South West irradiance — the data
Devon and Cornwall average 1,050-1,100 kWh/kWp/yr (PVGIS data, 2024 baseline). Bristol and Somerset 1,000-1,050 kWh/kWp/yr. Dorset and Wiltshire 975-1,025 kWh/kWp/yr. For comparison: Midlands/Yorkshire average 950-975 kWh/kWp/yr; Scotland 820-870 kWh/kWp/yr. The South West irradiance advantage translates directly to lower payback: a 500 kW system in Exeter generates approximately 40,000 kWh more per year than the identical system in Sheffield — worth £10,000/year in additional savings.
WPD DNO — G99 connections in the South West
Western Power Distribution (now National Grid Electricity Distribution in transition) covers the South West, South Wales, and East Midlands. G99 connection timelines for the South West (2026 data): Bristol/Avonmouth: 5-7 months. Exeter/Tiverton: 5-8 months. Plymouth/Cornwall: 6-9 months. Rural Cornwall: 6-11 months (some rural 11 kV network constraints). We submit G99 applications immediately after structural survey to start the clock. WPD is generally well-regarded for transparency in G99 process and has improved significantly since 2021.
South West food cluster — IETF grants
The South West food and drink cluster is one of the most IETF-eligible in the UK: Westcountry dairy (Dairy Crest/Saputo Davidstow — largest Cheddar plant in the world; Arla Foods Westbury; Anchor Butter); cider and drinks (Thatchers Milverton, Westons Much Marcle, Kopparberg UK Shepton Mallet); seafood (St Austell seafood, Newlyn fish market processing); bakery and speciality food (Ginsters/Samworth Brothers, Rowe's Bakery). IETF provides 30-50% capital grant for qualifying energy-intensive food processors. Minimum project £100k. Maximum £10m. We support IETF applications alongside commercial solar projects.
Key South West commercial solar locations
Avonmouth/Severnside (Bristol): prime logistics park, WPD 5-7 months G99, South West irradiance advantage, Severn Freeport (planned). Exeter Marsh Barton: Devon's primary industrial estate, excellent for 200 kW – 1 MW logistics/manufacturing. Tiverton (pharmaceutical cluster): pharma and advanced manufacturing, 4-5 year payback. Plymouth (South West's largest port): port logistics and food import cold chain, WPD DNO. Truro/St Austell (Cornwall): food processing, rural/agricultural, IETF-eligible. Weston-super-Mare (Somerset): logistics and food processing, 5-7 months WPD G99.
Common questions
Is the South West really the best location for commercial solar in England?
On irradiance alone, yes — Devon/Cornwall averages 1,050-1,100 kWh/kWp/yr versus 950-975 kWh/kWp/yr in the Midlands. The South West irradiance advantage is equivalent to getting a free 10-15% system size upgrade versus the Midlands. Combined with IETF eligibility for the food cluster and WPD DNO, the South West delivers among the fastest paybacks in England for food processing, cold chain, and manufacturing.
Does WPD cover the whole South West?
WPD covers all of the South West England (Devon, Cornwall, Bristol, Somerset, Dorset, Wiltshire), South Wales, and the East Midlands (Leicestershire, Nottinghamshire, Derbyshire). G99 process is managed centrally by WPD's Commercial Connections team.