Commercial battery storage: five value streams from one battery

Solar self-consumption, peak demand reduction, time-of-use arbitrage, wholesale market participation and frequency control ancillary services. All five run on the same hardware; the number captured is set by the control system and market registration.

It discharges into the interval that would otherwise set the peak, so the meter never records it. Because a single interval can set the charge for the whole month, the response must be forecast and automatic rather than manual.

No. Oversizing energy capacity on a site whose value sits in power delivery adds capital cost without adding return. Power and energy have to be sized against the streams the site can actually access.

Commercial battery cost is driven by four things: usable capacity in megawatt-hours, power rating in megawatts, the switchboard and protection work the site needs, and whether the system is registered to trade in wholesale and ancillary markets. Two sites with the same capacity can differ substantially on the third item alone. Vitalic prices against your interval data and network tariff rather than a per-kilowatt-hour rule of thumb, because the revenue side changes the answer as much as the hardware does.

It depends on how many of the five value streams the site can actually capture. A battery that only does solar self-consumption is working at a fraction of its capability. The same hardware can also cut the peak demand charge, arbitrage time-of-use rates, dispatch into high wholesale prices and provide frequency control services. Whether it is worth it is a question about the control system and market registration, not about the battery.

Sizing follows the load profile, not the solar array. The starting point is twelve months of interval data: the shape of the evening peak, how often and how sharply the demand charge is set, and how much surplus generation the site actually spills. A battery sized to store surplus solar and a battery sized to shave the monthly peak are usually different systems, and the second is frequently the one that pays.

Commercial lithium systems are generally warranted on both years and throughput — a number of years, and a number of full cycles or megawatt-hours delivered, whichever comes first. That matters because a battery worked hard across several value streams reaches the throughput limit sooner than one doing daily solar shifting. The warranty structure should be read against the dispatch strategy, since the strategy is what determines which limit binds.

Usually yes, and the constraint is normally the switchboard rather than the solar. Retrofitting requires establishing existing capacity, protection settings and network position before anything is specified. An existing array also changes the economics: the surplus it currently exports at a low feed-in rate is the cheapest energy a battery can store, which often makes a retrofit stronger than a new build on the same site.