5 approaches to increasing biomethane feed-in

Politically, the annual volume will be 2020 billion m by 63 The aim is biomethane, which is to be fed into the natural gas network. Germany is still a long way from this value, which was set in the Gas Network Access Ordinance (GasNZV) in 2008. The trend does not yet indicate that these goals have been achieved. What are the causes of the sluggish development of the feed-in quota and what options are there for countermeasures?

At the beginning of the year I have an article on the Obstacles to biomethane feed-in written.

I recently read a very exciting article on this topic in the July issue of the magazine “Renewable Energies” and was impressed by how clearly the author of the article, Dr Thorsten Gottwald, is aware of some obstacles to the development of biomethane feed-in, and how difficult the others are The association of conflicting interests appears on the side.

Advantages of biomethane feed

I would like to go into a few key statements of the complex situation here and at the same time recommend reading the entire article. There is no question in my mind that the possibility of feeding in processed biogas (biomethane) is good for the development of bioenergy and makes it even more flexible and environmentally friendly.

Since the electricity cannot be used extensively at the production site, the transport of the heat is necessary to improve the ecological balance (Link to an article on heat utilization concepts for biogas plants).

The greatest advantage of biomethane feed-in is thus a more efficient transport of the heat portion of bioenergy, which only arises during combustion or electricity generation in the CHP. While electricity can also be transported over medium distances without major losses, heat transfer leads to a rapid decrease in temperature and thus to loss of energy quality. Both the economic and the ecological potential of bioenergy are rapidly decreasing when the heat generated is transported directly across municipal boundaries.

The transport as gas (biomethane) to the respective incineration site, where the electricity and heat can then be used via combined heat and power, can also be integrated relatively well into the energy industry due to the already existing transport routes (natural gas network).

Arguments which currently speak against the achievement of the feed-in targets for biomethane

1. Number of existing feed systems

By 2020, around 1.200 biogas plants would have to be built, which have an average feed rate of 700 standard cubic meters of biomethane per hour. Based on the total number of biogas plants already built in Germany (approx. 4.600 BGA, July 2010), this is not utopian. However, currently (April 2010) only 32 of these plants feed into the natural gas network. A developmental explosion by a factor of 2020 would have to take place by 35! Of course, it has to be taken into account that a certain amount of experience must first develop and that after the initial difficulties have been overcome, the development can also proceed very quickly.

2. Low natural gas prices as strong competition for biomethane

The cost of electricity for natural gas and biomethane currently differ considerably. They are around € 17 / MWh for natural gas and around € 70-80 / MWh for biomethane. Therefore, from a purely economic point of view, a natural gas-powered CHP is in comparison to a biogas CHP even cheaper in most regions.

3. Excessive decrease in the Nawaro bonus with increasing output of the CHP

Biogas technology unfolds its strengths particularly in decentralized production and application. This fact has led to a legally anchored degression of the Nawaro bonus with increasing electrical output of the CHP and thus increasing catchment radius of renewable raw materials. However, the degression of remuneration begins very early with a CHP output of 150 kW (LINK on the compensation structure of the EEG).

The current legal text does not take sufficient account of the fact that the ecological balance of a combined heat and power plant increases significantly with an increase in output from 100 kW to 2000 kW. A 100 kW system has an electrical efficiency of around 34%, while a 2000 kW system enables an electrical efficiency of around 42%. A later degression of the bonus should be considered here in order to support this more efficient energy generation more strongly.

4. Barriers to planning for biogas plants based on definitions in the Building Code (BauGB)

The construction of a biogas plant in the outdoor area is "privileged" according to the BauGB. However, this privilege is tied to a “spatial-functional context” and thus the existence of an already privileged company on site. However, a situation with an already existing privileged company and a suitable biogas plant is not always easy to find and can only be implemented on very large farms. However, if the biogas plant cannot take on this "serving function", it is not permitted according to the current legal text (BauGB). The construction of biogas plants is therefore becoming increasingly problematic, which also makes it more difficult to achieve the targets for biomethane feed-in.

5. Conflicts between the natural gas network operator and the biomethane feeder

Both parties, some with very different interests and financial options, still have to find each other when connecting their goals and there are numerous problems in the implementation of feed-in projects. I was already aware of the problems of the network connection in a previous article (LINK) received.

The legally stipulated planning deadlines, the division of the costs incurred and the clarification of the resulting ownership structure for the new network connections often lead to hardened fronts or end up in court. There is still a need for clarification and adjustment in order to create a situation in which both parties see themselves in a win-win situation.

In order to advance the development of the feed-in quota of biomethane, the points mentioned offer good starting points for adjustments. An explanation of these arguments and suggestions for possible solutions are given in the article by Dr. Thorsten Gottwald in the July issue of the journal “Renewable Energies”, with additional figures.

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