Integrated Underground Gas Storage of CO2 and CH4 to Decarbonise the “Power-to-gas-to-gas-to-power” Technology

Geological storage capacity for green excess energy readily available in Germany

“…Energy storage on the basis of methane offers three major advantages over hydrogen storage: (i) it represents the current state-of-the-art and can be applied immediately, (ii) retransformation of methane into electricity can make use of established power plant technologies, and (iii) methane can be easily fed into the existing natural gas network. This is why an essential contribution to the electricity market in Germany and in Europe can be expected (Kühn et al, 2014a).…”

SNG based energy storage systems with subsurface CO2storage

“…[27][28][29] Hence, energy storage by means of CH 4 offers three major advantages: (i) it represents state of the art technology and can be deployed in the short term, (ii) novel and established power plant technology can be employed for the retransformation of CH 4 into electricity (gas to power; GtP), and (iii) the existing gas grid can be used for its storage and distribution, making it an energy carrier of outstanding significance for the energy transition process as well as the transformation of the industrial and transportation sector. 23,30 The coupling of large-scale underground storage of CO 2 and CH 4 with the Sabatier process and conventional methane-fired gas turbine power plant technology for seasonal energy storage of renewables in Germany under the premise of a circular and emission-free use of both gases was previously introduced by works of Ku ¨hn et al [30][31][32] Ku ¨hn et al investigated the use of enhanced gas recovery (EGR) and the feasibility of mutual storage of CO 2 and CH 4 in the same subsurface reservoir demonstrating the viability of EGR and the interlaced energy storage concept. The predicted energy storage costs have been determined to be approx.…”

“…The combination of the PtG process, the methane-fired Allam cycle and suitable large subsurface stores for CO 2 and CH 4 poses an enhancement over the system proposed by Ku ¨hn et al regarding its roundtrip efficiency. 30,34 As the end use of energy electrifies and the demand of electricity inevitably increases, energy systems predominantly based on renewable production will require flexible and largescale energy storage systems, capable of compensating the mostly fluctuating electricity production from these sources. Aside from the capture and storage of large quantities of CO 2 and CH 4 as well as all previously laid out conversion steps for a closed-loop energy storage system, the constitution of the respective national and international electricity production infrastructures will play a crucial role in the efforts of achieving net-zero emissions by the mid of the century.…”

“…27–29 Hence, energy storage by means of CH 4 offers three major advantages: (i) it represents state of the art technology and can be deployed in the short term, (ii) novel and established power plant technology can be employed for the retransformation of CH 4 into electricity (gas to power; GtP), and (iii) the existing gas grid can be used for its storage and distribution, making it an energy carrier of outstanding significance for the energy transition process as well as the transformation of the industrial and transportation sector. 23,30…”

Worldwide Status of CCUS Technologies and Their Development and Challenges in China

“…Unlike the CO 2 -EOR technology, CO 2 -EGR technology is still at the pilot-scale stage. Its efficiency is highly dependent on reservoir type, temperature and pressure conditions, heterogeneity, production strategy, and so on [55][56][57][58][59][60]. For some CO 2 -EGR projects, the gas recovered can reach 10%, while other projects have seen less or no enhancement [61][62][63].…”