How to Reduce Electricity Capacity Charges for Your Business

Businesses looking to cut energy costs usually start with consumption. Use less power, improve controls, replace equipment. That matters, but it is not the only way to reduce spend. For many larger UK sites, part of the electricity bill is tied to agreed capacity, often referred to as Maximum Import Capacity or MIC. If that level is higher than the site now needs, the business may be paying for network headroom it no longer uses

Reducing agreed capacity does not lower your electricity use. It lowers the amount of capacity your site is contracted to have available at any one time. Done properly, that can cut cost without changing a single kilowatt-hour of consumption.

Maximum Import Capacity is the maximum amount of power a property can draw from the network at any given time, measured in kVA. UK Power Networks states that customers sometimes reduce MIC when they are using less electricity than the maximum allowed, and that in some cases this can reduce electricity bills.

That matters because agreed capacity often stays in place for years after the site has changed. Plant may have been removed. Operating hours may have shifted. Loads may be better controlled. A building may simply no longer run at the peaks it once did. When that happens, the business can end up paying for spare capacity it does not need. That is not an efficiency issue. It is a billing issue.

This is common on mature commercial and industrial sites. The original capacity may have been set when the site first connected, expanded, or operated under a very different demand profile. Over time, that number can become a legacy setting that no longer reflects reality. Electricity North West explicitly notes that MIC should reflect the maximum power expected on site and recommends setting it around 10% above the highest peak achieved in the previous 12 months to allow for seasonal variation or anomalies.

That simple point creates a useful opportunity. If the highest real demand on site is materially below the contracted level, there may be room to reduce agreed capacity and remove an avoidable cost from the bill.

In one recent client review, the site’s agreed capacity was 2,000 kVA, while actual used kVA remained materially lower across the year, broadly around 950 to 1,100 kVA. Based on that demand profile, a revised capacity of around 1,350 kVA was identified using a 1.2 safety factor. In the model, the monthly capacity cost moved from about £5,320 to about £3,591 for most months, creating a projected annual saving of £20,748. Across the review, that translated to an average gain of 4% on the site’s total bill and a much larger reduction against the kVA element itself.

That is the point many businesses miss. A capacity review does not need to halve the total electricity bill to be worth doing. If it removes a persistent cost that has been sitting in the background month after month, it can still deliver a meaningful financial result.

The right approach starts with data. Review at least 12 months of demand data so you can see seasonal peaks, shutdown periods, unusual events and any short-term spikes that should not define the long-term position. Then identify the highest genuine import demand and add sensible headroom based on how the site operates. Electricity North West’s published rule of thumb is around 10% above the highest peak in the last 12 months, although some sites need more depending on process risk and future load plans.

This also needs to be treated as a formal network and billing change, not an informal optimisation exercise. UK Power Networks, National Grid Electricity Distribution and other DNO charging statements make clear that capacity reductions are governed by formal processes, are not backdated, and can generally only be made once in a 12 month period.

That is why the decision should be made carefully. A short-term dip in demand is not enough on its own. The target should reflect how the site genuinely operates now, not just what happened in one quiet month.

The obvious risk is cutting too far.

Current charging statements make clear that if a site exceeds its MIC, exceeded-capacity charges can apply. SSEN states that the exceeded portion is charged based on the gap between MIC and actual capacity used, and that this can be charged for the full month in which the breach occurs. The same statement also warns that once a lower level is agreed, the original higher capacity may not be available later without network reinforcement and associated charges.

That is why good capacity reduction is a commercial decision backed by operational evidence. Before changing anything, businesses should ask five practical questions. What was the highest genuine demand in the last year? Was it a normal event or an outlier? Are there known future loads coming, such as EV charging, new HVAC plant, or production growth? How much headroom does the site need to stay operationally comfortable? And is the business willing to live with that number for the next year?

Reducing agreed capacity sits in a useful middle ground. It is more targeted than a generic bill audit, but often faster and cheaper than a capital project. In many cases, the work is analysis, validation and contract change rather than physical installation.

That makes it especially relevant for finance teams, procurement teams and energy managers under pressure to find savings now. If the contracted capacity no longer reflects the way a site actually runs, there is a good chance money is being spent unnecessarily.