Prospects for solar thermal energy use in residential buildings in Lebanon

Unlike most of its neighbouring countries, Lebanon is a small country with limited natural resources. The country imports around 97% of its needs of energy in the form of fossil fuel resulting in a high energy import bill. Despite major steps done towards improving the energy sector, the country is striving to meet the energy demand of its population. In order to face this problem, the use of renewable energy and particularly the solar thermal energy represent one of the most promising alternative strategies. Indeed, Lebanon is located in a relatively sunny area with an average global horizontal radiation of 2200 kWh/m² per year. The residential sector represents 30% of the total energy consumption and thus offers an interesting opportunity for the development of the solar thermal market. In this paper an attempt is made to investigate the impact of the use of solar thermal equipments for heating and cooling on energy savings in the residential sector in Lebanon. The energy consumption is calculated for a typical building for four climatic zones using a validated transient simulation model. The payback period is calculated for each system in the four climatic zones. The analysis of the results showed that the solar domestic hot water system has a payback period of less than seven years, while the heating and cooling systems showed higher payback periods at current market prices. Prospects for the development of this sector are discussed at the end of this paper.