Analysis of System Optimization for CCHP System with Different Feed-in Tariff Policies

Considering the limitation of system optimization and feed-in tariff policy research on combined cooling, heating and power (CCHP) system, a novel multi-objective CCHP system optimization model using linear search method was proposed. The analytic hierarchy process was used to determine the weight factors of three objectives: economic, energy and environmental. The system optimization of an office building in Sino-Singapore Eco-City located in Tianjin was analyzed with two different feed-in tariff policies. Results show that compared with the no feed-in tariff policy, the feed-in tariff policies could be beneficial for economic and environment performance of CCHP system. The comprehensive performance of CCHP system with two feed-in tariff policies are approximately the same in optimal configuration but there was a huge gap in primary energy consumption. According to the sensitivity analysis of the feed-in tariff price, the carbon emissions reduction of CCHP system changed slightly with the variation of the feed-in tariff. The cost saving grew steadily while the primary energy saving decreased dramatically with the increasing of feed-in tariff. And when the feed-in tariff price ratio is more than 0.9 under the fixed feed-in tariff policy, the primary energy consumption would be sharply increased compared with separate system.