An Economic Investigation of a Solar-Powered Adsorption Cooling System

Read from local Zotero full-text PDF (group 5183627 / Joule Heist).

Key findings

• System & pair: solar-powered adsorption chiller with three coupled loops (hot-water, cooling-water, chilled-water). Working pair silica gel/water; flat-plate collector (η0=0.732, a=3.411, b=0.294), hot-water tank, auxiliary electric heater, cooling tower. Silica-gel desorption capped at 120 °C, nominally ~90 °C.
• Optimization method & variables: cost minimized via particle swarm optimization (PSO) over solar collector area A_c (10-100 m²), storage tank volume V_s (0.1-20 m³), and hot-water mass flow ṁ_w (0.1-5 kg/s). Cooling load from a 144 m² single-family house in Isfahan (EnergyPlus).
• Component capital costs (Table 2): flat-plate collector 221 US$/m², storage tank 811.2 US$/m³, adsorption unit 700 US$/kW, cooling tower 68 US$/kW, auxiliary heater 50 US$/kW, pumps 881·W^0.4 US$.
• Optimum vs base (Table 6): optimizer cut collector area 20→10 m² and tank 4→2.33 m³ while raising flow 0.4→0.87 kg/s; total annual cost fell 581.4 → 503.7 US$ (~13% cheaper). Solar fraction 0.864 (base) → 0.899 (optimum). Adsorption-unit annual cost fixed at 148.2.
• Cost-efficient scale: minimum cost per 1 kW of cooling capacity occurs in the 5-10 kW interval; loads under 50 kW are acceptable — confirms suitability for small-scale (single-family) applications. Above ~50 kW cost/kW rises toward a ~700 US$/kW plateau.
• Main bottleneck: sensitivity analysis shows the solar collector initial cost is the dominant bottleneck; with low Iranian electricity price (0.01 US$/kWh) the optimizer favors more auxiliary (electric) heating over solar.
• Environmental benefit: CO2 emission factor 0.178 kg/kWh. A 50 m² collector driving a 10 kW chiller avoids ~15.7 t CO2, worth 565.2-832.1 in environmental-benefit credit (CO2-capture cost 36-53 per ton). The environmentally friendly (high-solar) case costs 21% more annually than the optimum but is justified by CO2 credit.