There are generally two kinds of arguments against renewable energy: the cost and the lack of consistency. After all, solar panels can't work in the dark and wind turbines don't turn on still days, but we still need to charge our smartphones 24/7. The solution here is to build large-scale energy storage (read: really big batteries), but they're not economically viable.



Except that isn't true -- not anymore, anyway. Bloomberg recently reported that the price of batteries has fallen 40 percent since 2014. These plunging prices have been so pronounced that big financial institutions are now throwing their weight behind the energy-storage market. Bloomberg also reports that institutions like Investec and Prudential have piles of cash earmarked to put behind industrial battery projects. Indeed, the International Renewable Energy Agency (IREA) believes that we're on track to be able to store 250 gigawatts of electricity by 2030.



And as costs fall for big business, they begin to slide for the rest of us, with James Forrest at business consultancy Capgemini claiming that the current "adoption of renewable energy" is "driving down the price for everyday people." There's more good news, since Bloomberg believes that deals for battery projects will hit $2.5 billion in 2017, and that figure doesn't even take into account what Elon Musk is up to. During Tesla's most recent earnings call, Musk claimed that he would build up to five Gigafactories to mass-produce batteries for the Model 3 and Powerwall 2.



If Tesla is successful, it will create a seismic change in the way that we store and use energy in the home. You will not only be encouraged to buy a (cheap) battery to connect to your solar roof but also have a car that can power your home in an emergency. Not to mention, the running costs for an electric vehicle are continuing to fall, providing further incentives for buyers to make a switch.



It's not only batteries that are helping to effect massive change but also the increasing efficiency of solar panels in general. Damien Ryan, acting CEO of environmental nonprofit the Climate Group, says the world is "producing more megawatts of green energy for the same amount of money." He adds that the resulting price drop is a "powerful driver for change."

And such change is coming, because the economic argument for investing in carbon-intensive energy gets less credible by the day. Saudi Arabia -- home to the world's second-largest oil reserve -- has outlined its plan to build a huge 300MW solar plant. Electrek believes that the facility's eventual energy cost will be a staggering 1.99 cents per kWh. For comparison, the average price of electricity in the US at the end of 2016 was 12.75 cents per kWh -- and no coal-fired power station is likely to compete.



Speaking of which, the Navajo Generating Station is the largest coal-fired power station in the western US. It was originally going to be mothballed in 2044, but it's now expected to close in 2019, several decades ahead of schedule. As Fast Company explains, it's the seventh-largest individual source of pollution in the US, pumping 14 million tons of CO2 into the atmosphere per year. The cause of the plant's closure is the advent of natural gas stations and renewable energy, which is cutting deep into profit margins to the point where operations are no longer sustainable.



The falling cost of both panels and storage is a boon for the developing world, where 1.2 billion people live without energy each day. The head of the IREA believes that the cost of large solar installations will fall by more than half in the next two decades. That, combined with cheap batteries, will help poor communities get power and escape extreme poverty.





Of course, many will scoff and say that the renewable energy industry has so far survived on government subsidies. When those subsidies are withdrawn, the industry's unprofitability will be exposed once and for all, right? Not so, says Dr. Chris Case of the solar panel company Oxford PV. He is optimistic, saying that we're now on the cusp of living in a solar world. The use of photovoltaic panels "has doubled seven times since the year 2000," he said, "and only needs to double six times more by 2030 to generate 100 percent of our global power needs." He later added, citing the Saudi Arabia project, that it offers "the cheapest form of electricity anywhere in the world and has been achieved without subsidy."



He also said that while even a few years ago solar power would have needed help, the business is now strong enough to stand on its own. "Solar has the lowest cost of generation in many places," he said, "and when that statement can be made without the caveat of 'in many places,' then it'll be unstoppable." Case believes too that this force is enough to overcome even the most crafty of governments with a mission to rig the game in oil's favor. "There's no political or social force that can resist [lowering prices]," he said. "Not even the president of the United States can fight it."



But while the global market for renewables might be getting stronger, the US itself stands at a crossroads as to its future policy on climate change. Rachel Bronson of the Bulletin of the Atomic Scientists told the AV Club that any climate backsliding could be catastrophic. "It's not that far away where our children will be dealing with more difficult outcomes than if we got serious now," she said.



Bronson describes the hope that the success of President Trump, Rex Tillerson and Scott Pruitt represents the "last gasp" of climate denial because the evidence is overwhelming. But Bronson knows that "when carbon gets into the atmosphere, it can stay there for 10,000 years." She added, "Given the amount that we're pumping into the atmosphere, the changes have to happen now." As optimistic as we could be, unfortunately it's still going to take a lot of effort before we can say that our planet's future is safe.