Solent Freeport ECA — Portsmouth qualifying sites
The Solent Freeport has three designated tax sites. Portsmouth Port (Commercial Road, Gunwharf, Victory Gate area) and Portsmouth Airport / Hatch Warren (adjacent to Portsmouth Airport at the northern edge of the city) may be within the designated zones — check exact building-level eligibility at solentfreeport.co.uk. For sites within the zone: 100% ECA on plant and machinery (on top of standard 100% AIA). For a £1.5m solar install within a Solent Freeport zone: AIA £250k + ECA £125k = £375k year-one tax shield (versus £250k outside). Effective after-tax capex: £1.125m.
Portsmouth logistics and industrial estate
Portsmouth Industrial Estate (Fratton, Hilsea, North Harbour) hosts medium-format logistics and manufacturing units (20,000-150,000 sqft). Waterlooville and Fareham (immediately north of Portsmouth) have expanding logistics and industrial estates with modern buildings suitable for 200 kW - 1.5 MW PV. A27/M27 corridor: Fareham Solent Business Park, Segensworth. Self-consumption for logistics: 75-82%. Payback: 4.5-5.5 years. With South Coast irradiance advantage (8-10% better than Midlands/North): approximately 6-8 months better payback on equivalent systems.
SSEN DNO — G99 connection for Portsmouth
SSEN (Scottish & Southern Electricity Networks) covers Hampshire and the Isle of Wight. Portsmouth city commercial G99 timelines in 2026: 5-8 months for 250 kW - 2 MW systems. Portsmouth Port sites: SSEN G99 plus Portsmouth Port Authority approval (typically 2-4 weeks additional in parallel). North Portsmouth/Waterlooville/Fareham: 5-7 months. SSEN has improved connection timelines since 2023 — early G99 submission (immediately after structural survey) is essential.
Common questions
Does Portsmouth qualify for Solent Freeport ECA?
Some Portsmouth sites qualify — specifically those within the Solent Freeport designated tax sites. Portsmouth Port (Town Quay, Commercial Road area) is within a designated zone. Portsmouth city industrial estates (Fratton, Hilsea) are generally outside the designated zone. Confirm building-level eligibility at solentfreeport.co.uk or via our free desk feasibility service.
What is the solar irradiance advantage in Portsmouth?
Portsmouth irradiance: 990-1,020 kWh/kWp/yr in 2026. This is 5-8% better than the national average (950 kWh/kWp/yr) and 10-15% better than northern England. On a 1 MW system, the irradiance advantage is worth approximately 50,000-70,000 kWh/yr additional generation — equivalent to £11,000-£16,000 additional annual saving at 22p/kWh grid retail.
Can defence contractors install solar on sensitive sites?
Yes — defence contractor commercial and industrial buildings can install solar PV. The installation is on external roof surfaces and does not affect internal operations, security classification, or MOD DIO estate access. For buildings with BPSS/SC-cleared environments, we follow CPNI physical security guidelines for works on or adjacent to protected premises. MOD DIO buildings may require additional approval — timeline 4-8 weeks alongside SSEN G99.