Technology
The concept of using a high temperature concrete storage matrix as economic, large scale bulk thermal storage for solar thermal plants is relatively new and has the following advantages:
- Low cost
- Easy on site processing
- Aggregates to the concrete available everywhere cheaply
- Adapted technology that can be implemented in the sunbelt countries
- High specific heat
- Good mechanical properties (compressive and tensile strength, etc.)
- Thermal expansion coefficient near that of steel
- Mechanically highly resistance to cyclic thermal loading
Brief Description
- The block structure consists of several (identical) modules mounted vertically with internal piping protruding from the top and the bottom surfaces. Thermal insulation is applied on each module to minimize the heat loss.
- Internal piping suitably placed in an intermittent fashion is used to store and/or extract the heat. There is a gap between aluminum fins and the ceramic block filled with aluminum powder. This feature serves mainly two purposes: enables heat transfer from concrete block to aluminum tube and allows free thermal expansion of aluminum tube
- modular construction
- with HTF it can operate at higher temp (> 300 deg C)
- total flow control on both streams
- ability to add and or extract heat to different loops within the module simultaneously
The Great Rift Valley countries in Africa have an enormous potential for geothermal energy. With Kenya, Djibouti and Tanzania already developing this. DRC, Rwanda and Burundi will be next.
Entire thermal storage module showing cold/hot water connection manifolds