Case Study #5: Nurmijärvi (Finland)

Author: Green Net Finland

Keywords: Renting solar panels, grids, energy storage

Overview

Helen Ltd is a municipal energy company and its energy community is a complex project involving numerous stakeholders. The unifying aspect of the project is its location in the municipality of Nurmijärvi, in the Helsinki-Uusimaa region. Overall, the project consists of four solar power parks located in Nurmijärvi and an additional three parks located elsewhere, all operated by the same energy company. This case study will focus on the four solar parks in Nurmijärvi:

• Helen’s Nurmijärvi Solar Park: an existing solar park operated by Helen.
• Nurmijärvi Sähkö’s Solar Park: an existing solar park operated by the local electricity distribution company.
• Fortum’s Nurmijärvi Solar Park: a planned solar park announced in 2024.
• Yrjö and Hanna Foundation’s Solar Park: another planned solar park announced in 2024.

In addition to the solar parks (panels), the study also covers the relevant topic of renovation/new construction of the electricity distribution grid in Nurmijärvi and the planned energy storage facility in Nurmijärvi, which is a project of an energy company from another area, namely City of Helsinki.

The Helen’s Nurmijärvi solar PV station was completed in April 2023. Helen is an energy company owned by the City of Helsinki.  Before Nurmijarvi park, Helen had built three other solar parks in the City of Helsinki – Kivikko, Suvilahti, Messukeskus. Solar panels are available for rent in all four parks. Three earlier PV stations are rooftop installations, but Nurmijärvi’s park is a ground installation.

The members of the EC are the municipality-owned energy company and natural persons, which have energy sales contracts with the energy company. The natural persons are renting panels from the energy company. Future for Helen’s Nurmijärvi solar farm include energy storage facilities, other bigger solar parks and renovation of local electricity distribution grid. There are also other solar parks planned to be allocated to Nurmijärvi municipality.

Fortum and the municipality of Nurmijärvi are in the process of concluding a planning reservation agreement for the Sudentulli business area along the Klaukkala ring road. The reservation concerns approximately 85.6 hectares of land owned by the municipality, from which the municipality is prepared to assign a plot of at least 50 hectares to Fortum. Fortum plans to develop and market the area to the data center investor.

Another new solar power plant is planned for Nurmijärvi – a total of 118 hectares. The Yrjö and Hanna Foundation is behind the project. The solar power plant in question is planned near the Helsinki–Tampere highway (highway 3) about five kilometers north of Kirkonkylä and about 2.5 kilometers east of Rajamäki. The area is mainly arable land. Helen Oy’s solar power plant is located at roughly the same spot on the other side of the highway. The Yrjö Hanna Foundation is planning a solar energy production area of approximately 118 hectares on the site, which would consist of three separate areas. The annual production of the project would be approximately 53,500 MWh. In addition to the solar panels, transformers, service roads and fences surrounding the panels would be built in the area. The project is to be connected to Nurmijärvi Sähkö’s 110 kilovolt power line.

Legal form

The legal form of the ‘operator’ in the Helen’s Nurmijärvi solar park is a limited liability company Helen Ltd. The legal status of the organisation did not change recently. The latest change happened in 2015. The City of Helsinki (public entity) is the owner of the energy company Helen Ltd.

Technological setup

“Utility-scale solar farms are an efficient solution to increase solar energy production and meet the growing demand for electricity. They are an efficient addition to the electricity production mix, having already proved their productivity elsewhere in Europe”, says Sari Mannonen, Senior Vice President, Solutions & Portfolio Development, Helen Ltd.

To transfer the electric power produced by the solar panels to the grid, a conversion station was needed, where the 800V voltage produced by the solar park is converted to medium voltage (20kV) for feeding into the electrical grid. Norelco’s electricity distribution unit was chosen as the solution, where the entire electricity distribution is installed in a ready-to-use modular container. The containerized unit designed for the Nurmijärvi solar park contains a NorMax medium-voltage switchgear, a NorPower 5000 main switchboard and a NorBus 5000 rail bridge.

“In the energy sector, huge investments are being made in renewable energy and fossil forms of production are being replaced by wind and solar power. Renewable energy also needs electricity storage to bring stability to the electricity system and the electricity market”, Helen’s CEO Olli Sirkka said in the company’s press release.

A large 40 MW electricity storage facility at Nurmijärvi (at the intersection of Hämeentie and Muuntamontie) south of Nukari will be completed in early 2025. The electricity storage based on lithium-ion battery technology consists of approximately 36 modules the size of a large shipping container, which is connected to the grid that runs near the grid company Fingrid Oyj.

“We believe that a battery electricity storage system, which participates in the reserve market and supports the green transition, is an attractive investment for our renewable energy fund. The investment strategy of the fund includes traditional renewable energy targets, such as solar and wind power, as well as investments in infrastructures that increase the use of renewable energy. With these investments, we can promote sustainable development and positive change which enable long-term value creation,” says Antti Jaakonsaari, Evli Renewable Energy Infrastructure Fund II’s Portfolio Manager.

“Siemens is providing this interesting green investment project with its expertise in different systems and its capabilities in improving the flexibility and optimisation of energy consumption, storing and production facilities as well as in the development of related solutions and in adding sites to reserve market trading platforms,”says Miia Wallén, Head of Project Development in Energy Transition at Siemens Osakeyhtiö.

Nurmijärvi has significantly more Fingrid’s 110 kV power lines than Nurmijärvi Sähköverkko’s (local distribution grid company) 110 kV power lines. In addition, Fingrid’s 400 kV power line crosses Lake Nurmijärvi. Fingrid has the Nurmijärvi substation along Vanhan Hämeentie in Raala, from where the future power lines start to be built. The new transmission line also enables the connection of large, 30–60 MWp solar power plants to the distribution network. Without this transmission line, it would not be possible.

The environmental assessment of the new Nurmijärvi’s electricity distribution line has been completed in 2022 and the planning phase is already underway. The project’s fieldwork will be carried out in 2025–2026. The objects of the design are not only column structures, but also foundations, substation connections and minimization of environmental impacts.

“We try to carry out the construction in such a way that the consumer will not notice it other than as a better security of electricity supply. This is a significant investment, in my opinion the largest single investment of Nurmijärvi Sähköverkto’s ever”, states operations and development engineer Sami Rahkola. The cost of the entire project is approximately eight million euro, which is divided equally between Fingrid and Nurmijärvi Sähköverkko.

Facts about Nurmijärvi Sähkö:

• Nurmijärven Sähkö is an energy service company owned by the municipality of Nurmijärvi, which offers its customers services related to electricity and district heating.
• The company has approximately 27,800 electricity customers and approximately 530 heat customers.
• Nurmijärven Sähkö concern consists of the parent company Nurmijärven Sähkö Ltd. and its wholly owned subsidiary Nurmijärven Sähköverkko Ltd.
• Nurmijärvi Sähköverkko’s electricity distribution grid has a total of about 2050 km in the region,
  • which includes 110, 20 and 0.4 kV power lines,
  • there are 8 electricity stations in the area.
  • approximately 28,000 distribution customers
  • task is to transfer good quality electricity to customers at an affordable price in all situations.
  • extended annual replacement of electricity meters starts in 2024 and will continue until 2028.

The purpose is that the oldest measuring devices have been replaced well in advance of the deadline. Changing the electricity meter is part of the maintenance and renovation works of the grid. The exchange is free of charge for the customer. Meter replacements are carried out regionally according to the map. Exchanges start in the northern parts of the distribution network and continue from there in the southern direction.

Background information about the smart meter replacement:

• Under Measurement Decree 767/2021, the quart balance (orig.: varttitase) was introduced in Finland on May 22, 2023. At that time, limit point, medium voltage, large low voltage measurements and all measurements that can be updated remotely are obliged to use a 15 min time step. The remaining measurements must be transferred to the quarter measurement by 31 December 2028.
• In the distribution area of Nurmijärvi Sähköverkto, the large-scale introduction of a quart balance requires meter replacements. Currently, several types of meters are in use in our distribution network. Our oldest meter types in use cannot measure the consumption series with 15 min accuracy, so the oldest meter types must be replaced before the deadline.

According to Helen’s Minna Junnikkala, solar panels have developed a lot in recent years. He points out that, for example, Nurmijärvi uses efficient, double-sided solar panels. The power of one panel is 540 Wp. The total capacity of the solar park is 1.5 MWp, which corresponds to the annual electricity consumption of 750 apartment buildings. Nurmijärvi Aurinkopuisto is Helen’s first entirely own solar park. They company rented the field from a private landowner.

 “It is a total service for the electrification of the solar park: we designed and manufactured an electricity distribution unit that is optimal for the production capacity of the solar park, which is installed in a container solution designed by Norelco”, says sales director Juha Katainen from Norelco.

The power distribution unit achieves a very efficient packing density of the devices, and doors, openings, floors and interior walls, among other things, are built according to the needs of the project. When the equipment is manufactured in the factory, parameterized and tested, the customer saves on costs and site schedules.

Business model

The operator Helen is taking a fixed fee, which is 5,99 euro/month per panel, from all natural persons renting panels from Nurmijärvi’s solar farm.

“We credit the production of your panel on your electricity bill. The average credit is one euro per month, depending on the weather. You can add the solar panel to any electricity contract. If you don’t have electricity from Helen, start by making an electricity contract with us.”.

 “At best, a 285-watt monocrystalline panel generates electricity equivalent to more than 25 energy-saving bulbs. You receive the panel’s entire output without deductions.”.

An expansion option has been planned for the 40MW electricity storage project, which, if realized, will double the storage capacity. The electricity storage balances Finland’s electricity production and consumption by participating in Fingrid’s reserve market. The project combines the core competence of two reliable Finnish operators and an international technology company. Helen brings to the project an understanding and know-how of the energy system, which is complemented by the Evli Renewable Energy Infrastructure Fund II, which focuses on infrastructure investment, and Evli’s expertise in renewable energy project development. Siemens has been developing the project together with Evli from the beginning and continues in the project as an operation and management service partner.

Digital tools

Monitoring of the Helen’s Nurmijärvi solar farm is available online. Real-time view of the solar power plant output: customers can monitor the plant’s production online. The live camera shows how the sun shines onto the plant, and alongside you will see how the output changes with the sunshine. You can also compare your panel’s output to your own power consumption”.

Figure 23. Live monitor of Helen’s Nurmijärvi solar farm.

Nurmijärvi Sähkö’s solar park generation data also can be monitored online.

References

Helen. 2022. “Helen Increases Its Solar Energy Production at a Rapid Pace.” Helen.fi. https://www.helen.fi/en/news/2022/helen-increases-its-solar-energy-production-at-a-rapid-pace. Accessed on 25.3.2024

Helen. 2023. “History” Helen.fi. https://www.helen.fi/en/about-us/helen-ltd/about-us/history. Accessed on 20.3.2024

Helen. 2023. “Solar Power Plants.” Helen.fi. https://www.helen.fi/en/solar-panels/solar-power-plants. Accessed on 20.3.2024

Helen. 2024. “Helen Investoi Sähköjärjestelmän Joustavuuteen Sijoittamalla Suuren Mittaluokan Sähkövarastoon.” Helen.fi. https://www.helen.fi/uutiset/2024/helen-investoi-sahkojarjestelman-joustavuuteen-sijoittamalla-suuren-mittaluokan-sahkovarastoon. Accessed on 21.3.2024

Helen. 2024. “Nurmijärvi Solar Farm.” Helen.fi. https://www.helen.fi/en/solar-panels/solar-power-plants/nurmijarvi-solar-farm. Accessed on 21.3.2024

Helen. 2024. “Rent Solar Panels from Nurmijärvi.” Helen.fi. https://www.helen.fi/en/solar-panels/solar-power-plants/nurmijarvi-solar-farm.Accessed on 21.3.2024

Jaakkola, L. 2024. “Kaksi Merkittävää Energia-Alan Hanketta Nurmijärvelle – ‘Logistisesti Erinomaista Aluetta.'” Nurmijärven Uutiset, February 14, 2024. https://www.nurmijarvenuutiset.fi/paikalliset/6553910. Accessed on 21.3.2024

Ketola, R. 2022. “Nurmijärvelle 2800 Aurinkopaneelin Puisto – Sijoittuu Moottoritien Lähistölle.” Nurmijärven Uutiset, June 23, 2022. https://www.nurmijarvenuutiset.fi/paikalliset/4683125.Accessed on 21.3.2024

Norelco. 2023. “Nurmijärvelle Valmistui Teollisen Luokan Aurinkopuisto – Norelco Mukana Toteutuksessa.” Norelco.fi. https://www.norelco.fi/fi/ajankohtaista/nurmijarvelle-valmistui-teollisen-luokan-aurinkopuisto-norelco-mukana-toteutuksessa. Accessed on 21.3.2024

Nurmijärven Sähkö. 2024. “110 kV Linja Nurmijärveltä Lautalaan.” Nurmijärven Sähkö.https://www.nurmijarvensahko.fi/110-kvn-linja-nurmijarvelta-lautalaan/. Accessed on 22.3.2024

Nurmijärven Sähkö. 2023. “Sähkömittareiden Vaihdot.” Nurmijärven Sähkö. https://www.nurmijarvensahko.fi/sahkonsiirto/sahkomittareiden-vaihdot/. Accessed on 25.3.2024
Jaakkola, L. 2024. “Kaksi Merkittävää Energia-Alan Hanketta Nurmijärvelle – ‘Logistisesti Erinomaista Aluetta.'” Nurmijärven Uutiset, February 14, 2024. https://www.nurmijarvenuutiset.fi/paikalliset/6553910. Accessed on 21.3.2024

Vision GEF. 2023. “Aurinkosähköjärjestelmän Teho.” Vision GEF. https://vision.gef.fi/9810dba7-6e55-4e18-8772-976068f40704/. Accessed on 25.3.2024

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