Land or sea: where does the wind blow strongest to propel the energy sector forward?

We have become accustomed to seeing wind turbines spinning in the fields of Lithuania, providing our country with an increasing amount of green electricity. However, this renewable energy source can be harnessed even more efficiently by installing wind turbines offshore. An international green energy company, Ignitis Renewables, which is developing the largest wind energy projects in Lithuania and the Baltic States, explains why it is essential to generate green electricity both on land and at sea.

The first wind turbine in Lithuania was erected in 2004. Since then, and especially in recent years, the renewables sector in Lithuania has reached a breakthrough. According to Litgrid, electricity transmission system operator, Lithuania generated 3.972 terawatt-hours (TWh) of electricity from renewable energy sources last year, accounting for 70% of total generation. More than half of it, 2.524 TWh, was generated by wind turbines.

Head of Offshore Development at Ignitis Renewables, Vytautas Rimas, states that the results of wind energy in Lithuania are improving each year. However, this method of electricity generation could be even more efficient and contribute further to Lithuania's energy independence if the massive potential of the Baltic Sea is utilised.

Potential efficiency is significantly higher

The higher efficiency of offshore wind turbines compared to their onshore counterparts is related to the absence of barriers, such as trees, mountains or buildings, that can obstruct the wind. Moreover, the wind blows continuously at sea, even when it seems calm on land. All this allows for a more efficient and stable electricity generation.

“Electricity output of wind farms depends in large part on wind speed. The offshore wind’s potential is greater, and it is more stable than the onshore wind. This is why offshore wind turbines generate electricity even during periods when onshore wind turbines are inactive due to the lack of wind,” says V. Rimas.

Offshore wind farm generates electricity nearly all the time. Average figures, which are based on the data from the offshore wind farms in the North Sea of one of the largest international offshore wind farm developers, Ørsted, show that offshore wind farms generate electricity nearly all the time. Around 91% of the time there's enough wind to generate electricity. Only 8% of the time the wind is too weak, and around 1% of the time it is too strong.

According to V. Rimas, this means that an offshore wind farm can generate up to twice as much electricity as an onshore wind farm of the same capacity.

“The first offshore wind farm in Lithuania and the Baltic States, Curonian Nord, will generate around 3 TWh of electricity per year. This accounts for a quarter of Lithuania's current energy demand. If we add the onshore renewable capacities, we can confidently say that the national energy independence goals are effectively becoming a reality,” emphasises the representative of Ignitis Renewables.

Residents see the advantages too

The foundations of offshore wind farms are designed to withstand the harshest conditions, and they are located far away from residential areas, which makes it possible to install more powerful wind turbines and space them optimally. This also increases their generation efficiency and load factor.

“Also, since offshore wind farms are located further away from the coast, they have a reduced visual impact on the landscape,” explains V. Rimas.

He points out that Lithuanian citizens also understand these advantages of offshore wind farms. A representative survey showed that 77% of the country's population believes that offshore wind farms should be developed in Lithuania's Baltic Sea territory to meet the energy generation and independence goals, while only 9% are opposed to such projects.

“Residents understand that generating electricity from renewable energy sources is extremely important both from an environmental and energy independence perspective. Therefore, it is critical to take advantage of all the opportunities provided by nature and ensure the diversification of electricity generation as different methods of generating electricity from renewable energy sources complement each other. Solar energy is the most efficient during the summer days, onshore wind farms are particularly efficient during the colder months, while the offshore wind farms are the most stable compared to the first two methods,” notes Head of Offshore Development at Ignitis Renewables.

The Curonian Nord offshore wind farm, with a capacity of up to 700 megawatts (MW) will cover an area of about 120 square kilometres in the Baltic Sea and will be positioned least 37 km away from the shore and about 50 km from the Port of Klaipėda. The offshore wind farm is expected to become operational around 2030.

You can find more information about the project at curoniannord.com.