Effectiveness of utilizing energy storage to achieve maximum penetration

Thesis (S.M. in Technology and Policy)--Massachusetts Institute of Technology, Engineering Systems Division, Technology and Policy Program, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 110-112).Renewable energy resources are stochastic with seasonal and diurnal patterns, making electricity generation by these resources difficult to predict, and making it difficult to plan future generation expansion. Understanding these patterns is critical in determining whether various renewable energy sources compound or compete against one another. Renewable generation may reach highest output at periods of low demand, or their lowest output during periods of high demand. Short-term electricity storage could provide load-leveling for short periods of time, storing electricity for later use. Further, momentary and hourly changes in renewable generation make it hard to maintain electrical stability in the system when large quantities of these sources are installed. Sufficient reserves must be maintained to meet electricity demand at all times, but these reserves - usually fossil generation units - may displace renewable energy generation. Energy storage could help maintain reliability and ensure that sufficient energy is produced to meet demand, while minimizing the use of fossil fuel from traditional generation sources and providing carbon-free spinning reserves. This research characterizes wind and hydro generation patterns in the Azores. For example, in Flores it was found that winter had highest renewable generation potential, but low electricity demand, and that summer had the highest demand, but fairly low renewable energy potential. This research then investigated the extent to which additional renewable capacity could be added to the Flores electricity system and the impact of energy storage on achieving higher renewable energy penetration. It was found that adding additional renewable capacity always increased the amount of renewable energy generation and reduced average annual production costs. Adding storage to the system increased renewable energy generation by 10% and reduced annual production costs by 16%. In addition, storage in amounts greater than 1 MWh had diminishing returns, and the largest benefit of energy storage was its ability to act as a spinning reserve, allowing diesel units to turn off.by Pamela DeAmicis.S.M.in Technology and Polic