now and then to make sure everything is still running. Otherwise, your shiny new solar system might be history faster than you can say “energy transition.”

A More Detailed Breakdown of the Mistakes

  1. Checklist mismatch: Honestly, a PV system that doesn’t fit your needs is a waste of money. Too big? Throwing money away. Too small? You’ll still have to buy extra electricity – super annoying. Solution? Get someone on board who knows what they’re doing. Check your consumption, inspect the roof, and remember: if you plan to add an EV or heat pump soon, factor that in from the start.
  2. Buying cheap junk: Sure, cheap always sounds tempting. But those super-cheap panels and inverters? They break faster than you can say “subsidy” and produce less power anyway. Go for quality from reputable brands that will still exist in a few years – and can help you if needed.
  3. Ignoring the roof: The roof! Often overlooked. If it’s crumbling or unstable, your fancy system might just fall onto your sofa someday. Have a professional check it before you order anything.
  4. Battery storage? “We don’t need one…” (Yes, you do!) Without a battery, much of your solar power just goes into the grid instead of being used by you. Smart planning means including a battery from the start. You’ll be more flexible, save more, and even be prepared for power outages.
  5. Maintenance? “It’ll be fine…” Sure, it runs at first. But if you never check it, performance drops over time. And if something major fails, it gets expensive. Sign a maintenance contract or regularly clean and inspect the system – it’s worth it, honestly.

A Little Insider Tip

Make sure to hire a skilled installer – a true solar pro, preferably someone with several years of experience. With amateurs, things can go wrong fast – suddenly it’s leaking, or the system won’t even run. Then you’re left with nothing but stress and have to start all over again.

“Download our free buyer’s checklist”

This article is intended for informational purposes only and does not constitute a binding offer or professional advice.

Profisolar Bau GmbH
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