Thermal Storage

Efficent Low Cost Thermal Storage

Intermittent power generation has limited the use of renewable energy...until now.

SHEC Energy has developed a proprietary low cost technology to store themal energy so that it can push power to the grid 24 hours a day.

 

 

 

 

 

 

 

 

 

 

 

 

SHEC Energy offers the entire technology complement for an integrated solar thermal power generation and energy storage technology. 

 

 

 

This technology starts with a high temperature, high efficiency energy collection system consisting of super concentration solar arrays and complementary high temperature, high efficiency solar receivers.

 

 

 

 

 

 

 

 

 

 

 

 

Heat is transported from the receivers to the storage system via high temperature transport medium, typically at 850°C (1,532°F). Numerous technology developments were required to make this possible, including high temperature pumps and articulating joints.  

 

 

 

 

 

 

The heat is transferred to a thermal storage system capable of storing heat at 850°C (1,532°F). The heat from this storage system is then transported to a boiler to make steam to operate a turbine.
 

 

 

 

Two factors determine the storage capability of thermal inertia based storage systems One is the heat capacity of the storage medium and the other is the temperature drop of the medium as it is delivering its energy. Molten salt for example is limited to 560°C operating temperature. A typical temperature drop of 280°C would allow the turbine to operate at 280°C (560°C - 280°C). This is a very low temperature resulting in low turbine efficiencies and is even too low to operate Stirling engines.

SHEC Energy’s storage technology operates at 850°C. Applying the same 280°C temperature drop in SHEC Energy’s storage system would result in 570°C (850°C - 280°C) being delivered to the turbine, resulting in turbine efficiency improvement of about two times. The net result is lower levelized cost of power production.

SHEC Energy is also able to retrofit existing fossil fuel power plants due to its higher temperature operation.  Competitive technologies utilizing conventional storage cannot be utilized in the conversion of existing fossil fuel power plants since the turbine heat requirement is much higher than these systems can deliver.  Even solar trough systems without storage cannot generate enough heat for retrofit applications.




Competitive Advantage:

  • The collection of renewable energy is intermittent in its nature, requiring sufficient conventional power generation to fill the energy requirement when the renewable systems are not generating, such as at night or during cloud cover.
  • SHEC Energy’s thermal storage solution is one-tenth the cost of battery storage over a 30-year period.
  • Conventional renewable power generation deployment is limited by how much can go on the grid and still maintain grid integrity due to the intermittent nature of renewable power.  SHEC Energy has the capability to provide base-load power generation with its low-cost storage technology and the ability to use fossil fuels as a backup, since the solar thermal power plant can use heat from other sources besides the sun.
  • Storage further decreases the cost of levelized production since the plant is producing power for longer periods of time during a 24-hour day.

 

Competing technologies:

Current technologies use either hydrocarbon based heat carriers such as oil, or molten salt to transport heat from the solar collection array to the steam boiler or storage system. Both of these have limited operating temperatures of 390°C and 560°C respectively. This limited heat transport capability will limit overall power plant efficiency significantly, especially if thermal storage is incorporated.

SHEC Energy, out of necessity to exploit its high temperature advantage, has developed a complete suite of high temperature heat carrier technologies including the carrier, pumps and joints that can all operate at 850°C.

SHEC Energy’s high temperature solar collection and transport technologies enabled us to develop a low cost energy storage technology based on very low cost thermal storage mediums and using a proprietary energy transfer mechanism. The storage technology is based on thermal inertial storage in a solid state medium that does not undergo phase change. Due to the robustness of the storage system and minimal maintenance over its lifespan, the cost is less than one tenth that of battery storage technology over a 30 year lifespan.