Abstract: University buildings are major energy users，and there are two main forms of energy use：electricity

and heat. Making full use of the roof resources of university buildings to develop solar energy projects and

rationally allocate energy storage can effectively improve the energy economy. In order to improve the economy，

considered the equipment purchase and operation and maintenance costs，a rooftop photovoltaic photovoltaic

system including photovoltaic，solar collectors，heat pumps and power storage devices was designed. The

differential evolution algorithm was used to solve the problem，and the optimal capacity configuration result of the

equipment in the photovoltaic thermal system was obtained，so as to achieve the lowest cost per unit of electricity

on the user side. Finally，taked a university dormitory building in Northwest my country as an actual example，the

minimum unit electricity cost of the photovoltaic solar thermal system and the configuration scheme under the

optimal target were obtained. It provides a reference for the construction of green and low-carbon campuses.

      Key words: university buildings；rooftop photovoltaic thermal system；economy；differential evolution

algorithm；capacity allocation