Hertfordshire
Solar panels in Harpenden, priced before anyone visits.
About 6,470 kWh a year from 12 panels in Harpenden, £6,360 installed, with your system designed on a free 30-minute video call.
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- Free 30-minute video design call
- Priced before anyone visits
- Installed by our MCS-certified, fully insured teams
How much a Harpenden roof makes, month by month
PVGIS puts Harpenden at 1,017 kWh per kWp a year, level with our Hertfordshire county estimate. 68% of it arrives between April and September, peaking in July.
Generation per kWp, month by month
Show the monthly figures
| Month | kWh/kWp |
|---|---|
| January | 39.2 |
| February | 52.9 |
| March | 88.7 |
| April | 114 |
| May | 121 |
| June | 122 |
| July | 124 |
| August | 111 |
| September | 96 |
| October | 66.1 |
| November | 45.9 |
| December | 35.6 |
Source: PVGIS v5.2 (European Commission JRC), SARAH3 database, 1 kWp, 14% system loss, 35 degree pitch, due south, checked September 2026.
For scale: 1,017 kWh per kWp in Harpenden against 925, our GB average (the mean of our 85 county PVGIS estimates), which puts Harpenden 10% above it.
How Harpenden compares
Among the places we publish figures for, Harpenden is one of 27 Hertfordshire towns we track, and it ranks 17th of 27 for solar yield. It is a medium town in the House of Commons Library classification, with 31,337 residents, and its roofs see 2.79 peak sun hours a day across the year. That drives the standard 12 panel model to 6,468 kWh of generation, of which around 5,531 kWh is exported at 12p for £664 a year, with £247 saved on electricity you would otherwise buy at 26.32p.
These are starting numbers, not a quote. The calculator below opens on Harpenden's own PVGIS figure; change the panels, the battery or the export rate and it reruns. The design call replaces every assumption with your roof and your bills.
Planning applications here go through St Albans; nationally, the House of Commons Library classes Harpenden as a medium town.
The charger is in the installed price but left out of payback: charging savings depend on your mileage and tariff, which the design call models properly.
Your real roof and usage, worked through on a free 30-minute video call. Use the full form or leave three details below.
Price this for your roof
Three details. We call or text within one working day to book your free 30-minute design call, on video or by phone if you prefer.
Generation is modelled from PVGIS satellite data for Harpenden's own coordinates (51.81559, -0.35156), using the same 26.32p/kWh import value and £1,000 per kWp installed pricing as every Clearline estimate; the methodology is on our help page.
UK Power Networks and your Harpenden connection
Harpenden sits in UK Power Networks' East England licence area, so UK Power Networks is the network operator (DNO) any solar panels or battery here are registered with.
Below 3.68kW per phase of inverter and battery output, the G98 route applies: the installation is notified to UK Power Networks within 28 days of commissioning, with no prior approval.
Larger systems go through G99 instead, applied for before installation. On timing: Ofgem's guaranteed standard for a low voltage generation connection quotation is 45 working days, with £80 paid for each working day late, and it binds UK Power Networks as it does every network operator.
Sources: NESO DNO licence areas (3 May 2024); Ofgem, Distributed Generation Standards Direction guidance, checked 27 September 2026. G98 vs G99, explained.
Adding a heat pump or an EV charger in Harpenden
A heat pump in Harpenden
Heating demand peaks when solar is weakest. In Harpenden, a 12-panel system makes about 230 kWh in December and 250 kWh in January, a fraction of its 790 kWh in July, which is why a heat pump here is costed on its tariff first.
In England, the Boiler Upgrade Scheme pays £7,500 towards an air source or ground source heat pump and £2,500 towards an air-to-air one, with £1,500 more until March 2027 for homes heated by oil or LPG with no mains gas (gov.uk, checked 28 September 2026).
Charging an EV in Harpenden
Summer is where a car earns its place. In July, 12 panels in Harpenden make about 790 kWh, against roughly 70 kWh a typical home uses in daylight that month on our calculator's typical-use settings, so there is surplus a smart charger can put into the car instead of exporting it.
Renters and flat owners with private off-street parking can get 75% off a chargepoint and its installation, up to £500 per socket, until 31 March 2027 (gov.uk, checked 28 September 2026). The calculator above adds a 7.4kW smart charger from £1,100 installed.
What the named kit costs, installed
Every system is designed around your roof on the free call before anything is fitted.
Solar panel servicing and repair in Harpenden
If a system in Harpenden is underperforming, start with the guides below: repair benchmarks, service scope, and the inverter question.
Common questions about solar in Harpenden
How much energy would 12 solar panels make in Harpenden?
Harpenden averages 2.79 peak sun hours a day, which PVGIS turns into 1,017 kWh per kWp a year. On a 12-panel, 6.36 kWp roof that is about 6,470 kWh, 68% of it between April and September.
What does a typical solar system cost in Harpenden?
Solar is priced at £1,000 per kWp installed wherever you live, so a 12-panel, 6.36 kWp system costs £6,360 in Harpenden, exactly as it would anywhere else, before any battery. Location changes what the system makes, not what it costs: here that is about 6,470 kWh a year. The final figure comes from your roof on the design call.
Who is the network operator in Harpenden, and do I need a G99 application?
The operator is UK Power Networks. Most home systems use the G98 route, a notification within 28 days of switch-on for up to 3.68kW per phase, so nothing waits on the network. Above that, G99 applies and has to be granted first. Ofgem's guaranteed standard for a low voltage generation connection quotation is 45 working days, with £80 paid for each working day late, and it binds UK Power Networks as it does every network operator. Your design call checks which route yours needs.
What happens to the solar I do not use in Harpenden?
Around £664 a year at 12p per kWh, for the roughly 5,531 kWh a 12-panel system in Harpenden exports with typical use. Rates vary by supplier and some need their own tariff; the export rates table is dated and sourced.
How does solar perform in Harpenden in the winter months?
December is the weakest month in Harpenden: about 230 kWh from 12 panels, against 790 kWh in July. The panels still generate on bright winter days; they just cover a smaller share of what the house uses.
How Harpenden compares with its neighbours
The six closest towns we publish, run through the identical PVGIS query as Harpenden.
| Town | kWh per kWp a year | vs Harpenden |
|---|---|---|
| Harpenden | 1,017 | this town |
| St Albans | 1,023 | +6 kWh |
| Hatfield | 1,022 | +5 kWh |
| Hemel Hempstead | 1,016 | −1 kWh |
| Luton | 1,022 | +5 kWh |
| Welwyn Garden City | 1,021 | +4 kWh |
| London Colney | 1,022 | +5 kWh |
Same PVGIS v5.2 query for every town. Small differences are within year-to-year weather; more than about 30 kWh per kWp apart is geography.
Also for Harpenden: Solar panels in Harpenden from OVO Solar & Battery
See a number before you speak to anyone
Answer a few questions about your roof and usage and see an instant solar and battery estimate. No email needed to see the result.
Further reading for Harpenden
Sourced, dated and written by us. The same ground we cover on your free call.
Why your inverter is smaller than your panel array, and why that is correct
More panel capacity than inverter capacity is a deliberate design choice.
Read the guide →Adding a battery to solar panels you already own
Retrofitting a battery to working solar is straightforward. The paperwork is where people trip up.
Read the guide →The main home EV chargers, compared on what actually differs
Eight popular UK home chargers on cable, connectivity, warranty and tariff integration.
Read the guide →What MCS certification actually buys you on a heat pump job
The gate on the £7,500 grant, the design standard behind your running costs, and the noise sign-off.
Read the guide →Why the best export rates always carry conditions
The top export rates are acquisition offers. Here is how to price the condition.
Read the guide →NAPIT, NICEIC and competent person schemes: who tells building control about your solar
Solar work is notifiable. A competent person scheme means your installation team notifies, not you.
Read the guide →Get my free quote
Takes about two minutes. We call or text within one working day to book your free 30-minute video design call at a time that suits you. We design it around your roof and your numbers, and our MCS-certified, fully insured installation teams install it.