Alectrona
Use caseThe GB Capacity Market can pay your battery to be on standby for times of system stress, secured at auction years ahead. That payment is set by the auction, so it is not known in advance, and it sits on top of your on-site savings rather than replacing them.
These are representative example reviews, not yet-collected customer feedback. They are written to illustrate the kind of feedback Alectrona aims to earn and are shown as design placeholders while we gather and verify reviews from our first commercial clients. Alectrona is the commercial solar trading brand of RVTC LTD.
What set Alectrona apart was the documented design pack. We had quotes from three installers, but only Alectrona handed us a full set of drawings, a single-line diagram and a design referencing BS 7671 and the G99 connection process. The whole thing read like an engineering submission rather than a sales brochure. Our M&E consultant reviewed it and signed it off without a single query. That gave the board the confidence to release the capital.
Other firms priced our roof off a satellite image and a desktop guess. Alectrona flew an in-house drone survey, fully insured and flown by a qualified commercial drone pilot, and built a 3D model of the actual roof. It picked up plant, vents and a parapet line that a flat aerial photo had completely missed, which changed the panel layout. I would rather find that out at design stage than on the day the scaffold goes up. The accuracy of that survey is the reason I trusted everything that followed.
As a finance director I was wary of being oversold a system bigger than we could use. Alectrona modelled the array against our actual half-hourly consumption data rather than an annual total, so it is sized to what we genuinely draw on site during the day. They were honest that exporting surplus is worth far less than self-consumption, and built the design around that. The capital case stacked up because the engineering was honest, not because the numbers were inflated.
We were undecided between buying outright, leasing and a PPA. Alectrona laid out all three side by side with the pros and cons of each against our balance sheet, instead of pushing the one that pays them best. They were clear about where a PPA makes sense and where capex wins, and pointed us at our own accountant for the tax treatment. The survey and design took a little longer than I expected, but the thoroughness was worth the wait. Genuinely consultative.
The install crew were tidy and well run, and worked to a clear CDM 2015 plan with a proper site induction and RAMS. What impressed me most was the handover. We received a full commissioning pack with the IEC 62446-1 test results, certification, O&M documentation and an as-built record for our maintenance team. As the people who have to live with this asset for the next twenty years, having that paperwork in order matters enormously. Nothing was left loose.
I expected the usual hard sell and got the opposite. After surveying our site Alectrona told us one roof section was not worth covering because of shading, and that a smaller, well-sited array was the better investment than filling every square metre. There was no commission-driven upselling and no pressure. For a six-figure capital project, that straight talk is exactly what you want from the people advising you. We will be using them again on our second site.
The Capacity Market is the scheme that pays for firm, dependable capacity to keep the lights on when electricity demand is high and supply is tight. Providers hold a capacity agreement, earn a payment for being available, and agree to deliver when the system operator calls a stress event. A commercial battery can hold one of these agreements, which turns its availability into a planned income stream.
This page is about that one scheme specifically. It sits next to grid services, our page on the ancillary and frequency-response markets, but it is a different thing: the Capacity Market is an availability payment secured at auction rather than a payment for second-by-second balancing. We treat any capacity income as upside. The on-site case, lifting solar self-consumption and shaving expensive peaks, has to stand on its own first.
Engineer-led, assured to the non-MCS standard (CDM 2015).
The Capacity Market secures enough dependable capacity to meet a government reliability standard. Providers are paid to be available, and in return they must deliver when the system operator calls a stress event, which happens only at genuinely tight moments rather than as a routine. It is, in plain terms, a retainer for being ready.
A battery suits this well because it can respond instantly and on command. The catch is that it can only sustain that output for as long as its stored energy lasts, and the scheme accounts for exactly that through de-rating, covered below. A capacity agreement gives the income a defined shape: you know you hold the agreement and the obligation that comes with it, even though the price itself was set at auction.
Agreements are bought through two auctions. The T-4 auction procures capacity four years ahead of the delivery year, giving the system operator a long lead time to line up what it will need. The T-1 auction then tops up closer in, one year ahead, to true up against demand that has become clearer. A battery can compete in either, and the price clears separately in each.
The crucial point for an honest business case is that the capacity price is an auction outcome. It is not published as a rate you can pencil in today, and it can differ between the T-4 and T-1 rounds. New-build storage has, in recent rounds, been able to secure multi-year agreements, which can give a longer revenue horizon, but the terms and your eligibility depend on the round you enter and the rules in force at the time. We will not present a clearing price as a fact. We will tell you how the mechanism works and route the numbers to a survey-led model.
The Capacity Market does not pay for a battery's nameplate power. It pays for the capacity it can be relied on to deliver through a stress event, so each asset is de-rated by a factor that reflects its expected availability. For a battery, that factor is governed by duration, meaning how long it can hold its output before it empties.
A shorter-duration battery runs flat sooner, so it is de-rated more heavily and a smaller share of its nameplate counts toward an agreement. A longer-duration battery keeps a larger fraction. This makes duration a design decision with a direct bearing on capacity income, and it is one we take from your half-hourly load and the on-site jobs the battery is bought for, not from chasing a de-rating factor in isolation. We will not assert a specific de-rating percentage on this page, because the methodology is reviewed periodically and the numbers move; the principle that shorter duration is de-rated more is the part that holds.
A capacity payment is one layer in a stacked return, and not the foundation of it. The steadiest money is on-site: stored solar offsets expensive import, where export is paid far less, so self-consumption is the reliable base. Peak shaving trims your worst demand charges. The Capacity Market then sits on top as a planned-but-variable layer, and grid services can add a further, more active income stream alongside it.
Because the capacity price is an auction outcome and your earnings depend on de-rated capacity and eligibility, we model it as a variable, never as a banked return. Most sites access it through an aggregator that prequalifies and bids the asset, so the practical route and the revenue split matter as much as the scheme itself. The figure that ends up in your case comes from an on-site survey and a half-hourly model, sized to your building and confirmed before contract, not from an auction result we cannot predict.
A capacity agreement is a two-sided deal. In return for the availability payment, you take on a delivery obligation written into the Capacity Market Rules and the Electricity Capacity Regulations 2014, the statutory framework the scheme runs under. The part that matters to a battery owner is what happens when the system operator calls. The National Energy System Operator (NESO) issues a Capacity Market Notice when it forecasts that margins will be tight, typically a few hours ahead, and a System Stress Event is then declared if conditions actually deteriorate. During a stress event you are expected to deliver your de-rated capacity, and your performance is measured against that obligation.
Miss it and there are consequences. The scheme operates a penalty regime for under-delivery during stress events, capped per event and across the year under the Rules, alongside an Over-Delivery payment route for assets that exceed their obligation. There is also a satisfactory-performance test some way ahead of delivery, so an asset cannot simply hold an agreement and never demonstrate it can respond. For a single commercial battery this obligation management is one of the strongest reasons most owners go through an aggregator, which monitors notices, dispatches the fleet and absorbs much of the penalty exposure under the contract you sign. We will not put a penalty figure on this page, because the cap and the rate are set in the Rules and revised; the principle that the payment carries a real obligation, and that missing a called event costs you, is the part that holds. This is also why the on-site case has to stand first, covered on peak shaving and battery storage.
Holding an agreement starts with prequalification, the annual process where an asset is checked against the technical and metering rules before it can bid. For a battery this is not a formality. NESO and the Delivery Body assess the unit's declared connection capacity, its metering arrangement and its ability to deliver to instruction, and a Capacity Market unit must be metered in a way that lets settlement verify what it actually did during a stress event. A behind-the-meter battery sitting alongside solar has to demonstrate its capacity is genuine and separable from the rest of the site's load, which is a measurement and connection question as much as a hardware one.
That connection is where your local network matters. Any export-capable commercial battery needs a connection agreement with the Distribution Network Operator, which for sites across Yorkshire and northern and north-east Lincolnshire is Northern Powergrid, and the terms of that agreement, including any export limit, bound what you can offer into the market. The battery hardware itself should meet the recognised energy-storage and safety standards, IEC 62933 for grid-connected storage systems and IEC 62619 for the cells, with installation following NFPA 855 and the relevant BS EN guidance and the duties under the HSE framework. None of that is Capacity Market rule as such, but a unit that is not safely and properly connected is not a unit you can dependably bid. We confirm what your connection and metering actually allow during the survey, and size the asset for the on-site jobs first, then test whether the de-rated, qualified capacity that remains is worth prequalifying. Where it is not, we say so. The economics route to the ROI calculator and commercial finance, modelled from your load rather than an auction we cannot predict.
A single commercial battery is usually too small to enter the Capacity Market on its own. The auctions are built around a minimum capacity threshold per Capacity Market unit, and a behind-the-meter battery rarely clears it alone. The scheme's answer is to let several smaller assets be aggregated into one unit made up of components, so a fleet of batteries can be presented to the auction as a single qualifying unit. This is the mechanism that actually lets a commercial-scale battery participate, and it is why the route to market and the aggregator contract sit so close to the scheme itself. There is also a secondary-trading provision in the Rules that lets capacity obligations be transferred between parties after an auction, which an aggregator may use to manage its fleet, though it is rarely something a single site engages with directly.
Eligibility is not permanent either. New-build storage can secure a multi-year agreement that gives a longer revenue horizon, but the length you can win depends on the round and the capital-expenditure thresholds in force, and an existing or refurbishing asset is typically limited to shorter terms. Because the qualifying capacity, the agreement length and the clearing price are all set by rules and auctions rather than by us, we model any Capacity Market income as a variable layer with its basis disclosed, never as a banked return, and pair it with the finance guard that any modelled figure is market-dependent and not promised. The reliable money remains on-site, and the Capacity Market sits on top of it. For the wider set of services a battery can stack alongside this, see grid services.
The capital-allowances treatment of standalone battery storage is not settled in public HMRC guidance; confirm the position with your tax adviser.
No, and you should be wary of anyone who does. The capacity price is set by auction, so it is not known until that auction clears, and it differs between the T-4 and T-1 rounds. What your battery earns also depends on how much de-rated capacity it can offer, which is driven by its duration. We will not quote you a fixed per-megawatt figure for a price that is decided years ahead at auction. We build the business case on the on-site savings, which are far steadier, and treat any capacity payment as upside on top.
The Capacity Market does not pay for nameplate power. It pays for the capacity it can rely on at a time of system stress, so each technology is de-rated to reflect its expected availability during a stress event. For a battery, that hinges on duration: how long it can hold its output. A short-duration battery empties quickly and so is de-rated more heavily, meaning a smaller share of its nameplate counts toward a capacity agreement. A longer-duration battery keeps a larger fraction. Duration is therefore a design decision with a direct bearing on capacity income, and we size it from your load, not from the auction.
They are separate revenue streams and a battery can hold both. The Capacity Market pays you to be available, secured through the T-4 and T-1 auctions, and it calls on you only when the system is genuinely tight. Grid services, by contrast, cover the ancillary and frequency-response markets, where the battery is actively charging and discharging far more often to help balance the grid second by second. One is an availability payment, the other is paid for active response. We cover grid services on its own page; this page is specifically the Capacity Market scheme.
Almost never directly. Prequalifying a single commercial battery and bidding it into a national auction is a heavy administrative load with its own deadlines and rules. Most sites reach the Capacity Market through an aggregator, which prequalifies your asset, bids it, manages the agreement and handles the stress-event obligations, then passes back a share. We design the system so it can qualify where that adds up, and tell you plainly where a site's connection or profile makes it a poor fit.
Treat the tax position as a question for your accountant. The capital-allowances treatment of standalone battery storage is not settled in public HMRC guidance, and adding a capacity income does not change that, so confirm it before you commit. On the return itself, a capacity payment is one variable layer in a stack that leads with on-site savings. We feed it into the survey-led model alongside self-consumption and peak shaving rather than letting it carry the case. See how the return is built.
There is no off-the-shelf figure, because the cost depends on your metering, your Northern Powergrid connection and whether the asset already qualifies. We will not quote a Capacity Market revenue per megawatt either, since that price is set at auction and is market-dependent, modelled, never promised. We size and cost the battery for its on-site savings first, then test whether the qualified capacity that remains earns its keep. See battery costs and the ROI calculator.
Longer than most expect. The T-4 auction secures capacity four years before the delivery year, and even the T-1 round clears about a year ahead, so an agreement bought today pays out in a future delivery year well after you commission. Prequalification runs annually and must be completed before you can bid. Through an aggregator some steps move faster, but the auction lead times are fixed by the scheme. We treat Capacity Market income as a later, variable layer, and let the on-site savings carry the near-term case.
We model your half-hourly load and your solar against a battery sized from an on-site survey, so the figure you get is yours, not a from-price. Capex first, with the bankable brand that fits the project.