For a renewable energy transition, which includes the total final energy consumption (electricity, heat, fuels), we increasingly need renewable control energy. The current share of 25 percent renewable energy sources in the electricity market shows that renewables can take on a lot of responsibility on windy summer days. However, this success can only with little consolation that we have so far hardly been able to rely on the renewables family on windless winter days. In order not to head for supply gaps in the event of a further increase in solar and wind energy, supplementation with renewable balancing energy is essential. Biogas and processed biomethane are storable energy sources, which are ideal for use as a base load securing energy source.
The following text is a communication from the BMU funding program "Energetic use of biomass".
The future of biogas is the ability to provide electricity as needed to compensate for the feed-in of wind and sun and thus to contribute to the security of the electricity system. With the Flexibility premium of the EEG first incentives were set up for such an operation. The research project "OptFlex Biogas" launched by the DBFZ and the electricity dealer Next Kraftwerke in the BMU funding program "Energetic Biomass Use" is devoted to the question of which technical properties of a biogas plant are optimal for profitable marketing on the electricity market. In addition to the technical-economic optimum, the focus is on the greenhouse gas effects that result from the shift in electricity production.
Currently producing more than 7.000 biogas plants in Germany Electricity. The feed-in takes place comparatively continuously since the optimal operation within the framework of the fixed feed-in tariff of the EEG is with a maximum utilization of the equipment used. Many new plants today have a degree of utilization of 90% to 95% and partly above it. The generation of the entire inventory thus represents a comparatively safe provision of base load electricity. Due to the increasing share of fluctuating renewable energies, such as wind and photovoltaics, base load electricity will become an increasing problem, since these cannot relocate their production and can only be temporarily stored at high costs. The need for flexible power plants with fewer operating hours is growing. Biogas plants can be expanded by expanding the installed capacity, for example by installing another Biogas cogeneration plant (CHPs), and if necessary, an increase in gas and heat storage capacities provide a more needs-based mode of operation.
The costs caused by the plant adjustment are to be offset by the proceeds from direct marketing in connection with the flexibility premium. The electricity trader poses the question of which system equipment promises the highest possible profits from an optimized marketing of the electricity generated on the electricity exchange Next power plants GmbH and the DBFZ as part of the joint project "Determination of a technically and economically optimized operation of flexible biogas plants". To answer this question, various practice facilities that are already new Regulations of the EEG 2012 use or plan to use them, examined in detail. The operation of the systems is viewed over a longer period of time and analyzed for possible technical optimization potential. In addition, various marketing strategies are being developed for the corresponding systems in order to determine theoretical revenues from changes in the way of operating.
In addition to the technical-economic optimization, the project will also consider the greenhouse gas effects that result from the relocation. On the one hand, the emissions generated by the plant itself, and on the other hand, the emissions saved by replacing fossil fuels and the emissions saved by a possible reduction in the curtailment of fluctuating renewable energies are balanced.
The results of the two-year project (2012-2014) are intended to show plant operators in practice the possibilities and chances of supplying electricity as required, as well as providing information for an optimized expansion of further plants. Furthermore, recommendations for action are to be given to the legislator for a further practical design of the support framework for the needs-based provision of electricity from biogas.
Digression as needed
The need-based provision includes a scheduled provision based on the daily exchange prices. The schedule for the following day must be reported to the network operator by 14:30 p.m. every day. The forecasts for the schedule creation of wind and PV electricity have improved significantly in the past. Via a bilateral trade, market participants can compare possible deviations from their timetables up to 15 minutes before provision or demand. If there are supply-demand differences at the time of provision, these will be compensated for in the short term by the responsible transmission system operator for the purposes of frequency maintenance by calling up positive balancing energy in the event of increased demand and negative balancing energy in the event of an increased supply.
The funding program & the project
As part of the national climate protection initiative, the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) has launched the program "Promotion of research and development for the climate-efficient optimization of energetic use of biomass". In the course of this program, the joint project "OptFlex Biogas - Determination of a technically and economically optimized operation of flexible biogas plants" (FKZ: 03KB073) is funded. The DBFZ is also responsible for the scientific monitoring of the funding program. The BMU commissioned the project management company Jülich (PtJ) with the technical and administrative coordination of the same