Full Expensing for business solar PV
Full Expensing 2026 — UK limited companies can deduct 100% of commercial solar capex from corporation tax with no cap. Eligibility, examples...
100% first-year deduction — no upper limit
Tax relief · Updated 12 May 2026
Enhanced Capital Allowances for energy-saving solar equipment
Enhanced Capital Allowances 2026 — niche but valuable 100% FYA for specific energy-saving equipment. How it applies to commercial solar inverters and storage.
Overview
The Enhanced Capital Allowances (ECA) scheme provides 100% first-year tax relief on specific energy-saving equipment listed on the Energy Technology List (ETL). The list is maintained by the Carbon Trust on behalf of government and covers around 60 categories of energy-saving technology — including some inverters, energy management systems, certain pumps and motors, and various lighting products.
For commercial solar, ECA is rarely the headline relief because AIA and Full Expensing already provide 100% first-year deduction at much higher caps. ECA matters in two specific situations: (a) when your AIA is already exhausted by other capital purchases in the same year and you have ETL-listed solar inverters or battery storage; and (b) when you are a non-UK company with a UK permanent establishment that doesn't qualify for Full Expensing but where ETL equipment can still be claimed under ECA.
Key facts at a glance
| Eligible technology | Equipment listed on the Energy Technology List (ETL) |
| Relief rate | 100% first-year allowance |
| Cap | None (subject to the equipment being ETL-listed) |
| Practical relevance for solar | Niche — most solar capex is better claimed through AIA / Full Expensing |
| ETL maintainer | Carbon Trust |
| Last major update | ETL is updated quarterly |
Eligibility criteria
- The equipment must appear on the current Energy Technology List (ETL).
- The asset must be new (not second-hand) and brought into use in the trade.
- Available to all UK businesses regardless of structure — limited companies, LLPs, sole traders, partnerships.
- The relief is claimed through the same capital allowances mechanism as AIA on your tax return.
- Equipment that has been removed from the ETL after purchase still qualifies if purchased while the equipment was listed.
How to apply
Step 1 — Verify your equipment is on the ETL.
Check the Carbon Trust ETL website for the current quarter's list. Look for the specific model number; generic 'solar inverter' listings are not enough.
Step 2 — Obtain a manufacturer's certificate.
Manufacturers of ETL-listed products typically provide a certificate confirming the model and product code on the list. Keep this with your installation paperwork.
Step 3 — Claim through your tax return.
ECA is entered in the capital allowances section of CT600 or Self Assessment — typically as part of the first-year allowance schedule. Your accountant codes the relevant assets separately from the rest of the solar install.
Step 4 — Retain documentation.
Manufacturer certificate, installer invoice, MCS certificate (where applicable), commissioning report.
Watch-outs and pitfalls
- Most solar inverters are not on the ETL. The list is selective — products must meet specified efficiency thresholds. Many mainstream Tier 1 inverters (SolarEdge HD-Wave, Huawei SUN2000, Solis 5G) appear on the ETL; others don't.
- If you're using AIA or Full Expensing on the same equipment, you cannot also claim ECA — they are alternative reliefs.
- The ETL is updated quarterly. Products can be added or removed. Check the version active on your installation date, not the current version.
- ECA does not apply to all components of a solar install — only the specific ETL-listed equipment. So an inverter might qualify but the panels, mounting and cabling would need to fall under AIA or Full Expensing.
- Connected-party purchases. Same restrictions as AIA — buying from a connected party can disqualify the claim.
Stacking with other grants and reliefs
Most successful 2026 commercial solar projects use a combination of schemes — this is where independent advice earns its keep. Enhanced Capital Allowances for energy-saving solar equipment typically combines well with:
- Smart Export Guarantee for businesses — 3p–15p per kWh exported (2026 fixed tariffs)
- Annual Investment Allowance for business solar — Up to £1 million per year, 100% first-year deduction
Sources & further reading
Related schemes
Tax relief Tax relief
Other relevant grants & reliefs
Annual Investment Allowance for business solar
AIA 2026 guide — how UK businesses claim 100% first-year tax relief on commercial solar PV up to £1m. Eligibility, calculation worked exampl...
Up to £1 million per year, 100% first-year deduction
FAQs
Frequently asked questions
What is Enhanced Capital Allowances for energy-saving solar equipment?
The Enhanced Capital Allowances (ECA) scheme provides 100% first-year tax relief on specific energy-saving equipment listed on the Energy Technology List (ETL). The list is maintained by the Carbon Trust on behalf of government and covers around 60 categories of energy-saving technology — including some inverters, energy management systems, certain pumps and motors, and various lighting products.
Is the scheme open for applications in 2026?
As of May 2026, the scheme's funding status is: Permanent (Energy Technology List is updated quarterly). We re-check application windows monthly — if this is critical to your planning, request an eligibility check for the current programme status.
How much can a UK business get?
Typical award range: 100% first-year allowance on qualifying ETL-listed equipment. The size of any individual award depends on project capex, sector eligibility, match funding available and the scheme's per-applicant cap.
Who administers the scheme?
HMRC (relief); Carbon Trust (ETL maintenance). Applications are submitted through the administrator's process — we link the relevant gov.uk and scheme pages at the bottom of this guide.
What are the biggest pitfalls applicants fall into?
Most solar inverters are not on the ETL. The list is selective — products must meet specified efficiency thresholds. Many mainstream Tier 1 inverters (SolarEdge HD-Wave, Huawei SUN2000, Solis 5G) appear on the ETL; others don't. If you're using AIA or Full Expensing on the same equipment, you cannot also claim ECA — they are alternative reliefs. The ETL is updated quarterly. Products can be added or removed. Check the version active on your installation date, not the current version.
Check if your business qualifies
Free 60-second eligibility check tells you whether Enhanced Capital Allowances for energy-saving solar equipment applies — and which other schemes can stack.
Run free eligibility check Or call 0800 246 1132