Savings & payback
The disadvantages of solar panels, honestly
Most pages about solar drawbacks are written by companies selling solar, which is why they read like a sales script with a token 'cons' list. We don't sell or install anything, so here is the honest version.These are the genuine disadvantages — and where each one is manageable, we say how. The balancing view is is plug-in solar worth it?.
Written and edited by Christopher Panteli
Christopher is the founder and editor of MyPlugInSolar. He oversees the site’s research standards, data tools and editorial process. He is not an electrician or solar installer, and specialist technical claims are sourced from official documentation or reviewed by appropriately qualified professionals.
The disadvantages that really matter
- Upfront cost: rooftop systems are a four-to-five-figure purchase, and support is limited and targeted — see solar panel grants. Plug-in systems are far cheaper but aren't yet legal to use in the UK.
- The timing mismatch: panels peak at midday; many households use most electricity mornings and evenings. Only what you use as it's generated cuts your bill — the self-consumption problem. Fixing it with a battery adds cost.
- Seasonality: winter output is low exactly when demand is high — solar cuts summer bills far more than winter ones.
- Property constraints: a north-facing, shaded or ageing roof weakens the case — see is my roof suitable?. Flats, leaseholds and rentals add permission hurdles.
- Payback takes years: even a good installation returns its cost over years, not months — see payback period. Anyone promising fast, guaranteed payback is selling.
The smaller drawbacks
- No power in a blackout (usually): grid-tied systems shut down in a power cut unless you add backup-capable storage.
- Aesthetics and planning: looks are subjective; most rooftop solar is permitted development, but exceptions exist, especially for listed buildings.
- Some upkeep: minimal, but not zero — occasional cleaning and an eye on monitoring.
- Degradation: output declines slowly over decades — covered by performance warranties; see lifespan and warranties.
- Roof works later: panels may need removing and refitting if the roof beneath needs work — a real, occasionally expensive nuisance.
And specifically for plug-in solar
Plug-in solar dodges the big rooftop drawbacks — cost, scaffolding, permanence — but has its own list: it is not yet legal to sell, supply or use in the UK (the consultation response is awaited), output is deliberately small, exported surplus may earn nothing, and a vertical balcony mount gives up some output. We'd rather you knew all of this before buying anything.
Why we publish this
Frequently asked questions
- What is the biggest disadvantage of solar panels?
- The combination of upfront cost and the timing mismatch: panels generate most at midday while many homes use most electricity mornings and evenings, so without changing habits or adding a battery, a chunk of the generation doesn't cut your bill.
- Why might solar panels not be worth it?
- A poor roof (north-facing, shaded, needing repair), low daytime electricity use, a short expected stay in the home, or overpaying for the installation. In those cases the payback stretches badly. It's property-by-property arithmetic, not a universal yes or no.
- Do solar panels cause roof problems?
- A competent installation on a sound roof rarely does — but panels add load and penetrations, so roof condition should be checked first, and having panels removed and refitted for later roof work is a genuine cost worth knowing about.
Sources
- 1. PVGIS (Photovoltaic Geographical Information System) — European Commission, Joint Research Centre
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