Solar explained to clever people by people who are not trying to be clever
Home Regions
Insights
Big Roof Britain Solar Payback Index Standing Charge Drag

Solar Panels in CM1 (Chelmsford)

See if solar pays off for you in Chelmsford — 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
11.9 years
After this, it's pure profit
Upfront Cost
£10,173
What you pay to get started
Annual Benefit
£858
What you save every year
Profit Over 25 Years
£11,271
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

In Eastern, the current unit rate is 26.53p/kWh with a 48.25p/day standing charge. Your postcode’s south-facing sunshine yield is 1033 kWh/kW — 24 above the regional median (1009).

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 1033 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)
1033 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: £858, Upfront: £10,173, Break-even: 11.9 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2065 kWh 826 kWh 1239 kWh £219 £124 £343 £4,069 11.9 yrs £2,793
3 kW 3098 kWh 1239 kWh 1859 kWh £329 £186 £515 £6,104 11.9 yrs £4,189
4 kW 4131 kWh 1652 kWh 2478 kWh £438 £248 £686 £8,138 11.9 yrs £5,586
5 kW 5163 kWh 2065 kWh 3098 kWh £548 £310 £858 £10,173 11.9 yrs £6,982
6 kW 6196 kWh 2478 kWh 3718 kWh £658 £372 £1,029 £12,207 11.9 yrs £8,379
7 kW 7229 kWh 2892 kWh 4337 kWh £767 £434 £1,201 £14,242 11.9 yrs £9,775
8 kW 8262 kWh 3305 kWh 4957 kWh £877 £496 £1,372 £16,276 11.9 yrs £11,172

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: £1,028, Upfront: £12,273, Break-even: 11.9 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2065 kWh 1239 kWh 826 kWh £329 £83 £411 £6,169 15.0 yrs £2,059
3 kW 3098 kWh 1859 kWh 1239 kWh £493 £124 £617 £8,204 13.3 yrs £4,138
4 kW 4131 kWh 2478 kWh 1652 kWh £658 £165 £823 £10,238 12.4 yrs £6,217
5 kW 5163 kWh 3098 kWh 2065 kWh £822 £207 £1,028 £12,273 11.9 yrs £8,297
6 kW 6196 kWh 3718 kWh 2478 kWh £986 £248 £1,234 £14,307 11.6 yrs £10,376
7 kW 7229 kWh 4337 kWh 2892 kWh £1,151 £289 £1,440 £16,342 11.3 yrs £12,455
8 kW 8262 kWh 4957 kWh 3305 kWh £1,315 £330 £1,646 £18,376 11.2 yrs £14,535

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: £1,114, Upfront: £13,673, 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 2065 kWh 1446 kWh 620 kWh £384 £62 £446 £7,569 17.0 yrs £1,341
3 kW 3098 kWh 2169 kWh 929 kWh £575 £93 £668 £9,604 14.4 yrs £3,762
4 kW 4131 kWh 2892 kWh 1239 kWh £767 £124 £891 £11,638 13.1 yrs £6,183
5 kW 5163 kWh 3614 kWh 1549 kWh £959 £155 £1,114 £13,673 12.3 yrs £8,604
6 kW 6196 kWh 4337 kWh 1859 kWh £1,151 £186 £1,337 £15,707 11.8 yrs £11,024
7 kW 7229 kWh 5060 kWh 2169 kWh £1,342 £217 £1,559 £17,742 11.4 yrs £13,445
8 kW 8262 kWh 5783 kWh 2478 kWh £1,534 £248 £1,782 £19,776 11.1 yrs £15,866

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: £1,139, Upfront: £15,423, Break-even: 13.5 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2065 kWh 1508 kWh 558 kWh £400 £56 £456 £9,319 20.4 yrs £-204
3 kW 3098 kWh 2262 kWh 836 kWh £600 £84 £684 £11,354 16.6 yrs £2,319
4 kW 4131 kWh 3015 kWh 1115 kWh £800 £112 £912 £13,388 14.7 yrs £4,843
5 kW 5163 kWh 3769 kWh 1394 kWh £1,000 £139 £1,139 £15,423 13.5 yrs £7,366
6 kW 6196 kWh 4523 kWh 1673 kWh £1,200 £167 £1,367 £17,457 12.8 yrs £9,889
7 kW 7229 kWh 5277 kWh 1952 kWh £1,400 £195 £1,595 £19,492 12.2 yrs £12,412
8 kW 8262 kWh 6031 kWh 2231 kWh £1,600 £223 £1,823 £21,526 11.8 yrs £14,935

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: £1,156, Upfront: £17,173, Break-even: 14.8 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2065 kWh 1549 kWh 516 kWh £411 £52 £463 £11,069 23.9 yrs £-1,817
3 kW 3098 kWh 2324 kWh 775 kWh £616 £77 £694 £13,104 18.9 yrs £774
4 kW 4131 kWh 3098 kWh 1033 kWh £822 £103 £925 £15,138 16.4 yrs £3,366
5 kW 5163 kWh 3873 kWh 1291 kWh £1,027 £129 £1,156 £17,173 14.8 yrs £5,957
6 kW 6196 kWh 4647 kWh 1549 kWh £1,233 £155 £1,388 £19,207 13.8 yrs £8,549
7 kW 7229 kWh 5422 kWh 1807 kWh £1,438 £181 £1,619 £21,242 13.1 yrs £11,140
8 kW 8262 kWh 6196 kWh 2065 kWh £1,644 £207 £1,850 £23,276 12.6 yrs £13,731

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: £1,174, Upfront: £19,623, Break-even: 16.7 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2065 kWh 1590 kWh 475 kWh £422 £48 £469 £13,519 28.8 yrs £-4,131
3 kW 3098 kWh 2386 kWh 713 kWh £633 £71 £704 £15,554 22.1 yrs £-1,471
4 kW 4131 kWh 3181 kWh 950 kWh £844 £95 £939 £17,588 18.7 yrs £1,189
5 kW 5163 kWh 3976 kWh 1188 kWh £1,055 £119 £1,174 £19,623 16.7 yrs £3,849
6 kW 6196 kWh 4771 kWh 1425 kWh £1,266 £143 £1,408 £21,657 15.4 yrs £6,508
7 kW 7229 kWh 5566 kWh 1663 kWh £1,477 £166 £1,643 £23,692 14.4 yrs £9,168
8 kW 8262 kWh 6361 kWh 1900 kWh £1,688 £190 £1,878 £25,726 13.7 yrs £11,828

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.

Insights for CM1

Figures below are tailored to CM1 — click through for full league tables.

Big-Roof Britain Rank #1755 of 2182
4.5 kWp (UK avg 5.1 kWp)
~9 panels (≈430 W)
Solar Payback Index Rank #306 of 2997
10.3 years (UK avg 11.3 years)
~£986 /yr • £10,173 upfront
Standing-Charge Drag Rank #975 of 2997
17.9% (UK avg 21.7%) drag on savings
£176 fixed • ~£986 /yr value

Your Area at a Glance

Your Electricity Rate
26.53p/kWh
Daily Fixed Charge
48.25p/day
Local Sunshine
1033kWh/kW
A 1 kW system generates ~1033 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: 57% • Flats: 34% • Bungalows: 6% Based on 21,030 properties

Coverage

Chelmsford (99%)|Uttlesford (1%)

Areas Covered

Moulsham and Central, Springfield North, Chelmer Village and Beaulieu Park, Broomfield and The Walthams, Marconi, The Lawns, St Andrews, Writtle + 4 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.

Compare nearby areas

Nearby in Eastern

CM99 (Chelmsford)
≈1.9 km away
Local sunshine: ~1,039 kWh/kWp · +1% vs CM1
CM2 (Chelmsford)
≈1.9 km away
Local sunshine: ~1,033 kWh/kWp · +0% vs CM1
CM98 (Chelmsford)
≈3.3 km away
Local sunshine: ~1,036 kWh/kWp · +0% vs CM1
CM3 (Chelmsford)
≈8.6 km away
Local sunshine: ~1,035 kWh/kWp · +0% vs CM1
CM4 (Brentwood)
≈10.3 km away
Local sunshine: ~1,023 kWh/kWp · -1% vs CM1
CM8 (Braintree)
≈13.1 km away
Local sunshine: ~1,050 kWh/kWp · +2% vs CM1

Similar sunshine across the UK

TR6 (Cornwall)
~1,032 kWh/kWp · -0% vs CM1
RH17 (Mid Sussex)
~1,033 kWh/kWp · +0% vs CM1
CF33 (Bridgend)
~1,033 kWh/kWp · +0% vs CM1