Carbon-neutrality targets are pushing industry, transport and other sectors of society to use clean electricity. The energy transition is increasing the need for renewable forms of energy, as fossil fuels need to be replaced cost-effectively.
The spotlight is now on wind and solar power, which still have plenty of growth potential. Wind power currently accounts for 20 per cent of Finland’s electricity consumption, while solar power makes up just one per cent. However, by 2030, the goal is for wind power to produce half of Finland’s electricity, with solar power contributing 5–10 per cent.
Power plants, transmission lines, substations and connections are now being built at a brisk pace. Over the next ten years, Fingrid will invest up to EUR 4 billion in the main grid. Transmission connections are especially needed in the north-south direction to carry electricity from production locations to consumption centres. Most electricity is consumed in Southern Finland, while most new electricity production plants are built in Western, Central and Northern Finland.
The energy transition also calls for flexibility and regulation of renewable and weather-dependent energy sources. The production capacity of wind and solar power plants is entirely dependent on the weather, which cannot be controlled. However, wind and solar power complement each other because when it is calm, the sun often shines, and there is often more wind during cloudy weather.
“Power plants with side-by-side solar and wind power facilities are currently under development.”
“Power plants with side-by-side solar and wind power production are currently under development. These plants can share one grid connection. In the future, hybrid power plants could also include grid energy storage in the form of a battery, further raising the utilisation rate of the connection,” says Risto Kuusi, Senior Expert at Fingrid.
Connection enquiries going digital
An enormous number of connection enquiries and investments in facilities such as electric boilers, data centres, and grid energy storage are currently underway in Southern Finland.
Several operators are simultaneously replacing fossil-based energy with electricity, increasing the local electricity consumption. At the same time, combined heat and power (CHP) plants are being phased out, and their output is being replaced by electricity consumption.
“Many things are happening at the same time, on a tight schedule and a massive scale, exerting pressure to develop the main grid in densely populated areas,” says Markus Talka, Customer Manager at Fingrid.
“We can meet our customers’ needs for connections over the long term, but perhaps not tomorrow or even a year from now. System reinforcements can take five to ten years to build,” he adds.
According to Talka, connection needs would be easier to forecast if all potential customers did not hesitate to submit connection enquiries via Fingrid’s digital service. In such a case, a project in the design phase would then be placed in the right spot on the map. Then, Fingrid could monitor its life cycle and determine at which stage new customer projects require the development of the main grid and what needs to be done.
“The connection enquiries we receive are essential for planning the development of the main grid.”
“Main grid development is based on network plans prepared according to customer needs, the electricity market, the condition of the main grid, and transmission requirements. Consequently, the connection enquiries we receive are an essential factor in planning the development of the main grid,” Talka says.
When the data has been entered into the system, Fingrid can easily analyse it en masse. All of Fingrid’s responses are also saved in the system for every party to see, so no information relies on phone calls, for example.
Fingrid has analysed some favourable locations for industrial-scale grid energy storage in Finland. For this reason, it is advisable to contact the transmission system operator in advance when studying projects, as this may help to avoid significant challenges or delays in projects.
“It is a good idea to ask us where the best locations are, for example, for an industrial-sized grid energy storage facility to provide the greatest benefit to the customer while serving the needs of the entire power system,” Talka recommends.
Flexibility counteracts price spikes
The challenge with weather-dependent forms of energy is that energy consumption rarely adapts to the weather. When it is very cold, a lot of electricity is needed, but it may not be windy or sunny at that moment. On such days, failures in power plants and transmission links could lead to an electricity shortage, resulting in a price spike for consumers.
In August 2023, for example, the electricity price hit a sudden high when planned outages at the Swedish border coincided with faults in parallel lines in Sweden. The cooling system at the Olkiluoto nuclear power plant failed, and planned annual maintenance was taking place at the Loviisa nuclear power plant. On top of all this, the wind did not blow.
Solar power helped in the middle of the day and during the afternoon, but the electricity could not be stored for the hours of higher consumption in the early evening and on weekday mornings. Weather-dependent forms of energy are challenged by inflexibility.
Conversely, a coal-fired power plant has a huge pile of coal that acts as a form of energy storage and provides production flexibility. The power system now needs new energy storage facilities, such as batteries, pumped storage hydro power plants, thermal energy storage, and storage of hydrogen and electric fuels.
In the future, hydrogen may be stored in rock caverns similar to those used for natural gas today. The benefits of hydrogen for storing renewable energy will become increasingly apparent as technology evolves.
A power system dominated by weather-dependent forms of energy also needs more and more flexibility in electricity consumption, as is already the case in industry. Demand-side management occurs naturally in tandem with electricity prices: when electricity is expensive, people use it more sparingly, and consumption falls.
All flexibility and storage that is implemented counteracts price spikes. Large production plants can also earn money by offering demand-side management in the reserve market. Fingrid uses reserves to balance the power system. Weather-dependent forms of energy can also be flexible. Today, technology can increasingly enable wind and solar power to participate in the reserve market.
Solar and wind power are changing the grid
When a new power plant connects to the main grid, it undergoes several phases in the connection process in line with Fingrid’s grid code specifications.
The rapid propagation of converter-connected solar and wind power has created various technical challenges that the current demands, technology, and established operating models can no longer address.
For this reason, the grid code specifications for power generating facilities (VJV) and for grid energy storage systems (SJV) will be updated this year. The update will pay greater attention to the technical requirements caused by the increased share of wind power, solar power, and grid energy storage systems.
“The goal is to keep our power system as stable as possible as the number of converter-connected installations increases and the technology and operating models change,” Talka says.
The new grid code specifications lay the foundations for the stable operation of power plants under all operating conditions and in the event of disturbances. They require new power plants and operators to have high technical performance, regulation capacity, visibility and foresight.
