Can an intelligent energy system pay off for an industrial business with multiple production sites? We developed a business case for a Danish industrial group with two very different locations. The answer was in the portfolio.
The first site is a large distribution facility: round-the-clock operations and a high base load of 1,093 MWh per year with a 446 kW peak, a strong foundation for solar self-consumption. The second is a production plant with a seasonal double-pulse profile of 503 MWh per year and evening peaks around 118 kW.
Solar (300 + 200 kWp) and two 0.5 MW / 2 MWh batteries, developed, tendered and operated by Stroem, with the two batteries dispatched as one virtual 1 MW / 4 MWh plant across the sites. Value comes from four co-optimized streams: solar self-consumption (85–95% with battery), spot arbitrage across 96 daily intervals, ancillary services to the Danish TSO (FCR, aFRR and mFRR, the largest line), and peak shaving against capacity tariffs.
Run separately, each site delivers a solid case: roughly 0.9–1.0m DKK net in year 1, payback of 3.8–3.9 years and 15-year IRR of 23–24%. The decisive move is bidding the batteries together into the ancillary-service markets.
On top of each plant's own revenue. Combined IRR rises to 29.4% and payback falls to 3.1 years. Every additional site improves the economics for all of them.
The system also future-proofs the sites: the battery keeps peak grid draw below the connection limit even as new electric loads such as boilers, heat pumps and EV charging are added, avoiding a costly grid upgrade.
Figures are from a real Stroem business case built on 2025 metered consumption data, anonymized at the client's request. Full study paper available on request.