HALF-HOURLY ELECTRICITY / kVA CAPACITY REVIEWS
Smart Energy reviews your site’s Authorised Supply Capacity, demand history and capacity charges to establish whether the reserved level still fits your business. No supplier switch is required.
Free review. No obligation. No supplier switch required.
Completed client review
Manufacturing business
DNO-approved capacity reduction. Calculated using the capacity rate at the time of review. Your outcome depends on your site’s evidence and requirements.
01 / CAPACITY HEALTH CHECK
Enter your current kVA if you know it, or upload a recent electricity bill and we’ll identify the capacity information we can verify. A bill establishes the current position — it does not decide the right future capacity.
I KNOW MY CURRENT CAPACITY
Use the actual authorised capacity if you know it — not a cumulative quantity such as kVA × billing days.
Is your electricity supplier British Gas?
Some British Gas bills show capacity as cumulative kVA-days. For example, 100 kVA × 30 days = 3,000. If you copied a figure like 3,000 from the bill, that may not be your actual Authorised Supply Capacity.
READ THE CAPACITY FROM MY BILL
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CAN’T CONFIRM THE CAPACITY?
Enter the kVA manually if you know it, or continue without it and Smart Energy will verify the capacity as part of the review.
WHAT THIS FIRST CHECK DOES
Read from your bill or entered by you.
We distinguish the actual capacity from quantities accumulated across billing days.
A recommendation needs demand evidence and an understanding of your site.
YOUR CAPACITY / IDENTIFIED
Authorised Supply Capacity
This is not a guaranteed saving. The amount that can actually be reduced depends on your verified peak demand, sensible operating headroom and future site requirements. We’ll talk you through the demand evidence and our findings before recommending any change.
SUPPLY FOUND / CAPACITY NEEDS CHECKING
We could not confidently establish the Authorised Supply Capacity from this invoice.
Using the Capacity Health Check starts a private review session so your progress can be retained and, if you upload a bill, the document can be read. It does not submit a completed review request until you choose to continue and provide your contact details and consent.
02 / THE STRAIGHT ANSWER
The number on the bill is the capacity held for your site. The review asks whether that reserved level still matches how the business operates today.
Authorised Supply Capacity (ASC) is the amount of electrical capacity reserved for a site, measured in kVA. On eligible Half-Hourly supplies, capacity charges can apply to that reserved level whether the business uses all of it or not.
03 / A SIMPLER WAY TO THINK ABOUT IT
Your business has four lanes reserved exclusively for it. Every month, you pay to keep all four available — even though your busiest period may only ever need two.
The other lanes can sit empty while you continue paying for the privilege of having them there “just in case”.
But we don't automatically close every empty lane. The site may still need sensible headroom for future or seasonal demand.
The visual explains the difference between capacity the site actually needs and spare capacity it may still be paying to reserve.
Know your current kVA already? Use it as the starting point — the full review establishes whether it is actually right for the site.
04 / REAL REVIEWS
These are reviews Smart Energy has actually completed. The recommendation is the right level for the site — sometimes lower, sometimes unchanged, and occasionally higher.
930 kVA of authorised capacity was removed. The saving came from changing the existing network cost, not from switching supplier or agreeing a new supply contract.
The final recommendation retained headroom above recorded peak demand rather than simply reducing the site to the highest observed figure.
The capacity was reduced while maintaining headroom above the site's observed demand. Every site needs its own evidence and operational context.
Not every site saves. Where demand is close to the limit, the right recommendation can be to hold — or even increase — capacity to avoid excess-capacity penalties.
“Tom was very helpful in pointing out an issue with our TCR banding that other brokers had missed after a recent kVa review saving us some money with a simple change.”
Your result will be site-specific. These examples show why it is worth checking, not what your own reduction should be.
05 / WITHIN YOUR EXISTING CONTRACT
A capacity review does not require a supplier switch or a new electricity contract. We check the evidence and explain any proposed change, its effective date and the effect on your bills.
06 / HOW SMART ENERGY REVIEWS IT
The customer journey stays simple. The technical work happens behind it, and nothing changes until you decide to proceed.
A recent electricity bill is the quickest place to start. We identify the supply and current capacity position.
We request your site’s historical maximum demand directly from your Distribution Network Operator (DNO). Turnaround varies by network—some return data the same day, while others take up to 10 working days. As soon as it arrives, we let you know.
For the capacity review, we normally work from up to 24 months of demand evidence where available.
Demand evidence is considered alongside current operations, likely future requirements and appropriate headroom.
If a change looks sensible, we show the proposed capacity and financial effect. If not, we say so.
If you want to proceed, Smart Energy handles the change process. There is no obligation to act on the review.
Seasonality, equipment starting loads, new machinery, EV charging and expansion all matter. The recommendation may be to reduce, retain or increase capacity.
07 / THE WIDER HALF-HOURLY PICTURE
A good Half-Hourly review should not blur every network charge together. Some charges relate directly to capacity; others sit alongside it and need separate analysis.
The recurring charge linked to the authorised kVA reserved for the site. This is the core charge a capacity reduction can affect.
If demand exceeds the agreed level, additional excess-capacity charges can apply. That is why reducing capacity too aggressively can create a different cost.
These are separate network charges and should not be presented as automatically reduced by a kVA change. They can still be worth reviewing as part of the wider Half-Hourly cost picture.
Distribution charges can also vary by time band and usage profile. They are distinct from the capacity charge and need their own analysis.
The current measurement class and meter setup may also be worth reviewing, particularly where the site has materially changed.
Your kVA review focuses on the capacity charges linked to your Authorised Supply Capacity. Other network costs, including TCR/TNUoS and DUoS, are separate charges and are not automatically reduced by changing your kVA.
08 / ANOTHER POSSIBILITY
Where a site's agreed capacity is around 70 kVA or below, a Change of Measurement Class can be worth investigating. In some cases the better answer is not simply a smaller capacity charge, but a different metering arrangement altogether.
09 / GOOD TO KNOW
These are the practical questions businesses usually ask before deciding whether a capacity review is worth doing.
kVA is the unit used for the electrical capacity reserved for a site. On eligible Half-Hourly supplies, Authorised Supply Capacity can carry a recurring capacity charge whether the business uses all of that headroom or not.
A large gap between authorised capacity and recorded peak demand is a strong reason to review the site, but it is not an automatic instruction to reduce it. Current operations, seasonality and future requirements also matter.
No. A bill may show the current capacity and charge, but a responsible recommendation needs additional demand evidence and operational context. The bill is the starting point, not the answer.
We can usually start from a recent bill, MPAN or site details. For the full review we obtain the relevant network demand information needed to assess the site's peak position and likely headroom.
Our standard Letter of Authority can run for up to 24 months, can cover your sites and can be withdrawn at any time. It allows Smart Energy to obtain the supplier and network information needed for the review and deal with the agreed review process on your behalf. It gives us zero authority to sign or switch an electricity supply agreement for you.
Potentially, yes. A justified capacity change relates to the site's network capacity rather than requiring a new electricity supply contract. That is why savings can be available even when renewal is years away.
No supplier switch is inherently required for a capacity review. The current supply agreement can remain in place while the network capacity position is reviewed separately.
If the site exceeds its agreed capacity, excess-capacity charges can apply and the operational headroom may be inappropriate. That is why the goal is the right capacity, not the lowest capacity.
No. TCR/TNUoS residual charges are separate from the basic capacity charge and should be reviewed separately. A kVA change should not be sold as automatically reducing every Half-Hourly network charge.
A business can deal with the relevant network operator itself. Smart Energy's role is to obtain the right evidence, interpret it in context, quantify the financial effect and manage the process so the business does not have to learn the industry workflow first.
Not every electricity supply has a separately billed Authorised Supply Capacity or availability charge to reduce. If your bill does not show one, the kVA review may not be relevant in the same way. Upload the bill and we’ll identify the charging arrangement before asking you to proceed.
Some British Gas electricity bills can show the capacity quantity accumulated across the billing period rather than only the static Authorised Supply Capacity. For example, a site with 100 kVA reserved across a 30-day billing period can show a quantity of 3,000. That does not mean the site has 3,000 kVA of capacity. Where the billing data allows it, Smart Energy normalises the quantity across the billable days and cross-checks it against the daily availability rate and line-item charge before treating the result as the site's ASC.
Yes. The review is free and there is no obligation to proceed with a capacity change. If the current level is appropriate, that is a valid outcome of the review.
10 / HALF-HOURLY INSIGHTS
Capacity is one piece of it. TCR/TNUoS, DUoS, metering, MHHS and other technical changes sit around the same supply — the latest relevant articles are pulled in automatically.
Understand the change to half-hourly settlement.
Read the guide ↗ CAPACITY CHARGESLook at the capacity behind the recurring charge.
Read the guide ↗ COMPLETED CLIENT WORKSee the review and how the saving was calculated.
Read the case study ↗FREE kVA CAPACITY REVIEW
Start with your bill or current kVA. We’ll establish the current position, investigate the evidence and explain your options. If you’ve already started, continue the same review below.
YOUR REVIEW / ONE CONTINUOUS JOURNEY
Enter your kVA or upload a recent electricity bill. We'll identify the current position first, then you decide whether you want Smart Energy to investigate it properly.
