{
    "title": "High-Concentration Photovoltaic-Thermal System",
    "inventor_name": "Bruno Michel",
    "publication_year": 2013,
    "device_name": "High Concentration Photovoltaic-Thermal (HCPVT) system",
    "goal": "Provide affordable, high-efficiency solar electricity together with potable water and cooling air for remote, sunny locations.",
    "problem_addressed": "Current solar PV and solar-thermal technologies are too expensive, require rare-earth materials, and cannot simultaneously supply electricity, desalinated water and cooling.",
    "concept_summary": "A solar-concentrating dish (~=2000x) focuses sunlight onto micro-channel-cooled triple-junction photovoltaic chips. The liquid cooling removes waste heat, which is then used for membrane-distillation desalination and for a thermal-driven adsorption chiller, delivering electricity, clean water and cool air from a single platform.",
    "detailed_description": "The prototype uses a large parabolic dish composed of inexpensive pneumatic metal-foil mirrors mounted on a sun-tracking system. Light is reflected onto a receiver that holds hundreds of 1 cm^2 triple-junction PV cells mounted on micro-structured layers with embedded micro-channels. A low-power pump circulates coolant (water) through the channels, keeping the cells near ambient temperature even at 2000-sun concentration. The heated coolant (~=90  deg C) is routed to a porous-membrane distillation unit for water desalination (30-40 L m^-^2 day^-^1) and to an adsorption chiller (silica-gel based) for air-conditioning. The system is built from lightweight high-strength concrete for structural parts, metalized foils for mirrors, and standard semiconductor PV cells, aiming for an aperture cost below $250 m^-^2 and a levelized electricity cost < $0.10 kWh^-^1.",
    "category": "Thermal Systems",
    "principles": [
        "Solar concentration (parabolic dish, 2000x)",
        "Micro-channel liquid cooling",
        "Triple-junction photovoltaic conversion",
        "Heat recovery for membrane distillation",
        "Thermal adsorption cooling"
    ],
    "scientific_domains": [
        "Solar Energy",
        "Photovoltaics",
        "Thermodynamics",
        "Heat Transfer",
        "Materials Engineering",
        "Mechanical Engineering",
        "Renewable Energy"
    ],
    "mechanisms_of_action": [
        "Concentrated sunlight raises photon flux on PV cells",
        "Micro-channels transport coolant directly under the cells, removing heat",
        "Coolant absorbs waste heat and transfers it to downstream thermal processes",
        "Hot water drives membrane-distillation for desalination",
        "Heat powers a silica-gel adsorption chiller for cooling"
    ],
    "materials": [
        "High-strength concrete",
        "Pneumatic metal-foil mirrors",
        "Triple-junction semiconductor PV cells (III-V compounds)",
        "Silicon/metal micro-channel structures",
        "Water (coolant)",
        "Porous polymer membrane",
        "Silica gel (adsorbent)"
    ],
    "energy_sources": [
        "Solar radiation"
    ],
    "inputs": [
        "Sunlight",
        "Water (coolant & feed-water for desalination)",
        "Electric power for sun-tracking motors (small)"
    ],
    "outputs": [
        "Electrical power (~=25 kW prototype)",
        "Desalinated water (30-40 L m^-^2 day^-^1)",
        "Cool air (via adsorption chiller)"
    ],
    "claimed_performance": "2000x solar concentration, up to 80 % of incoming solar energy converted to useful forms, 25 kW electrical output from a prototype receiver, 30-40 L m^-^2 day^-^1 potable water, > 25 % electrical yield per m^2, cost per aperture < $250 m^-^2, levelized electricity cost < $0.10 kWh^-^1.",
    "experimental_evidence": "Prototype HCPVT system tested at IBM Research - Zurich; earlier multi-chip receiver demonstrator built with Egypt Nanotechnology Research Center; video demonstration on YouTube; patents filed (US2013255753).",
    "replication_status": "Prototype being tested; additional prototypes planned for Biasca and Rueschlikon, Switzerland.",
    "keywords": [
        "Concentrated photovoltaics",
        "Hybrid PV/T",
        "Micro-channel cooling",
        "Membrane distillation",
        "Adsorption cooling",
        "Solar desalination",
        "High-concentration solar"
    ],
    "related_technologies": [
        "Concentrated Photovoltaics (CPV)",
        "Solar thermal collectors",
        "Membrane distillation desalination",
        "Adsorption chillers",
        "Ray-tracing optical design"
    ],
    "controversy_level": "low",
    "confidence_score": 0.9,
    "practicability_score": 0.7,
    "fringe_score": 0.2,
    "evidence_strength": 0.6,
    "risk_score": 0.2,
    "trl_estimate": 5,
    "source_urls": [
        "http://www-03.ibm.com/press/us/en/pressrelease/40912.wss#release",
        "http://www.youtube.com/watch?v=J_zzE8xMdZc",
        "http://worldwide.espacenet.com/advancedSearch?locale=en_EP"
    ],
    "organizations": [
        "IBM Research - Zurich",
        "Airlight Energy",
        "ETH Zurich",
        "Interstate University of Applied Sciences Buchs (NTB)",
        "Egypt Nanotechnology Research Center"
    ],
    "applications": [
        "Remote power generation",
        "Potable water production in arid regions",
        "Air-conditioning for hot climates",
        "Tourism resorts on small islands"
    ],
    "limitations": [
        "Requires precise sun-tracking and high-quality mirrors",
        "Water supply needed for cooling and desalination",
        "Potential material degradation under 5000x concentration",
        "Scale-up cost and logistics of large parabolic dishes"
    ],
    "open_questions": [
        "Long-term durability of micro-channel cooling under cyclic thermal loads",
        "Economic viability at utility scale",
        "Performance under variable cloud cover",
        "Optimal balance between electrical and thermal output"
    ],
    "red_flags": [
        "Efficiency claims (80 % useful energy) are based on prototype estimates, not independent peer-reviewed data",
        "No published quantitative performance data beyond the prototype description"
    ],
    "evidence_quotes": [
        "Concentrates sunlight 2000x, converts 80% to useful energy, desalinates water, & refridgerates...",
        "The prototype HCPVT system uses a large parabolic dish ... The entire receiver combines hundreds of chips and provides 25 kilowatts of electrical power.",
        "The coolant maintains the chips almost at the same temperature for a solar concentration of 2,000 times and can keep them at safe temperatures up to a solar concentration of 5,000 times.",
        "Such a system could provide 30-40 liters of drinkable water per square meter of receiver area per day, while still generating electricity with a more than 25 percent yield or two kilowatt hours per day.",
        "A prototype of the HCPVT system is currently being tested at IBM Research - Zurich."
    ]
}