At Frederikshavn Forsyning, a significant amount of energy was still present in the flue gas from production. The temperature was typically around 45–50°C, but with return water at approximately 40°C, the remaining heat was difficult to utilize with conventional solutions. At the same time, the plant had already been optimized with measures such as an economizer, meaning the most obvious energy savings had already been achieved. Still, there was more value to recover.
This is exactly the kind of facility where hidden energy potential is often overlooked.
When existing solutions reach their limit
The limitation in the existing setup was that the flue gas could not be cooled any further without affecting operations. As a result, part of the energy remained out of reach, even in a plant that was already highly optimized.
To recover this remaining energy, ME Production implemented a closed-loop heat pump solution. The system extracts energy from the flue gas at a low temperature and raises it to a usable level, where it can be reused in the plant, including for preheating water in the boiler process.
The solution was developed and implemented by ME Production in collaboration with Danfoss. A key part of the project was ME Production’s ability to adapt the system to the existing plant. Integration, controls, and component interaction were all optimized to match the specific operating conditions at Frederikshavn Forsyning.
Stable operation and new insights
After approximately 1.5 years of operation, Frederikshavn Forsyning reports a stable and trouble-free solution. The noise level has also proven to be significantly lower than expected. The system is compact relative to its output and can be adapted and scaled to meet different needs.
The solution does not depend on a specific boiler type. Its core principle is to recover waste heat regardless of the source. This makes the technology relevant for a wide range of facilities, including plants where hidden potential is often overlooked.
Measurable results
The system has so far produced approximately 388 MWh net, corresponding to the annual heat consumption of around 25 households, when electricity consumption is deducted.
At the same time, operational data points to a much greater potential. In an optimal heating season, with full utilization and stable operating conditions, production is expected to be up to five times higher. In the most favorable operating scenario, the system could reach up to around 2,800 MWh.
The high energy efficiency of the solution is a key factor. It contributes directly to lower operating costs and supports a strong business case.
An investment that makes sense
For Frederikshavn Forsyning, the financial aspect was crucial. With a payback period of around three years, based on the expected level of operation under optimal utilization, the solution represents a profitable investment.
The case also underlines an important point: if the business case works in an already optimized plant, the potential is often even greater in facilities that have not yet been optimized to the same extent.
Frederikshavn Forsyning describes the solution as stable, flexible, and financially attractive. They also recommend ME Production’s solution and approach to others in the industry looking to make better use of their existing energy resources.
