# US 12,181,180 B2 · Photovoltaic-phase change energy storage system and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,181,180 B2 - Document ID: US12181180B2 - Status: Granted - Kind: B2 - Application number: 18/781,642 - Filed: 2024-07-23 - Published: 2024-11-14 - Granted: 2024-12-31 - Earliest claimed: 2022-10-13 - Assignees: King Fahd University of Petroleum and Minerals - Applicants: King Fahd University of Petroleum and Minerals - Inventors: Kashif Irshad - Web page: https://patentgrep.com/patent/US12181180B2 ## CPC - F24F 5/0021: {using phase change material [PCM] for storage} - F25B 25/005: {using primary and secondary systems} - F25B 27/005: {in compression type systems} - F25B 40/00: Subcoolers, desuperheaters or superheaters - H02S 10/00: PV power plants; Combinations of PV energy systems with other systems for the generation of electric power - H02S 20/20: Supporting structures directly fixed to an immovable object (H02S20/30 takes precedence) - F24F 2005/0025: {using heat exchange fluid storage tanks} - F24F 2005/0067: {with photovoltaic panels} - F25B 27/00: Machines, plants or systems, using particular sources of energy (F25B30/06 takes precedence) - F25B 39/02: Evaporators - F25B 2400/06: Several compression cycles arranged in parallel - Y02E 60/14: Thermal energy storage - F24F: AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING (removing dirt or fumes from areas where they are produced B08B15/00; vertical ducts for carrying away waste gases from buildings E04F17/02; tops for chimneys or ventilating shafts, terminals for flues F23L17/02) - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS - H02S: GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES (obtaining electrical energy from radioactive sources G21H1/12; light sensitive inorganic semiconductor devices H10F; light sensitive organic semiconductor devices H10K30/00; thermoelectric devices H10N10/00; pyroelectric devices H10N15/00) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A solar photovoltaic powered phase change material thermal energy storage system includes a refrigerator unit having a phase change material (PCM) tank and a photovoltaic (PV) panel to provide electrical energy to the PCM tank to melt a PCM stored therein. The PCM tank includes a refrigeration coil immersed in the PCM and configured to circulate refrigerant to between the PCM tank and a condenser. Energy released and absorbed during solidification and melting of the PCM is used to support an air-conditioning (AC) unit and substitute power used by a compressor of the AC unit, to handle demand during peak hours, thereby reducing overall power requirement of a facility. The melting of the PCM is also controlled, so that the AC unit may operate with the aid of the PCM for longer duration during the day. ## Claims ### Claim 1 A solar photovoltaic powered phase change material thermal energy storage system, comprising: a refrigerator unit; an ethylene glycol (EG) flow unit; an air handling unit; and an air conditioning (AC) unit, wherein the refrigerator unit comprises: a photovoltaic (PV) panel, a phase change material (PCM) tank, a refrigeration pump, a cooling fan assembly, a first compressor, a first condenser, a first expansion valve, and an evaporator; wherein the PV panel provides electrical energy to the first compressor to cool a PCM material housed within the PCM tank; the PV panel is directly adjacent and covers a top side of the PCM tank; the PCM tank is in thermal communication with the first condenser through a refrigeration coil and is configured to flow a refrigerant from the PCM tank to the first condenser via the refrigeration pump, wherein the refrigerant comprises water, ethylene-glycol and at least one component selected from the group consisting of copper oxide, titanium dioxide and silicon dioxide; the PCM tank further comprises a door, at least 20 ventilation vents, and a drainage passage; the refrigeration pump is housed inside a same compartment as the compressor; and the refrigeration coil in the PCM tank is immersed in the PCM material and configured to circulate the refrigerant to the PCM tank and the first condenser; and the cooling fan assembly is positioned proximal to the first condenser; the EG flow unit comprises a heat exchanger, a pump, and a fan coil; and the air handling unit comprises an AC evaporator and two three-way valves, wherein a first three-way valve directs heated air through the AC evaporator and a second three-way valve directs heated air through the fan coil; and the AC unit comprises a second compressor, a second condenser, and a second expansion valve. ### Claim 2 (depends on 1) The system of claim 1, wherein the refrigeration coil is fabricated of copper and housed in a thermal energy storage (TES) tank disposed within the PCM tank. ### Claim 3 (depends on 2) The system of claim 2, wherein the refrigeration coil housed in the TES tank within the PCM tank is configured to absorb heat from the PCM material to minimize heat gain. ### Claim 4 (depends on 2) The system of claim 2, wherein the refrigerant circulates through the refrigeration coil and configured to absorb heat from the PCM material within the PCM tank. ### Claim 5 (depends on 1) The system of claim 1, wherein a thermostat is disposed within the PCM tank to monitor a PCM temperature of the PCM material within the PCM tank. ### Claim 6 (depends on 1) The system of claim 1, wherein the system further comprises a first controller electrically connected to the PV panel and is configured to monitor electrical energy transfer to the first compressor. ### Claim 7 (depends on 1) The system of claim 1, wherein the system further comprises a second controller electrically connected to the PCM tank and configured to handle switching operations during a cooling supply. ### Claim 8 (depends on 1) The system of claim 1, wherein the refrigerator unit further comprises a battery bank configured to maintain stability in energy supply during operation. ### Claim 9 (depends on 8) The system of claim 8, wherein the battery bank comprises an inverter configured to transform electrical energy collected by the PV panel into AC current for the first compressor. ### Claim 10 (depends on 1) The system of claim 1, wherein the first condenser is in fluid communication with the evaporator by circulating the refrigerant from the first condenser to the evaporator via the refrigeration pump. ### Claim 11 (depends on 10) The system of claim 10, wherein a cooling coil is disposed within the evaporator to receive the refrigerant from the first condenser. ### Claim 12 (depends on 1) The system of claim 1, wherein the fan coil is configured to provide at least 5.5 kW of cooling per hour to the heated air leaving the second three-way valve. ### Claim 13 (depends on 1) The system of claim 1, wherein the ethylene-glycol water solution contains an amount of water of from 50 weight percent (wt. %) to 70 wt. % of the ethylene-glycol water solution and an amount of ethylene glycol of from 30 weight percent (wt. %) to 50 wt. % of the ethylene-glycol water solution. ### Claim 14 (depends on 1) The system of claim 1, wherein the PCM tank, first compressor, first condenser, and evaporator are all connected by a first pipe network; and the refrigerator unit, the EG flow unit, the air handling unit, and the air conditioning (AC) unit are all connected by a second pipe network. ### Claim 15 (depends on 14) The system of claim 14, wherein the first pipe network is insulated with a first insulating material to avoid overheating and the second pipe network is insulated with a second insulating material to minimize heat gain of the PCM material. ### Claim 16 (depends on 1) The system of claim 1, wherein the system further comprises a data acquisition unit configured to record measurement data. ### Claim 17 (depends on 16) The system of claim 16, wherein the data acquisition system further comprises thermocouples, flow meters, solar radiation sensors, wind speed meters, current sensors, and voltage sensors to record the measurement data. ### Claim 18 (depends on 1) The system of claim 1, wherein a temperature sensor is attached to an outlet of the air handling unit to measure an exiting temperature of an air stream from the air-handling unit.