{"id":9527,"date":"2024-12-04T14:49:10","date_gmt":"2024-12-04T13:49:10","guid":{"rendered":"https:\/\/fvb.se.ny.haus.se\/fvb-news\/world-class-energy-storage-malarenergi-leads-the-way\/"},"modified":"2025-11-26T08:29:39","modified_gmt":"2025-11-26T07:29:39","slug":"world-class-energy-storage-malarenergi-leads-the-way","status":"publish","type":"fvb-nytt","link":"https:\/\/fvb.se.ny.haus.se\/en\/fvb-news\/world-class-energy-storage-malarenergi-leads-the-way\/","title":{"rendered":"World-class energy storage \u2013 M\u00e4larenergi leads the way"},"content":{"rendered":"\n
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\nCarl-Oskar Bohlin, the Minister for Civil Defence was given a guided tour around the bunker by Stefan Winkler from FVB and Ivette Farias, Project Manager at M\u00e4larenergi. Photo: M\u00e4larenergi.<\/i>\n<\/p>\n\n\n

The world\u2019s biggest energy storage facility \u2013 located in V\u00e4ster\u00e5s \u2013 will be fully operational by the end of December. It will allow M\u00e4larenergi to cap output spikes and increase electricity production from its CHP plant. The project, in which FVB has played a key role, will yield financial and environmental benefits.
<\/strong><\/p>\n

\u201cM\u00e4larenergi decided to convert its old underground oil storage bunker into underground thermal energy storage (UTES) in 2021. The idea is even more relevant today, given the higher fuel prices and the stricter environmental regulations,\u201d says Ivette Farias, Project Manager at M\u00e4larenergi.<\/p>\n

\u201cThe UTES gives us a number of benefits, including greater flexibility for production, and that we can prioritise electricity production even when district heating demand is high, as we can use heat from the storage instead,\u201d she adds.<\/p>\n

There are three parallel underground cavities in total which can be operated independently of each other. They can hold a total of 300,000 cubic metres of water in total. The bunker was built in the 1970s to store fuel oil. It was decommissioned in 1985 and has stood empty since then. The first stage of conversion to a UTES facility for hot water was therefore to drill into the rock and clean out the remaining oil, a process that took more than a year.\u201cOne of the biggest challenges for the project was all the oil. Initial estimates were around 400 cubic metres of oil still in the bunker, but it turned out to be 3,300 cubic metres, which had to be removed. The clean-up process took longer and cost more than expected,\u201d explains Ivette.<\/p>\n

While the cleanup process was under way, a DN 500 district heating pipe running from the CPH plant to the bunker was built, with a connection to the existing boiler. Once that process and the cleanup was finished, it was time to install heat exchangers and pipes in the bunker.\u00a0<\/p>\n

\u201cUnconventional and durable solutions were needed, as these were installations that would have to work in an unusual environment, i.e. underground, and that would be in a location where repairs and service would be difficult. The bunker will be sealed up again when we’ve finished down there,\u201d says Stefan Winkler at FVB. Stefan was the Engineering Project Manager and designer, responsible for system construction, rule definitions and commissioning of the UTES facility.<\/p>\n\n\n

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Facts<\/h2>\n\n\n\n

The cost of the UTES facility was SEK 175 million, of which M\u00e4larenergi received a grant of SEK 15 million from \u2018Klimatklivet\u2019, the Climate Leap initiative. The facility can store 13 GWh of district heat and provides a range of benefits, such as:<\/p>\n\n\n\n

    \n
  • Improving the energy efficiency of M\u00e4larenergi\u2019s heat production through increased use of invested baseline production\u00a0<\/li>\n\n\n\n
  • Reduced carbon emissions through cutting the need for fossil fuels in reserve production<\/li>\n\n\n\n
  • Better planning options for optimised CHP production<\/li>\n\n\n\n
  • Better supply security through rapidly available peak and reserve capacity<\/li>\n\n\n\n
  • Lower costs for audit stops<\/li>\n\n\n\n
  • Retasking an old, existing facility.<\/li>\n<\/ul>\n\n\n\n

    \nSource: M\u00e4larenergi\n<\/p>\n<\/div>\n<\/div>\n\n\n\n

    Pumps have been installed outside the bunker which can be repaired and serviced when required, but finding the right pumps turned out to be another challenge.  \n\n\u201cWe needed pumps able to handle the low input pressure and hot water without cavitation. Cavitation occurs when hot water evaporates due to the low pressure, creating steam bubbles which can damage the pumps,\u201d explains Winkler.\n\nWhen they were in place, the bunker was filled with around 100,000 cubic metres of clean water in addition to the 200,000 cubic metres that could be reused.\n\n\u201cOnce all the water was in place, we heated it up to 90\u201395 degrees via the heat exchangers. We thought the first heating cycle would be expended on heating up the surrounding rock and that the water would therefore cool relatively quickly. But it turned out that the water retained its heat and was sufficiently hot to be used for discharge to the district heating grid several weeks later,\u201d says Winkler.  \n\nM\u00e4larenergi can store 13 GWh of district heat in the UTES, enough for all the customers in V\u00e4ster\u00e5s for up to two weeks. Being able to use such a big old oil bunker as a modern thermal energy storage facility has generated a lot of interest from energy industry journalists and the energy industry, both in Sweden and abroad. \n\nAccording to Winkler, other energy companies will be looking at large-scale storage facilities of this type. \n\n\u201cIf a disused underground bunker is available near a combined heat and power plant, such a solution may well be financially viable. There are a lot of empty, disused underground bunkers that could be converted to thermal energy storage. Plans are already being made in several other locations, including G\u00e4vle and Sundsvall,\u201d concludes Winkler.<\/p>\n\n\n

    For more details, contact:<\/i>
    \n<\/i>Stefan Winkler, +46 (0)21 81 80 93<\/i><\/p>\n\n\n

    \"\"<\/figure>\n\n\n

    The new UTES facility was opened by H.M. the King, who found M\u00e4larenergi\u2019s UTES exciting and put a stream of technical questions to Magnus Eriksson, Deputy CEO of M\u00e4larenergi. Photo: M\u00e4larenergi, Henrik Mill.<\/i><\/p>","protected":false},"excerpt":{"rendered":"

    Carl-Oskar Bohlin, the Minister for Civil Defence was given a guided tour around the bunker by Stefan Winkler from FVB and Ivette Farias, Project Manager at M\u00e4larenergi. Photo: M\u00e4larenergi. The world\u2019s biggest energy storage facility \u2013 located in V\u00e4ster\u00e5s \u2013 will be fully operational by the end of December. It will allow … <\/p>\n","protected":false},"featured_media":9532,"menu_order":0,"template":"","expertise-cat":[329,253,328],"services-cat":[178],"fvb-categories":[],"fvb-nytt-cat":[262,263],"class_list":["post-9527","fvb-nytt","type-fvb-nytt","status-publish","has-post-thumbnail","hentry","expertise-cat-combined-heat-power","expertise-cat-district-heating","expertise-cat-district-heating-network","services-cat-projekt","fvb-nytt-cat-all-news","fvb-nytt-cat-fvb-news-55"],"acf":[],"_links":{"self":[{"href":"https:\/\/fvb.se.ny.haus.se\/en\/wp-json\/wp\/v2\/fvb-nytt\/9527","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fvb.se.ny.haus.se\/en\/wp-json\/wp\/v2\/fvb-nytt"}],"about":[{"href":"https:\/\/fvb.se.ny.haus.se\/en\/wp-json\/wp\/v2\/types\/fvb-nytt"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/fvb.se.ny.haus.se\/en\/wp-json\/wp\/v2\/media\/9532"}],"wp:attachment":[{"href":"https:\/\/fvb.se.ny.haus.se\/en\/wp-json\/wp\/v2\/media?parent=9527"}],"wp:term":[{"taxonomy":"expertise-cat","embeddable":true,"href":"https:\/\/fvb.se.ny.haus.se\/en\/wp-json\/wp\/v2\/expertise-cat?post=9527"},{"taxonomy":"services-cat","embeddable":true,"href":"https:\/\/fvb.se.ny.haus.se\/en\/wp-json\/wp\/v2\/services-cat?post=9527"},{"taxonomy":"fvb-categories","embeddable":true,"href":"https:\/\/fvb.se.ny.haus.se\/en\/wp-json\/wp\/v2\/fvb-categories?post=9527"},{"taxonomy":"fvb-nytt-cat","embeddable":true,"href":"https:\/\/fvb.se.ny.haus.se\/en\/wp-json\/wp\/v2\/fvb-nytt-cat?post=9527"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}