An anonymous reader writes: Bill Gates has invested about a billion dollars in renewable energy, and now he's ready to double down. Gates announced he will increase his investment in renewable energy technologies to $2 billion in an attempt to "bend the curve" on limiting climate change. He is focusing on risky investments that favor "breakthrough" technologies because he thinks incremental improvements to existing tech won't be enough to meet energy needs while avoiding a climate catastrophe. "There’s no battery technology that’s even close to allowing us to take all of our energy from renewables and be able to use battery storage in order to deal not only with the 24-hour cycle but also with long periods of time where it’s cloudy and you don’t have sun or you don’t have wind. Power is about reliability. We need to get something that works reliably." At the same time, Gates rejected calls to divest himself and his charitable foundation of investments in fossil fuel companies.