The problem of climate change became a hot topic for the last few decades. Renewable energy appeared to be the only sound alternative to fossil fuels that have already made a dramatic impact on ecosystems. After all, they are exhaustible natural resources, and population cannot eternally benefit from precious reserves of their land. At this point, scientists popularized the concept of solar and wind power as well as hydroelectricity. More than 100 years ago, the knowledge of renewable sources came down to biomass, geothermal power, and heat. Today industries widely use biomass gasification and ocean energy alongside with solar and wind power stations.
As soon as the perspective of depletion became more realistic, progressive industries started the production of renewable energy. According to the global renewable energy policy network, renewables made up nearly 20 percent of humans energy consumption all over the world. To achieve these result, hundreds of billions of dollars were invested in renewable technologies. China and the US are currently the largest investors, and the whole industry created more than 7 million jobs all over the world. Governments generally stimulate commercialization of this sector of energy and offer various policies for consumers and producers. The part of renewables in total consumption of energy tends only to grow in the next decades.
At the present moment, solar and wind power are the major renewables. Though the part of solar and wind is rather small as compared to hydroelectricity, solar power has extraordinarily accelerated for the last few years. With the current tempo of growth, solar power is expected to outrun wind and hydro power soon.