Introduction to Photovoltaics

Photovoltaic technology converts sunlight directly into electricity using semiconducting materials. This process is emissions-free at the point of generation, making PV a cornerstone in sustainable energy discussions.

Solar cells operate on the photovoltaic effect. When photons hit a PV cell, they can excite electrons, creating free carriers and an electric current. The efficiency of this process is crucial for energy yield.

Silicon is the predominant material in solar cells, but alternatives like perovskite, cadmium telluride, and CIGS (copper indium gallium selenide) are gaining traction due to potential cost and efficiency benefits.

A complete PV system includes panels, inverters to convert DC to AC power, mounting structures, and sometimes batteries for energy storage. System design impacts overall performance and lifespan.

PV cell efficiency has soared, with records surpassing 46% under lab conditions using multi-junction concentrator cells. Real-world efficiencies are lower but improving, with PERC, HIT, and bifacial technologies leading the way.

PV technology has a lifecycle carbon footprint of around 20g CO2e/kWh. It's lower than fossil fuels but not zero due to manufacturing and disposal. Recycling efforts are critical for sustainability.

The PV market is skyrocketing, with China leading in production and installation. Innovation, policies, and decreasing costs drive growth, making solar one of the fastest-growing energy sources worldwide.