Central solar heating plants with seasonal storage (CHSPSS) are among the most promising technologies for the industrial and residential-commercial building sector. These systems store solar radiation for its later usage during the periods of increased heating demands. Among the CSHPSS available, the most commonly used incorporate flat plate solar collectors and large hot water tanks for seasonal thermal energy storage.
Recent technological advances have made it possible to implement CSHPSS in the industrial and residential-commercial sector, thereby becoming a potentially viable and effective alternative to conventional forms of energy supply. It was determined that CSHPSS are able to reduce non-renewable energy consumption by more than 50%. Unfortunately, no plants have been so far installed in Spain, which offers an appealing opportunity to meet the environmental goals of the European Commission for 2020.
In the present work we simulated a CSHPSS system using the TRNSYS 17 software, where environmental impact equations and cost estimating correlations were incorporated. A multi-objective optimization routine was then implemented on this model to contrast the environmental and economic criteria. To this end, we used a hybrid multidimensional metaheuristic optimization algorithm integrated in the GenOpt software, which provides as output a set of solutions with different economic and environmental performance.
This overall methodology was applied to a case study of a CSHPSS located in Barcelona (Spain), which partially satisfies a heating demand of more than 1,000 dwellings of one neighborhood. Results show how significant environmental and economic improvements can be attained through this system when compared to a base case of a conventional natural gas heating system. Particularly, we identified CSHPSS configurations attaining reductions of up to 83% in environmental impact and 14% in economic cost.