Solar power is going big. Carlos Barria/Reuters

Clean energy is killing fossil fuels.

Investment in renewable energy technology — solar and wind power — is now seeing twice as much global funding as fossil fuels, according to Bloomberg.

The reason: the economics of renewable energy are drastically improving.

Solar power is a technology, not a fuel, so efficiency increases and prices fall as time goes on, reports The Economist.

So renewable energy is getting cheaper all the time, independent of oil prices, according to McKinsey.

The cost of solar power has fallen to 1/150th of its level since the 1970s, while total solar installation has increased 115,000 fold, reports ETF Trends.

Developments like the Tesla Powerwall, and other rechargeable batteries have also smoothed over the inconsistency of solar power when the sun isn't shining.

The story is similar for wind.

The amount of global electricity produced by wind power has doubled four times over since 2000 to almost 6% of total electricity production, per Bloomberg.

Fossil fuels are getting dominated by falling oil prices, and more recently, a lack of investment. The number of oil rigs in the US is the lowest it has been since 1940, according to Bloomberg.

It's important to note, however, that renewable energy and oil do operate in different markets. Oil is used primarily for transportation, while renewables are used for electricity production. That's why renewable energy investment is largely independent of the price of oil, according to McKinsey.