Renewable Energy Production in Decommissioned Power Plant Sites for Sustainable Cities—The Case Study of Romania

Minimizing the energy inputs and decentralized energy production by using renewable sources are high priorities for the future of sustainable cities. Also, rehabilitation and reusing of decommissioned power plant sites are specific objectives of urban design when public decision is concerned. The paper presents an original solution aiming at the revival of five former industrial sites: Baia Mare, Brasov, Pitesti, Targu Jiu and Copsa Mică where tall industrial chimneys and available space is still existing. For each site, a solar park is proposed, where two different solar applications provide electricity: a solar chimney with upward air flow and a solar photovoltaic farm. After technical evaluations, the average installed power for each solar park is 5 MW. An economic assessment is provided based on energy production and other activities such as a charging system for electric vehicles and electrical buses used by the local transportation company and rental services to public/private consumers operating in the park. An analysis of the basic investment of approx. 19.5 M Euro—65% for the solar park and 35% for the architectural conversion works—revealed that the project is financially viable only if the revenue from the proposed activities is over 2.6–2.8 M Euro/year.