UK commercial solar glossary — every term, scheme, regulator.

Annual Investment Allowance — first-year capital allowance up to £1m on qualifying plant for unincorporated businesses, partnerships and sole traders. For incorporated companies, Full Expensing has largely superseded AIA. Detail →

Building Research Establishment Environmental Assessment Method — UK environmental certification for buildings. BREEAM Outstanding/Excellent ratings frequently require on-site renewable generation; solar PV contributes Energy (Ene01, Ene04) credits. Detail →

Distribution Network Operator — regional electricity distribution monopoly (UKPN, NPg, ENWL, NGED, SSEN, SP Energy Networks). DNOs approve grid connection applications (G98 for sub-3.68kW per phase, G99 above). Detail →

Enhanced Capital Allowance — 100% first-year allowance on qualifying plant. Active 2026 in UK Freeport tax sites and Investment Zones; stacks with Full Expensing. Detail →

Energy from Waste — combustion-based electricity and heat generation from non-recyclable waste. Major UK operators include Cory, Viridor, Veolia. Detail →

Engineering, Procurement and Construction contract — single-contractor turnkey delivery model dominant in UK commercial solar. Alternative: split contracts with separate D&B and EPCM packages.

100% first-year capital allowance on qualifying plant for incorporated companies (active since April 2023, made permanent in 2024). Effective tax saving 25% on solar PV capex at 25% main rate corporation tax. Detail →

Great British Energy — UK Government-owned clean energy company launched 2024. Operates a Community Fund (£200m) plus Local Power Plan supporting community-scale renewables.

Energy Networks Association Engineering Recommendation G99 — DNO approval process for grid-connected generation above 16A per phase. Required for almost all commercial solar installations. Typical turnaround 60-120 working days.

Industrial Energy Transformation Fund — capital grants for industrial decarbonisation. ENGLISH IETF Phase 3 closed Spring 2024 (no Phase 4 announced as of 2026). Scottish IETF remains active. Detail →

£1.5bn (over 3 years from April 2026) UKSPF successor for the 11 Mayoral Strategic Authority areas: Greater Manchester, West Midlands, Liverpool, West Yorkshire, South Yorkshire, NEMCA, East Midlands, Tees Valley, West of England, Cambridgeshire-Peterborough (pre-Mayoral exclusion), GLA London. Detail →

Microgeneration Certification Scheme — UK certification for renewable installers and product. MCS commercial certification (Solar PV ≥50kWp scope) required for SEG eligibility.

Megawatt-peak — installed capacity rating of solar PV (1 MWp = 1,000 kWp). UK 2026 commercial solar deployments routinely 1-15 MWp single-roof.

Office for Zero Emission Vehicles — UK Government department managing EV charging grants including Workplace Charging Scheme (WCS) and EV Infrastructure Grant for Staff and Fleet. Detail →

Power Purchase Agreement — long-term electricity supply contract between solar generator and off-taker. UK 2026 commercial solar PPAs typically 15-25 years at 5.5-9p/kWh fixed (or RPI-linked). Detail →

Public Sector Decarbonisation Scheme — Salix-managed capital grants for English public sector decarbonisation. PHASE 4 CLOSED November 2024 (no Phase 5 formally announced as of May 2026). Salix BAU loans remain active.

Photovoltaic — solar cell technology converting sunlight to electricity. Typical UK commercial deployment uses 400-450W monocrystalline modules.

Industry-standard solar yield modelling software. UK commercial solar quotes should specify PVsyst-derived annual yield in kWh/kWp.

Rural England Prosperity Fund — successor to LEADER funding for rural English businesses, capital grants up to £100k typically. Administered via District Councils (rural classification eligibility). Detail →

Science Based Targets initiative — corporate net zero target validation framework. Major UK companies (Tesco, M&S, Unilever, BT, AstraZeneca) have validated SBTi targets. Detail →

Smart Export Guarantee — UK regulatory scheme requiring electricity suppliers to pay for surplus solar export. 2026 best tariffs: Octopus 15p flat (Outgoing Fixed) or dynamic Outgoing Agile. Detail →

Standard Industrial Classification — UK business activity coding. IETF eligibility historically anchored on specific SIC codes (10, 11, 17, 18, 20, 22, 23, 24, 25, 27, 28, 29, 30, 31).

UK Shared Prosperity Fund — replaced EU Structural Funds 2022-26. Closed for new applications March 2026. Local Growth Fund is the successor for Mayoral Strategic Authority areas.