Visualizing Energy Production in the U.S.
Are renewables on the rise? Depends where you are.
Welcome to Earth Week on Nightingale! In honor of Earth Day on April 22, we are publishing earth-related data-visualization content all week. Data viz can enhance our appreciation of the planet, illuminate our relationship to it, and call us to action to preserve it. After all, we only have one and it means the world to us. You can keep up with all of our Earth Week articles here.
Energy: we all use it, but we rarely think about where it comes from. That’s a problem for climate action! In the U.S., more than 90% of our anthropogenic (human-caused) CO₂ emissions come from burning fossil fuels for energy, and while states have been slowly transitioning to use more renewable energy, the overall energy picture is still dirty with coal dust.
I wanted to show how that’s changed — or not — over the last few decades.
As an energy analyst who’s passionate about data viz, I spend a lot of time thinking about how to make a wonky topic more accessible to the general public. The energy system is complex. On one side of the equation, you have energy consumption — how much people are using. On the other side, you have production, which is itself an intricate web of markets linked through imports and exports. Since I couldn’t depict the whole energy system in one chart, I decided to focus just on electricity production, to highlight changes in energy sources over time. I used data from the Energy Information Administration on net generation (the amount of electricity available for use by consumers, after subtracting the energy that power plants use themselves), which is tracked by state, year, and type of resource.
My goal in visualizing the data was to clarify, without overly simplifying, the story of electricity production in the U.S. I wanted to convey both my optimism — look at all that new renewable energy! — and my concern — why aren’t we doing more?
But as I finished arranging the state-level charts I had made into a map of the U.S., I realized there was more nuance to the story than I had expected. Even though I had worked with this data set before, I’d never seen it visualized state by state, and I had no idea how strong the regional patterns were. While coal production has in fact declined in some parts of the country and across the U.S. as a whole, it hasn’t budged a bit in my home state of Missouri. (Or West Virginia, or Nebraska…) The band of wind energy blowing through the Plains States is immediately clear. And while we hear a lot about solar energy in the news, it represents an almost imperceptible portion of most states’ energy portfolios. If I squint, I can kind of see some solar in California…
So what accounts for these differences? The first thing to note is that the U.S. as a whole has made progress in cleaning up its energy supply — since 1990 coal production has declined by 28%, and renewable production has nearly doubled. That’s encouraging, but because the U.S., unlike many other countries, doesn’t have a federal target for renewable energy generation, those gains have largely come from state-level efforts.
To understand some of what’s going on at the state level, let’s take a closer look at two states in particular: my home state of Missouri, which is sorely lagging in renewables development, and California, which is a consistent leader. Some of the differences in production can be explained by differences in climate and the energy resources available — California is sunnier than Missouri, so solar energy just makes more financial sense there. But differences can also be explained by policy and political climate. As you can see below, California has adopted increasingly ambitious renewable portfolio standards (requirements for how much renewable energy must be produced) since 2002. Missouri, in contrast, only adopted its renewable portfolio standard in 2008 and set it lower than what had been initially adopted by California six years earlier.
There are, of course, many other factors that contribute to state-level differences in renewables development. (The energy system is complex.) But most point to one key conclusion: cleaning up our energy system won’t happen unless people demand it. Unfortunately, many barriers to clean energy development are invisible to the public. For example, one issue currently slowing renewables development in Missouri is the lack of support for innovative financial strategies that reduce the cost of closing dirty power plants to shift toward renewable energy. (Because utilities recover construction costs slowly over the expected life of a plant, closing a plant early can leave utilities and their customers (us!) with huge unrecovered costs.) With so many coal plants expected to operate for decades to come, states like Missouri will continue to lag on renewables until their residents push for change. And while the ins and outs of financial policy may be best left to lawmakers, the public’s job is to keep the pressure on.
Looking back at this map, I think it tells an important piece of the energy story, but of course it doesn’t capture everything. As with any viz, I had to make tough choices about what to show and what to leave out. In this case, because the story I ultimately wanted to tell was about trends in the adoption of renewable energy, I chose to focus on the percentage breakdown of energy sources from state to state, rather than the amount of energy produced. This decision allowed me to show each state on the same axis scale, but it also meant that the final viz doesn’t convey anything about the relative amount of production in each state — like the fact that, in 2018, the barely-visible sliver of solar energy produced in California (27 million MWh) was roughly equal to the total amount of energy produced in Massachusetts. And as for some of those dramatic shifts in energy resources, like Vermont in 2015? Vermont didn’t suddenly adopt an aggressive clean energy policy — it simply decommissioned its only nuclear plant, dramatically decreasing total production. Magnitude is an important piece of the story, but I couldn’t find a way to incorporate it. Let me know in the comments if you can think of a creative way to include both together!
What I hope this viz communicates is that, yes, the U.S. overall is on a positive trajectory toward phasing out fossil fuels, but we have so much work left to do. We can’t afford to be sluggish in shifting away from fossil fuels. We shouldn’t have to squint to see the contribution of renewable energy.
My experience creating this viz also made me think more broadly about the role that data viz might be able to play in climate analysis and climate action. Even as an energy analyst, I learned something new simply by displaying the data in a new way. Seeing Missouri’s dark gray coal production continue, unchanged, for nearly three decades makes me angry, and that anger inspires me to keep pushing for local large-scale renewables. Data viz is about taking numbers and complicated messages, which don’t typically motivate people, and translating them into stories, which do. So, to enable big, bold climate action, what needs to change in each of our communities? And can data viz help us get there by changing the story we tell?
