With numerous solid, liquid and gaseous energy sources, bioenergy has a broad base and offers possible uses for every energy sector. In the public bioenergy debate, the strengths and weaknesses of biogas and Biofuels discussed and we are looking for the ideal application paths of bioenergy in the electricity and fuel market. In contrast, solid bioenergy sources based on the raw material wood dominate the less focus on renewable heat supply. A hotly debated field for wood energy is co-incineration in central large power plants. With one of the dena organized dialogue on biomass co-incineration, the opportunities and risks of this bioenergy use were felt. Inspired by the discussion of the event, this article gives an insight into the current state of wood energy in Germany and arguments of the specialist dialogue are presented.
Wood energy in Germany
As the graphic shows, the energetic use of wood accounts for almost half of the wood used in Germany every year. Expressed in numbers, 55 million cubic meters of wood (around 35-40 million tons) are used to generate heat and electricity. The currently used wood-based energy sources are the following:
- Wood pellets
- Wood chips
- wood briquettes
No high-quality wood may be felled in Germany for their use in the energy sector! Certification according to PEFC or FSC is responsible for ensuring the sustainability of fixed bioenergy sources in Europe.
As a trend in recent years, it can be seen that the production of wood energy sources in Germany is increasingly shifting from decentralized to centralized production. Decentralized and medium-sized production companies are increasingly being replaced by large energy suppliers. It is easy to understand that this market change also leads to conflicts.
As a concrete example, I would like to take a closer look at the current growth market for wood pellets. The production and consumption of wood pellets differ significantly in Germany and of the almost 2 million tons of wood pellets produced in 2011, only about 1.4 million tons were used in Germany. About a third of the wood pellets are therefore exported. Italy, France and Switzerland are the most important importing countries for the pellets produced here.
"Western Europe is the driving force in the trade and use of wood pellets" - Dr. Hubert Röder, Pöyry
Development of the wood pellet market
16 million tons of wood pellets were consumed worldwide last year, with Dr. Hubert Röder from Pöyry Management Consulting suspects that consumption will even increase to 2020 million tons by 20. In terms of production capacity, the following countries are the largest markets worldwide, with the list starting with the largest market: USA, Brazil, Russia, Canada, Great Britain, Germany and China. The largest transhipment point for wood pellets is Europe, despite the larger production markets overseas. 4.4 million tons of wood pellets are traded here every year.
Above all, their favorable price development contributes to the success of the fixed bioenergy sources. The graphic shows that the biogenic solid fuels listed have been closed below the price level of heating oil for 3 years. In the case of wood chips, the price is currently only a third of the heating oil price. Matthias Edel (dena) sees one of the great advantages of bioenergy sources such as wood energy or biogas in the fact that they entail comparatively low CO2 avoidance costs and thus support affordable climate protection. In the medium-term perspective of Dr. Röder will neither drop nor explode the price of wood pellets.
The solid bioenergy sources offer promising advantages within the energy transition. Some of the major power plant operators also see it that way and therefore deal extensively with the co-combustion of biomass in coal and natural gas power plants.
Co-incineration as a point of contention between central and decentralized wood energy
The topic of co-incineration by biomass is on the one hand a great bearer of hope, but also leads to concerns about the possible handling of our forests as a result. In my opinion, we in Germany can afford a balanced level of optimism about co-incineration. After all, Germany belongs to those countries that have a long tradition in sustainable forest management and the concept of "sustainability" was first introduced by the German forest scientist Hans Carl von Carlowitz embossed. Originally, its use in 1713 even refers directly to the sustainable Use of forests.
What does the co-combustion of biomass mean?
To make it easier to understand the scale, the graphic provides an overview of the development of Biomass CHP plants in Germany for the past 11 years. What is special about these systems is that they only use organic substrates (“biomass”) for incineration. In this way, the BMHKW supply electricity and heat with an impressively good climate balance. The absolute CO2 emissions from biomass cogeneration plants are significantly more favorable for climate protection than those from coal-fired power plants. However, this did not mean that the carbon footprint of biomass combustion was not also viewed critically.
The performance development of the graphic also shows that the installed electrical output of biomass heating plants in Germany (1.3 GW) in comparison with the Plant performance in the biogas area (3.2 GW) is still low. The use of biomass in BMHKW roughly corresponds to the output of two medium-sized coal-fired power plants. Since we have at least 2 coal-fired power plants in Germany with an individual output of over 65 MW, the co-combustion of biomass in coal-fired power plants (biogenic solid fuels) and natural gas power plants (biogenic gas fuels) has found quick access to the climate protection debate.
The co-firing of biomass in large central power plants offers the following advantages:
- Rapid contribution to climate protection
- The high efficiency of large power plants enables the efficient use of biomass for energy
- Comparatively low investment costs and thus an affordable contribution to climate protection
The co-combustion of biomass has the following disadvantages:
- The central use reduces the proportion of biomass that is available for a decentralized energy transition. Due to the large quantities required for co-combustion, the biomass can only be obtained to a limited extent from the immediate vicinity of the incineration plant. With numerous small / decentralized plants (e.g. wood pellet plants) the transport routes would be shorter.
- The infrastructure of the fossil energy industry will be consolidated in the medium term, making the complete switch to 100 percent renewable energies difficult.
One of the big questions of the energy transition is that of the degree of decentralization of increasing electricity and heat generation from renewable energies. This question also arises in the further expansion of bioenergy. What mix of rural and industrial biogas plants do we want? Let us use our wood pellets mainly in central large power plants (see biomass strategy and Co-incineration of Vattenfall Europe AG) or in decentralized pellet plants? We will probably see a mix of both systems and both politics, the market and science will influence the further design.
What do you think about co-incineration? Do you mainly support the central or decentralized wood energy?
Download of the lectures on co-combustion of biomass
You can do this here at the specialist dialogue “Co-incineration and sustainability of biomass - a contradiction? ”Download the lectures held. The graphics used for this article are from the Agency for Renewable Resources (FNR). Many thanks to both actors for enriching and deepening the bioenergy debate!