UK solar farms, wind projects, energy suppliers and heat networks in numbers (October 2026)
Part of section D: Electricity, gas, steam and air conditioning supply.
Key figures compared with the UK
| Measure | SIC 35 | All UK | Difference |
|---|---|---|---|
| Active companies | 16,516 | 5,166,057 | 0.3% of UK |
| Median company age (years) | 7.5 | 5.6 | 34% higher |
| Incorporated in the last 3 years | 22.5% | 34.0% | 11.5 pts lower |
| Filing micro-entity accounts | 19.8% | 32.4% | 12.6 pts lower |
| Filing dormant accounts | 11.8% | 10.8% | close to UK |
| Accounts overdue | 5.8% | 1.8% | 4.0 pts higher |
| Under a proposal to strike off | 5.3% | 7.4% | 2.1 pts lower |
| In liquidation, administration or receivership | 2.1% | 2.0% | close to UK |
| With outstanding charges (secured lending) | 21.4% | 12.1% | 9.3 pts higher |
| Median net assets | £2,499 | £3,113 | 20% lower |
| Negative net assets | 23.4% | 18.8% | 4.6 pts higher |
| Net current liabilities | 37.4% | 36.2% | close to UK |
| Median cash at bank | £25k | £10k | 152% higher |
| Cash covers creditors due within a year | 32.1% | 35.3% | close to UK |
| Holding £100k or more in cash | 30.9% | 20.3% | 10.6 pts higher |
| Median employees (where stated) | 1 | 1 | close to UK |
Balance sheet measures use each active company's most recent machine-readable (iXBRL) accounts with a period ending in 2024 or later: 9,757 companies here (59.1% of active). Net assets 25th to 75th percentile: £1 to £134k. Cash 25th to 75th percentile: £977 to £155k.
What the numbers say
SIC division 35, electricity, gas, steam and air conditioning supply, is the whole of the energy supply section, so the headline figures match that page. The detail worth adding is what sits beneath them. Code 35110 production of electricity accounts for 11,006 live companies, probably including many solar, wind and battery storage sites set up as separate companies. Then comes 35140 trade of electricity with 2,505, the suppliers and brokers that sell power on, and 35300 steam and air conditioning supply with 1,801, where district heat networks and cooling schemes are likely to register. The grid itself is a small part of the count: 35130 distribution (995) and 35120 transmission (478). Gas is smaller still, with 35230 trade of gas through mains (373), 35210 manufacture of gas (353), which can include biogas producers, and 35220 distribution of gaseous fuels (334).
The accounts mix looks more like a corporate sector than a small-business one. Small accounts make up 10.7% of last filings, full accounts 9.4% and audit-exempt subsidiaries 7.5%, while micro-entity accounts are only 19.8% against 32.4% for the UK. That suggests a sector built largely from subsidiaries and project companies inside investment groups. Fuller accounts take longer to prepare and audit, which may help explain why 5.8% of companies are overdue, more than three times the UK rate. Our glossary entry on accounts categories explains what each filing type means.
Size shows up in the tails rather than the middle. Median net assets are only £2,499, below the UK's £3,113, but the top quarter of companies report £133,735 or more (UK £47,001). Cash is a different matter: a median of £25,481 against £10,127, and 30.9% hold £100,000 or more. Creditors are large too, with a median of £32,886 falling due within a year, which likely reflects intercompany balances owed to parent companies and project lenders.
Formation has not followed the national boom. Of today's active companies, 1,283 were incorporated in 2023, 1,119 in 2024 and 1,218 in 2025, a flat line while 643,753 of all active UK companies date from 2025. The median company is 7.5 years old (UK 5.6) and 40.8% are more than ten years old, possibly because many projects date from earlier subsidy schemes.
Negative net assets affect 23.4% (UK 18.8%), almost unchanged from 22.9% for financial years ending in 2014 to 22.3% in 2025, while the UK figure rose from 16.4% to 18.6%. Strike-off proposals are below average at 5.3% (UK 7.4%), while 2.1% are in an insolvency process, close to the UK's 2%. Water utilities are covered separately under water collection, treatment and supply.
Share with negative net assets, 2014 to 2025
Share of accounts with net liabilities (total liabilities larger than total assets) by financial year end, for companies on the live register. Dissolved companies are not included because the register no longer lists their industry, so earlier years show survivors. Negative net assets is a warning sign, not proof of insolvency: see what negative net assets means.
Accounts types filed
| Type of last accounts | Share here | Share UK |
|---|---|---|
| Total exemption full | 23.2% | 23.8% |
| Micro-entity | 19.8% | 32.4% |
| No accounts filed yet | 13.4% | 26.0% |
| Dormant | 11.8% | 10.8% |
| Small | 10.7% | 1.2% |
| Full (audited) | 9.4% | 1.5% |
| Audit exemption subsidiary | 7.5% | 0.7% |
| Unaudited abridged | 2.5% | 2.9% |
The type shows how much a company has to disclose. Micro-entity and abridged accounts contain no profit and loss account on the public record. Read more about accounts categories and micro-entities.
Active companies by year of incorporation
Companies incorporated in each year that are still active today. Younger cohorts are larger partly because older ones have been dissolved.
Most common activity codes
| SIC | Activity | Live companies |
|---|---|---|
| 35110 | Production of electricity | 11,006 |
| 35140 | Trade of electricity | 2,505 |
| 35300 | Steam and air conditioning supply | 1,801 |
| 35130 | Distribution of electricity | 995 |
| 35120 | Transmission of electricity | 478 |
| 35230 | Trade of gas through mains | 373 |
| 35210 | Manufacture of gas | 353 |
| 35220 | Distribution of gaseous fuels through mains | 334 |
Methodology
Industry is the first SIC code each company declares on the Companies House register (snapshot 1 October 2026); the dormant placeholder 99999 is excluded. Status, accounts type and due dates come from the register. Financial measures come from our parse of 37 million iXBRL accounts filed since 2008; values above £100bn are treated as extraction errors. Companies filing paper or PDF accounts are not in the balance sheet figures. Full details: methodology.
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