How much does a warehouse roof in Bethesda generate?

The model gives 704 kWh for every kWp installed here, so 500 kWp comes out at about 352,000 kWh a year before any shading losses. You need roughly 1,485 sqm of clear roof to fit it. Source: EU PVGIS v5.2, SARAH3, 10 degree pitch, 14 percent system loss.

Does the grid around Bethesda have capacity?

SP Energy Networks is the distribution network operator for Gwynedd. Anything above 3.68 kW per phase connects under G99, and the application sets the export limit. We submit it as part of the design.

Solar panels for warehouses in Bethesda

The economics of a Bethesda rooftop array turn on how much of the generation the occupier uses on site. The survey measures the roof, not the postcode: cladding profile, purlin centres, remaining sheet life and the load the frame can take.

704 kWh per kWp a year at this latitude, so a 500 kWp array models at about 352,000 kWh. Source: EU PVGIS v5.2, SARAH3, 10 degree pitch, 14 percent system loss.

Book a roof survey in Bethesda

Drawing Bethesda unit

Roof 96 x 62 m

Array 500 kWp

Yield 352,000 kWh/yr

Scale 1:500 / Rev A / Gwynedd

Illustrative layout for a unit of this size. Your own figures come from the roof survey.

Bethesda / Gwynedd

Aerial view of an industrial estate where some warehouse roofs carry solar arrays and others are bare steel — Industrial stock of the kind we survey across Gwynedd.

Warehouse rooftop solar across Gwynedd

What a roof in Bethesda actually generates

Modelled irradiation at this latitude is 902 kWh per square metre a year in the plane of a shallow-pitched roof, which works out at 704 kWh for every kWp installed (EU PVGIS v5.2, SARAH3, 10 degree pitch, 14 percent system loss). That is about 21 percent below the mean across the towns we cover, so the case here leans harder on how much you use on site rather than on raw generation.

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

Jun produces 9.6 times what Dec does on the same roof. A 500 kWp array here models at about 352,000 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	500 kWp array
Jan	14	7,000
Feb	27	13,500
Mar	57	28,500
Apr	89	44,500
May	105	52,500
Jun	106	53,000
Jul	99	49,500
Aug	80	40,000
Sep	62	31,000
Oct	35	17,500
Nov	18	9,000
Dec	11	5,500

Source: EU PVGIS v5.2

FIG. 2 Bethesda against the rest of Gwynedd

Pwllheli887
Porthmadog820
Caernarfon798
Dolgellau746
Bangor733
Bethesda704

Bethesda ranks 6 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 500 kWp array that is about 91,500 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 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 Gwynedd the planning database records 19 solar schemes totalling 221 MW, of which 6 are operational (REPD Q1 2026).

Book the survey

Send us the postcode

Tell us where the unit is and roughly how big the roof is. 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.

Questions about solar in Bethesda

How much does a warehouse roof in Bethesda generate?: The model gives 704 kWh for every kWp installed here, so 500 kWp comes out at about 352,000 kWh a year before any shading losses. You need roughly 1,485 sqm of clear roof to fit it. Source: EU PVGIS v5.2, SARAH3, 10 degree pitch, 14 percent system loss.
Does the grid around Bethesda have capacity?: SP Energy Networks is the distribution network operator for Gwynedd. Anything above 3.68 kW per phase connects under G99, and the application sets the export limit. We submit it as part of the design.