Principle: It leverages the photovoltaic effect. When sunlight irradiates solar panels made of semiconductor materials (primarily silicon), photons excite electrons to generate direct current (DC).
Key Components: Solar panels (composed of multiple solar cells), inverters (convert DC to alternating current/AC), mounting brackets, cables, and energy storage systems (e.g., batteries).
Features: Adopts a modular design that can be scaled up or down, suitable for applications ranging from calculators and rooftop power stations to large-scale photovoltaic plants.
Principle: Converts solar radiation into thermal energy.
Main Forms:
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Low-temperature Utilization: Solar water heaters, solar greenhouses.
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Medium-to-high Temperature Utilization: Concentrated Solar Power (CSP). It uses reflectors to focus sunlight onto receivers, producing high-temperature steam to drive turbines for power generation.
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Distributed Photovoltaics: Installed on the rooftops of households, factories, and commercial buildings for on-site consumption with surplus electricity fed into the grid.
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Centralized Photovoltaic Power Stations: Large-scale ground-mounted power plants built in sun-rich areas, supplying electricity directly to the power grid.
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Solar Thermal Power Stations: Typically constructed in regions with extremely high solar irradiance, such as deserts.
Solar water heating systems are among the most widely adopted solar energy applications globally.
Serves as auxiliary power for solar-powered vehicles and ships; supplies electricity to electric vehicle charging stations.
Solar-powered water pump irrigation, agricultural greenhouses, and agrivoltaics (complementary integration of agriculture and photovoltaic power generation).
Provides independent power supply for remote areas, communication base stations, street lamps, spacecraft, etc.
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Inexhaustible & Renewable: The sun has an estimated remaining lifespan of about 5 billion years, making it a truly sustainable energy source.
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Clean & Environmentally Friendly: The power generation process produces zero emissions, no noise, and no pollution, serving as a key technology for addressing climate change.
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Widely Distributed: Available everywhere, particularly suitable for solving power supply problems in remote, off-grid regions.
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Low Maintenance Costs: Photovoltaic systems operate stably; once installed, subsequent operation and maintenance are straightforward, with energy sourced from free sunlight.
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Continuous Technological Advancement & Rapid Cost Reduction: Over the past decade, the cost of photovoltaic modules has dropped by more than 90%, making solar power the cheapest electricity source in many regions.
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Intermittency & Volatility: Heavily affected by day-night cycles, weather conditions, and seasonal changes. Stable power supply requires integration with energy storage systems (e.g., batteries) or complementarity with other energy sources.
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Low Energy Density: A large collection area is required to obtain a considerable amount of energy.
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High Initial Investment: Despite favorable long-term returns, the upfront equipment and installation costs remain a financial burden for individuals and enterprises.
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Land Resource Requirements: Large-scale power stations occupy extensive land areas, potentially triggering land-use conflicts with agriculture and ecological conservation (compound utilization models, such as agrivoltaics and fishery-solar hybrid systems, are now widely promoted).
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Materials & Recycling: The production of solar panels requires materials like silicon, and the manufacturing process consumes energy; the eco-friendly recycling system for waste solar panels is still under development.
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High-efficiency Solar Cells: Such as perovskite solar cells (with a laboratory efficiency exceeding 25%, boasting enormous potential), heterojunction (HJT) cells, and tunnel oxide passivated contact (TOPCon) cells.
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Building-integrated Photovoltaics (BIPV): Integrates solar panels directly as building materials (e.g., glass curtain walls, roof tiles), enabling buildings to generate electricity on their own.
Combines photovoltaic power generation with agriculture, fishery, animal husbandry, ecological restoration, etc., to achieve three-dimensional, value-added land utilization.
Integrates artificial intelligence and the Internet of Things (IoT) technologies to build local smart energy networks centered on solar energy, coupled with energy storage and intelligent regulation.
Uses solar-generated electricity to electrolyze water for producing "green hydrogen", which serves as a clean energy storage medium and industrial raw material, addressing long-duration energy storage and decarbonization in hard-to-abate sectors.
