How Many Solar Panels Do I Need in Plymouth? (Calculator + Local Examples)
Introduction
If you’re considering solar panels for your Plymouth home, one of the first questions is: “How many panels will I actually need?”
The answer depends on:
Your electricity usage
The size of your roof
The efficiency of the panels
Whether you add a battery
In this guide, we’ll show you how to estimate system size, provide real-world examples from Plymouth homes, and give you a simple calculator you can use.
⚡ Step 1: Understand Your Electricity Usage
Check your energy bills — most Plymouth households use 2,900–3,500 kWh per year.
Low usage (flat/small home): ~2,500 kWh
Average semi-detached: ~3,200 kWh
Large family home: 4,500–5,000+ kWh
☀️ Step 2: How Much Power Does a Solar Panel Produce?
In 2025, most solar panels are rated at 380–420W each.
In Plymouth, one panel produces around 350–400 kWh per year (thanks to our above-average South West sunshine hours).
📊 Quick Calculation (Rule of Thumb)
Annual Usage ÷ 350 = Approx. Panels Needed
3,200 kWh ÷ 350 = ~9 panels
4,500 kWh ÷ 350 = ~13 panels
🏡 Plymouth Examples
Example 1: Small Terraced Home (St Judes)
Usage: 2,700 kWh/year
System: 3.2kW (8 panels, 400W each)
Roof: south-facing, no shading
Savings: ~£650/year
Example 2: Semi-Detached (Plymstock)
Usage: 3,500 kWh/year
System: 4.5kW (11 panels)
With 5kWh battery
Savings: ~£900/year
Example 3: Large Detached (Saltash, Cornwall border)
Usage: 5,200 kWh/year
System: 6kW (15 panels, plus 10kWh battery)
Savings: ~£1,400/year
🔋 Should You Add a Battery?
Without a battery → you’ll use ~40% of your solar directly.
With a battery → self-consumption rises to 70–80%, maximising return.
✅ Simple Calculator
(Here’s a text-based calculator you can present on the blog until we build a proper web calculator for you)
Find your annual electricity usage (kWh).
Divide by 350.
Round up to get panels needed.
🎁 Grants & Incentives (2025)
0% VAT until 2027
Smart Export Guarantee (SEG) for selling excess back
Local schemes (Devon & Cornwall councils) may occasionally run group-buys
📍 Call to Action
Want to know exactly how many solar panels your Plymouth home needs?
Use our Solar Panel Installation Service Page →
Or call +447939190302 for a free survey
Serving Plymouth, Devon & Cornwall
FAQ
Q: How many solar panels does the average Plymouth home need?
A: Most semi-detached homes need 9–12 panels (~3.5–4.5kW system).
Q: How much roof space do I need?
A: Each panel is about 1.7m x 1m. A 4kW system (~10 panels) needs ~18m².
Q: Do I need planning permission in Plymouth?
A: No, most homes don’t — unless it’s a listed building or in a conservation area.
