Study of Medium Scale Solar Water Heating Plants in Lithuania
Abstract
1. Introduction The EC plan “20-20-20” for the year 2020 encourages Lithuania as a member State to pay more attention to the renewable energy sources. Lithuania took the obligation to increase the part of renewable energy up to 23 percent in the State primary energy balance till 2020. General problem that existed in Lithuania was slow solar energy market grow due to the absence of promotion schemes. In the beginning of 2011 year Lithuanian Parliament has approved a law on renewable energy sources, introducing different type stimulation mechanisms in Lithuania. In this study we analyzed two medium – scale solar water heating plants in State owned institution. One of the projects implemented in 2009 year at Kruonis Pumped Storage hydroelectric Plant with 21 m2 active surface flat solar collectors. Other solar hot water heating system was installed in 2011 year at the same object with 106 m2 active surface flat type collectors. Kruonis Pumped storage hydroelectric plant is the only hydro power plant of such type in Baltic States. After commissioning of the fourth unit in 1998, installed capacity of the plant has reached 900 MW. During periods of low demand, usually at night, Kruonis PSHP is operated in pump mode, and, using cheap surplus energy raises water from lower reservoir to upper one. With fully filled upper reservoir the plant can generate 900 MW for about 12 hours. Automatically started, the plant can reach full capacity in less than 2 min.