Energy Conservation Potential of Large Capacity Solar-Assisted Heat Pumps for Low Temperature IPH Applications

Energy conservation and economic potential of large capacity (∼MW_th) solar-assisted water-to-water heat pumps (SAHP) is evaluated for year round low temperature (<100° C) industrial process heating applications at four locations in the United States. The long-term thermal performance of the SAHP system is determined by a recently proposed utilizability method that accounts for the variable coefficient of performance of the SAHP system. The large SAHP system appears to be an attractive energy conservation alternative to fuel oil and electricity for locations with high solar resources and low electricity costs. In all but one location, the SAHP system was clearly superior to the solar only systems, such as flat plate and concentrating collectors, from the point of view of the annualized delivered energy cost. For the ranges of collector area and load temperatures considered in this study, the large SAHP system has clearly superior energy conservation potential at all four locations compared to other alternatives such as fuel oil or electricity. However, the practial suitability of SAHP cycle, as determined by the levelized cost of delivered energy, is unfavorable at all four locations when compared with fuel oil.