Wind, solar and four other forms of renewable resources have the potential to outstrip energy demand by 2020 and replace fossil fuels as a power source, according to a new report by the United Nations.

The report is called the “Renewables Bible,” and will serve as a reference guide  for renewable energy growth. The report indicates that there’s enough potential for the six renewable energy sources — which also include geothermal power, biomass fuel, hydropower and power harnessed from oceanic waves — can grow 20-fold over the next decade. The United Nations examined 164 scenarios to come to the conclusion in a comprehensive survey of the current renewable energy environment.

But in reality, only around 2.5 percent of that potential growth will happen based on the current growth trajectory for renewable energy, according to the report. That’s because a complete shift to renewable energy sources will cost global markets around $12.3 trillion by 2030. Global markets will have to invest around $5.1 trillion over the next decade and an as much as an extra $7.1 trillion between 2020 and 2030 to complete the shift.

Most of the scenarios examined by the United Nations still pointed to a substantial increase in the amount of renewable energy deployed by 2020 and 2030. Global markets added around 140 gigawatts of power from renewable sources between 2008 and 2009, bringing the world total up to around 300 gigawatts. That’s mostly dominated by biomass energy sources, which account for around 10 percent of renewable energy generation.

Paris-based International Energy Agency said that a total of $20 trillion needs to be spent on energy infrastructure to expand it and meet demand by 2030. Right now, renewable energy sources account for around 13 percent of global energy usage. In some of the best scenarios, renewable energy would account for up to 77 percent of global energy usage by 2050.

[Photo: s-ariga]