9.4 Advanced solar cell technologies and applications

Advanced solar cell technologies are pushing the boundaries of efficiency and versatility. From tandem cells that stack multiple materials to bifacial designs that capture light from both sides, these innovations are boosting energy conversion rates and expanding applications.

Building-integrated photovoltaics and concentrator systems are revolutionizing how we harness solar power. These technologies seamlessly blend into architecture or use lenses to amplify sunlight, making solar energy more accessible and efficient in various settings.

Advanced Solar Cell Architectures

Tandem Solar Cells and Bifacial Solar Cells

Top images from around the web for Tandem Solar Cells and Bifacial Solar Cells

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  Comparison between Amorphous and Tandem Silicon Solar Cells in Practical Use View original

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  Frontiers | Recent Progress in Developing Monolithic Perovskite/Si Tandem Solar Cells View original

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  Frontiers | Recent Progress in Developing Monolithic Perovskite/Si Tandem Solar Cells View original

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  Comparison between Amorphous and Tandem Silicon Solar Cells in Practical Use View original

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  Frontiers | Recent Progress in Developing Monolithic Perovskite/Si Tandem Solar Cells View original

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Top images from around the web for Tandem Solar Cells and Bifacial Solar Cells

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  Comparison between Amorphous and Tandem Silicon Solar Cells in Practical Use View original

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  Frontiers | Recent Progress in Developing Monolithic Perovskite/Si Tandem Solar Cells View original

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  Frontiers | Recent Progress in Developing Monolithic Perovskite/Si Tandem Solar Cells View original

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  Comparison between Amorphous and Tandem Silicon Solar Cells in Practical Use View original

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  Frontiers | Recent Progress in Developing Monolithic Perovskite/Si Tandem Solar Cells View original

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• Tandem solar cells consist of multiple layers of different semiconductor materials stacked on top of each other
  • Each layer absorbs a specific portion of the solar spectrum, allowing for more efficient energy conversion
  • Common materials used in tandem cells include perovskites, silicon, and III-V semiconductors (gallium arsenide, indium phosphide)
• Bifacial solar cells can absorb light from both the front and back sides of the cell
  • Enables capturing reflected light from the ground or surrounding surfaces, increasing overall energy yield
  • Requires transparent or glass backsheets to allow light to pass through to the rear side of the cell
  • Well-suited for installations on highly reflective surfaces (white roofs, snow-covered ground)

Transparent Solar Cells

• Transparent solar cells are designed to be partially or fully transparent, allowing visible light to pass through while still generating electricity
  • Can be integrated into windows, skylights, or other transparent surfaces in buildings
  • Typically use organic or perovskite materials that selectively absorb ultraviolet and infrared light while transmitting visible light
  • Trade-off between transparency and power conversion efficiency; higher transparency results in lower efficiency
• Applications include building-integrated photovoltaics (BIPV), solar-powered electronic devices (smartphones, tablets), and solar-powered greenhouses

Concentrator and Building-Integrated Photovoltaics

Concentrator Photovoltaics (CPV)

• Concentrator photovoltaics (CPV) use optical elements (lenses or mirrors) to concentrate sunlight onto small, high-efficiency solar cells
  • Concentration ratios can range from a few suns to over 1000 suns, significantly increasing the power output per cell area
  • Requires precise solar tracking systems to maintain optimal alignment with the sun throughout the day
  • Well-suited for regions with high direct normal irradiance (DNI) and low cloud cover
• High-efficiency multi-junction solar cells, typically made of III-V semiconductors (gallium arsenide, indium gallium phosphide), are commonly used in CPV systems
  • These cells can achieve efficiencies over 40% under concentrated light conditions

Building-Integrated Photovoltaics (BIPV) and Solar Tracking Systems

• Building-integrated photovoltaics (BIPV) involve the integration of solar cells directly into building components
  • Can replace conventional building materials in roofs, facades, windows, or shading devices
  • Provides both electricity generation and building functionality, reducing overall construction costs
  • Examples include solar roof tiles, solar facades, and semi-transparent solar windows
• Solar tracking systems are used to optimize the orientation of solar panels or concentrators relative to the sun's position
  • Single-axis tracking systems rotate the panels along one axis (usually east-west) to follow the sun's daily path
  • Dual-axis tracking systems adjust the panels along both the east-west and north-south axes for more precise tracking
  • Tracking systems can increase energy yield by 20-40% compared to fixed-tilt systems, but add complexity and maintenance requirements

Solar Power System Configurations

Grid-Connected and Off-Grid Systems

• Grid-connected solar power systems are directly connected to the utility grid
  • Excess solar energy generated can be fed back into the grid, earning credits or payments through net metering policies
  • Provides a reliable backup power source when solar energy is insufficient to meet demand
  • Requires grid-tie inverters to convert DC power from the solar panels to AC power compatible with the grid
• Off-grid solar power systems operate independently of the utility grid
  • Suitable for remote locations without access to the grid or for applications requiring energy autonomy
  • Requires energy storage systems (batteries) to store excess solar energy for use during periods of low or no sunlight
  • Sizing of the solar array and battery storage must be carefully designed to meet the specific load requirements

Energy Storage Integration

• Energy storage systems, primarily batteries, are used to store excess solar energy for later use
  • Lithium-ion batteries are the most common type used in solar applications due to their high energy density and long cycle life
  • Other storage technologies include lead-acid batteries, flow batteries, and mechanical storage (pumped hydro, compressed air)
• Energy storage enables better matching of solar energy supply with demand, improving system reliability and flexibility
  • Allows for energy time-shifting, storing excess solar energy during peak production hours and using it during peak demand periods
  • Provides backup power during grid outages or periods of low solar energy production
• Proper sizing and management of energy storage systems are crucial for optimizing system performance and economics
  • Factors to consider include storage capacity, power rating, depth of discharge, and cycle life
  • Energy management systems (EMS) are used to control the charging and discharging of the storage system based on solar production, load demand, and grid conditions