What would a 210 kWp array produce in Grays?

Yes. At 927 kWh per kWp a year, a 210 kWp array on a Grays roof models at around 195,000 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.

Is planning permission needed for panels on a Grays office or shop?

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 Thurrock 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.

Will rooftop solar improve the EPC rating of a let building in Grays?

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.

Does the grid around Grays have capacity for export?

UK Power Networks is the distribution network operator for Essex. Arrays above 3.68 kW per phase connect under G99, and the application sets the export limit. It is part of the design work we arrange.

Commercial building solar panels in Grays

Whether solar pays on a Grays commercial building depends less on the panels than on who owns the roof and who pays the bill. Each survey records the usable area once edge strips, plant and walkways are taken out, the load the deck can take, and whether the lease lets the occupier alter the roof.

927 kWh per kWp a year at this latitude, so a 210 kWp array models at about 195,000 kWh. Source: EU PVGIS v5.2, SARAH3, 10 degree pitch, 14 percent system loss.

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Drawing Grays commercial roof

Roof 60 x 32 m, 1,920 m²

Array 210 kWp, east-west

Yield 195,000 kWh/yr

Scale 1:400 / Rev A / RM17

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.

44,345: people in the Grays built-up area (ONS Census 2021)
470: office properties on the rating list in Thurrock (VOA, March 2025)
1,140: retail properties, 90 of them large-format (VOA, March 2025)
1: named commercial rooftop scheme on the planning record nearby (REPD, Q1 2026)

Offices and a retail park on the edge of a town in the east of England, several roofs carrying solar — Commercial stock of the kind we survey across East of England. Generated illustration, not a named site.

Solar PV for commercial property across Essex

What a flat roof in Grays generates

Modelled irradiation here is 1,190 kWh per square metre a year on a low-tilt array, which works out at 927 kWh for every kWp installed (EU PVGIS v5.2, SARAH3, 10 degree pitch, 14 percent system loss). That is around 5 percent above the mean across the towns we cover.

Commercial stock in Thurrock

Thurrock has 470 office premises and 1,140 shops and other retail premises on the non-domestic rating list, according to the Valuation Office Agency. By office stock the district sits in the bottom quarter of the 318 districts in England and Wales; by retail stock it sits below the median of the 318 districts in England and Wales.

90 of those retail properties are superstores, large food stores, large shops or retail warehouses, together about 180,000 square metres. Single storey boxes of that size are where most commercial rooftop solar actually gets built, because the roof is big, flat or shallow, and uninterrupted.

The same list carries 190 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.

Commercial rooftop solar already planned near Grays

The Renewable Energy Planning Database records one roof-mounted scheme on supermarket and retail buildings in this postcode district. These are other organisations' projects, listed from the public record, not ours.

Scheme	Applicant	Type	Capacity	Status
Morrisons	WM Morrisons Supermarkets Plc	retail	0.43 MW	Awaiting Construction

The built-up area holds about 44,345 people, so the stock here runs to high street premises, a supermarket or two and the odd hotel (ONS Census 2021 built-up areas).

Surveys run across RM postcodes, RM17 outward.

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

Jul produces 5.9 times what Dec does on the same roof. A 210 kWp array here models at about 195,000 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

Month	kWh per kWp	210 kWp array
Jan	25	5,250
Feb	38	7,980
Mar	73	15,330
Apr	107	22,470
May	124	26,040
Jun	128	26,880
Jul	130	27,300
Aug	109	22,890
Sep	86	18,060
Oct	54	11,340
Nov	32	6,720
Dec	22	4,620

Source: EU PVGIS v5.2

FIG. 2 Grays against the rest of Essex

Colchester953
Canvey Island945
Southend-on-Sea942
Basildon933
Braintree932
Chelmsford930
Grays927
Brentwood913
Harlow908

Grays ranks 8 of 10 towns we cover in Essex on modelled yield, against a national mean of 886 kWh per kWp. The county runs from 908 to 973, a spread of 65 kWh per kWp. On a 210 kWp commercial roof that is about 13,650 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 UK Power Networks

UK Power Networks is the network operator here, and their answer on export capacity shapes the design. Any commercial array above 3.68 kW per phase connects under G99 rather than G98, and the application fixes what you are allowed to push back onto the network. If the local network is tight, limiting export rarely breaks the case here: most of the generation is consumed on site while the building is working.

Across Essex the planning database records 221 solar schemes totalling 2787 MW, of which 46 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.

Your name Company Email Phone Site postcode Building type Your interest in the building Roof area Annual electricity spend What are you looking at?

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

Questions about solar in Grays

What would a 210 kWp array produce in Grays?: Yes. At 927 kWh per kWp a year, a 210 kWp array on a Grays roof models at around 195,000 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.
Is planning permission needed for panels on a Grays office or shop?: 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 Thurrock 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.
Will rooftop solar improve the EPC rating of a let building in Grays?: 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.
Does the grid around Grays have capacity for export?: UK Power Networks is the distribution network operator for Essex. Arrays above 3.68 kW per phase connect under G99, and the application sets the export limit. It is part of the design work we arrange.

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