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Commercial building solar panels in Dolgellau

Commercial roofs in Dolgellau tend to be flat, membrane covered and cluttered with plant, which shapes the layout more than the size does. We check the covering and the lease together, because a roof with eight years of membrane left and a tenant with a break in three changes the answer.

746 kWh per kWp a year at this latitude, so a 210 kWp array models at about 157,000 kWh. Source: EU PVGIS v5.2, SARAH3, 10 degree pitch, 14 percent system loss.

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60 m 32 m N plant screen shade, kept clear stair core edge strip 1.5 m phase 1
Drawing Dolgellau commercial roof
Roof 60 x 32 m, 1,920 m²
Array 210 kWp, east-west
Yield 157,000 kWh/yr
Scale 1:400 / Rev A / Gwynedd

Illustrative layout for a flat commercial roof of this size, with plant, shade and access kept clear. Your own figures come from the roof survey.

790
office properties on the rating list in Gwynedd (VOA, March 2025)
1,610
retail properties, 40 of them large-format (VOA, March 2025)
0
named commercial rooftop schemes on the planning record nearby (REPD, Q1 2026)
Aerial view of an out-of-town retail park where some of the large unit roofs carry solar arrays and others are bare
Commercial stock of the kind we survey across Gwynedd. Generated illustration, not a named site.

Commercial rooftop solar across Gwynedd

Yield on a Dolgellau commercial roof

Modelled irradiation here is 957 kWh per square metre a year on a low-tilt array, which works out at 746 kWh for every kWp installed (EU PVGIS v5.2, SARAH3, 10 degree pitch, 14 percent system loss). That is about 16 percent below the mean across the towns we cover, so the case here rests more on daytime consumption than on raw generation.

How many commercial buildings Gwynedd has

On the Valuation Office Agency's count, Gwynedd holds 1,610 retail and 790 office properties on the rating list. By office stock the district sits below the median of the 318 districts in England and Wales; by retail stock it sits above the median of the 318 districts in England and Wales.

The big roofs are in the 40 large-format retail units, superstores and retail warehouses in the district, about 74,000 square metres of floorspace under largely single storey roofs.

The same list carries 500 hotel, leisure and assembly properties in the district. Leisure centres and hotels run seven days a week, which puts weekend generation to use that an office would export.

Source: Valuation Office Agency, Non-domestic rating: business floorspace, 31 March 2025 (published December 2025), counts and floorspace by special category code and local authority district, England and Wales.

FIG. 1 What a Dolgellau roof makes, month by month

What a Dolgellau roof makes, month by month

Modelled output per kWp installed, for a shallow-pitched south-facing array. Source: EU PVGIS v5.2.

0255075100Jan: 16 kWh per kWpJanFeb: 29 kWh per kWpFebMar: 61 kWh per kWpMarApr: 93 kWh per kWpAprMay: 110 kWh per kWpMay110 kWh Jun: 109 kWh per kWpJunJul: 105 kWh per kWpJulAug: 86 kWh per kWpAugSep: 66 kWh per kWpSepOct: 38 kWh per kWpOctNov: 21 kWh per kWpNovDec: 12 kWh per kWpDec

May produces 9.2 times what Dec does on the same roof. A 210 kWp array here models at about 157,000 kWh across the year, but it arrives unevenly, which is why we size against your summer daytime load and then look at whether storage is worth adding for the shoulder months.

Monthly figures as a table
MonthkWh per kWp210 kWp array
Jan163,360
Feb296,090
Mar6112,810
Apr9319,530
May11023,100
Jun10922,890
Jul10522,050
Aug8618,060
Sep6613,860
Oct387,980
Nov214,410
Dec122,520
Source: EU PVGIS v5.2
FIG. 2 Dolgellau against the rest of Gwynedd
  • Pwllheli887
  • Porthmadog820
  • Caernarfon798
  • Dolgellau746
  • Bangor733
  • Bethesda704

Dolgellau ranks 4 of 6 towns we cover in Gwynedd on modelled yield, against a national mean of 886 kWh per kWp. The county runs from 704 to 887, a spread of 183 kWh per kWp. On a 210 kWp commercial roof that is about 38,430 kWh a year between the strongest and weakest town in the county.

Bars are zero based, so length is proportional to the figure. Where a county is flat, that is the finding: location is not the lever, consumption is. Source: EU PVGIS v5.2, modelled per town

Grid connection through SP Energy Networks

SP Energy Networks operates the distribution network across Gwynedd, so the export application goes to them. Anything larger than 3.68 kW per phase falls under G99, which means an application before commissioning rather than a notification afterwards. A constrained network is not the end of a scheme. Capping export costs little when the building already absorbs most of what the roof produces.

Across Gwynedd the planning database records 19 solar schemes totalling 221 MW, of which 6 are operational (REPD Q1 2026).

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Send us the postcode

Tell us where the building is, roughly how big the roof is, and whether you own it or lease it. We come back with what it can carry, what it would generate against your consumption, and the three ways to pay for it.

Lenzie Consulting Ltd arranges the survey and passes your details to our MCS-certified installation partner so they can quote.

We pass your details to our MCS-certified installation partner so they can quote. Read the privacy notice.

Questions about solar in Dolgellau

What would a 210 kWp array produce in Dolgellau?
Yes. At 746 kWh per kWp a year, a 210 kWp array on a Dolgellau roof models at around 157,000 kWh. What changes the answer is how much of that the building uses during opening hours rather than exports. Source: EU PVGIS v5.2, SARAH3, 10 degree pitch, 14 percent system loss.
Do we need planning permission for solar on a commercial building in Gwynedd?
Usually not a full application. In England, panels on the roof of a non-domestic building are permitted development under Class J of Part 14 of the General Permitted Development Order, with no capacity cap since December 2023. Above 50 kW, which covers most commercial arrays, you must first apply to Gwynedd for a determination on prior approval of the design and appearance, in particular glare on neighbouring land. On a flat roof panels may stand no more than 1 metre above the roof and must sit at least 1 metre from its edge, and listed buildings and scheduled monuments are excluded. See our planning permission guide for the detail.
Does solar help a Dolgellau landlord meet MEES?
It can. A non-domestic EPC is an asset rating, and on-site generation counts in the calculation, so an array usually lifts the score. Let property in England and Wales must be EPC E or better today. The government's interim response of 18 June 2026 proposes EPC B, where cost effective, from 2031 for let buildings over 1,000 m², and drops the EPC C step once planned for 2027. How far solar moves a particular building depends on its fabric and services, which is why the EPC assessor models it before anything is fitted.
Which network operator handles the connection in Dolgellau?
Capacity varies street by street and only SP Energy Networks can answer it for your connection. We ask early, because an export-limited offer changes the design rather than ending the scheme, and most commercial buildings use most of what they generate anyway.

Nearby

All Gwynedd locations