BKW is investing four billion in the energy system by 2030

From hydropower in the Bernese Oberland and the wind farm in southern Italy to battery storage and the extra-high-voltage line in Germany: as part of its «Solutions 2030» strategy, BKW is specifically implementing projects in Switzerland and Europe that address the requirements of society and the economy for the energy system of the future. To this end, BKW plans total investments of four billion Swiss francs by 2030 – half of this in Switzerland.

More electricity from renewable energies

These investment projects also include the hydropower plants at Grimsel in the Bernese Alps. Lake Grimsel is the most important reservoir in the extensive power plant network of Kraftwerke Oberhasli AG (KWO), half of which is owned by BKW. Its storage volume is sufficient for around 100,000 households per year. The example shows how, in electricity production, the expansion of existing infrastructure and expansion projects go hand in hand:

On the one hand, the replacement Spitallamm dam at Lake Grimsel was inaugurated last June. In total, the project cost around 125 million Swiss francs. The new build became necessary because the existing dam from the 1930s was in need of refurbishment. It measured 114 metres from the foundations to the crest – making it one of the highest dams in the world at the time of its construction. The new dam now stands in front of the old one – and is approximately the same height. However, with the Grimsel lake enlargement project, the dam could be raised by 23 metres in future. It is one of 16 selected federal projects for expanding domestic electricity production from hydropower. For this project, KWO submitted a concession application to the cantonal authorities in May 2024. By raising the Spitallamm dam and enlarging Lake Grimsel, the power plant could store an additional 240 gigawatt hours of electricity per year. This means that the expansion project, estimated at around 300 million Swiss francs, will contribute in particular to electricity production in the winter months, when less electricity is generated from run-of-river and solar power in Switzerland.

BKW is also investing in run-of-river hydropower: current projects include the construction of the new Sousbach hydropower plant for around 69 million francs. The plant went into operation at the end of 2025 and supplies around 6,700 households with renewable electricity. In addition, BKW will start the complete renovation of the Mühleberg hydropower plant in 2028. It is investing a total of around 120 million francs in this project.

In addition to hydropower, BKW is also driving forward wind power. Here, BKW connected the Cerignola wind farm in Apulia (southern Italy) to the electricity grid at the end of 2025 after almost a year of construction. The 29 turbines supply enough electricity for 140,000 households each year. With 800 landowners, two substations and 27 kilometres of high-voltage line, it is a complex infrastructure project – and at the same time BKW’s currently largest construction project abroad. Its completion marks an important step in the «Solutions 2030» strategy, with which BKW aims to expand its portfolio by more than 600 megawatts of renewable electricity production by 2030 and reduce emissions in the energy business to net zero by 2040.

Growing need for flexibility in the energy system

Expanding or building new wind turbines, hydropower plants and solar installations is an important prerequisite for the success of the energy transition. Another, however, is that the electricity produced by these installations is available at the right time, in the right place and in the right quantity. Flexibility is therefore required here. This is because as renewable energy sources increase, especially wind and solar power, fluctuations in electricity production also rise.

This is literally dependent on wind and weather – that is, on the time of year and day, as well as on meteorological conditions. To take a holistic approach to the energy transition, flexibility and storage solutions are therefore needed. This opens up exciting growth opportunities for BKW – thanks to its broad expertise, from production, marketing and distribution through to the use of energy. With its «Solutions 2030» strategy, BKW aims to build its own flexibility assets, such as hydropower plants and batteries, with a capacity of more than 600 megawatts by 2030. It also intends to manage flexible third-party assets of more than 700 megawatts and, as a pooler, connect small-scale installations of more than 200 megawatts to form virtual, flexible power plants. BKW has already launched a number of ambitious projects in these areas: in Waltrop (Germany), BKW is expected to begin construction of a large-scale battery at the end of 2026, with a capacity of 300 megawatts and a storage capacity of 600 megawatt hours. BKW’s investment of around 200 million euros includes the development, construction and operation of the large-scale battery storage system. The facility will help stabilise the energy system in an increasingly volatile energy market. At the same time, BKW is strengthening its activities in international energy markets, where flexibly dispatchable electricity storage systems are becoming increasingly important.

Also in Germany, in Holenbrunn (Wunsiedel), a battery is currently being built which BKW will plan, build and operate. In addition, last autumn BKW signed a long-term financing agreement with Zelestra, a global renewable energy company. This enables the construction of a large-scale battery in northern Italy with a storage capacity of up to two gigawatt hours. Construction is scheduled to start in 2027, with full operation planned for 2028. Zelestra will make part of the facility’s generation capacity available to BKW in order to manage and optimise flexibility in the market. The approach of this large-scale project is highly innovative, as it combines improving power grid flexibility with the faster integration of renewable energies, helps decarbonise Italian electricity generation and increases security of supply.

BKW also has a stake in the Grimsel 4 pumped storage power plant via KWO. KWO submitted the building permit application for this underground expansion project at the end of 2024; construction is scheduled to start in summer 2026 and commissioning is planned for around 2032. With an investment of around CHF 250 million, Grimsel 4 is intended to make more efficient use of the water between the two existing reservoirs, Lake Grimsel and Lake Räterichsboden. Two new pump turbines with a total output of 150 megawatts are planned between the two reservoirs; thanks to a full converter on each turbine, they will be able to adjust their output in pumping mode. This will allow electricity production to be optimally aligned with demand. At the same time, Grimsel 4 will also be able to flexibly provide important balancing energy services for the power grid, for example by quickly supplying large amounts of electricity during periods of very high electricity consumption (peak load). Storage solutions such as large-scale batteries and pumped storage power plants thus make an important contribution to the energy transition and to stabilising the power grid.

Infrastructure for the new energy world

In addition to renewable power generation plants and storage solutions, the energy system of the future also needs a reliable electricity grid to transport the electricity produced and stored to where it is needed at any given time. One of BKW's strategic priorities with «Solutions 2030» is the expansion of energy grids in Germany and Switzerland. LTB Leitungsbau GmbH from BKW's network is involved in the Ostküstenleitung, one of the largest current projects for the energy transition and grid stability in Germany.

The Ostküstenleitung is a 380-kilovolt extra-high-voltage line in Schleswig-Holstein that is intended to transport electricity from the wind turbines on the Baltic Sea coast to the high-demand south of the country and strengthen Germany's connection to the European electricity grid. LTB has won various subcontracts in this major project. Among other things, it has erected 51 electricity pylons along 22 of the line's total length of around 120 kilometres. In addition, LTB is converting and upgrading existing power lines in Germany so that the increased volume of electricity in future can be transported from the north to the south. The Ostküstenleitung is scheduled to be commissioned in 2028.

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