Energy efficiency in practice
There has been a lot of talk in recent years about the transformation of pulp mills into bio-refineries and green energy producers. But this is nothing new for Södra Cell - we actually installed our first back-pressure turbine back in 1962, a pioneering move at the time.
We have been growing the energy side of the business in earnest since 2000 when we issued bold strategic guidelines and targets on energy for all of our mills:
· All mills to become free of fossil fuels for day-to-day operations;
· Maximise production of electricity and become a net producer rather than a net consumer;
· Use surplus process heat from the mills for district heating for local communities;
· Maximise the production and sale of biofuels.
These were the days before high-pressure recovery boilers, and before mills exported process heat to neighbouring towns - so Södra was ahead of the game, explains Knut Omholt, former Development Manager at Södra Cell Värö. “The company was thinking ahead to expansion of its pulp mills and it knew that increasing energy production would be an important part of that process.”
The energy strategy has helped shape the pulp mills into what they have become today. Perhaps the shining example of forward thinking is Värö which was the first of the pulp mills to achieve independence of fossil fuels for daily operations, in 2008 (and a world first for the pulp industry). Later our remaining two mills at Mönsterås and Mörrum followed suit.
“We knew that we would want to expand significantly at Värö,” Omholt explains, “although back in 2000, the path was not fixed. But we realized that a final major step would only be made possible after a series of several smaller debottlenecks and small capacity increases, all of which had a bearing on energy use.”
Södra decided that investment was the answer, not just to flattening out its energy consumption curve, but to forcing it downwards. It began a series of energy efficiency projects to ensure that Värö produced more energy than it consumed, even during the winter months. On average, at least one project with an energy aspect was undertaken every year.
A key move was a rebuild of the recovery boiler in 2001 to increase high-pressure steam generation and later increase electricity output. The boiler was prepared for increased capacity and this proved to be a key component of making Värö’s extensive rebuild in 2016 economically feasible. Coupled with energy consumption reductions through the following years, the investment meant that Värö was able to rely solely on the energy from the recovery boiler all year round with some to spare. Better uses were found for the surplus, including selling it to the grid, for district heating and drying then selling biofuels.
The quest for greater energy efficiency continues today. Södra has just announced a set of new sustainability goals, including for all transportation to become free of fossil fuels by 2030. Some of the sawmills are also now running on fossil-free fuels and the drive will continue in one direction only, says Omholt.
The results speak for themselves. Södra has now turned energy from a net cost into an additional source of revenue and we are now one of Sweden’s leading green energy providers.
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