1135368 (Nguyen). Our electrical grids are currently overloaded because of simultaneous peak electrical energy demand. This simultaneous demand sets the peak power generation level for power plants and peak power delivery capacity of the electrical grids. The peak power demand in the US and around the world is expected to increase significantly as the population grows and electrification of transportation is implemented. This creates a significant pressure for the need to build new power plants and upgrade the electrical grids. While the total daily electrical energy demand is fairly constant, its distribution rate (power) is not uniform with daytime load being almost double the night time load. If we can create a way in which this total daily energy demand is delivered at a constant rate, our existing electrical power plants and grids, which were designed for peak power, could produce and transmit energy more efficiently and economically. Furthermore, new power plants deployment and electrical grid upgrades or replacement can be done at a rate that is more manageable and less disruptive. A concept that may make this possible is to store electrical energy locally at the ?point of use? when demand is low or not needed for use when it is needed. An example of this is to buy and store electricity at night, when the demand and cost are low, for use in the day time when the demand and cost are high. This distributed energy storage approach allows the power plants and electrical grids to operate at more economical and sustainable levels. This one-year proposed project plans to conduct a systems and economics study of this concept and its impacts on the current energy production and distribution systems. Two storage applications will be evaluated, phase change systems for air-conditioning, a major use of electrical energy, and electrochemical storage systems (stationary batteries, flow batteries and fuel cells). The research team will identify the requirements of each application and determine the minimum round-trip storage efficiency and costs that these systems must have to be competitive using existing price differences. They will determine the percent of power plant and grid capacity that will become available when local energy storage capacity is used in various application sectors (commercial and residential). This work will be done by two undergraduate students, one each from Chemical Engineering and Electrical Engineering. The results generated will be used in an elective course called ?Energy for Sustainability? that the PI is developing for all disciplines in the school of engineering at the University of Kansas. This distributed energy storage concept may have a transformational impact on our current electrical energy production and transmission infrastructures. The data generated by this study will be very useful to the energy generation and transmission industries and the research community. Finally, this research will serve as an excellent venue to introduce issues on energy and environmental sustainability to the participating undergraduate students and to contribute to the development of a workforce that is more knowledgeable of these sustainability issues.
This NSF funded study was to evaluate the effectiveness of distributed energy storage in helping to reduce the load on the electricity generation and transmission infrastructures in the US, enabling of the use of renewable but intermittent energy sources like wind and solar, and to determine the current state of the art of various energy storage technologies. A case study of distribution energy storage was conducted with electricity usage and cost information for the Texas region showing that cost saving could be made. The results could be used by the storage technology developers to determine if their systems would be cost effective in this application. Results from this study show that distributed energy storage can find applications in many areas such as providing higher electricity qualifty, load shaving and/or levelling, and enabling of greater use of renewable but intermittent energy sources such as wind and solar in the electrical network. Through peak load shaving and levelling, implementation of distributed energy storage could free up a significant amount of electricity generation and transmission capacity in the US and around the world. This study also shows that distributed energy storage is most effectively used in urban areas where environmental issues (safety and toxicity) are very important. However, these applications tend to be much smaller in size and to have more change overs due to city planning in urban areas, and therefore, do not require large scale energy storage technologies with longer operational life.
