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Sizing and economic analysis of gravity storage

Energy storage plays a key role in providing more flexibility and balancing to the electric grid. With the increasing penetration of renewable energy technologies, there is a need to instantaneously match demand with supply. Energy storage has the potential to provide a back-up to intermittent renewable energy by storing electricity for use during more valuable periods. At this time, there are limited storage options, because several technologies are at very early stage of development. Pumped hydro energy storage is currently the most widely installed technology. This form of storage has some drawbacks which include the technology siting, as it cannot be implemented everywhere. This paper presents a concept that is similar to the existing pumped hydro storage technology. This concept is known as gravity storage, as it stores electricity in the form of gravitational potential energy. This storage option provides better operating characteristics and economically sounds solution over conventional pumped hydr...

Ant Colony Optimization for Optimal Low-Pass Filter Sizing

In analog filter design, discrete components values such as resistors (R) and capacitors (C) are selected from the series following constant values chosen. Exhaustive search on all possible combinations for an optimized design is not feasible. In this chapter, we present an application of the Ant Colony Optimization (ACO) technique for optimal filter design considering different manufacturing series for both the resistors and capacitors. Three variants of the Ant Colony Optimization are applied, namely, the AS (Ant System), the MMAS (Min-Max AS) and the ACS (Ant Colony System), for the optimal sizing of the Low-Pass Butterworth filter. Different optimal designs of the filter are provided depending on the preference between two conflicting factors, namely the cutoff frequency and selectivity factor. SPICE simulations are used to validate the obtained results/performances. A comparison with published works is also highlighted.