Renewable procurement

Renewable energy procurement: the UK routes, and what each one proves

Renewable energy procurement is how an organisation buys, or makes, the renewable electricity it claims. In the UK there are five main routes: generating on site, a private wire from a nearby generator, a PPA with a generator elsewhere, a green tariff from a supplier, and REGO certificates bought on their own. They are not equal. This guide sets out what each proves under UK Green Building Council guidance, the RE100 criteria and the GHG Protocol.

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The five ways to buy renewable electricity in the UK

RE100, the global initiative for companies committed to 100% renewable electricity, sorts corporate procurement into five broad types. In UK terms they look like this, from the most direct to the least.

RE100's fifth type is passive: renewable electricity delivered by default through the grid. You do nothing to get it, so it is not a procurement choice. The routes are not equal, and the rest of this page shows how three standards rank them.

Source: RE100 technical criteria, version 5.0 (24 March 2025), section four. Read 14 Oct 2026.

UKGBC's three principles: renewable, additionality and time-matched

The UK Green Building Council published its renewable energy procurement guidance on 31 August 2023, aimed at those buying energy for businesses and commercial buildings. It judges any approach against three principles, renewable, additionality and time-matched, and its recommended actions are specific.

• On site first. On-site generation such as solar PV gives the most robust and direct emissions reductions, so UKGBC says it should be prioritised.
• New capacity off site. Owning, or signing a PPA with, a new or repowered unsubsidised renewable generator should be prioritised, because it provides the strongest additionality. As a minimum, directly procured PPAs should be with generators less than three years old, run by companies investing in new renewable assets.
• Match all grid imports. Match 100% of the electricity you import from the grid with REGOs from UK generators, all retired by you or on your behalf.
• Buy a "deep green" supply for what you import, and ask suppliers to show how they meet additionality.
• Move towards time-matching. Most renewable products match supply and demand only over a year, so a "100% renewable" buyer is still exposed to fossil generation at times. UKGBC recommends matching hourly or better.

UKGBC also scores a building's whole strategy across the three principles: 8 to 10 points is Gold, 5 to 7 Silver, 2 to 4 Bronze and 0 to 1 unrated. It labels that methodology a beta.

Source: UKGBC, Renewable Energy Procurement: Summary Report (August 2023).

What RE100 accepts for UK electricity

If your group reports to RE100, version 5.0 of its technical criteria, published on 24 March 2025, sets the rules.

• Same market. Claims must rest on generation in the same market as the consumption. The UK is outside RE100's European single market and does not issue EU Guarantees of Origin, so UK consumption needs UK generation, and RE100 lists the REGO as the UK's certificate.
• A 15-year age limit. A claim for 2025 must rest on projects commissioned or repowered on or after 1 January 2010.
• Exemptions from that limit include self-generation, physical PPAs with on-site projects or projects connected by a direct line with no grid transfer, long-term project-specific procurement as the original off-taker, and contracts that began before 1 January 2024.
• A 15% allowance. Buyers may allocate up to 15% of total consumption to older projects that no exemption covers.
• Certificate cancellation. From the 2027 CDP disclosure cycle, renewable procurement must include cancelling certificates where they are in common use, by or on behalf of the buyer.

RE100 describes impactful procurement as long-term, project-specific contracting with recently commissioned projects. It also notes that unbundled certificates can only ever be an extra cost on top of your electricity.

Source: RE100 technical criteria, version 5.0 (24 March 2025).

The GHG Protocol test for a market-based Scope 2 claim

For carbon reporting, the GHG Protocol's Scope 2 Guidance sets eight quality criteria that every contractual instrument must meet to be used in the market-based method. That covers PPAs, supplier contracts and certificates such as REGOs. The first five are the ones buyers trip over. An instrument must convey the emission rate of the electricity produced. It must be the only instrument carrying that claim. It must be tracked and retired or cancelled by or for you. It must be issued and redeemed as close as possible to the period of consumption. And it must come from the same market as your operations.

Companies with operations in markets that offer contractual instruments must report Scope 2 two ways: a location-based figure and a market-based figure. The Protocol consulted on revising the guidance from 20 October 2025 to 31 January 2026. Until a revision is published, the 2015 guidance applies. How this plays out for a PPA is on our Scope 2 emissions page.

Sources: GHG Protocol Scope 2 Guidance, Table 7.1; GHG Protocol, Scope 2 Guidance page.

Where REGOs fit, and where they fall short

Ofgem issues one Renewable Energy Guarantee of Origin for each megawatt-hour of eligible renewable output, administering the scheme for Great Britain on behalf of DESNZ. Their main use is supplier fuel mix disclosure, the label that tells customers how much of a supplier's electricity is renewable. Two cross-border rules matter. The EU stopped recognising UK REGOs on 1 January 2021, and EU Guarantees of Origin cannot be used for GB fuel mix disclosure from the period starting 1 April 2023.

The weakness is that REGOs can be traded separately from the electricity they certify. UKGBC warns that buying these unbundled REGOs can lead to double counting and does not actively drive grid decarbonisation. The government's 2026 corporate PPA call for evidence adds that their low price makes them a cheaper way for some businesses to show green credentials, which affects the competitiveness of PPAs. The mechanics are covered on our REGO certificates page.

Sources: Ofgem, Renewable Energy Guarantees of Origin; UKGBC, Renewable Energy Procurement: Summary Report (August 2023); DBT and DESNZ, Corporate Power Purchase Agreements: call for evidence (9 January 2026).

Green tariffs: what to check before you sign

A green tariff is the easiest route and the one that proves least on its own. In 2021 the government said it would review how suppliers market green tariffs, amid concerns that some overstate their environmental benefit. Until you know what sits behind yours, ask three things.

1. Which REGOs are retired against your supply, and from which generators? UKGBC's minimum is 100% matching with UK REGOs retired by you or on your behalf.
2. Does the supplier own, or hold PPAs with, renewable generators? UKGBC asks buyers to make suppliers show how they meet additionality.
3. Over what period is supply matched? Annual matching is the norm; UKGBC recommends moving towards hourly.

How a green tariff compares with a solar PPA on the claim it supports is set out in our green tariff vs solar PPA comparison.

Sources: GOV.UK, government to tighten rules to stop greenwashing of electricity tariffs (2021); UKGBC, Renewable Energy Procurement: Summary Report (August 2023).

PPAs and private wire: what the 2026 government review found

The government's 2026 call for evidence on corporate PPAs drew 125 responses, and its July 2026 response adds a buyer's-eye view of the main routes.

• Sleeved PPAs are seen as the dominant and most accessible structure in Great Britain, though some respondents say they carry hidden costs and complexity.
• Private wire and on-site arrangements are seen as the most cost-competitive, but difficult to deploy at scale because of proximity, land and tenancy.
• Several respondents said PPAs give a more credible link to low-carbon generation than unbundled REGOs or standard green tariffs.
• For smaller users, minimum volumes and transaction costs remain a barrier, and respondents backed multi-buyer or pooled PPAs.

Source: DBT and DESNZ, government response (7 July 2026).

Public sector buyers: the framework route

Public bodies usually buy through a framework or dynamic purchasing system. Crown Commercial Service became the Government Commercial Agency on 1 April 2026. One of its agreements, the Demand Management & Renewables dynamic purchasing system (RM6313), runs from 28 November 2022 to 23 February 2029. It supports public-sector net zero strategies with a range of energy products and services. Check the agreement documents for the specific lots before you assume a PPA can be bought through it. Schools, councils and NHS estates can compare structures on our PPA structures hub.

Source: Government Commercial Agency, agreements.

A procurement order that holds up

Put the three standards together and a sensible order emerges for most UK organisations.

1. Use the roof and land you have. On-site solar, owned or through an on-site PPA, is UKGBC's first priority and is exempt from RE100's age limit.
2. Look for a generator nearby. A private wire gives a direct link and the same RE100 exemption.
3. Contract new capacity off site. A PPA with a new or repowered generator gives the strongest additionality. Go in knowing the deal is long, and the negotiation is not quick.
4. Cover the rest with a supply contract you can evidence. Ask for REGOs retired on your behalf, and for evidence of the supplier's own generation.
5. Report both ways. Publish location-based and market-based Scope 2 figures, and keep the certificates that support the second.

To see what the first step could cost per kWh, start with our guide to solar PPA rates, or tell us about your sites.

Figures and sources on this page

FAQs

Frequently asked questions

What is renewable energy procurement?

It is how an organisation sources the renewable electricity it claims: generating on site, a private wire, a PPA with a generator, a green tariff, or certificates bought separately. Standards such as UKGBC's guidance, the RE100 criteria and the GHG Protocol decide how much each route proves.

Is buying REGOs enough to claim renewable electricity?

REGOs are the UK's renewable certificates, and the GHG Protocol accepts certificates that meet its quality criteria in a market-based Scope 2 figure. But UKGBC warns that REGOs bought without the power can lead to double counting and do not actively drive decarbonisation, and RE100 notes they are always an extra cost.

Does on-site solar count under RE100?

Yes. Self-generation and physical PPAs with on-site projects are RE100 procurement types, and both are exempt from its 15-year commissioning limit. UKGBC also puts on-site generation first.

What does UKGBC say about PPAs?

That owning, or signing a PPA with, a new or repowered unsubsidised renewable generator should be prioritised off site, because it gives the strongest additionality, and that as a minimum directly procured PPAs should be with generators less than three years old.

Can a UK company use EU Guarantees of Origin?

Not for GB fuel mix disclosure: Ofgem says GoOs are no longer recognised for it from the period starting 1 April 2023. RE100 also treats the UK as a separate market, so UK consumption claims rest on UK generation and REGOs.

How do public bodies buy renewable electricity?

Usually through a framework. Crown Commercial Service became the Government Commercial Agency on 1 April 2026, and its Demand Management & Renewables dynamic purchasing system (RM6313) runs to 23 February 2029. Check its lots before assuming a PPA can be bought through it.

Related on this site

• Corporate PPAs explained — Structures, terms and the 2026 review
• REGO certificates — How the UK certificate works
• Scope 2 emissions and PPAs — Location vs market-based
• Private wire PPAs — A direct line from a nearby generator
• Green tariff vs solar PPA — Which claim holds up
• Solar PPA rates — What on-site solar costs per kWh