Offshore at Pietarsaari, more than a tenth of the electricity used in Finland could be generated. The environmental impact assessment of the large offshore wind farm has started.
OX2 is exploring hydrogen production in connection with its offshore wind farms in the Baltic Sea.
The Laine wind farm would be located about 35 kilometres west of Pietarsaari, 29 kilometres from the coast and 24 kilometres from the nearest islands.
At the same time, the company is planning a similar offshore wind farm off Oulu and Raahe.
Hydrogen production could be done at centralized unmanned sea stations or in each power tower separately. It would also be possible for the hydrogen stations to be located on land.
Energy production balancers
Wind electricity can be used to produce hydrogen, in which case the energy can be stored. Hydrogen is produced using electrolysis, which requires a lot of electricity, by separating hydrogen and oxygen atoms from water.
Hydrogen plants built in connection with wind power balance energy production.
– Combined hydrogen production increases the profitability of the offshore wind farm, because we need more even energy production. Even at sea it is not always windy, although the wind conditions are more consistent and stronger than on land.
On land, the waste heat of hydrogen production can be utilized – at sea, it could improve the ecosystem of the Baltic Sea
Waste heat for useful use
OX2 still has a lot to figure out when it comes to hydrogen production.
If it is decided that hydrogen would be produced at sea, it would be piped ashore.
– When producing hydrogen at sea, the advantage is that there is no transmission loss when the hydrogen is produced next to the power plants. Integrating production with power plants is new and the manufacturers already have plans for it, but they have not been implemented.
On the other hand, if hydrogen is produced on land, there is no need to run a hydrogen pipeline either, and the waste heat from the production can be used.
Depending on the technology used, about a third of the energy in hydrogen production is wasted in the process, but if the waste heat can be utilized, the efficiency rises to 80–90 percent, according to Takalammi. In addition, energy loss also occurs if hydrogen is converted back into electricity.
– We have included all options in the environmental assessment so that we can evaluate their implementation and at the same time move forward with technical development and planning, says Takalammi.
In the best case, hydrogen production at sea could also improve the ecosystem of the Baltic Sea.
– One great alternative would also be that the pure oxygen produced as a by-product could be blown into the bottom of the Baltic Sea, which is suffering from oxygen loss, and thus the biodiversity could be improved.
Marine Park production would be in a class of its own compared to country wind parks
The Laine offshore wind farm would comprise a maximum of 150 wind turbines and its annual output is estimated to be around 11 terawatt hours.
Finland’s electricity consumption was around 87 TWh last year.
The outputs of the individual power plants are at least double compared to those currently installed on land, i.e. 15–25 megawatts. There are already 15 MW power plants on the market, but marine power plant technology is moving forward quickly, which means that power and power plant sizes are increasing.
The total height of the power plants is 270 meters with current technology, but may increase to 370 meters in the future. The power plants should be more than two kilometers apart in the direction of the main wind.
Ice conditions, depth, bottom structure…
On a larger scale, there is no offshore wind power in Finland yet. Before construction, there is still a lot to figure out.
For example, pack ice moving in the Pärämere can press against power towers with enormous force.
– Among other things, we cooperate with VTT on how ice conditions can best be taken into account in planning, says Olli Takalammi.
The depth of the sea varies in the planning area between 18 and 70 meters, with current technology, power plants can be established at a depth of 60 meters. It shouldn’t be too shallow either, because the ships used to install the power plants need at least ten meters of water under them.
In offshore wind power, you also have to find out the structure of the bottom, how deep, for example, the bedrock is.
There are three different options for foundations.
– Advance information about the bottom conditions is very lacking when you go 30 kilometers from the coast. We have now set out to find out the matter ourselves and establish a foundation. At a later stage, the conditions will be confirmed by drilling. There is a soft and a harder base, based on which the foundation method is chosen.
The environmental impact assessment has started
The EIA methods and results used for land-based environmental impact assessments in marine parks differ considerably from each other. The Yva investigation requires, among other things, diving and wading on beaches.
The planned park would be located so far out to sea that yachtsmen would rarely be in the same waters.
The biggest environmental impacts are during the construction period, which causes, for example, clouding of the water.
The project may also cause harm to holiday homes, for example, at the landing sites of power and hydrogen lines.
Uusikaarlepyy or Pietarsaari?
Four options are presented for power line landings in Uusissakaarlepyy and one in Pietarsaari.
If Pietarsaari were chosen, the power line would be drawn to Kokkola Hirvikoski substation. If the project were to be realized in its entirety, two 400 kV power line connections would be needed to transfer the offshore wind farm’s electricity to the main grid.
In the options considered in the EIA, the hydrogen pipeline coming from the sea would land either in the port of Pietarsaari or in the port of Kanäs in Uussakaarlepyy.
A public meeting open to all regarding the environmental impact assessment program will be held on October 25, 2022 at 6-8:30 pm in the Optima auditorium in Pietarsaari. You can also follow the event electronically.