A Comparative Cost Assessment of Low Carbon Process Heat Between Solar Thermal and Heat Pumps
Abstract
Lower temperature renewable process heat derived from the sun can be generated from solar thermal collectors and a photovoltaic powered heat pump. To determine which can produce lower cost heat under certain technical and financial parameters, a robust methodology was developed to determine the maximum solar thermal project investment for it to remain the lower cost technology. This result can also serve as a target for the solar thermal industry to ensure its role in the future of renewable heat. The assessment methodology was used in a case study analysis, consisting of typical industrial process heat load and temperature profiles, meteorological conditions, technology costs and performance. Results indicated that for constant energy demand processes when a heat pump can operate the majority of the year, a photovoltaic heat pump system delivers lower cost heat. In a typical five day one shift work week where a heat pump has limited access to a heat source, solar thermal remains the lower cost heat provider. For the same five day one shift case but without a constrained heat source, allowing the heat pump to operate for 2000 hours a year, solar thermal plants must be built for less than 250 €/m2ap in low irradiation regions like Copenhagen and 525 €/m2ap in high irradiation regions like Chile or North Africa. For solar thermal to remain a primary renewable heat provider in the future, project investments should consistently be less than 200 €/m2ap. The presented results are highly variable based on numerous technical and financial parameters. Therefore the use of the methodology described in this work is critical to quickly determine which technology produces lower cost solar derived renewable heat.