If you're researching solar for a UK farm in 2026, you'll encounter abbreviations and jargon that fall into six broad areas: grants and tax (FETF, AIA, SFI, CARES, DAERA), finance routes (PPA, Private Wire PPA, asset finance, capital purchase), technical specification (kWp, Tier-1, TOPCon, MCS, NICEIC, G98/G99), planning and regulation (PD, BMV, AONB, LVIA, Class A/J GPDO), operations (O&M, P50, PR, SEG, export limitation), and tenure (FBT, AHA, agrivoltaics).
Below is every term you're likely to meet in a farm solar enquiry, quote or grant application. Each is linked to the relevant pillar page where you can read the practical implications in depth.
A
- Agrivoltaics
- Dual-use solar — panels installed so the land beneath remains productive for sheep grazing, pollinator wildflower mix, or shade-tolerant crops.
- AIA (Annual Investment Allowance)
- UK tax relief letting farms write off 100% of capital expenditure on plant and machinery (including solar PV) against profits in year one, up to a £1m cap.
- AONB (Area of Outstanding Natural Beauty)
- Protected landscape designation. Roof-mounted solar on existing buildings usually permitted; ground-mounted needs full planning with LVIA.
- Asset finance
- Fixed-rate finance over 5–10 years against the installed system. Zero deposit, repayments structured below projected energy savings. You own the asset.
B
- BESS (Battery Energy Storage System)
- Commercial-scale battery storage, typically 100kWh+ in modular cabinets or 250kWh+ in shipping-container format. Stacks with solar PV.
- Bifacial panels
- Solar panels that generate from both front and rear surfaces, lifting yield 8–20% on suitable mountings (ground-mount, agrivoltaic, east-west).
- BMV land (Best and Most Versatile)
- Defra grading for Grade 1, 2 and 3a agricultural land. Solar development on BMV land tightened since 2024.
C
- CARES (Community and Renewable Energy Scheme)
- Scottish scheme delivered by Local Energy Scotland for non-profit community groups, not farms — it does not fund farm solar.
- Capital allowance
- Tax relief on plant and machinery. AIA covers 100% up to £1m a year; solar panels are special-rate plant, so any cost the AIA does not cover goes into the special rate pool at 6% a year.
- Class A (GPDO)
- Permitted development rights for solar on dwellings. Maximum 200mm projection above roof surface.
- Class J (GPDO)
- England's permitted development right for rooftop solar on a farm building (Part 14, GPDO 2015): no capacity limit; no more than 0.2 m proud of a pitched roof; at least 1 m from the roof edge; council prior approval on design and glare above 50 kW; listed buildings excluded.
- CO2 saving
- Tonnes of carbon avoided per year by the solar installation. Typical UK farm system: 6–53 tonnes/year. Increasingly material for Scope 3 reporting.
D
- DAERA (Department of Agriculture, Environment and Rural Affairs)
- Northern Ireland department. No DAERA scheme pays for solar panels: its Sustainable Farming Investment Scheme (40%, up to £25,000; round 1 closed 3 September 2026) did not list them, the Farm Business Improvement Scheme – Capital closed in 2022 and excluded renewable energy, and there is no DAERA Farm Energy Efficiency Scheme.
- DC string
- Series-connected group of solar panels feeding one inverter MPPT (Maximum Power Point Tracker) input. Typical 8–24 panels per string.
- DNO (Distribution Network Operator)
- The local electricity grid operator. Six UK DNOs: UKPN, NGED, SSEN, SP Energy Networks, Northern Powergrid, NIE Networks. Handles G98/G99 grid connection.
E
- EPC (Energy Performance Certificate)
- Building energy rating. Commercial EPCs valid 10 years. Solar PV typically lifts an EPC rating by anywhere from five to fifteen points.
- Export limitation
- DNO-imposed cap on how much electricity a solar system can export to the grid. Doesn't affect self-consumption.
F
- FBT (Farm Business Tenancy)
- Post-1995 farm tenancy framework under the Agricultural Tenancies Act 1995. Most modern FBTs allow solar with landlord consent.
- FETF (Farming Equipment and Technology Fund)
- England-only equipment grant. Its 2026 window closed at midday on 12 May 2026, and its 2023–2026 item lists did not include solar panels to power a farm. England's Improving Farm Productivity (IFP) grant, which paid up to 25% for rooftop solar, closed to full applications on 31 July 2025 with no further round announced.
G
- G98 application
- DNO grid connection for systems under 16A per phase (~3.68kW single-phase / 11kW three-phase). Fast-track approval.
- G99 application
- DNO grid connection for systems above G98 threshold. Engineering Recommendation G99 covers commercial/industrial scale. Typical 6–14 week turnaround.
- Ground-mount
- Solar panels installed on the ground rather than on a building. Driven post, screw foundation, ballast or elevated agrivoltaic configurations.
H
- Half-hourly meter data
- 12 months of 30-minute electricity consumption readings. Required for accurate system sizing and self-consumption forecasting.
- Heterojunction (HJT)
- Premium solar cell technology combining crystalline and amorphous silicon. Higher efficiency (22–24%) and better temperature performance than standard mono-PERC.
I
- Inverter
- Converts DC from solar panels to AC for grid/load use. String, micro, or central architectures. Typical 12–15 year lifespan.
- IWA-backed warranty
- Insurance-Backed Workmanship Warranty. Protects the buyer for 10 years if the installer goes out of business. Critical on £100k+ jobs.
K
- kWp (kilowatt-peak)
- Solar system nameplate capacity at Standard Test Conditions. Typical UK system delivers 850–1,100 kWh per kWp per year.
- kWh (kilowatt-hour)
- Unit of electricity. 1 kWh = 3.6 MJ. UK rural commercial tariffs run 25–32p/kWh in 2026.
L
- LCOE (Levelised Cost of Energy)
- Lifetime cost-of-energy across the asset life. Farm capital-purchase solar delivers around 2p/kWh effective LCOE vs grid 30p/kWh.
- LiFePO4 (Lithium Iron Phosphate)
- Battery chemistry — safer, longer-cycle than NMC. 6,000+ cycles to 80% capacity. Industry standard for farm BESS.
- LVIA (Landscape and Visual Impact Assessment)
- Planning study required for ground-mount solar in sensitive landscapes (AONB, conservation area, listed setting). Typically £8k–£25k for chartered assessor.
M
- MCS (Microgeneration Certification Scheme)
- Required UK certification for residential and SME solar PV. Mandatory for Smart Export Guarantee and most grant eligibility.
- Microinverter
- Single-panel inverter mounted under each module. Best for partial shading; higher cost per panel but longer warranty (25 years).
- MWp (megawatt-peak)
- 1,000 kWp. Large UK solar farms typically 5–70 MWp ground-mount; large farm rooftop installations 0.5–1 MWp.
N
- NICEIC
- National Inspection Council for Electrical Installation Contracting. Standard certification for UK commercial electrical contractors.
O
- O&M (Operations & Maintenance)
- Ongoing service contract for solar systems. Annual servicing £250–£3,500/yr depending on system size.
P
- PD (Permitted Development)
- Planning rights that allow specific developments without full planning permission. Most farm rooftop PV qualifies.
- PPA (Power Purchase Agreement)
- 15–25 year contract where an investor finances and installs solar in exchange for selling you the electricity at a discounted unit rate (typically 10–16p/kWh).
- PR (Performance Ratio)
- Solar system output efficiency vs theoretical maximum. UK average 80–85%; well-designed farm systems hit 88%+ year 1.
- Private Wire PPA
- PPA variant supplying an adjacent commercial user (food processor, glasshouse) under a direct wire rather than via grid export. Higher unit price for the developer.
- P50 / P75 / P90
- Probability-weighted energy yield forecasts. P50 = 50% probability of exceeding; P90 used for finance underwriting.
R
- Roof pitch
- Roof angle from horizontal. Optimal UK pitch for solar is 30–40°; flat roofs use 5–15° ballast frames.
S
- SEG (Smart Export Guarantee)
- Ofgem-mandated payment for solar electricity exported to the grid. Tariffs roughly 4–12p/kWh from licensed energy suppliers (as at July 2026).
- Self-consumption %
- Proportion of solar generation used on-site (vs exported). Dairy/poultry farms 70%+; arable farms 40–60%; with battery: 80–90%.
- SFI (Sustainable Farming Incentive)
- England agri-environment scheme. It has no solar items.
- SP Energy Networks (SPEN)
- DNO covering Manweb (Cheshire, Merseyside, North Wales) and SP Distribution (Scotland Central Belt).
- SSEN (Scottish & Southern Electricity Networks)
- DNO covering southern England (Hampshire/Berkshire/Oxfordshire) and most of Scotland north of the Central Belt.
- String inverter
- Single inverter handling one or more DC strings of panels. Most common UK farm architecture. 12–15 year typical lifespan.
T
- Tier-1 panel
- Bloomberg New Energy Finance classification for financially stable solar manufacturers. Includes Trina, JA Solar, REC, Meyer Burger, SunPower, LONGi.
- TOPCon
- Tunnel Oxide Passivated Contact — modern solar cell technology with 22–23% efficiency. Standard on premium 2024-2026 panels.
- Tracker (single-axis)
- Ground-mount system that rotates panels east-to-west following the sun. Lifts yield 15–25% but adds capital and maintenance complexity.
- TrustMark
- UK Government-endorsed quality scheme for trades. Required for some grant eligibility (e.g. Green Homes Grant).
U
- UKPN (UK Power Networks)
- DNO covering London, South East England and East of England.
Related pillar pages
- • Farm solar grants 2026 — what is open and closed
- • Finance options — capital, asset finance, PPA, Private Wire PPA
- • Farm solar pricing 2026 — costs by system size
- • Planning permission for farm solar
- • Installation process — quote to commissioning
- • Battery storage for farm solar
- • Agrivoltaics — solar + grazing + SFI