PUMP STORAGE AND ITS INTEGRATION WITH RENEWABLE ENERGY SOURCES

Abstract

Today most of the rural parts of India and remote areas are suffering from electricity supply. Although fossil fuel plays a vital role in meeting electricity demand but the economic and environmental aspects have triggered down their viability and sustainability. Environmental concern and high rise in electricity cost are leading to search for cost competitive and sustainable source of energy. Energy from renewable sources like: wind, solar and hydro is reliable and clean. As on March 2015, India has RE capacity of 34.35 GW (13% of installed capacity). The renewable sources of energy i.e. wind and solar energy is intermittent in nature. In order to limit the impact of intermittence nature in power generation storage of energy is required. In the power sector, the most common form of existing electricity storage is pumped-storage, which is a long term energy storage method as compared to other sources. It converts low cost off-peak energy into high value on-peak power. Thus the hybridization of energy generate with storage like pumped storage with renewable sources is needed. In the field of pumped storage rapid development has been made on large scale (MW-size). This large scale pumped storage can be scaled down for their utilization at small scale in remote area. As the remote area are far from the main transmission line then in such a situation small scale pumped storage is a most feasible and economic solution in off-grid mode. Literature review shows that earlier studies have not considered the small scale pumped storage integration with RE sources in India. Limited studies on potential, economics and technology have been carried out on Small scale PHS system. A study area, located on 2450 m above mean sea level with good sun shine during winter and good rainfall during monsoon has been selected where Harsil Small Hydro Power Plant exist. It is located 25 km before Gangotri in district Uttarkashi of Uttarakhand. The electricity is supplied in off grid mode to nearly villagers and defense personnel. The area has a high volume of pilgrimages from April to October every year. Area is facing difficulties in supplying electricity due to limited generation through small hydro. The area has a large number of apple orchards and due to non availability of storage facilities fruits are sold at very cheap rates. Thus to increase the financial returns on apple setting-up of cold storage is iv proposed. A 160 kW solar photovoltaic plant is proposed as hybrid source to take care the electricity demand. The natural topography of the area supports the construction of small pumped storage plant. The design and economic analysis is performed which reveals the feasibility of small scale pumped storage and its integration with renewable energy sources on existing site. The scheduling of solar-hydro PHS has been done on C++software. The economic analysis is also performed by HOMER software delivering the cost of energy of hybrid plant to be 12.31 Rs/kWh.