Malawi's hydropower fleet gives up a seven-hour window each weekend until June.

An asset owner drawing power from the Malawian grid now has a known seven-hour gap in hydro supply on one weekend night at a time, running until the end of June 2026. Malawi's state generation company published a notice on 26 March 2026 setting out rotating sediment flushing at its three largest hydropower stations, Nkula, Tedzani and Kapichira, from 9pm on Saturday until 4am on Sunday.

One station is flushed each weekend, and generation at that station stops for the full window. The rotation repeats every weekend until the cycle is complete, and the notice sets out no station-by-station order, so which of the three is offline on a given weekend is not stated.

The purpose is maintenance rather than repair. Silt and debris accumulate at the station intakes, and clearing them improves water flow and the efficiency of generation. The company says it will run the hydropower stations not being flushed harder, and draw on its diesel plants, to hold supply steady through each window.

Of 444.67MW of installed capacity, 390.15MW is hydro and 53.22MW thermal, so the hydro fleet carries close to 88 per cent of the total. Assessment: the reserve margin available to cover a station under flushing sits mostly in the remaining hydro units rather than in the diesel plant, so grid reliability across each window rests on river flows holding and on no unit tripping elsewhere in the fleet.

For an offtaker or a large energy user with weekend-night consumption, what matters is the overlap between those windows and their own load profile, and the order of the rotation, which the notice does not give. Until that is known, the timing is fixed and the location is not. The schedule runs to the end of June 2026, after which weekend nights return to ordinary dispatch.