Abstract
This paper explores a replacement option for the heating boilers at the California State Polytechnic University, Pomona. The retrofit proposed uses solar thermal energy, thermal energy storage, and a combined cooling, heating, and power (CCHP) cycle with a focus on efficiency and reduced carbon emissions. The primary source of high-grade input heat energy for the Rankine cycle is a Concentrated Solar Power (CSP) farm. During times of high heating demand, steam is bled off to drive a lithium bromide (LiBr/H2O) cycle to produce auxiliary on-demand part load cooling and heating, with Coefficient of Performance (COP) values of COP = 1.5 (heating), and COP = 0.75 (cooling). The facility will produce up to 1.565 MW of electricity, 813.54 tons (2862 kW) of heating, and 220 tons (774 kW) of cooling. This system will utilize an 11-acre CSP facility to be located on the site of the former dorm units at the university. The CSP has a capacity factor of 34% and produces 4.260 MW of thermal energy which will be used to drive the reheat Rankine cycle. Equipment selection and specification using Commercial-off-the-shelf (COTS) components are cited herein. Economic analysis shows the Levelized Cost of Energy (LCOE) to be 8.10 ¢/kWh for the proposed trigeneration powerplant.
