Solar explained to clever people by people who are not trying to be clever

Solar Panels in SG7 (North Hertfordshire)

See if solar pays off for you in North Hertfordshire — price, savings and payback in under a minute (official UK data).

Solar Calculator

Change the settings below to see how costs and savings work for your situation.

System Size

Roof Direction

Battery Storage

Export Value

Your Numbers

Break-even
12.3 years
After this, it's pure profit
Upfront Cost
£10,173
What you pay to get started
Annual Benefit
£829
What you save every year
Profit Over 25 Years
£10,544
After paying itself off, you're this much ahead

Ready to Get Started?

Get your free quote from Blue Ape Renewables. They'll connect you with MCS-certified installers in your area and handle all the paperwork.

Get Solar Quote →
4.8★ Trustpilot • Octopus Energy trusted partner • MCS certified • No obligation
How we calculate this

Solar generation: Based on typical south-facing roof at 35° angle. We account for weather, dirt, and system losses (14%).

How much you'll use directly:

  • Without battery: You'll use about 40% of what you generate. The rest gets sold back to the grid.
  • With 5 kWh battery: You'll use about 70% (battery stores extra for evening use).
  • With 10 kWh battery: You'll use about 75% (more storage means less exported).
  • Panel-only payback: Bigger systems don’t shorten payback—cost and savings rise together per kW.
  • Battery & payback: Batteries raise self-use and cut bills, but added hardware cost often lengthens break-even at typical UK rates.
  • When a battery can still make sense:
    • Evening-heavy usage patterns
    • Time-of-use tariffs / cheap night rates
    • Low export rate vs. high unit rate
    • Heat pump or EV charging synergy
    • Optional backup/resilience (system-dependent)
    • Lower evening-hour CO₂ vs. grid

Costs: Battery prices are typically £700 per kWh. Export tariffs vary by supplier (usually 5–15p per kWh).

Grid connection: Systems up to about 3.7 kW typically need just a notification (G98). Larger systems may need permission (G99).

These are typical values based on average usage patterns. Your actual results will vary based on your roof, shading, and how you use electricity.

Your area in context

Read the full story

A typical roof here lands around 5.0 kW, with most eligible homes comfortably fitting within 3–6 kW. Each kilowatt of panels produces roughly 998 kWh per year on a south-facing roof. We value self-used electricity at 26.5p and exported surplus at a baseline 10p via SEG. Use the calculator above for your exact tariff.

Unit rate
26.5p/kWh
Standing charge
48.2p/day
Sunshine yield (south)
998 kWh/kW
Export price (baseline)
10p/kWh

Browse the scenarios below. Each battery size has its own expand — open the one that matches your plan (or just explore). For each system size (2–8 kW) we show annual output, how much you use directly, what gets exported, annual benefit, upfront cost, break-even, and a 20-year net. Negative numbers are possible — that’s the honest trade-off when adding more battery than your usage profile justifies.

No battery 5 kW example → Annual benefit: £829, Upfront: £10,173, Break-even: 12.3 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1995 kWh 798 kWh 1197 kWh £212 £120 £331 £4,069 12.3 yrs £2,560
3 kW 2993 kWh 1197 kWh 1796 kWh £318 £180 £497 £6,104 12.3 yrs £3,840
4 kW 3991 kWh 1596 kWh 2394 kWh £423 £239 £663 £8,138 12.3 yrs £5,121
5 kW 4988 kWh 1995 kWh 2993 kWh £529 £299 £829 £10,173 12.3 yrs £6,401
6 kW 5986 kWh 2394 kWh 3592 kWh £635 £359 £994 £12,207 12.3 yrs £7,681
7 kW 6984 kWh 2793 kWh 4190 kWh £741 £419 £1,160 £14,242 12.3 yrs £8,961
8 kW 7981 kWh 3193 kWh 4789 kWh £847 £479 £1,326 £16,276 12.3 yrs £10,241

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 2,035, battery £/kWh = 700.

3 kWh battery 5 kW example → Annual benefit: £994, Upfront: £12,273, Break-even: 12.4 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1995 kWh 1197 kWh 798 kWh £318 £80 £397 £6,169 15.5 yrs £1,780
3 kW 2993 kWh 1796 kWh 1197 kWh £476 £120 £596 £8,204 13.8 yrs £3,719
4 kW 3991 kWh 2394 kWh 1596 kWh £635 £160 £795 £10,238 12.9 yrs £5,659
5 kW 4988 kWh 2993 kWh 1995 kWh £794 £200 £994 £12,273 12.4 yrs £7,599
6 kW 5986 kWh 3592 kWh 2394 kWh £953 £239 £1,192 £14,307 12.0 yrs £9,539
7 kW 6984 kWh 4190 kWh 2793 kWh £1,112 £279 £1,391 £16,342 11.7 yrs £11,479
8 kW 7981 kWh 4789 kWh 3193 kWh £1,270 £319 £1,590 £18,376 11.6 yrs £13,418

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 2,035, battery £/kWh = 700.

5 kWh battery 5 kW example → Annual benefit: £1,076, Upfront: £13,673, Break-even: 12.7 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1995 kWh 1397 kWh 599 kWh £371 £60 £430 £7,569 17.6 yrs £1,039
3 kW 2993 kWh 2095 kWh 898 kWh £556 £90 £646 £9,604 14.9 yrs £3,309
4 kW 3991 kWh 2793 kWh 1197 kWh £741 £120 £861 £11,638 13.5 yrs £5,579
5 kW 4988 kWh 3492 kWh 1497 kWh £926 £150 £1,076 £13,673 12.7 yrs £7,848
6 kW 5986 kWh 4190 kWh 1796 kWh £1,112 £180 £1,291 £15,707 12.2 yrs £10,118
7 kW 6984 kWh 4889 kWh 2095 kWh £1,297 £210 £1,506 £17,742 11.8 yrs £12,387
8 kW 7981 kWh 5587 kWh 2394 kWh £1,482 £239 £1,722 £19,776 11.5 yrs £14,657

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 2,035, battery £/kWh = 700.

7.5 kWh battery 5 kW example → Annual benefit: £1,101, Upfront: £15,423, Break-even: 14.0 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1995 kWh 1457 kWh 539 kWh £386 £54 £440 £9,319 21.2 yrs £-513
3 kW 2993 kWh 2185 kWh 808 kWh £580 £81 £660 £11,354 17.2 yrs £1,856
4 kW 3991 kWh 2913 kWh 1077 kWh £773 £108 £881 £13,388 15.2 yrs £4,224
5 kW 4988 kWh 3641 kWh 1347 kWh £966 £135 £1,101 £15,423 14.0 yrs £6,593
6 kW 5986 kWh 4370 kWh 1616 kWh £1,159 £162 £1,321 £17,457 13.2 yrs £8,962
7 kW 6984 kWh 5098 kWh 1886 kWh £1,353 £189 £1,541 £19,492 12.6 yrs £11,330
8 kW 7981 kWh 5826 kWh 2155 kWh £1,546 £215 £1,761 £21,526 12.2 yrs £13,699

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 2,035, battery £/kWh = 700.

10 kWh battery 5 kW example → Annual benefit: £1,117, Upfront: £17,173, Break-even: 15.4 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1995 kWh 1497 kWh 499 kWh £397 £50 £447 £11,069 24.8 yrs £-2,131
3 kW 2993 kWh 2245 kWh 748 kWh £596 £75 £670 £13,104 19.5 yrs £304
4 kW 3991 kWh 2993 kWh 998 kWh £794 £100 £894 £15,138 16.9 yrs £2,738
5 kW 4988 kWh 3741 kWh 1247 kWh £993 £125 £1,117 £17,173 15.4 yrs £5,173
6 kW 5986 kWh 4490 kWh 1497 kWh £1,191 £150 £1,341 £19,207 14.3 yrs £7,607
7 kW 6984 kWh 5238 kWh 1746 kWh £1,390 £175 £1,564 £21,242 13.6 yrs £10,042
8 kW 7981 kWh 5986 kWh 1995 kWh £1,588 £200 £1,788 £23,276 13.0 yrs £12,476

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 2,035, battery £/kWh = 700.

13.5 kWh battery 5 kW example → Annual benefit: £1,134, Upfront: £19,623, Break-even: 17.3 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1995 kWh 1536 kWh 459 kWh £408 £46 £454 £13,519 29.8 yrs £-4,449
3 kW 2993 kWh 2305 kWh 688 kWh £611 £69 £680 £15,554 22.9 yrs £-1,948
4 kW 3991 kWh 3073 kWh 918 kWh £815 £92 £907 £17,588 19.4 yrs £552
5 kW 4988 kWh 3841 kWh 1147 kWh £1,019 £115 £1,134 £19,623 17.3 yrs £3,053
6 kW 5986 kWh 4609 kWh 1377 kWh £1,223 £138 £1,361 £21,657 15.9 yrs £5,553
7 kW 6984 kWh 5377 kWh 1606 kWh £1,427 £161 £1,587 £23,692 14.9 yrs £8,054
8 kW 7981 kWh 6146 kWh 1836 kWh £1,630 £184 £1,814 £25,726 14.2 yrs £10,554

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 2,035, battery £/kWh = 700.

Figures are illustrative and use the same method as the calculator above. For exact results, adjust your roof direction, tariff, and usage in the calculator.

Your Area at a Glance

Your Electricity Rate
26.53p/kWh
Daily Fixed Charge
48.25p/day
Local Sunshine
998kWh/kW
A 1 kW system generates ~998 kWh per year. A typical home uses ~2,700 kWh per year.
Typical System Size
5.0kW
For houses & bungalows in this area

Local Property Data

Property Types

Houses: 68% • Flats: 24% • Bungalows: 6% Based on 3,514 properties

Coverage

North Hertfordshire (98%)|South Cambridgeshire (2%)

Areas Covered

Baldock West, Arbury, Baldock East, Letchworth South East, Weston & Sandon, The Mordens, Ermine, Potton + 2 more

Data Sources & Assumptions

Solar yield: PVGIS (EU Joint Research Centre), January 2025 data

Electricity rates: Ofgem price cap, Q4 2025

Installation costs: MCS certified installer data, March 2025

Property data: EPC open data (Open Government Licence), aggregated

All estimates are typical values. Actual results vary based on your specific situation, roof characteristics, and usage patterns.