Solar energy is the most abundant energy resource on Earth. After hydro and wind power, solar photovoltaic (PV) energy is the third most important renewable energy source, in terms of global installed capacity. A whole range of solar technologies exists to capture the energy from the sun and convert it to deliver heat, cooling, electricity, lighting and fuels for many applications. Around 85% of all new PV systems, though, are based on crystalline silicon technology, which is now mature. Novel technologies are being explored based on nanomaterials and could give rise to breakthroughs in terms of efficiency.
As the cost of PV technology continues to decrease and electricity prices remain high, PV is on its way to becoming commercially competitive in the energy sector. In countries with plenty of sunshine, payback on the initial investment can take as little as two years.