It seems like a new prediction pops up for how we will use renewable energy in the coming decades every day. Will we be using all solar in two years? In five? Will we use more nuclear, or less? Experts love making predictions. Here, we round up some of the most exciting (and upsetting) predictions that have been made in the last few months. We don't have a crystal ball to say which of these will end up being correct, but with so many options, someone is going to look like a genius.
Prediction: Solar Energy Will Be More Economical Than Fossil Fuels In 10 Years
So says the Institute of Electrical and Electronic Engineers  (IEEE). According to the organization, solar PV systems may end up being the most economical form of electricity within the decade--but only if the solar industry continues to rapidly improve solar cell efficiency and create economies of scale. "As the cost of electricity from solar continues to decrease compared to traditional energy sources we will see tremendous market adoption, and I suspect it will be a growth limited only by supply. I fundamentally believe that solar PV will become one of the key elements of the solution to our near- and long-term energy challenges," said James Prendergast, IEEE Executive Director, in a statement.
Prediction: Solar Power Will Be As Cheap As Coal in Two Years
No need to wait a decade--the researchers over at Bloomberg New Energy Finance  think  that solar power could reach grid parity (the point at which solar is as cheap for utilities as fossil fuels) in the next two years. In ultra-sunny regions like the Middle East, the researchers contend that solar power is already competitive. Coal currently costs approximately 7 cents a watt, compared to 22 cents for solar. By 2013, these costs are expected to be equal. But what of our natural gas glut? Will that slow solar development?
Prediction: Natural Gas Will Kill Renewables
Natural gas produced from shale will kill the economics of renewable energy in the coming years, according to a report from Reuters . As solar and wind prices continue to fall, natural gas will stay on top. Because even if, say, offshore wind costs the same as natural gas by 2015 (as predicted by German utility E.ON), there is still an extra cost of building backup power for when the wind doesn't blow. As long as prices are cheap, it's simply easier for utilities to opt for always-on fossil fuels instead of intermittent renewable sources.
Prediction: Renewable Energy Use Will Grow, But So Will Coal And Natural Gas Use
The good news: The International Energy Association believes that renewable energy will grow from 8% of total energy use in 2009 to 13% in 2035. The bad news: Coal and natural gas will also grow--energy generation from coal will increase by 25% from 2009 to 2035, and shale gas production will grow nearly fourfold during that same time frame. So much for cutting down on carbon emissions.
Prediction: We Could Power 100% Of the Planet With Renewable Energy By 2050
Sure, it's unlikely, but a Stanford research team believes  that we could power the planet entirely with renewable energy by 2050--if we mandate that all new energy production plants use renewable energy by 2030 and convert existing plants by 2050. In this happy-go-lucky prediction, 90% of energy production would come from wind and solar  energy , and the other 10% would come from hydroelectric, geothermal, and wave/tidal power. Cars, trains, ships, and other forms of transportation would use hydrogen-powered fuel cells, and aircraft would run on hydrogen fuel. The only problem: somehow beating back the fossil fuel industry to a point of nonexistence. This is a pipe dream at best--but one that we should at least aspire to. Check back in 2050.