Published 2026-09-10 · Event 2024-09-05

Stockholm heat reuse: Data Parks invitation versus delivered heat

Stockholm Data Parks invites data centers that recover heat into a city system named by the City of Stockholm, Stockholm Exergi, Ellevio and Stokab. atNorth and Conapto publish operator wording about Stockholm Exergi. Those sentences sit in the prepared or described band unless a dated delivery start or a measured volume is shown. GleSYS’s 1 October 2020 start of delivery to Falkenberg Energi is the dated west-coast contrast. This register does not invent Stockholm megawatt-hours.

Heat reuse is a contract problem before it is a sustainability slogan. A hall produces rejected heat at a temperature. A pipe must exist. A buyer must exist. Commercial terms must exist. A dated start or a measured volume must exist before anyone should speak of delivered heat. Stockholm’s public pattern is an invitation to join that chain. It is not, in the pages used here, a city-wide ledger of megawatt-hours received from named halls.

Read the file in this order. First, the Stockholm Data Parks page, which states the partners and the vision that excess data-center heat should not be wasted. Second, atNorth’s SWE01 page, which names a partnership with Stockholm Exergi and describes capturing heat outputs and recycling residual heat through the district-heating plant. Third, Conapto’s 5 September 2024 opening release for Stockholm 4 South, which states heat recovery to Stockholm Exergi in related materials. Fourth, GleSYS’s 1 October 2020 Falkenberg release, which is the dated delivery-start contrast. Fifth, EcoDataCenter’s Falun heat language, if a reader is tempted to build a national heat market from three municipal utilities.

Stockholm Data Parks describes itself as an initiative by the City of Stockholm, district heating and cooling provider Stockholm Exergi, power grid operator Ellevio and dark fiber provider Stokab. The page’s vision is a data-center industry where no heat is wasted. It ties that vision to the city’s objective to be entirely fossil-fuel free by 2040 and says the city has invited data centers to play a key role. It also says the partners have made Stockholm an attractive hub for large data centers which employ heat recovery. Those are invitation and policy sentences. They name counterparts. They do not publish a delivered-heat table for SWE01, Conapto South, or any other hall in this register.

The same page turns cost into a commercial claim: data centers can be paid when they become part of the city’s energy system. That claim is a reason to ask for a contract. It is not the contract. Prepared connections — pipes, valves, substations, design temperatures — can exist without a sale. A letter of intent can exist without delivery. A contract can exist without a public measured volume. DataCenterSweden keeps those four states separate: prepared, intent, contract, delivered.

atNorth’s SWE01 wording is the clearest operator heat sentence in the Stockholm set used here. The Kista page says the campus captures heat outputs generated by the site’s data halls and recycles residual heat through the district-heating plant to provide heat and hot water for the local community, in partnership with Stockholm Exergi. The same page states 12 MW site power capacity, 6,400 square metres, design PUE 1.2, and direct liquid cooling as part of a design that maximises heat recovery. Occupied IT load is not published. Heat actually delivered is not quantified on that page. Liquid cooling that “aids the heat reuse process” is a design description, not a megawatt-hour.

Conapto’s 5 September 2024 release is a dated opening claim for Stockholm 4 South. Together with Stockholm 2 South, the campus was said to offer 5,200 square metres of computer rooms and 24 MW of power. Heat recovery to Stockholm Exergi is operator-stated in related materials. A Stockholm 2 South data sheet states five computer rooms with a total capacity of 4 MW; that phase figure is not added on top of the 24 MW campus figure. The opening release is treated as an operator commissioning claim for the hall, not as an inspected heat-delivery certificate. No megawatt-hour figure is taken from that release.

Other Stockholm operators in this register do not fill the heat ledger. Equinix SK1 and SK2 are published as operating IBX sites without a retail megawatt on the pages used here and without a dated Exergi delivery start in those extracts. Digital Realty’s campus page states 22.7k square metres and does not state a campus megawatt total or a delivered-heat series. STACK’s market page states 18 MW without a heat-volume sentence used here. Bahnhof Pionen and Thule are inner-city halls without megawatts or heat ledgers on the cited pages. GleSYS Stockholm in Västberga has no megawatt on the cited Stockholm page. Absence of a heat sentence is not proof that pipes do not exist; it is proof that this file has no dated delivery claim.

GleSYS Falkenberg is in the file as a contrast, not as a Stockholm measurement. On 1 October 2020 GleSYS said it had started supplying district heating to Falkenberg Energi from a newly constructed west-coast hall. The same release listed 3 MW utility power at completion and used potential wording about annual recovered energy and residential buildings. Those potentials are not stored as measured megawatt-hours. The later operator page states 5 MW total capacity and continues to describe district-heat recovery. A dated start on the west coast does not prove a dated start in Kista. It proves that a delivery-start sentence can exist in Swedish public material, and that Stockholm pages used here have not published the same kind of sentence with a date and a counterpart for the named Stockholm halls.

EcoDataCenter’s Falun language about recovery with Falu Energi & Vatten is a third municipal utility, not a Stockholm fact. It belongs in the Dalarna file. Adding Falun, Falkenberg and Stockholm Exergi wording into one national heat market would invent a market that none of the cited pages published. Heat reuse needs a temperature, a pipe, a buyer and a contract in each municipality. District-heating networks are local. A buyer in Falkenberg is not Exergi. A buyer in Falun is not Exergi.

Mechanisms inside Stockholm still split power from heat. Ellevio is named as the power-grid operator on the Data Parks page. That is the counterpart for a local connection question. It is not a reserved import and not a heat volume. Stokab is dark fiber. Fiber does not warm a radiator. The City remains the planning authority for detaljplan and bygglov. Svenska kraftnät remains the transmission counterpart if a load is large enough. Inspektionen för strategiska produkter remains the screening authority for certain investments. None of those institutions publishes a Stockholm data-center heat ledger on the pages cited here.

Common misreads are cheap. One is to treat Data Parks copy as proof that a named hall is already delivering heat. Another is to treat atNorth’s Exergi partnership sentence as a measured annual volume. A third is to treat Conapto’s opening-day heat sentence as a 2024 megawatt-hour. A fourth is to add 12 MW, 24 MW and 18 MW and call the sum recovered heat. A fifth is to import GleSYS’s 2020 potential annual figure into Stockholm. A sixth is to treat a design temperature or a liquid-cooling loop as a sale. A seventh is to treat the city’s 2040 fossil-fuel-free objective as a 2026 delivery certificate.

What to ask next belongs in the data room. For each Stockholm hall: is there a heat-sale contract with Stockholm Exergi or another buyer, and what temperature, capacity and take-or-pay terms does it use? Has delivery started, and on what date? Is any measured volume public, and for which period? Is the connection prepared only? Which detaljplan covers the building? Which network-owner paper sits beside the heat paper? If the answers are missing, write “unknown” rather than pasting the Data Parks vision paragraph into the project file.

This article proves that Stockholm has a named municipal-and-utility invitation and that two operators in this register publish Exergi heat wording, while a west-coast hall has a dated delivery start. It does not prove how many megawatt-hours Stockholm halls delivered in any year. It does not prove that every Stockholm operator is connected to Exergi. It does not invent a city total. Prepared, contracted and delivered remain three different facts.

Why it matters

Establishment files collapse if an invitation is filed as a delivery. Stockholm Data Parks names the right counterparts. atNorth and Conapto name Exergi. GleSYS shows what a dated start looks like — in Falkenberg, not in Stockholm. None of those sentences is a Stockholm megawatt-hour.

What remains unknown

Measured Stockholm heat volumes, contract terms and whether every named hall is actually delivering remain unpublished in the sources used here. Annual megawatt-hours after GleSYS’s 2020 start are also unpublished on those pages.

Sources