Optimising the Price of Renewable Energy Certificates

What exactly are REGOs?

Renewable Energy Guarantees of Origin (REGOs) are certificates that renewable generators get to prove that their energy is from green sources. They’re issued by Ofgem to accredited generators: one REGO per megawatt of renewably-sourced energy.

In the UK, REGOs have long been the mechanism for certifying energy as renewable. But they’re frequently sold separately from the energy itself. That’s because it’s often cheaper for suppliers to get their energy from a mix of sources, then buy a matching quantity of REGOs from renewable generators. As long as the quantity of electricity they sell you is matched by an equal quantity of REGOs by the end of the year, your tariff is legally classed as renewable.

How much is a REGO in the UK now?

As we go into summer 2026, the price of REGOs is hovering between £1 and £2 per REGO.

REGOs used to be much cheaper. When they were first brought in, back in 2003, each one cost just a few pence. For many years afterwards, they stayed cheap with only minor price fluctuations. But prices have become much more changeable in the past five years or so, hitting a record high of over £20 in October 2023. Although the price is much lower now, the market for 2026 and beyond remains volatile.

Why are REGOs so expensive?

There are many reasons why REGOs cost more than they used to.

Growing demand for green electricity. In the past couple of decades, renewable electricity tariffs have gone from niche to mainstream. Over half of new tariffs are now labelled as green, as suppliers respond to rising demand from both businesses and homes. For a supplier, the cheapest way to sell electricity as “renewable” is to get the actual power from the cheapest available source at the time, then match it retrospectively with REGOs bought separately. 

The rise of CPPAs. Corporate power purchase agreements (CPPAs) are growing in popularity as an alternative to the traditional supplier tariff. For many businesses, they are a way to protect budgets from energy price volatility while still supporting renewables. But a green CPPA also requires REGOs – which further increases overall demand, driving the price up.

Renewables build-out progress. Progress on UK renewables suffered a significant setback in September 2023, when there were zero potential developers bidding for offshore wind contracts. Having less renewable capacity in the pipeline means lower predicted output, which means fewer REGOs available, driving up the price. It’s one of the reasons why the price of REGOs hit record highs in October 2023 before thankfully correcting.

Brexit. We’ve now diverged from the EU system, which means electricity suppliers here can no longer choose between REGOs and the Guarantee of Origin (GoO) certificate from the EU. Suppliers here are limited to just REGOs, and this smaller supply makes the price higher than before Brexit.

Will REGO prices fall?

After the offshore wind setback of September 2023, the government took steps to get back on track. These included increasing the maximum price for projects and reshaping the Contracts for Difference system to do better in future. It’s paid off already; in January 2026 the government secured a record-breaking amount of offshore wind capacity. The price of REGOs has responded, steadily falling in 2024 and 2025. 

Later in 2026 we’ll start to see how a new type of contract for renewable generators will affect the REGOS market.

We’re unlikely to see another spike like the late 2023 one, but we’re probably never going back to the days when REGOs cost a small and predictable amount. For high-volume energy users, fluctuations in the price of REGOs can make a big difference to your budget.

What you can do

Are you purchasing REGOs separately or are they included in your energy supply? Either way, there’s good news:

• If you’re on a green tariff, you don’t have to accept whatever costs your supplier passes on to you.
• If you buy your own REGOs, you don’t have to stay vulnerable to a volatile market.

There are ways to protect your business from the changing price of REGOs. At Sustainable Energy First, we’ve been proactive in trying to manage this cost for our customers, and we can now supply REGOs from alternative sources – often at a lower price.

If you have REGOs in high volumes, the savings can be significant.

To explore more or to understand how you can manage this challenging green energy related cost, get in touch.

A simpler route to stable, renewable energy pricing

For organisations looking to go further than REGO optimisation, the Sustainable Energy Consortium (SEC) offers a simple, structured alternative to traditional supplier contracts.

By joining SEC, organisations can access half-hourly matched renewable electricity through a group-buying framework, with capped pricing that reduces exposure to wholesale market volatility and non-commodity costs. It removes the need to negotiate complex CPPA agreements individually, while still delivering transparency and traceability of supply.

SEC currently brings together over 100 renewable generation assets and connects them with over 80 businesses, enabling a simpler, more scalable route to energy stability.

To explore how the SEC can support your organisation’s energy strategy, speak to Sustainable Energy First.