Evaluation of the operational performance of a parabolic trough CSP plant

Abstract: Renewable energy technologies are in the spotlight. On the one hand, they are called to have a leading role in the battle against climate change. On the other hand, with constantly growing installed capacity and more than generous Feed-in-Tariffs (FiT’s), they might represent the financial demise of the energy sector of some countries. This is the case for concentrated solar power (CSP) in Spain. It is one of the country’s trademark industries and it is also a financial sink, with Feed-in Tariffs that were more than six times higher than the regular market price, before an energy reform had to be introduced. This work is divided in three main parts. The first part consists of an assessment of the regulatory changes and their impact on the Spanish CSP industry, which by July 2013, amount to at least 17% in revenue losses for the industry without taking into account variable losses related to the use of backup fossil fuels. These changes have created an atmosphere of great uncertainty for the industry, since the profitability of their projects has been severely challenged. The second part of this report consists of an evaluation of the operational performance of two parabolic trough CSP plants during their commissioning period. Two different methods were used; the first method consists of an annual or semi-annual evaluation where the main intakes and outputs (gas, water and electricity consumption, as well as, power generation) are compared with fixed guaranteed values. The second method consists of a daily evaluation of the power generation curves of the plants. The first evaluation showed positive results, with both power plants operating within the guaranteed values. The second evaluation fulfilled its objective by highlighting opportunities for improvement for both plants. Problems were brought up by the evaluation and subsequently identified and solved by the operation and maintenance (O&M) crew, increasing the net output of the plants by more than 1.5 MW. Last but not least, some critical components were successfully identified by means of reviewing the corrective actions performed during the year, opening an opportunity to reduce downtime by having proper spare parts stocks, and addressing design issues with equipment suppliers. The results presented by this report are not specific to these two power plants. The regulatory changes and the reduction of the FiT’s present a difficult challenge for the whole Spanish renewable energy (RE) industry and a real threat to the future development of these technologies. In the case of CSP, there is still work to do, especially by equipment suppliers, since the most relevant issues found were related to a lack of reliability of the components. These financial and technological problems should be solved jointly by the government, the producers, and the equipment suppliers in order to bring the CSP industry closer to its financial and technological maturity.