Greek Day-Ahead Power Spike Exposes Evening Battery Gap, Analysts Say
A day-ahead price surge in Greece during the week of June 29 highlighted the grid's vulnerability to evening renewable shortfalls, with new storage projects due this month.
Greece's day-ahead electricity market recorded a sharp price spike during the week of June 29, 2026, driven by a shortfall in renewable output during evening demand hours when solar generation falls away, analysts told Montel.4
The episode points to a gap in flexibility that new battery projects, expected to enter service in Greece during July 2026, could help close. Batteries charging on midday solar surplus and discharging into the evening peak can compress intraday price spreads, analysts said.4
Greece is not alone in grappling with the pattern. In Bulgaria, rapid battery storage deployment has widened the country's spot power discount with Romania to EUR 5.80 per MWh in the second quarter of 2026, up from EUR 0.80 per MWh a year earlier, Montel reported. The seven-fold spread increase reflects Bulgaria's improved ability to absorb renewable variability, giving it an export advantage during hours of surplus generation.3
The Greek spike came during a broader period of elevated battery revenues across Europe. Battery storage revenues have surged amid volatile European power and gas prices caused by the war in the Middle East, Montel analysts said. In the United Kingdom, batteries used for energy storage doubled their revenues since the end of February 2026, following US and Israeli strikes on Iran, according to Fintan Devenney, senior energy analyst, as quoted by Montel.1
Aurora Energy Research also found that revenues from Britain's battery energy storage systems more than doubled between February and March 2026, driven by the energy price shock linked to the Iran war, according to Montel. The Aurora research noted that revenue persistence depends on continued price volatility.2
ICE Endex TTF front-month gas stood at €43.83 per MWh as of July 2, 2026, setting the gas-to-power cost floor against which battery dispatch economics are measured. At that level, combined-cycle gas turbines remain the marginal price-setter in most European evening peaks, giving batteries a spread to work against wherever renewable output falls short.1
The structural driver is consistent across markets: as solar capacity grows, intraday price swings widen in grids that lack matching storage. Greece generates surplus energy through much of the afternoon but faces a steep demand ramp after sunset. Storage that could bridge the two periods would reduce both peak prices and the need for gas-fired backup.4
Analyst views on Greek battery deployment timelines carry uncertainty. Projects scheduled for commissioning this month could face grid connection delays or supply chain lags. The Aurora findings on UK battery revenues also cautioned that elevated returns require sustained price volatility — if European gas markets ease, the arbitrage compresses.2
The near-term signal is whether Greece's incoming storage projects reach commercial operation during July 2026. If commissioning slips into the autumn, the grid enters the peak summer demand period without the flexibility buffer that analysts say the spike during the week of June 29, 2026 exposed as missing.4