Greenhouse gas (GHG) emissions associated with Liquid Air Energy Storage (LAES) systems depend significantly on the type of fuel or energy source used in charging the system and the associated system configuration.
Emissions from LAES Using Different Fuels
- Renewable Energy Sources (RES) Charging: LAES systems charged primarily by renewable electricity (e.g., wind, solar) enable significant reductions in CO2 emissions. A study shows that integrating LAES can reduce CO2 emissions by up to 21% compared to scenarios without LAES, mainly by enhancing the utilization of renewable energy generation and displacing fossil fuel use in the grid. In a robust case in Spain, LAES integration lowered CO2 emissions by as much as 78% compared to conservative non-LAES use scenarios.
- Natural Gas Displacement: LAES can replace a portion of natural gas used for electricity generation. Since natural gas combustion produces substantial CO2 emissions, LAES reduces emissions by cutting natural gas consumption by approximately 25% in some grid scenarios. This displacement effect is vital because natural gas is a significant source of CO2 emissions in power generation.
- Fossil Fuel-Based Charging: If LAES is charged from fossil fuel-derived electricity, especially coal or petroleum-based sources, the net emissions reduction is much less or could be negative since the upstream GHG emissions of the fuel still apply. Therefore, LAES systems are only environmentally beneficial when charged with low-carbon or renewable electricity.
- Comparison with Other Storage Technologies: LAES shows superior environmental performance compared to some other energy storage technologies, particularly in grid mixes with high fossil fuel shares, owing to its ability to integrate with renewables and cogeneration systems.
Additional Notes on Life Cycle Emissions
- LAES systems involve energy-intensive air liquefaction and compression processes, but these can be offset by renewable charging and heat recovery during discharge, which reduces overall GHG emissions.
- Other fuel types, such as biomass or wood fuels, have distinct GHG profiles. For example, wood-cogeneration systems show emissions in the range of 11–19 g CO2-equivalent/MJ depending on emission control technologies but are generally not directly related to LAES operation.
Summary Table
| Fuel/Charging Source | GHG Emissions Impact in LAES Systems | Notes |
|---|---|---|
| Renewable electricity | Up to 21-78% CO2 emissions reduction | Largest emissions benefit, especially displacing natural gas |
| Natural gas (displaced) | ~25% reduction in natural gas consumption | LAES reduces reliance on natural gas generation |
| Fossil fuel-based electricity | Limited or no emissions benefit; possibly higher | Depends on fuel; petroleum and coal cause direct emissions |
| Biomass/wood fuels | Not directly related to LAES; emissions vary 11-19 g CO2-eq./MJ | Different system; biomass emissions depend on combustion and controls |
In essence, the greenhouse gas emissions from LAES systems vary widely with the fuel or energy source used to charge them. The greatest emission reductions occur when LAES employs renewable electricity to charge, enabling significant displacement of fossil fuel generation, particularly natural gas, leading to meaningful cuts in CO2 emissions on the grid. Conversely, if charged with fossil fuel electricity, the GHG benefits are minimal or negative.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/what-are-the-greenhouse-gas-emissions-from-using-different-fuels-in-laes-systems/
