| Work Detail |
An international group of researchers has designed a new hybrid liquid-air photovoltaic energy storage system (PV-LAES). Their economic evaluation of the proposed 2 MW PV-LAES project showed that the payback period of the investment can be as long as 10 years, and the cumulative net benefit can reach USD 2.2 million from a life cycle perspective. Researchers from Sichuan Normal University (China) and the University of Cambridge (UK) have studied the technical-economic feasibility of a new hybrid system that integrates photovoltaics and liquid air energy storage (LAES). Conceived for large-scale application, LAES systems store electricity in the form of liquid air or nitrogen at cryogenic temperatures - below -150ºC. They are charged using excess electricity to power the compression and liquefaction of air, which is then stored as a liquid at temperatures close to -196ºC. To discharge, the liquid air is heated and converted into a pressurized gas that drives a turbine to generate electricity. The proposed system consists of a local 2 MW photovoltaic plant equipped with a boost converter based on maximum power point tracking (MPPT). The facility is capable of generating low carbon electricity with small fluctuations of between 12.89 and 12.99 MWh per day. The LAES unit uses the surplus power of the photovoltaic plant and compensates the power of the local load with an inadequate power level. The duration of energy storage of the system in off-peak hours is 9.13 hours, and the duration of energy release in peak hours is 6.27 hours. In the case of the proposed PV-LAES project, the results show that the renewable electricity surplus of 6.73 MWh sent to LAES is used to generate 27.12 tons of liquid air as energy reserve during the day. In this case, the LAES unit has a round-trip efficiency of 47.4% and can deliver flexible power compensation to the load at night. Meanwhile, main grid power demand drops significantly in one day, from 12.78 to 3.33 MWh. Based on these data, the annual energy savings are estimated at 3,449.25 MWh, and the corresponding carbon emission can be reduced by 2,607.63 tons. In terms of economic performance, the PV-LAES system has a dynamic payback period of 9.33 years and a cumulative net benefit over the life cycle of $2,260,011, according to the researchers. Their conclusions are presented in the article “ Hybrid photovoltaic-liquid air energy storage system for deep decarbonization ”, published in Energy Science and Engineering. The proposed PV-LAES scheme is economically viable from a life cycle point of view and can achieve flexible energy interaction with local renewables to achieve an integrated low-carbon energy generation and storage system, they conclude. the researchers. |
