Solar panels can significantly cut your electricity bills — but the upfront cost and the quality of the installation matter enormously. Here's what homeowners should know before booking a solar installation.
How Much Do Solar Panels Cost?
A typical UK residential solar PV system (3–4kW, 8–12 panels) costs between £5,000 and £8,000 installed. The price depends on:
- System size — more panels means more power but higher cost
- Panel type — monocrystalline panels are more efficient and slightly more expensive than polycrystalline
- Inverter quality — the inverter converts DC to AC; a better inverter lasts longer and performs more reliably
- Battery storage — adding a battery (£2,000–£5,000) lets you store excess power for evenings, dramatically increasing savings
- Roof complexity — scaffolding, multiple roof angles, or slate roofs all add to installation cost
How Much Could You Save?
A typical 3.5kW system in the UK generates around 3,000–3,500 kWh per year. Depending on how much you use during daylight hours (vs exporting back to the grid), annual savings range from £300 to £700+. With a battery, savings can be higher because you use more of what you generate.
What to Check Before You Book
- MCS certification — your installer should be MCS certified; this is required for any export tariff payments
- Roof condition — panels last 25+ years, so your roof should be in good condition before installation
- Roof orientation — south-facing roofs generate the most; east/west still work but produce less
- Shading — significant shading from trees, chimneys, or neighbouring buildings reduces output
- Warranty — check both the product warranty (typically 10–12 years) and performance warranty (typically 25 years)
Battery Storage: Is It Worth It?
A battery lets you store excess daytime generation for evening use, rather than exporting it cheaply and buying it back at full price. For most households that are out during the day, a battery significantly improves the financial return — but it adds £2,000–£5,000 to the upfront cost.
Planning Permission
Most domestic solar installations don't need planning permission (they fall under permitted development), but exceptions include listed buildings, conservation areas, and ground-mounted systems over a certain size.
Getting Quotes
Always get at least three quotes from MCS-certified installers, and compare the system size, panel brand, inverter, and warranty — not just the total price. The cheapest quote isn't always the best value over 25 years.