Wendell Hortop (GB Market Lead, Modo Energy) and host Quenton presented a Transmission Today interview-style market update focused on what happened to battery storage revenues in Great Britain over the recent winter and what it implies for the year ahead. Modo’s index (annualized revenue per MW) averaged about £27,000/MW/yr from November to February excluding Capacity Market payments; adding typical Capacity Market value (≈£13,000/MW/yr on average) pushed some assets toward ~£40,000/MW/yr. Those figures contrast with 2023’s ~£57,000/MW/yr and 2022’s ~£153,000/MW/yr—showing a steep drop driven by lower wholesale volatility, reduced peak prices, and growing battery supply (≈3.9 GW online today with 2–3 GW expected this year and >10 GW plausible by 2027).

Hortop attributed the revenue squeeze to three interacting forces: saturation of frequency response (its share fell from >90% historically to ~5–10% this winter), a materially smaller intraday spread (≈£60–70/MWh average this winter, about a third of prior winters), and lower system peak demand (average peak ~37 GW). Interconnectors (≈9.2 GW total, including the 1.4 GW Viking Link) and returning French nuclear and Norwegian hydro suppressed UK peak prices. Operational practice in the control room amplified the problem—batteries were often ‘skipped’ in favour of single, simpler-to-dispatch units (e.g., Dinorwig or pumped hydro). Positive developments include the Open Balancing Platform (launched December), introduction of bulk dispatch, and the March change increasing the dispatch visibility from 15 to 30 minutes. The long-term aim is no fixed‑duration rule: dispatch decisions driven by real‑time state‑of‑charge and algorithmic least‑cost selection. Hortop’s outlook: winter hurt revenues but the Balancing Mechanism should become the main growth channel for battery value as more capacity joins the BM, and summer negative‑price events could restore arbitrage spreads—while asset returns will continue to depend heavily on location and contract terms.