Swedish Armed Forces oppose planned Baltic Sea wind farms, citing national defence concerns 

The Swedish Armed Forces have voiced serious concerns over planned offshore wind farms in the Baltic Sea, asserting that thousands of proposed turbines could compromise Sweden’s defence capabilities. Recent analysis suggests large wind farms could interfere with radar and sensor operations critical to national security, potentially delaying threat detection by crucial minutes.

According to Lieutenant General Carl-Johan Edström, head of the Swedish Defence Staff, the radar echoes and electromagnetic disturbances from wind turbines could obscure military radar and underwater sensors, impacting the ability to detect threats such as cruise missiles or submarines. “It is not something we can accept with today’s threat picture and the responsibility we have towards Sweden as a nation,” Edström stated.

As radar relies on clear signals to detect objects at sea, the reflections and interference from turbine blades can create ‘clutter’ on radar screens, making it harder to identify real targets. ATDI, a French company specialising in radio frequency management solutions for civilian and defence markets, notes that such issues could arise globally and may result in potential threats going undetected. Furthermore, underwater noise from turbines can impact sonar equipment, making it more difficult to identify enemy submarines.

A report by the Ministry of Defence outlines concerns for vast areas of the Baltic Sea, from Åland in the north to Öresund in the south, where wind farms could hinder military situational awareness, according to sources at SVT News.

To address these challenges, some countries have implemented mitigation strategies, such as adjusting turbine locations or using radar-absorbing materials, which reduce interference without undermining renewable energy goals. These strategies could be crucial as Sweden considers its defence needs alongside renewable energy demands. Edström emphasised the importance of early military involvement in planning, saying, “We are dependent on a sustainable energy supply for our business and want to define where it is good to build.”

Balancing defence and renewable energy goals

Sweden’s government faces a challenging decision in balancing the Armed Forces’ defence needs with the benefits of renewable energy. Wind farms, such as the proposed Aurora and Erik Segersäll projects, could provide up to 24 TWh and 19.5 TWh per year, respectively, a significant boost to Sweden’s renewable energy capacity. However, as Defense Minister Pål Jonson noted, these projects require careful evaluation. “We naturally weigh what the Swedish Armed Forces say, but I do not want to prejudge the assessment,” he stated.

Potentially affected wind farm projects

Several wind farms are in planning stages across the Baltic Sea, including:

• Aurora – 370 turbines, 24 TWh/year

• Erik Segersäll – 225 turbines, 19.5 TWh/year

• Neptunus – 207 turbines, 13-15 TWh/year

These projects, along with others in designated sensitive areas, reflect the pressing need to find solutions that support both Sweden’s defence integrity and its renewable energy goals.