Abstract
This review paper aims to provide a comprehensive review of the history and the best practices of solar water heaters in Libya. Although Libya is blessed with high solar potential, there is no widespread implementation of this technology due to many reasons such as: the cheap price of both electricity and electric water heaters, lack of clear and systematic policy, and lack of environmental awareness. Th Center for Solar Energy Research and Studies (CSERS) has given attention to this technology since its establishment in 1978, and the solar water heating system field test project is one of the research projects in the Center. Th paper has shown that there was no attention paid to this technology and even to renewable energy in general in the previous years. However, preliminary information clearly shows the importance of continuing research in this field. Numerous valuable information on solar water heating systems from the literature was dedicated and made available for researchers and decision-makers. The studies conducted in this fild for Libya are arranged in this review on the basis of the topic studied: performance evaluation, optimization, on-site measurements and policies and strategies. One of the most important results retrieved from these studies shows that the daily quantity of hot water withdrawn per capita at 45 °C is estimated at around 60 liters. The estimated annual amount of energy consumed for water heating per person is 510 kWh. For an average Libyan family of six persons, the annual amount of energy consumed per dwelling is estimated at about 3060 kWh. The review also presented the history of solar water heaters implementation, manufacturing, and testing facilities for quality control in Libya. The study calls upon the Libyan decision-makers to take their responsibility and put an urgent action plan to help the widespread implementation of solar water heaters in the residential, services, and industrial sectors. Such a plan will surely alleviate the ever-increasing demand for electricity, save fossil fuel reserves and mitigate GHG emissions.

Key words: active solar water heaters, field study, policy, strategic plans, SWH testing facility