Multi-energy complementarity is an important development direction of distributed energy system. Compared with fossil energy driven distributed energy system

the evaluation method of energy saving characteristics is still inadequate. The input non-fossil energy of low grade is converted into fuel according to the work ability

and the energy saving ratio is then obtained by comparing with the conventional sub-production system which has the same products. The effect of parameters such as the proportion of renewable energy

different energy output ratios and inputting heat temperature of thermal or thermochemical complementarity on the energy saving characteristics of the system is analyzed through a typical solar energy and fuel complementary distributed energy system

and a specific cogeneration case is studied to verify the applicability of the proposed calculation method of energy saving ratio. The results show that the evaluation method of energy saving ratio proposed can more reasonably evaluate the energy saving characteristics of multi-energy complementary system with non-fossil energy. The energy saving ratio increases with the increase of the renewable energy proportion and decreases with the increase of the solar collecting temperature of thermal complementarity. With the increase of the solar collecting temperature of thermochemical complementarity

the energy saving ratio rises first and then declines. The results reflect that rational use of non-fossil energy according to the energy grade and the performance improvement of multi-energy complementary technologies can improve the energy saving characteristics of the system.