Moya Diego, Paredes Juan, Kaparaju Prasad
Institute for Applied Sustainability Research (iSUR), Av. Granados E13-55 e Isla Marchena, No.44, Quito, 170503, Ecuador.
Carrera de Ingeniería Mecánica, Facultad de Ingeniería Civil y Mecánica, Universidad Técnica de Ambato, Avd. Los Chasquis y Rio Payamino, 1801314, Ambato, Ecuador.
MethodsX. 2018 May 21;5:524-531. doi: 10.1016/j.mex.2018.05.010. eCollection 2018.
RETScreen presents a proven focused methodology on pre-feasibility studies. Although this tool has been used to carry out a number of pre-feasibility studies of solar, wind, and hydropower projects; that is not the case for geothermal developments. This method paper proposes a systematic methodology to cover all the necessary inputs of the RETScreen-International Geothermal Project Model. As case study, geothermal power plant developments in the Ecuadorian context were analysed by RETScreen-International Geothermal Project Model. Three different scenarios were considered for analyses. Scenario I and II considered incentives of 132.1 USD/MWh for electricity generation and grants of 3 million USD. Scenario III considered the geothermal project with an electricity export price of 49.3 USD/MWh. Scenario III was further divided into IIIA and IIIB case studies. Scenario IIIA considered a 3 million USD grant while Scenario IIIB considered an income of 8.9 USD/MWh for selling heat in direct applications. Modelling results showed that binary power cycle was the most suitable geothermal technology to produce electricity along with aquaculture and greenhouse heating for direct use applications in all scenarios. Financial analyses showed that the debt payment would be 5.36 million USD/year under in Scenario I and III. The correspindig values for Scenario II was 7.06 million USD/year. Net Present Value was positive for all studied scenarios except for Scenario IIIA. Overall, Scenario II was identified as the most feasible project due to positive NPV with short payback period. Scenario IIIB could become financially attractive by selling heat for direct applications. The total initial investment for a 22 MW geothermal power plant was 114.3 million USD (at 2017 costs). Economic analysis showed an annual savings of 24.3 million USD by avoiding fossil fuel electricity generation. More than 184,000 tCO eq. could be avoided annually.
RETScreen提供了一种经过验证的专注于预可行性研究的方法。尽管该工具已被用于开展许多太阳能、风能和水电项目的预可行性研究，但地热开发并非如此。本方法论文提出了一种系统方法，以涵盖RETScreen国际地热项目模型的所有必要输入。作为案例研究，RETScreen国际地热项目模型分析了厄瓜多尔背景下的地热发电厂开发情况。分析考虑了三种不同的情景。情景一和情景二考虑了每兆瓦时132.1美元的发电激励和300万美元的赠款。情景三考虑了电价为每兆瓦时49.3美元的地热项目。情景三进一步分为IIIA和IIIB案例研究。情景IIIA考虑了300万美元的赠款，而情景IIIB考虑了直接应用中出售热能每兆瓦时8.9美元的收入。建模结果表明，在所有情景中，双循环发电是最适合发电的地热技术，同时水产养殖和温室供热适合直接应用。财务分析表明，情景一和情景三下的债务支付将为每年536万美元。情景二的相应值为每年706万美元。除情景IIIA外，所有研究情景的净现值均为正。总体而言，情景二被确定为最可行的项目，因为净现值为正且投资回收期短。情景IIIB通过出售直接应用的热能可能在财务上具有吸引力。一座22兆瓦地热发电厂的总初始投资为1.143亿美元（按2017年成本计算）。经济分析表明，通过避免使用化石燃料发电，每年可节省2430万美元。每年可避免超过18.4万吨二氧化碳当量的排放。
