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How to store energy for consumption peaks?

Since the 1950s, the Swedish city of Boras laid the groundwork for a sustainable city, notably through the gradual implementation of virtuous energy models that enabled them, among other things, to store the energy from its biomass and incineration plants. In this way, Boras was able, without using fossil fuels, to meet the peaks in the city’s heat consumption during harsh winters.

© Photothèque VEOLIA - Adam IHSE / Interlinks Image

Detailed Solution description

BORAS, A MODEL FOR THE STORAGE OF THERMAL ENERGY In a country that exemplary in the area of recycling and recourse to their own energy, the Swedish city of Boras aims to become energy neutral in terms of CO2 emissions, by 2025. This goal has been progressively implemented since the end of the 1950s. Today, Boras recycles its household waste, uses fuel wood and recovers heat from wastewater.  In 2010, it also built a facility for the storage of thermal heat that allows it to meet peak winter energy consumption without resorting to fossil fuels. Christened the “thermos” by the 103,000 inhabitants of Boras, this storage facility is one of the largest hot water storage unit in Europe. Eighty meters high, with a capacity of 37,000 m3, it was installed on the Ryaverket site, at the outlet of the thermal production plant of the city; its operations produce: 2 biomass furnaces of 65 MW, 2 solid combustible furnaces using sorted waste of 20 MW and, finally, 2 steam turbines operating in co-generation of 37 electric MW. Supplied by the renewable energy of these installations, the storage facility stores hot water when demand by the users of city heating is lower than production, and returns the accumulated energy when it is higher. By relying on the expertise of Veolia for heating or cooling networks, Boras is thus provided with a solution that meets its need to de-couple supply from demand. The city can, in effect, smooth out fluctuations in production, avoiding recourse to supply units that use fossil fuel. Its environmental performance is enhanced. Thanks to its “thermos”, Boras has effectively reduced its CO2 emissions by 7,700 tons per year. The technology used in Boras can be used in various kinds of sites. This is evident especially in energy storage solutions implemented by Veolia in France: in Melun on a geothermal installation, in Lyon on a wood gas furnace, or in La Rochelle on an incinerator. Depending on the capacity of the storage unit, from a few dozen to several thousand m3, energy storage can supply a heat network for several hours over many days.

© Borås Energi och Miljö

Launch Date

Implementation began on

2010 for the construction of the store of thermal energy. Collaboration of Boras with Veolia began in 2005.

Key figures illustrating Solution deployment and results

- 37,000 m3, the capacity of the thermal energy storage facility of Boras
- 7,700 tons of CO2 emissions prevented per year.

Performance, impact and results

Boras meets the challenge of its urban heating in winter without recourse to fossil fuel (CO2 emissions reduced by 7,700 tons per year).

The guarantee of continuity of energy service.

The supplying of the storage facility with energy from the biomass and incineration installations avoids recourse to supply units that use fossil fuel.

The largest hot water storage unit in Europe, with a storage capacity of 37,000 m3. A solution designed to meet the need for de-coupling supply from demand

  • Professional contact
    Fanny Demulier
    CSR Officer
  • Press Contact
    Marie Bouvet
    Press relations