Peak Shaving and the DUoS Red Band, Explained for Business

Your bill is banded, and the red band is the expensive one

To understand why battery storage for businesses saves money, you have to understand how a commercial electricity bill is built. A large and rising share is non-commodity, and the biggest lever within it is Distribution Use of System (DUoS). DUoS charges are banded by time of day: green (cheap, usually overnight and weekends), amber (mid), and red (the expensive band, typically weekday late afternoon into early evening). If your site draws hard through the red band, you pay a premium the moment demand lands there.

What peak shaving actually does

Peak shaving is simple in principle. The battery charges when power is cheap, overnight in the green band, or from surplus solar at midday, and discharges across the red band and your demand peaks. Your metered import stays flat while production, refrigeration, or trade continues as normal. That does two things at once:

• It cuts the red-band DUoS unit charges on your most expensive half-hours.
• It shaves the measured peak that sets your capacity and availability charges, so you can renegotiate a lower agreed supply capacity (kVA).

Triad avoidance is dead, DUoS avoidance is not

Businesses that looked at this a few years ago will remember Triads, the three winter-peak half-hours that set transmission charges, and the game of avoiding them. That regime has been replaced by fixed, banded residual charges, so classic Triad avoidance no longer exists in its old form. Anyone still selling you Triad avoidance is out of date. The value has shifted to DUoS red-band avoidance, demand-charge reduction, capacity-market exposure, and solar self-consumption, all of which a battery captures. We model the current charging structure, not the old approach.

How much can it save?

The saving depends entirely on your demand profile and your red-band exposure, which is why we model it from twelve months of your half-hourly meter data rather than quoting a generic figure. On a spiky, predictable profile, red-band avoidance and capacity-charge reduction usually make up the bulk of a business battery’s saving, with lifted solar self-consumption on top where panels are present. Most behind-the-meter systems land at a six-to-eight-year payback.

Sizing follows the peak, not a rule of thumb

Power (kW) is sized to the peak you need to clip; energy (kWh) to how long that peak lasts. Most behind-the-meter commercial systems land at 1.5 to 2.5 hours of duration, for example 250 kW / 500 kWh. Get the ratio wrong and you either cannot cover the peak or you pay for capacity you never use, which is why sizing from real data matters.

See how peak shaving works as a service, the cost by size, or get your red-band saving modelled from your own meter data below.