A Comprehensive Study on Integrated Optimization Design of Combined Cooling, Heating, and Power System Coupled with Solar and Biomass Energy

This study presents a renewable energy sources integrated combined cooling, heating, and power
(RES-CCHP) system, driven by a biogas fueled internal combustion engine (ICE) and photovoltaic
(PV) panels, which is different from the traditional natural gas CCHP system. Exploration of renewable
energy sources (RES) is an important way to address the energy and environmental crisis, which has
become one of the main tasks and strategic subjects for the development of the national economy.
Combined cooling, heating, and power (CCHP) systems coupled with solar energy and biomass
energy can meet the needs of island or rural decentralized and small-scale integrated energy use,
which have become increasingly popular in recent years. Owing to the solar energy volatility and the
constraint of biomass gas production, the traditional optimization design method is no longer
applicable. To improve the energetic, economic and environmental performances of the system, an
integrated design method with renewable energy capacity, power equipment capacity and key
operating parameters as optimization variables is proposed. In addition, a case study of a small farm
in Jinan, China, is conducted to verify the feasibility of the proposed RES–CCHP system structure and
the corresponding optimal design method. The results illustrate that the implementation of the optimal
design is energy-efficient, economical and environmentally-friendly. The values of primary energy
saving ratio, annual total cost saving rate and carbon emission reduction ratio are 20.94%, 11.73%
and 40.79%, respectively. Finally, the influence of the volatility of renewable energy sources on the
optimization method is analyzed, which shows that the RES–CCHP system and the method proposed
are robust. The RES–CCHP system can effectively stabilize the randomness and volatility of the solar
energy and biomass energy through the optimization design proposed in this study. It can significantly
improve the energy efficiency and the solar and biomass energy utilization rate, and is suitable for
supplying energy to a decentralized rural area.