Varberg Energi is building a new district cooling system utilizing the sea as a natural cooling resource, plus surplus heat from a nearby factory. The result is cooling production up to five times more efficient than the systems owned and used by customers. FVB is main project leader and responsible for process design.
Varberg Energi is investing in district cooling, a totally new product for the company. Production will be a mix of geocooling, absorption cooling and compressor cooling, giving peak production of 15 mW in total. An accumulator will also be built.
“This was the best combination in terms of economy and the environment. Total COP for our production plant is 15 mW, compared to customer plants achieving only 3–4 mW. That means we save huge amounts of electricity currently used by inefficient cooling machinery,” says Michael Slättberg, Development Engineer at Varberg Energi.
Multiple production options enable highly competitive cooling prices
“For example: in the event of negative electricity prices, we can make use of the compression cooling plant to a greater extent. It will be a system we can optimise in various ways and with a high level of redundancy, as we have a range of production options,” explains Slättberg.
During the warmer months, Varberg Energi will mainly use surplus heat from Södra Cell Värö to produce absorption cooling, but the sea will provide the main source of cooling all year round. Varberg harbour is so deep that Varberg Energi can avoid having to lay long pipelines to reach sufficient depth, although the permit application process has taken time.
“It is always a sensitive issue to extract and discharge water from the sea, which is why the decision on a permit took so long,” says Aksel Holmberg at FVB. He is a Process Engineer responsible for process design and function description of the production plant.
“The project also requires altering the entire harbour to make room for the new Västerport residential development, which involves extensive coordination with other projects in the area and detailed planning,” he adds.
The objective is to connect the first customer, the city’s hospital, in 2027, initially using a temporary cooling unit. Varberg Energi plans to complete the central cooling plant in the harbour no earlier than 2029.
The hospital will be the largest customer, alongside offices, the university campus, hotels and retirement homes. A horseshoe‑shaped district cooling network will connect these customers, with a southern branch supplying the hospital and a northern branch extending to the Holmagärde industrial zone.
Interest in connecting to district cooling is strong in Varberg, driven by clear economic and environmental benefits
“District cooling is a highly flexible solution that means customers avoid the hassle of maintenance. Having your own cooling machinery places a heavy environmental burden on the owner. The machinery often contains hazardous coolants that require leak detection. Most businesses do not have these resources in-house and have to outsource. District cooling customers avoid all that,” say Aksel Holmberg. Michael Slättberg adds:
“We also find that our customers are attracted by the sheer convenience. Running cooling machinery is expensive and requires a lot of maintenance. District cooling eliminates ten tonnes of coolant from the centre of Varberg. Then there’s the reduction in noise levels from fans attached to coolant chillers and outdoor cooling units.”
In short, district cooling offers significant opportunities in Varberg, but a small organisation faces complexity when developing both the customer base and the technical systems. Varberg Energi therefore brought in external expertise at an early stage. As a result, FVB has been involved from the outset — from the feasibility study to Bernt Andersson from FVB now leading the project as Chief Project Manager.
“FVB has been key to our project. They have been able to provide everything from project management and design to procurement and commissioning,” concludes Michael Slättberg.
