Given the issues surrounding climate change and the desire to reduce fossil fuel consumption, energy production is becoming an increasingly important issue that requires constant technological advances in order to meet demand.
However, there is no point in producing power that cannot be used. This is where the problem lies for intermittent energy sources, such as wind and solar power: how can it be ensured that energy production and consumption are in synch.
There are many different types of energy storage systems, such as batteries, hydrolysis (hydrogen storage), etc. However, all of these systems have major drawbacks that prevent their large-scale use. Sigma Energy Storage has developed a compressed air energy storage system, which includes recovery of thermal energy, in order to address the problem of how to store energy efficiently.
Energy storage systems: Sigma Energy Storage and HT-CAES technology
We interviewed Martin Larocque, the CEO of Sigma Energy Storage, to learn more about the company’s new HT-CAES technology, which is expected to revolutionize energy storage in the coming years.
QUESTION: What are the fundamental principles underlying your company’s energy storage technology?
ANSWER: The technology is based on the principles for mechanical energy (air compression) and thermal energy (heat recovery). One of the great complexities of compressed air energy storage systems relates to the air compression process, which generates a significant amount of heat. We developed a highly efficient thermal energy transfer system to capitalize on this phenomenon, which allows us to store the heat (potential energy) created during compression and to reinject it into our process when producing energy for the power grid. By combining thermal and mechanical energy, we have a major competitive advantage, allowing us to build a more efficient, higher pressure system (providing benefits in terms of storage density).
QUESTION: What are the advantages of your system as compared to other energy storage systems currently available on the market?
ANWER: The way in which we manage thermal energy is unique and gives us a competitive edge over other air compression systems (CAES systems). Our competitive environment also includes various types of batteries (which store chemical energy) that stand out in terms of their useful life: a battery will last on average between 2,000 and 3,000 cycles while our HT-CAES system will last 40,000 cycles, for a Levelized Cost of Energy (LCOE) that is 5 to 10 times lower than for batteries currently available on the market. Our HT-CAES system also makes it possible to operate in harsh weather conditions, such as seen in the Canadian climate (including the Arctic). HT-CAES technology performs particularly well in these conditions.
QUESTION: What types of applications could be benefitted by your technology?
ANWER: Our procedure was developed with various applications in mind: a micro-network using very high capacity diesel generators or storage units in a large and complex power grid. Where micro-networks are concerned, our system uses air storage pressure vessels. This requires no particular geological features, while allowing for the benefits of our HT-CAES solution on a smaller scale (from 500 kW to several MW). For a larger power grid, we use geological cavities (salt or rock seals) to have a very large air reservoir. In such situations, it becomes possible to integrate a large quantity of intermittent renewable energy (solar, wind and tidal energy) and to stabilize the power grid by making it possible to store energy as it is produced and distribute it on the power grid as it is required.
QUESTION: What are the main technological hurdles that must still be overcome before your system can be introduced into the market?
ANSWER: From a development standpoint, the design work for the HT-CAES procedure has been completed. As for the immediate future, we are optimizing each of the related sub-systems to improve Round Trip Efficiency. In addition, we are working on a number of other innovation streams, such as CO2capture, liquefaction and transformation, as well as the integration and recovery of a exergy generated by external industrial processes. The future is bright for our technology, which makes it possible to stabilize power grids while integrating renewable energy.
QUESTION: What types of future or derivative applications do you see for your system?
ANSWER: We expect that each renewable energy infrastructure project will require an energy storage system, which generally represents one third of the power generated. In the short term, these are the applications that could benefit from our HT-CAES solution. In the medium term, our capacity to recapture and liquefy CO2 as part of our process, and to capture the thermal energy from an external process (i.e. exergy), will open up new industrial applications.
Exergy: In given thermodynamic conditions, the maximum useful work which can be extracted from a system, i.e. the capacity of energy to do physical work.