Presently, energy in Europe is provided mainly via four separate supply chains:
the gas grid (supplied with natural gas)
the electricity grid (supplied mainly by fossil and nuclear power plants)
the heat distribution grid (supplied by local waste heat mainly from large power plants)
distribution of fossil fuels on road trucks
Thus, the majority of Europe’s energy sources emits carbon dioxide and other pollutants. This does not even include the domestic sector or private mobility. It is a matter of common knowledge that those carbon dioxide emissions are causing global warming and therefore must be reduced via global climate deals.
After a number of climate conferences lacking either participation or agreement, the Paris climate conference in December 2015 was a huge step forward, as 195 countries adopted the first-ever universal, legally binding global climate deal. While the agreement is due to enter into force in 2020, the EU has already committed itself to reduce emissions by at least 40 percent by 2030, compared to 1990. By 2050, the EU aims to cut its emissions even further – by 80 - 95 percent compared to 1990. These targets can only be reached by turning the vast majority of energy sources from fossil/nuclear into renewable ones.
The integration of such large amounts of renewable energy sources poses technological difficulties, as those sources – like wind and solar – are volatile and generate electricity intermittently. Thus, at times there will be a surplus of energy when there is no demand for it, and vice versa there will be at times high demand when there is not enough renewable energy available. There are two ways that go hand in hand to compensate for the volatile character of the renewables.
- Extending the existing electricity grid will help to reduce regional imbalances of energy demand and production, e.g. transport of offshore wind energy to consumers in the inland
- Storing large amounts of electric energy from renewable sources will enable countries to deal with long periods without sufficient wind and sun available, as e.g. during a dull November.
The latter method is addressed in the project STORE&GO.
Nowadays, pumped hydro power offers the largest energy storage capacities among the implemented storage technologies. Covering the total energy demand of the EU by pumped hydro would, however, drain those storage units within hours. Pumped hydro is therefore not an option for long-term seasonal energy storage, but will remain a cost- and energy-efficient backbone of the energy grid for short- and mid-term storage.
Battery arrays are becoming more and more relevant to help stabilizing the electrical grid – something that becomes increasingly difficult with the growing number of renewable energy sources. Long-term energy storage demands, however, for a higher energy density, lower costs and less self-discharging.
A process called Power-to-Gas (PtG) allows for storing the surplus of renewable energies on sunny or windy days by the creation of synthetic natural gas (SNG), as shortly explained along the following lines. In PtG-systems electrolysers split water into hydrogen H2 and oxygen, the latter of which can simply be released into the atmosphere. Using CO2 from a source like e.g. biomass or waste water, the hydrogen produced is then used for the production of methane CH4, which is basically SNG.
The produced gas can be stored in the existing gas grid or in underground caverns. As a chemical energy carrier in gaseous form, SNG offers the highest energy density of available storage technologies. The existing gas grid allows for the transportation of the gas to various applications whenever and wherever it is needed, e.g. for the generation of electricity, the generation of heat, or mobility. Power-to-Gas thereby facilitates the coupling of different energy sectors. In Europe approximately 70 million consumers of gas can be served using the 2.2 million km long gas grid.
Generating gas from renewable electrical power using Power-to-Gas processes is by far the most promising way to store large amounts of energy and to reach the targets of the Paris agreement for 2030 and beyond. Power-to-Gas diminishes the need for power grid expansion and reduces the associated CAPEX and OPEX costs as well.
STORE&GO goes beyond the state of the art of Power-to-Gas, which has been studied in several research projects. The project focuses on the integration of PtG into the daily operation of European energy grids to investigate the maturity level of the technology. Three different demonstration sites offer highly diverse testing grounds for PtG:
- available energy sources (high wind power; PV and hydro; PV and wind power)
- local consumers (low consumption; municipal region; rural area)
- electricity grid type (transmission grid; municipal distribution grid; regional distribution grid)
- gas grid type (long distance transport; municipal distribution grid; regional distribution grid)
- type of CO2 source (biogas; waste water; atmosphere)
- heat integration (veneer mill; district heating; CO2 enrichment)
Moreover, three different innovative methanation processes will be developed and improved from Technology Readiness Level 5 (TRL) close to maturity (TRL 6–7):
- catalytic honeycomb/structured wall methanation reactors
- biological methanation
- modular milli-structured catalytic methanation reactors
These technologies will be demonstrated at a considerable scale between 200 kW and 1 MW in three different demonstration environments for a runtime of about two years. The resulting product – synthetic natural gas (SNG) – will be injected into the existing grid and delivered to customers. The image shows the innovative STORE&GO approach with respect to the technology and the integration with the power grid, which is also part of the project.
STORE&GO will exploit the project’s results to safeguard the technology. In addition to the technical work packages linked to Power-to-Gas processes, STORE&GO will address the cross-cutting topics of Power-to-Gas. STORE&GO will accomplish the demonstration with a thorough economic and logistic/placement analysis. The integration into the existing power grid will be examined and recommendations for the electricity grid management including Power-to-Gas systems will be given. Furthermore, STORE&GO will assess the economic and business aspects and analyse the large-scale storage and market-uptake potential of the STORE&GO technology. This will lead to business models, a Power-to-Gas roadmap for Europe as well as recommendations for policy makers. Another objective is to reduce the barriers in social public acceptance. Linked to this STORE&GO will examine legislative and legal aspects on European, national and local level, which have a deep impact on the installation and operation of future STORE&GO based Power-to-Gas plants. Finally, STORE&GO will release news on the project here on this website as well as in media and on conferences.
STORE&GO will pave the way towards a society whose energy supply chain is almost completely decarbonized.
The ambitious goals and targets of STORE&GO will be reached with the strong partnership established in the project. The consortium is built of 27 partners from six European countries having expertise in the energy sector, process engineering, economics, law and social science. The interdisciplinary collaboration of the consortium is symbolized in the jigsaw image.