Post: Getting Capacity Market-ready

Getting Capacity Market-ready

As Great Britain’s electricity system leans more heavily on wind, solar and other weather-dependent generation, the National Energy System Operator (NESO) needs a reliable backstop to guarantee the lights stay on during periods of peak demand or low renewable output. That backstop is the Capacity Market (CM), and for energy-intensive businesses, it represents one of the most accessible flexibility revenue streams available.

In this article we look at the programme, how it works and how businesses can participate.

What is the Capacity Market?

Introduced by the UK government in 2014, the Capacity Market is designed to ensure enough electricity capacity is available across the system, particularly at times of stress. It works by running competitive auctions in which generators, storage assets, interconnectors and demand side response (DSR) providers bid to guarantee capacity for a future “delivery year”.

Two main auction types run each year:

• T-4: held four years ahead of the delivery year, giving longer lead time for new-build assets and larger flexibility projects to plan and invest.
• T-1:  held one year ahead of delivery, offering a shorter-term route to market for existing and more flexible assets.

Successful participants sign a Capacity Agreement and receive a fixed £/kW payment for the delivery year, in exchange for a firm commitment to either generate power or reduce demand when NESO issues a system stress warning.

Those that don’t meet their obligation when called are financially penalised, so participation needs to be backed by genuine, verifiable capability, which is where a specialist flexibility partner adds real value.

Why the Capacity Market matters for businesses right now

The most recent auction round showed just how competitive this market has become. In the 2026 auctions:

• the T-1 auction for the 2026-27 delivery year, secured 7.2GW of capacity at a clearing price of £5/kW/yr. This was a steep fall from the previous year, driven by a wave of new entrants and stronger competition
• the T-4 auction for the 2029-30 delivery year secured over 40GW of capacity at a clearing price of £27.10/kW/yr, again below prior years as prequalified capacity flooded the auction

Lower clearing prices are good news for consumers and the wider cost of the scheme, but they also signal something important for businesses considering participation: competition for capacity contracts is intensifying. Assets that can demonstrate reliable, well-optimised flexibility are best placed to prequalify successfully and secure contracts.

For industrial and commercial energy users, participating in the Capacity Market offers several advantages:

• a new revenue stream: businesses are paid simply for having the capability to reduce or shift demand when required, turning existing flexibility (backup generation, battery storage, or curtailable processes) into an income line rather than a cost
• support for the business case for flexibility assets: Capacity Market income can materially improve the payback period on batteries, on-site generation, or demand management technology, helping unlock capital
• multi-year revenue certainty: T-4 contracts can run for several years, giving businesses predictable income to plan around
• improved resilience: the operational discipline required to participate (testing, monitoring, and readiness) often improves a site’s own understanding of its energy flexibility and resilience more broadly
• compounding revenue with other markets: Capacity Market income can typically be stacked with other flexibility revenue streams (such as the Balancing Mechanism, frequency response, or wholesale optimisation) maximising the value of a single flexible asset. This is where working with a platform like GridBeyond, which manages multi-market optimisation in real time, allows businesses to capture value from the Capacity Market without it competing against other revenue opportunities

Upcoming auctions and prequalification windows

With the 2026 auction round now concluded, attention turns to the next cycle. Based on the latest guidance from NESO, Ofgem and government:

• prequalification window: Expected to open in early August 2026 and run through to the end of September 2026. This window covers applications for the next T-4 auction (2030-31 delivery year) and the next T-1 auction (2027-28 delivery year).
• next auctions: The T-4 auction (2030-31 delivery year) and T-1 auction (2027-28 delivery year) are both expected to take place in March 2027, with detailed auction parameters and the formal launch process expected to be confirmed later in 2026.
• rule changes to note: Ofgem has been consulting on a package of Capacity Market rule changes intended to apply from the opening of the 2026 prequalification round, including extended conditional prequalification arrangements for projects still working through grid connection reform (helpful for businesses whose connection offers are pending), tighter de-rating and insolvency rules, and a new mechanism allowing the Delivery Body to extend the prequalification window by up to five working days in the event of severe IT issues

Given the scale of oversubscription seen in the 2026 auctions, businesses considering entering the next round should expect continued competitive pressure. Early preparation, robust metering and monitoring evidence, and a clear demonstration of deliverable flexibility will be crucial.

Getting Capacity Market-ready

Prequalifying for the Capacity Market involves technical assessment, testing requirements, and ongoing compliance obligations that can be difficult to navigate without support. Specialist flexibility providers help businesses assess their eligible capacity, manage the prequalification process, meet testing obligations, and optimise that same flexible asset across multiple revenue streams simultaneously, so Capacity Market participation adds to the bottom line rather than adding administrative burden.

With the next prequalification window opening in a matter of weeks, now is the time for energy-intensive businesses to assess whether their sites have untapped flexibility capable of generating meaningful, multi-year revenue through the UK Capacity Market.

How GridBeyond can help 

• auction participation: our experts oversee the entire auction process, from registration through to final bidding, ensuring your assets achieve the most competitive agreements available 
• Satisfactory Performance Days (SPDs): we work closely with customers to help them meet their capacity commitments by achieving SPDs and confirming asset performance during periods of critical system demand 
• maximising revenue: taking part in the Capacity Market does not always limit your ability to generate revenue from other flexibility services. We ensure your assets can benefit from the Capacity Market while also participating in additional income-generating opportunities 
• asset assessment and preparation: we prepare and qualify a diverse range of assets for Capacity Market participation, including both new and existing generators, flexible loads, and energy storage systems. This includes verifying metering configurations to ensure they meet all compliance standards 
• connection and operational integration: your assets are integrated with our 24/7 Network Operations Centre (NOC) via API or hardware, allowing for continuous communication and real-time data transfer. When a Capacity Market Notice is issued, our operators work directly with your site to ensure assets are ready and able to respond 
• contract support: we support businesses with Capacity Market Agreements throughout the full term of their contracts. Using advanced data analytics and intelligent scheduling, we help ensure performance obligations are met. If operational circumstances change and a site cannot fulfil its commitment, our Secondary Trading Clearing House enables the buying or selling of capacity obligations with other qualified participants. This reduces the risk of penalties and provides flexibility to adapt to changing conditions 

Whether you are a new entrant seeking prequalification or an established participant aiming to enhance performance and manage trading, GridBeyond delivers the expertise, tools, and market insight needed to succeed in the Capacity Market.