Greater direct use of renewable energy resources means that the electricity grid is either dependent on weather variations or on tidal flows. Too little, or too much, energy may be generated and there is little control of when the energy is generated. This provides an issue for grid stability as energy production is not controllable. The problem is likely to become more severe with the increasing application of renewable energy resources, especially as the EU aim to generate 20% of the energy used in Europe from renewable sources by 2020. One method to balance the issue of generation and demand is to store energy during periods of low demand and use it at times when there is high demand.
Cryogenic storage makes use of low-temperature liquids (such as liquid air or liquid nitrogen) as an energy storage and transfer medium. Cryogenic storage can provide large scale, long duration energy storage.
The prime objective of the CryoHub project is to investigate the potential of large-scale LAES (Liquid Air Energy Storage) at refrigerated warehouses and food factories and to use the stored energy for providing both cooling on site and electrical energy generation during peak demand periods. There are several benefits to this approach:
1. To provide large scale energy storage to aid grid balancing on daily and weekly timescales (take grid energy when there is too much and put in energy when there is not enough).
2. To store energy from local intermittent RES (Renewable Energy Sources) before supplying to the grid.
3. To ‘peak shave’ (i.e. remove the peak power requirement from the grid) refrigerated warehouse/food factory energy use and at the same time generate and supply part of the required peak energy back to the grid.
4. To provide free cooling to the cold stores during power generation.
5. To decarbonise the electricity grid.
By utilising LAES there are considerable benefits in being able to use low carbon resources more effectively.
To achieve this overall goal the CryoHub project has the following sub-objectives:
1. Evaluate the present and future potential for LAES at refrigerated warehouses, disseminate to stakeholders and end users from the energy and food refrigeration sectors.
2. Determine key processes and unit operations to make use of LAES in a common refrigerated warehouse and identify how waste heat and the stored cryogenic cold should be integrated in the best possible way.
3. Identify the energy and carbon savings that the LAES could achieve in refrigerated warehousing and food factories against the background of conventional facilities.
4. Identify engineering solutions to consolidate a LAES system with a typical warehouse refrigeration plant for performance optimisation and efficiency enhancement.
5. Develop a software system for automated decision support and management of the RES proportion and cryogen expenditure as a function of predicted warehouse and grid behaviour, environmental conditions, energy demand and availability, price variation (depending on tariff plans negotiated and/or fluctuations on the stock market), etc.
6. Build, validate and demonstrate the performance of LAES system technology for a refrigerated warehouse.
7. Elaborate a strategy for LAES implementation across Europe.
