Are renewables actually replacing fossil fuels?

The answer is more complicated than you might expect

Last week, I published a story in the Cleanview newsletter about the staggering growth of solar and battery storage in the United States.

In 2023, the U.S. added a record 19.3 GW of utility-scale solar capacity—72% more than in 2022. It’d be reasonable to assume that after a record year, the annual growth rate would fall this year. Instead, the U.S. is on track to add 38 GW of new capacity this year, nearly twice as much as last year, according to Cleanview data.

As adoption has become more widespread, solar energy’s growth rate has expanded instead of slowing down.

The recent growth of battery storage has been no less impressive.

Last year, the U.S. added 6.6 GW of utility-scale storage to the grid. This year, the country is on track to add 14.7 GW—123% more than in 2023. Here too, growth is accelerating.

In response to the story, one reader asked: “Am I right in thinking that [this] hasn’t actually replaced ANY fossil fuel use?” Another reader answered in the comment thread: “Yep, it’s just more energy thrown onto the heap. We’re actually still increasing our use of fossil fuels, year over year.”

I’ve written many stories about renewables over the years and this question—if we’re even making any progress—is one of the most common questions I hear. It’s not just Substack commenters arguing that renewables aren’t replacing fossil fuels either.

Respected academics and writers have made similar arguments. In The Price is Wrong—one of the most popular books on climate change written this year—Brett Christophers writes:

Here’s the terrifying thing. For all the recent uptick in the rate of growth of renewables output, we — globally — nonetheless have been falling ever further behind the curve in terms of the amount of renewables capacity that still needs to be installed.

In this newsletter, I’m going to dig into this question to explore how much progress we’re really making in decarbonizing electricity, the largest source of emissions globally.

Spoiler alert: The answer is more complicated and nuanced than you might expect. In what is a theme of the Anthropocene, it rejects simple narrative¹.

Are we making any progress?

My story about the growth of solar and batteries was about the United States. So we’ll start there and then zoom out to what’s happening around the world.

Over the last 25 years, America’s share of electricity coming from fossil fuels like coal, gas, and oil has fallen from 71% to 59%.

Much of the decline in fossil fuel consumption in the power sector has come from the steady decline of coal power. As I wrote in a story last year:

At its peak in 2007, America’s coal power plants were responsible for about half of the country’s electricity generation. Last year, coal was responsible for about 20% of power generation. 

Over that same period, the share of electricity generated from solar and wind has risen from almost zero to 16%. Nuclear and hydro—still the country’s largest sources of low-carbon energy—fell slightly from a combined 27% of generation to 24%. Meanwhile, fossil gas power generation rose from 16% in 2000 to 42% in 2023.

Not all the changes in the power sector have been good for the planet. Fossil gas, which puts both methane and carbon dioxide into the atmosphere, has become the largest source of electricity generation. (Academics are still debating whether or not gas is better or worse, after accounting for methane leaks, than coal).

But we can’t just look at the share of electricity generation from fossil fuels vs. low-carbon energy sources. We have to look at the absolute amount of electricity generated and the resulting emissions.