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Innovative large-scale energy STOragE technologies AND Power-to-Gas concepts after Optimisation

Periodic Reporting for period 3 - STOREandGO (Innovative large-scale energy STOragE technologies AND Power-to-Gas concepts after Optimisation)

Reporting period: 2019-03-01 to 2020-02-29

The project STORE&GO started in March 2016 with the aim to demonstrate the maturity of power-to-gas (PtG) energy storage concepts, to analyse key drivers for their market uptake, and to better understand their potential role in the transition to a sustainable energy system. For this purpose, the 27 STORE&GO partners erected and tested three different PtG pilot plants for storage of renewable electricity in methane, or Synthetic Natural Gas (SNG). The plants are located at three different sites, in Falkenhagen (Germany), in Solothurn (Switzerland), and in Troia (Italy).
The overall objectives of the project can be summarised in the following points:
• Erection and operation of the three pilot plants showing 4000 hours of operation.
• Reaching an overall energy efficiency > 75 % for the PtG process chain by producing SNG and using waste heat.
• Decrease in capital costs for industrial scale methanation plants by at least 15 % compared to state-of-the-art technologies.
• Increase of operating flexibility of methanation technologies aiming at load modulations from 20 to 100 %, and ensuring long-term stability of the methanation reactors/catalysts.
• SNG qualities suitable for injection into the gas grids (CH4 content > 90 Vol.-%).
• Demonstration of same or better carbon footprints of the produced gases compared to biomethane produced by state-of-the-art anaerobic fermentation.
• Evaluation and analysis the role of PtG as tool for flexible power generation and supply.
• Development of business models and market entrance measures for PtG in different energy sectors.
• Elaboration of suggestions and recommendations on how to modify/ simplify regulatory and legal issues for further implementation of PtG.
• Thorough overview, based on site-specific surveys and other information, of stakeholder participation potential and public acceptance.
• Assessment, based on various 2050 and beyond energy scenarios, of the potential of PtG to fulfil future storage needs at EU level, and identification of optimal locations for PtG EU-wide.
• Elaboration of a policy agenda that helps to develop PtG technologies.
Concerning the activities at the demo sites:
In Falkenhagen, the existing process to produce hydrogen from an alkaline electrolyser unit was expanded in May 2018 by a methanation unit with a capacity of approximately 1 MW. The operation of the demo site started in January 2019 and run until February 2020. The plant produced SNG for a total of 1.186 hours of operation, and for 668 hours of them gas was injected into the gas grid, corresponding to a total amount of 11.367 kg of injected gas. The developers of the plant (TKIS, UST, KIT) and particularly TKIS, had the chance to develop design rules for plants suitable for large-scale continuous electricity storage.
For the plant in Solothurn, the commissioning was completed in July 2019, and afterwards continuous operation started. The plant produced SNG for a total of 1.300 hours, with gas injection for 1.057 hours. The total amount of injected gas is 11.165 kg. In the framework of these activities, the project partner Electrochaea built a fully automated biological methanation plant with several new features, leading to an improved technology outcome for future commercial exploitation.
Finally, the plant in Troia, after commissioning in April 2019 and performing first test sessions, a continuous testing period started in October 2019. The plant produced 4.669 m3 of SNG for a total of 1.142 hours of operation. Liquefaction was conducted for 191 hours generating 441 kg of LNG. The project gave to the partners KHIMOD (ATMOSTAT) and CEA the opportunity to bring their methanation technology to a level at which commercialisation can start. The partner HST had the chance to realize a small-scale liquefaction plant, which has been added as a new product to their portfolio, and the partner Climeworks had the chance to conduct further field tests of their innovative CO2 capturing unit.
Other highlights from the activities include:
•A technical and economical evaluation was performed for the three different PtG technological solutions developed within the project, based on data collected from the erection and operation of the plants. Results show that all three plants were able to meet the gas quality goal (CH4 > 90 Vol -%) at different loads.
•An estimation of the development of production costs until 2050 was performed for different sub-components of PtG plants. Both electrolysers and methanation systems, show promising cost reduction behaviour related to scaling effects and technological learning. Taking 5 MW as reference scale, CAPEX reductions are estimated, for electrolysers in a range from 60 – 75%, and for methanation systems from 50 – 60%.
•The interactions between the future electricity transmission system and PtG technologies were investigated. Results show that investments in PtG will promote an increase in the range from 7 up to 20%, in the amount of RES dispatchable in Europe, and can also lead to a decrease in electricity costs, ranging from 13 up to 23%.
•The European and national (Germany, Italy, Switzerland) legal framework applicable to power-to-gas was thoroughly examined to identify obstacles for PtG. Studies included various aspects, like the legal classification of power-to-gas, the authorisation procedures for PtG, the legal measures facilitating the injection of SNG into the gas network, the exemptions from network tariffs and other charges, etc.
•An EU-wide identification of potential locations for PtG plants was performed based on the geographical availability of wind energy and substation distribution, combined with industrial and biogenic CO2 sources. Potential for power-to-methane (PtM) technologies exists all over Europe, and the total theoretical PtM potential by 2050 will range from 1200 up to 1400 TWh/a with CO2 from biogenic sources alone.
•A roadmap with policy recommendations for the implementation of PtG until 2050 in Europe was created.
Concerning the demo sites, testing in parallel three different methanation technologies after adaptation and optimisation is itself a unique outcome. Results from their operation showed that the developed methanation technologies are mature enough to be deployed for commercial use in different PtG concepts. Moreover, the plant configuration used in Troia, with small-scale electrolysis, CO2 capture from air, methanation and liquefaction, can theoretically be deployed almost wherever there is an excess of renewable electricity production. All these have of course great importance for future activities of the plant developers, and particularly for SME companies like KHIMOD (ATMOSTAT), CW and HST.
Barriers that may hinder implementation of PtG were identified and include the difficulty in finding contractors for fabricating special parts of the plants, the lack of trained personnel for taking over or supporting PtG plant operation in remote areas, as well as the lack of clear and structured procedures for authorising the erection of PtG installations and for certifying their safe operation.
The outcomes of the STORE&GO cross-cutting activities generated a unique basis for evaluation of the market potential of PtG and of impacts from its implementation. The STORE&GO roadmap constitutes a major contribution to an otherwise poorly explored field.
Landscape showing how PtG connects various components of the energy system