Intraday Electricity Prices: What They Are and How They Work
Intraday prices are the prices at which electricity is traded after the day-ahead auction has closed — from the evening before delivery right up to a few minutes before the power physically flows. Two products exist side by side: the continuous intraday market (trading around the clock, prices changing minute by minute) and the intraday auction (a single clearing price per quarter-hour).
The intraday market is where market participants correct their positions after the day-ahead auction. If your wind forecast was too optimistic or a power plant trips, you buy the missing volume — or sell the surplus — on the intraday market. Delivery periods are typically quarter-hours, half-hours and hours. Because trading continues until shortly before delivery, intraday is the most volatile of the wholesale energy markets, and that volatility is precisely its purpose: it is the market's answer to forecast errors.
Continuous intraday works like a stock exchange order book: bids and offers meet whenever they match, so there is no single price for a delivery period — there is a stream of trades, usually summarised as a volume-weighted average price (VWAP). The intraday auction is different: all orders are collected and cleared at one point in time, producing one uniform price per quarter-hour. Traders use the auction to set a reference position, then fine-tune it continuously as forecasts firm up.
After the day-ahead auction clears (around midday for the following day), intraday trading opens. A participant sees the order book for, say, the quarter-hour 14:15–14:30 and either hits an existing offer or places their own. Trading in a delivery period closes shortly before that period begins — the exact lead time depends on the exchange and whether the trade is cross-border or within one grid zone. Everything traded must still be physically delivered, so intraday is a physical market, not a purely financial one.
Three things drive intraday volatility. First, forecast error: wind and solar output that was estimated 12–36 hours earlier is now known much more precisely, and the gap has to be bought or sold. Second, unplanned outages: a large unit dropping out has to be replaced within minutes. Third, thin liquidity in individual quarter-hours: a single sizeable order can move the price far more than it would in the deep day-ahead auction. Prices can go negative when there is more must-run and renewable generation than demand.
Minute-by-minute price movement is what makes intraday attractive for assets that can react fast. A battery can charge in one quarter-hour and discharge in the next; a flexible load can shift consumption into cheap periods. Stromfee's BESS Academy quantifies the theoretical scope: for the German market it puts the continuous intraday (VWAP) revenue potential at 15,824 €/MW for May 2026, based on ENTSO-E/SMARD and Montel data. Read that figure honestly — it is a perfect-foresight maximum per market, not revenue anyone actually earned. Real results depend on your forecasts, cycle limits, round-trip efficiency and trading fees.
Intraday prices are published by the power exchanges and mirrored by public data platforms. For the German/Luxembourg zone, Stromfee shows 15-minute exchange prices at stromfee.ai/strompreis-heute.html. For the US, wholesale markets work differently — PJM, CAISO, MISO, ERCOT and ISO-NE run real-time markets on five-minute intervals rather than a European-style continuous intraday order book; Stromfee tracks those at stromfee.ai/us-electricity-prices.html. If you are comparing markets, do not assume the products are equivalent.