Wind reliance could hamper Sweden's winter power supplies

[OSLO] The rising share of intermittent wind power in Europe's energy supplies and grid constraints could make it harder for Sweden to source power imports at peak demand times in winter, grid company Svenska kraftnaet said on Monday.

Sweden may need to import up to 1,600 megawatts (MW) of electricity to cover peak consumption during a normal winter, roughly 6 per cent of last winter's peak demand of 25,500 MW, the transmission system operator (TSO) said in an annual review.

This projection was little changed from the previous winter, it added.

"However, Svenska kraftnaet's analyses show that the import possibilities for dealing with such a deficit may be limited if the same wind and temperature conditions also prevail in our neighboring countries, or if the import possibilities are reduced by network restrictions or other reasons," it said.

Sweden is expected to add 2,900 MW of new wind power capacity this year, but output is typically low at times of extreme cold, it added.

Across Europe, countries are also building out wind power to replace fossil fuels and cut emissions of carbon dioxide.

The majority of Sweden's wind power is situated in the north, while the populous south could see a power deficit of 9,200 MW during the winter peak, Svenska kraftnaet's report showed.

Maximum grid transmission capacity between north and south would range between 6,300-7,300 MW, it forecast.

Svenska kraftnaet said it saw little progress in increasing the share of controllable electricity sources and flexibility among consumers, which could help curb imports.

Meanwhile, the TSO said it did not anticipate any need to secure back-up power contracts this summer to cover maintenance outages at power plants and on the grid.

Last year, it concluded such deals with operators of the since closed Ringhals 1 nuclear reactor, the oil-fired station Karlshamsverket and the gas-fired Rya district heating plant.

In 2020, Sweden's electricity generation mix was dominated by hydropower (45 per cent), nuclear (30 per cent) and wind power (17 per cent), according to industry figures.

REUTERS