Numbers in government scheme documents have a habit of staying abstract until you put them against a real electricity bill, so let’s do that.

The headline figure the government has put on BICS is an exemption worth roughly £35 to £40 per megawatt-hour of eligible grid electricity, which some of the accompanying analysis has translated into a bill reduction in the region of 25% for businesses that qualify for the full exemption. Whether that lands closer to £35 or £40 per MWh for your business will depend on the detail of how the three exempted levies — the Renewables Obligation, Feed-in Tariffs, and the Capacity Market — apply to your specific supply arrangement, but as a planning figure it’s a reasonable one to work with.

The bit that actually determines what you receive isn’t the sector test or the product test — it’s what share of your site’s electricity goes toward eligible manufacturing, because the exemption is pro-rated against that figure rather than applied as a flat discount. Use a quarter or less of your site’s grid electricity on eligible production and the exemption is zero. Get that up into the range between a quarter and a half, and you receive half the exemption. Cross the halfway mark and you get the full amount. It’s a banded system, not a sliding scale, so a site that’s just under one of those thresholds is leaving real money on the table compared with a site just over it — which makes an accurate electricity-mix calculation worth doing properly rather than estimating.

It’s also worth being honest about when the money actually shows up. Exemptions from the Renewables Obligation and Feed-in Tariff charges begin in April 2027, with a one-off retrospective payment at that point backdating support to April 2026 — so there’s a real gap between applying in autumn 2026 and seeing it reflected in cash flow. The Capacity Market exemption follows later still, from October 2027. None of that changes the case for applying if you’re eligible, but it does mean BICS is worth planning into next year’s budget as a known, quantifiable saving rather than expecting it to show up on the next bill after a successful application.

For a manufacturer running multiple sites, or with electricity split across metered supplies for different processes, the mix calculation is where it’s genuinely worth getting proper support rather than doing the sums on the back of an envelope — the difference between two bands can be the difference between no saving and a five- or six-figure one, depending on your consumption.