Huge, specially designed heat pump saves a Norwegian agricultural cooperative millions Lisa Lock Scientific Editor Andrew Zinin Chief Editor There are some magical limits to how much energy we can get out of a heat pump. This story is about pushing the technical limits. It is about getting more energy out than you put in.

And it's about how SINTEF—one of Europe's largest applied research organizations—the renewable energy company Aneo, and the Norwegian agricultural cooperative Felleskjøpet together managed to shift the recovery of process heat from theoretical calculations in researchers' notebooks to becoming an industrial electricity-saving project on a large scale. The energy used to produce concentrated livestock feed is cut significantly, thanks to a first-of-its-kind heat pump solution. A happy side effect is even higher feed quality.

Experts describe the project as a bold undertaking: No one has ever dared to combine the two systems in this way, and on such a large scale. Norway's biggest kitchen? The characteristic storage silos can be found in Trondheim's Skansen neighborhood.

Next to them is the animal feed factory. Large parts of the food supply for people living north of Dovre municipality depend on getting the concentrated feed made here to farmers in the region. The factory produces about 200,000 tons of feed each year and can justifiably be called one of Norway's largest and most important kitchens.

Now this facility has a heat pump—a really big one. To match the size of the need, we are not talking about the typical version that ordinary homes have mounted on their living room walls. This is a gigantic heat pump that is more reminiscent of the innards of the engine room of a large ship—with huge pipes, compressors, valves and connections.

Precision in every pellet Felleskjøpet's feed development is the gourmet department for livestock meals. But before chickens and cows can enjoy the fortified feed, it has to pass stringent quality controls. Norwegian animals are not served just any feed.

Vebjørn Nilsen is the technical manager at Felleskjøpet and explains what is involved. "The raw materials go into a mixer where steam is injected. The temperature has to permeate the feed so that it is guaranteed to be above 81°C," he says.

"No more than a 1-degree deviation is allowed. If the mixture gets too hot, some nutrients are destroyed. And if the temperature is too low, bacteria can escape, and animals and humans could be exposed to Salmonella." Michael Bantle is the general manager of Aneo Industry and puts the process in perspective.

"The production line here processes 20 tons of product per hour, and each batch has 15 seconds in the mixer to reach exactly the right temperature. At home, you spend 15 minutes baking a pizza," he says. The machine is designed to stop automatically if the temperature is wrong for just 10 seconds.

Valuable steam was being lost right above the roof After the steam treatment, the mixture is first pressed into long rods, which are then cut into even pieces. When the resulting pellets come out of the press, they are hot and moist, and need to be cooled. They then fall into a cooling tunnel where colder outside air absorbs the moisture and cools the pellets down to storage-ready temperature.