Published 3 April 2017
Stora Enso strives to produce renewable packaging, construction materials, and paper using low-carbon energy – but what exactly does it mean?
Heinz Felder, Stora Enso’s Head of Investments and Energy, and Johan Holm, Head of Environmental Policies and Programmes, explain how Stora Enso’s products are largely made using fossil-free energy – and how this helps to combat global warming.
What types of energy does Stora Enso use to produce pulp, board, and other renewable materials?
Heinz Felder: All our pulp, paper, and board mills have their own power plants, and so do most of our sawmills. When producing energy we first use biomass-based residual materials from our own production processes. At pulp mills this means burning black liquor, whereas at sawmills we use bark and sawdust as fuels. Overall, 82% of the fuel we use is biomass-based, and thus fossil-free. So in addition to providing us with renewable raw materials, sustainably managed forests also give us renewable energy as a by-product. However, we still also use small amounts of fossil fuels, such as gas, coal, and peat.
How are biomass-based fuels better for the environment than fossil fuels?
Johan Holm: These renewable fuels originate from trees, which capture carbon dioxide from the atmosphere as they grow. When these fuels are burned, this carbon dioxide is released back into the atmosphere. Forests growing where trees were earlier harvested will then reabsorb it. As long as forests are managed sustainably, using biomass-based fuels doesn’t add carbon to the atmosphere. Biomass fuels form part of the natural carbon cycle, whereas non-renewable fossil fuels do not.
We are quite unique among energy-intensive heavy industries in that only 20% of our carbon dioxide emissions are fossil-based, whereas 80% are fossil-free and result from the combustion of renewable biomass-based fuels.
Is Stora Enso fully self-sufficient in terms of energy use?
Felder: Just over half of the electricity we use is purchased from the market, with a preference for low-carbon energy sources. In 2016 some 89% of the electricity we purchased was low-carbon, including nuclear and renewable energy. The share of renewable energy on the Nordic market has been increasing, making it easier for us to buy clean electricity. With regard to heat, we are self-sufficient.
Some of Stora Enso’s production units run on 100% renewable energy already. How is this possible?
Felder: Pulp mills generate more renewable energy as a by-product than they need for their production, so their operations are free of fossil carbon dioxide. The excess energy is sold to the national grid. In addition, eleven of our mills produce surplus heat that is used in local district heating networks, reducing the need for fossil fuels in these localities. In Austria, our sawmills have switched to purchasing 100% renewable electricity from the national grid. We make such switches whenever this is technically and commercially feasible.
How do you work out if the energy that you use is clean?
Holm: One of our key performance indicators at Stora Enso measures the share of fossil fuels in our energy consumption – and this figure is fairly low, amounting to 62 kg of fossil carbon dioxide emissions per MWh. This is a good indicator for all industries to show how clean their energy is.
We are highly ambitious when it comes to combatting global warming. For over a decade we have been actively reducing the energy intensity of our operations – and in many places also our dependency on fossil fuels. It is our firm intention to drive down our fossil fuel use even more over the next ten years, so that we can get as close to zero as possible using technically and commercially feasible means. We are running pilot studies examining opportunities to use even more low-carbon options at some of our mills. We have reduced our direct and indirect fossil CO2 emissions by 39% since 2006.
However, our carbon intensity will in future be adversely affected by our Beihai board mill in China. Coal is currently the only feasible energy source for an industrial unit of this scale in this location, but we are already investigating options that could enable the mill to shift to non-fossil fuels in the long term.
What actions are you taking to improve your energy efficiency?
Felder: Every year we spend about 10 million euros on energy saving investments through a special fund. Best practices in place at one mill can then be adopted by other mills to multiply the savings. Recent examples include the use of LED lightning, and the installation of frequency converters to fine-tune energy flows.
How can new technology contribute to Stora Enso’s work on energy?
Felder: The company’s whole energy system is already automated, but digitalisation can always help us to take another step forward. There are many structural changes on the horizon, such as the development of large scale energy storage systems, and increases in the numbers of small producers of renewable energy on the market. These developments will bring new opportunities for society as a whole. We are on an interesting journey towards a low-carbon bio-economy!