Capacity is reserved for your premises
Your network operator holds a set amount of electrical capacity for your site, whether the business reaches that level or not.
Services
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Metering & Technical
You could be paying for capacity you never use.
A Half-Hourly & kVA review checks your agreed capacity against what your site actually draws — then right-sizes it, so you stop overpaying on availability charges without risking excess-capacity penalties.
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The hidden cost
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Your bill reserves power you may never draw.
Most businesses expect to pay for the electricity they use. What often gets missed is that larger half-hourly supplies can also be charged for the electrical capacity held in reserve for their premises.
A simpler way to think about it
Imagine paying for four motorway lanes.
Your business has four lanes reserved exclusively for it. Every month, you pay to keep all four available — even though your busiest period only ever uses two. The other two lanes remain empty, but you continue paying for the privilege of having them there “just in case”.
Four lanes reserved and charged
Only two lanes genuinely needed
Capacity your site actually needs
Spare capacity you may still be paying for
How that translates to your bill
That is how agreed capacity works.
The motorway is the network. The number of lanes reserved for your premises is your agreed capacity, measured in kVA. Your availability charge is based on how much capacity is held open for you.
You pay to keep it available
Availability charges are applied to the agreed kVA every month. That means unused headroom can continue costing you even when actual demand is much lower.
The original figure may no longer fit
Capacity may have been based on an old estimate, expected growth or equipment that is no longer used. Unless it is reviewed, the same figure can remain in place for years.
A kVA review checks how many lanes your site genuinely needs — then removes unnecessary spare capacity while keeping sensible headroom for peak demand.
We analyse your historic half-hourly data and actual peak demand before making any recommendation. Where your existing capacity is already right — or needs increasing to avoid excess-capacity charges — we will tell you that too.
Real reviews
Right-sized to reality — not just cut.
A few capacity reviews we’ve actually completed. We recommend the right kVA for the site — usually a reduction, sometimes a hold or an increase to avoid penalties.
1000
70
kVA
£33,945
saved per year
140
25
kVA
Actual peak demand: 13 kVA
£2,099
saved per year
100
20
kVA
Actual peak demand: 14 kVA
£1,171
saved per year
Not every site saves. Where your peak demand is close to your limit, we’ll tell you to hold — or even increase your capacity, to keep you clear of excess-capacity penalties. The review is the honest answer either way.
Real reviews completed by Smart Energy. Figures are annual and specific to each site — yours will differ.
How it works
Four steps, and we do the hard part.
You give us a couple of minutes. We do the DNO legwork, the analysis and the paperwork — and you only proceed if the numbers stack up.
- 1
Send us your supply
Share your MPAN and contact details — or upload a recent bill and we’ll read them off it. Takes a couple of minutes.
- 2
We pull your DNO data
We go direct to your Distribution Network Operator for your actual 24-month peak demand — the real numbers behind your capacity. The data is usually back within about 10 working days .
- 3
You get a savings report
A clear, jargon-free report: your ideal kVA, what you’re overpaying now, and the exact annual saving. No obligation to proceed.
- 4
We implement it — and you save straight away
Happy to go ahead? We handle the change with the DNO, and it’s typically backdated to the first of the month it’s agreed. Crucially, it’s applied within your current contract — even if you’re years from renewal — so your supplier updates your rates and the saving shows on your very next bill.
- DNO data back ~10 working days
- Savings applied Within your contract
- What we need MPAN & contact
- Cost to you Free · no obligation
Curious what your number is?
Request your free review
Another option
You might not need the meter at all.
If your agreed capacity is around 70 kVA or below , a Change of Measurement Class can move you off half-hourly metering onto a simpler meter — taking the kVA capacity charges, and their standing charges, off your bill for good. Sometimes the honest answer isn’t a smaller capacity; it’s no capacity charge at all.
See if you can downgrade your meter Good to know
Your questions, answered straight.
kVA is your agreed capacity
— the amount of power your network operator reserves for your site. On a half-hourly meter you pay a fixed availability charge for every kVA of it, every month, whether you use it or not. If it was set higher than you need — which is common — you’re paying for headroom that just sits there.
The tell is a gap between your agreed capacity and your actual peak demand. If your reserved kVA sits well above the most you ever draw, you’re almost certainly overpaying — but you can’t see it without your half-hourly data, which is exactly what our review pulls from your DNO.
To start, just your MPAN
(or your business address) and contact details. From there we request your actual 24-month peak-demand data directly from your DNO. If you’ve a recent bill to hand, uploading it is the quickest route.
An LOA is a standard industry document that lets us speak to your supplier and network operator on your behalf — so we can pull your capacity and usage data, and request the adjustment you ask for. Crucially, it does not let us switch you, sign you into a new contract, or commit you to anything
: the letter states in writing that any new supply agreement must be signed by you. It covers all your sites, lasts 24 months (or your contract length), and you can withdraw it at any time.
The DNO data is usually back within about 10 working days
. Once you agree, the change is typically backdated to the first of that month and applied within your current contract
— even if you’re years from renewal — so your supplier updates your rates and the saving shows on your very next bill.
No. We only ever recommend a level your actual demand sits comfortably within, so your supply and day-to-day running are unaffected. If your peak is close to your limit, we’ll tell you to hold — or even increase — rather than risk excess-capacity penalties.
Capacity can be increased again if your needs grow, so right-sizing now doesn’t lock you out later. We only recommend a reduction where your demand data shows clear, comfortable headroom.
No. The report is yours to keep with no obligation
, and we only make a change if you’re happy with the recommendation.
Yes — the review is free, and there’s no obligation to proceed. You get a clear picture of where you stand either way.
kVA capacity charges only apply to half-hourly meters, so a reduction is specific to those. And if your agreed capacity is around 70 kVA or below
, you might not need a half-hourly meter at all — a Change of Measurement Class
could remove the charges entirely.
Half-Hourly insights
The wider half-hourly picture.
Capacity is one piece of it. Half-hourly sites also carry TNUoS and TCR banding, DUoS time-bands, MHHS changes and more — the desk’s latest on all of it.
A plain-English guide to MHHS for UK businesses: how half-hourly settlement works, the rollout timeline to 2027, and the one myth that could cost you money.
Many Half-Hourly businesses overpay for unused capacity. Our free kVA review can cut costs mid-contract — without switching supplier.
Can’t downgrade your Half-Hourly meter? Discover cost-saving tips for UK businesses, including capacity reviews and supplier switching advice.
Request your review · under 2 minutes
