Finland – The global leader of wood bioenergy
Wood energy is historically humanity’s first fuel and still continues to be an important source of energy. Particularly in developing countries, wood energy provides the majority of total energy supply, and surprisingly, even in several developed countries, such as Finland.
In Finland, bioenergy plays a key role in the production of renewable energy and is largely integrated into the forest industry. According to data of Statistics Finland, in 2018 the total consumption of wood fuels was 105 terawatt-hours (TWh). Wood fuels represented the most important energy source in Finland, covering 27 percent of the total energy consumption. Most wood fuels are obtained from forest industry by-products, including black liquor derived from the pulp-making process and bark, sawdust, and other industrial wood remnants. Remnants from timber harvesting or other low-value biomass from forestry and harvesting activities are also used for energy production.
Finland is an ideal region for utilizing wood energy, since forests cover approximately 3/4 of the land as of today. The annual growth of Finnish forests has nearly doubled since the 1950s, and so has the amount of wood that can be sustainably extracted from these forests. The amount of wood in forests are increasing, although wood is widely used for the production of wood and paper products and today also for the production of wood energy. Less than half of all recovered wood is used for heat and energy, while more than half is converted into products. The reasons for Finland’s exceptionally strong forest sector is not only geographical, there’s been a strong research, development and extensive investments since the 1980s. There have been concerns about the targets set for the use of renewable energy causing an increase in the price of wood and direct small-diameter wood suitable for use as a raw material in the pulp and paper industry. E.g. the Finnish forest industry has announced that it makes more sense to process timber into commodities first, recycle a large proportion of them and burn the biomass in them only after recycling. In this way, timber can be used as a material several times before it was used for bioenergy.
Wood energy sources in Finland are typically used in high-efficiency district heating (DH) systems and combined heat and power plants. Most of these depend on direct combustion, but high-tech CHP plants use a fluidized bed boiler or circulating fluidized bed technology to gasify a wider range of low-quality forest residues, reducing operating costs. The gas also makes it possible to displace forest residues from coal burned with coal.
Wood as an energy source
Wood energy has some clear advantages. It does not have the same limitations as other renewable energy sources, as it’s storable and is able to produce energy despite the conditions such as sun, wind, or when hydropower generation capacity is limited. In addition, the use of wood as fuel for energy enables the clean disposal of wood waste and reduces the amount of wood waste sent to landfills – meaning producers of waste can add value by channeling their garbage to create a more profitable use in the form biomass energy. In fact, even the ash left-over from a wood boiler can be used, e.g. as fertilizer. However, using wood for energy can have negative consequences if not used properly, when it can be a significant source of indoor and outdoor pollution. Also, over-exploitation of forests has serious environmental effects such as deforestation, destruction of ecosystems and animal habitats, accelerated soil erosion among others.
Nonetheless, wood energy can be a very clean and sustainable fuel, if best practices are applied to sourcing, processing, and combustion efficiency. As a natural part of photosynthesis, properly used wood fuels only release the same amount of carbon into the atmosphere as was absorbed by plants in the course of their life cycle.
Wood to energy process
Finnish wood energy production is modern. Wood pellets, made from compressed wood particles, are changing the way wood is used for heat and power generation in the virtue of their efficient combustion, convenience, and the fact that they are more energy-dense than traditional firewood. The manufacture of wood pellets and their distribution supports employment in the forest sectors, often in rural areas where job opportunities are needed. This development has also provided market options for what had been low-value residual wood products, such as sawdust, post-consumer wood and wood from harvest sites, which had often been seen as not having value and thus left in the forest or burned in the harvest area.
Wood fuels play a significant role also in the future in targets and means for increasing the share of renewable energy in Finland. As we can learn from Finland, by investing in research and development can lead to great results. The successful existing implementation has awakened global interests towards wood fuels as a potentially environmentally friendly source of energy which in turn has increased the number of initiatives and projects already.