DUoS red band charges explained: what they are, why they’re the most expensive few hours on your bill, and what businesses can actually do about them.
DUoS — Distribution Use of System — is the charge your electricity supplier passes on for using the local distribution network that delivers power to your premises. Rather than one flat rate, DUoS is split into red, amber and green bands depending on the time of day: red band is the peak period, typically weekday afternoons and early evenings around 4pm–7pm, and it’s by far the most expensive of the three — commonly costing many times more per unit than the green, off-peak band. It costs businesses so much because demand on the local network is highest in exactly this window, and DNOs price it to reflect that. For businesses running equipment, lighting or machinery through those hours, red band charges can quietly account for a disproportionate share of the network cost on the bill — and unlike the wholesale energy price, it’s a cost you can meaningfully reduce simply by shifting when you draw power.
Most business owners can quote their unit rate and standing charge without much thought. Far fewer could explain what DUoS is, or why their bill quietly gets far more expensive between 4pm and 7pm on a weekday — even though the wholesale price of the electricity itself hasn’t moved. That gap in understanding is expensive, because DUoS red band pricing is one of the few charges on a commercial energy bill that a business can genuinely influence.
This guide explains what DUoS is, how the red, amber and green band system works, why red band specifically costs so much, and the practical ways businesses reduce their exposure to it — including how solar and battery storage change the picture entirely.
Unless your business is on a half-hourly metered contract, DUoS charges are usually bundled invisibly into your standing charge and unit rate rather than itemised separately. That doesn’t mean red band pricing isn’t affecting you — it just means the cost is hidden inside a blended rate rather than shown as its own line, which is exactly why so many businesses have never heard the term.
DUoS stands for Distribution Use of System. It’s the charge that funds the operation, maintenance and expansion of the local electricity distribution network — the substations, transformers and cables that carry power from the wider transmission grid to your premises. Every business connected to the grid pays it, collected by your energy supplier and passed on to your regional Distribution Network Operator (DNO).
There are 14 DNO regions across Great Britain, and each sets its own DUoS tariff structure using an Ofgem-approved methodology, which is why two similarly sized businesses in different parts of the country can see quite different DUoS charges. DUoS sits alongside TNUoS (which funds the national high-voltage transmission network) as one of the “non-commodity” costs on a bill — charges that have nothing to do with the wholesale price of electricity itself, but which have grown to make up the majority of what many businesses now pay.
Smaller businesses on standard contracts typically won’t see DUoS itemised separately — it’s folded into the unit rate and standing charge your supplier quotes. Larger businesses with half-hourly metering are more likely to see it broken out explicitly on their bill.
For businesses on a half-hourly metered or time-of-use tariff, DUoS unit charges are split into three time bands rather than a single flat rate. Each reflects how much strain your usage places on the local network at that moment.
Typically weekday afternoons and early evenings, commonly falling somewhere in the 4pm–7pm window, though the exact hours vary by DNO region and time of year. This is when demand on the local network peaks — homes and businesses drawing power simultaneously — so DNOs price this band to reflect the real cost of that strain.
Covers the hours around the red band peak — typically daytime working hours outside the sharpest peak — where demand is moderate. Amber pricing sits between red and green, and usually covers the majority of a standard business’s working day.
Covers the lowest-demand periods on the network — typically overnight, early morning and weekends. Green band DUoS charges are a fraction of red band, which is exactly why shifting flexible electricity use into this window is one of the most direct ways a business can cut its network costs.
Red band pricing is expensive because it’s designed to be a demand signal, not just a cost recovery mechanism. DNOs size their local networks to cope with peak demand — the busiest half-hour of the busiest day — and that peak capacity is expensive to build and maintain. Charging more during the hours when demand is highest reflects the genuine cost of that infrastructure, and gives businesses and households a financial reason to shift flexible usage elsewhere.
The scale of the difference is significant: red band charges are commonly reported as costing many times more per unit than green band, in some cases up to around twenty times the off-peak rate, depending on the DNO region. For a business running energy-intensive equipment — refrigeration, manufacturing lines, HVAC, EV charging — through the red band window every weekday, that difference compounds into a meaningful annual cost, even if total electricity consumption doesn’t change at all.
| Band | Typical timing | Relative cost |
|---|---|---|
| Red | Weekday afternoon/early evening peak | Highest — commonly several times green band |
| Amber | Daytime, outside the sharpest peak | Moderate |
| Green | Nights, early mornings, weekends | Lowest |
2026 has brought some of the steepest DUoS and TNUoS increases in years, largely driven by the investment needed to connect new renewable generation and reinforce the grid. Even businesses that hold consumption flat are seeing network charges take a growing share of their total bill — which makes reducing red band exposure specifically more valuable now than it’s been in previous years.
Before making any changes, it’s worth establishing how much of your usage actually falls in the red band window, since this varies enormously by business type.
Once red band exposure is understood, most businesses have several practical levers, ranging from simple scheduling changes to on-site generation and storage.
- Reschedule flexible processes — production runs, EV fleet charging, non-urgent equipment cycles — into green band hours
- Use building management systems or timers to automatically restrict discretionary loads during red band hours
- Review and correct your contracted capacity (kVA/MIC) if it’s set higher than your business actually needs
- Install commercial solar to generate your own electricity during daytime demand, reducing what you draw from the grid during amber and red hours
- Add battery storage to charge during cheap green band hours or from solar surplus, then discharge through the red band peak instead of importing
Battery storage is particularly effective against red band pricing specifically, because it lets a business use stored, cheaply-charged electricity during exactly the hours the grid is most expensive — a form of peak shaving that reduces both DUoS exposure and demand charges in one move. For a full breakdown of what a system like this actually costs to install, see our guide to commercial battery storage cost in 2026.
- Meaningful electricity use between weekday early-to-late afternoon and early evening
- Equipment, shifts or processes that can’t easily be rescheduled
- No visibility yet into your half-hourly consumption by time band
- On a half-hourly meter, or considering moving to one for better visibility
- Contracted capacity (kVA/MIC) not reviewed in the last 12 months
- DUoS currently bundled into a blended rate rather than itemised
- Flexible loads identified that could shift into green band hours
- Solar and battery storage considered as a way to reduce peak-hour grid draw
- Site assessment booked to quantify actual red band cost and savings potential
- DUoS funds the local distribution network and is split into red, amber and green time bands.
- Red band is the weekday peak, typically mid-afternoon to early evening, and by far the most expensive band.
- Red band pricing can cost several times more per unit than green band — sometimes up to around 20 times.
- Smaller businesses often don’t see DUoS itemised separately — it’s usually blended into the unit rate.
- Battery storage and solar are among the most effective ways to reduce peak-hour grid draw and red band exposure.
Curious what red band is actually costing you?
We’ll review your usage pattern and tariff to show exactly how much red band charges account for on your bill — and what solar and battery storage could save.
