and generate power close to where it is consumed. Photovoltaics grew fastest in China between 2016 and 2021 adding 560 GW, more than all advanced economies combined. Solar PV’s installed power capacity is poised to surpass that of coal by 2027, becoming the largest in the world. This requires an increase of installed PV capacity to 4,600 GW, of which more than half is expected to be deployed in China and India. Commercial concentrated solar power plants were first developed in the 1980s. As the cost of solar electricity has fallen, the number of grid-connected solar PV systems has grown into the millions and utility-scale solar power stations with hundreds of megawatts are being built. Many solar photovoltaic power stations have been built, mainly in Europe, China and the United States. The 1.5 GW Tengger Desert Solar Park, in China is the world's largest PV power station. Many of these plants are integrated with agriculture and some use tracking systems that follow the sun's daily path across the sky to generate more electricity than fixed-mounted systems. Biofuel development Bioenergy global capacity in 2021 was 158 GW. Biofuels avoided 4.4% of global transport fuel demand in 2021. Policies in more than 80 countries support biofuels demand. Since the 1970s, Brazil has had an ethanol fuel program which has allowed the country to become the world's second largest producer of ethanol (after the United States) and the world's largest exporter. Brazil's ethanol fuel program uses modern equipment and cheap sugarcane as feedstock, and the residual cane-waste (bagasse) is used to produce heat and power. There are no longer light vehicles in Brazil running on pure gasoline. Biojet is expected to be important for short-term reduction of carbon dioxide emissions from long-haul flights. Geothermal development Global geothermal capacity in 2021 was 15 GW. Geothermal power is cost effective, reliable, sustainable, and environmentally friendly, but has historically been limited to areas near tectonic plate boundaries. Recent technological advances have expanded the range and size of viable resources, especially for applications such as home heating, opening a potential for widespread exploitation. Geothermal wells release greenhouse gases trapped deep within the earth, but these emissions are usually much lower per energy unit than those of fossil fuels. As a result, geothermal power has the potential to help mitigate global warming if widely deployed in place of fossil fuels. In 2017, the United States led the world