Most people don't give too much thought to where their electricity comes from. Flip a switch, and the lights go on. That's all. The origins of that energy, or how it actually got into our homes, is generally hidden from view.

Yet the makeup of America's energy infrastructure matters enormously — it's at the heart of everything from President Obama's upcoming rules on climate change to the endless squabbling over the Keystone XL pipeline. So if you're curious to see what that infrastructure actually looks like, check out this fascinating map tool from the Energy Information Administration. It lets you explore every power plant, coal mine, oil well, and pipeline in the country.

Below, I've pulled out 11 maps that give a particularly good overview of America's energy landscape, circa 2015. (Apologies upfront for excluding Alaska and Hawaii, you can see those on EIA's page.)

1) Coal still provides 34 percent of electricity — but it's declining fast

This first map shows every coal-fired power plant in the contiguous United States:

Not too long ago, King Coal was the dominant source of power in the United States, in part because it was so cheap. In 2003, there were 629 coal plants providing fully half the nation's electricity.

But coal has been dying out since then. As of 2015, there were just 491 coal plants left, providing just 34 percent of our electricity. And more retirements are coming. Coal is still our biggest single source of electricity, but it's clearly on the wane.

What happened? For one, the fracking boom in the late 2000s flooded the country with cheap natural gas (a cleaner competitor to coal), and many electric utilities have been switching over. Then, during the Obama years, the EPA cracked down further on mercury, sulfur, and other pollution from coal — the dirtiest of all energy sources and a major contributor to global warming. In addition, the Sierra Club has been waging an effective campaign to persuade utility regulators to retire their coal plants by 2020 rather than incur endless cleanup costs.

As a result, utilities have been closing dozens of their oldest, dirtiest, and least-efficient coal plants, with more closures yet to come (here's a comprehensive casualty list). And as a final blow, next week the EPA will finalize sweeping climate rules to limit carbon dioxide from US power plants. No surprise the agency expects coal's share of US electricity to fall to 30 percent by 2030, maybe even lower.

2) Natural gas has surged, and now provides 30 percent of electricity

This second map shows all the large natural gas power plants in the contiguous United States:

As of 2015, there were more than 1,725 gas plants providing about 30 percent of the nation's electricity. In the month of May, gas even eclipsed coal very briefly.

Natural gas plants tend to be smaller, cheaper to build, and easier to ramp up and down in response to demand fluctuations — which helps explain why they are so many of them. Gas also burns more cleanly than coal, with fewer air pollutants and about half the carbon dioxide.

In the past, the big downside of natural gas was that prices could fluctuate wildly. But thanks to the fracking boom in the late 2000s, many utilities are betting that they can count on a steady supply of cheap natural gas for years to come. Meanwhile, the EPA's big plan to reduce carbon emissions from power plants depends, in part, on a continuing switch from coal to gas.

3) Nuclear power has stagnated at 20 percent of electricity

Here are all the nuclear power plants in the contiguous United States:

As of 2015, there were 61 nuclear power plants in operation containing 99 reactors. Those reactors provide roughly 20 percent of the nation's electricity — without emitting any heat-trapping greenhouse gases.

Over the last two years, five nuclear reactors have closed down in Florida, Wisconsin, California, and Vermont, under pressure from cheaper natural gas and wind power, plus rising maintenance costs. (Indeed, the map above is slightly outdated, since Vermont Yankee just closed for good in December.) At the same time, many power plant operators have managed to squeeze more power out of their existing reactors. That practice is known as "uprating" and has helped nuclear power maintain its share of electricity.

Few people are building new reactors these days — there are just five in the works at existing sites in Tennessee, Georgia, and South Carolina. In general, the high cost of nuclear plants is a deterrent (these five reactors are all being built in highly regulated states where utilities can recoup their costs by raising rates). The big question is how many more existing plants might retire in the years ahead. The EPA's new climate rules may give states some incentives to keep their nuclear reactors open for longer.

4) Hydropower is the biggest renewable source, at 7 percent of electricity

This map shows hydroelectric dams around the country:

Hydropower is still, by a fair margin, the biggest source of clean renewable power in the United States. As of 2015, there were more than 1,420 hydroelectric dams providing 7 percent of the nation's electricity.

But not all dams are equal. The massive dams in the West provide a disproportionate amount of electricity — Washington, home of the Grand Coulee Dam, produces nearly one-third of the nation's hydropower. The Hoover Dam in Nevada is another huge one. Then there's a vast array of smaller dams around the country providing more modest jolts of power.

It's unlikely that the United States will ever build any more gigantic dams — most of the best sites are already tapped, and dams can be controversial. (No one's going to dam up the Grand Canyon.) If anything, there's been a push in recent years to tear down some older dams that have ravaged ecosystems — like the 108-foot Elwha River dam in the Pacific Northwest, dismantled in 2011 to ease salmon flows.

Still, given our quest for carbon-free power to avert global warming, hydropower will always attract some interest. In 2013, Congress passed a bill aiming to eke more power out of smaller rivers and streams by adding generating capacity to existing dams.

5) Wind power is surging in the Midwest and Great Plains

Here's a map of the major wind farms in the contiguous United States:

Wind has been rising fast, albeit from a low base. In 2008, wind provided just 1 percent of the nation's electricity. That's gone up to 4.9 percent in the first half of 2015 as turbines have sprouted up around the country.

There are two big reasons for that rapid growth. The federal government has provided both tax credits and subsidies for wind. Many states also have laws requiring utilities to get a certain portion of their electricity from renewables. (One notable exception here is the Southeast, which is why you don't see many wind farms there.)

Most analysts expect wind to keep rising in the future, especially in breezy places like the Midwest and Great Plains. True, Congress might eventually take away those federal tax credits. But on the other hand, the EPA's forthcoming plan to limit CO2 emissions will give states incentives to boost renewable sources like wind. What's more, the costs of wind have been falling in recent years. Lately, there's even been interest in building wind offshore — the first such US project just got underway off the coast of Rhode Island.

6) Solar is also growing fast, though it's still pretty tiny

The map below shows large solar power plants around the country (it doesn't, however, show every last rooftop solar system):

For all the hype it gets, solar power still plays only a small role in the US energy system — providing around 0.6 percent of electricity in the first half of 2015.

But solar is also growing very fast, and it has a lot of devoted fans. Hillary Clinton is proposing to boost solar's share of electricity to around 5 percent by 2020.

What's behind the solar surge? It helps that solar panel prices have plummeted, thanks to a boom in Chinese manufacturing. But US installers like SolarCity have also been experimenting with creative financing schemes, making it easier for people to put up rooftop panels without paying high upfront costs. Then there are subsidies, like a 30 percent federal tax credit and "net metering" laws that allow homeowners to sell excess solar electricity back to the grid. These incentives can vary from state to state, which explains why you see a lot of solar in New Jersey but less in, say, Oklahoma.

Meanwhile, some electric utilities have fretted that as more and more people install photovoltaic systems on their roofs, that could cut into electricity sales from traditional power plants. David Crane, CEO of NRG Energy, has called these trends "a mortal threat to the existing utility system," and some power companies have been pushing to scale back net metering laws. See here for the backstory.

7) All those power plants require a lot of transmission lines

Here's a map of all the major (345 kV or more) transmission lines in the contiguous United States:

The regulation of the US power grid is insanely complicated — and it tends to be really tough to build big new transmission lines. If you want to transport electricity from a giant new wind farm out in the Great Plains to population centers, it's not always easy.

8) Coal mining has shifted from Appalachia to out West

Here's a map of all the major coal mines in the United States:

Judging by this map alone, you'd get the impression that Appalachia is the center of coal country. But in fact, that's no longer true. Ever since the late 1990s, the majority of America's coal has come from west of the Mississippi — particularly from public lands in Wyoming and Montana — rather than from the East.

There are a few reasons for that. The coal out West tends to be lower in sulfur, which is useful for US coal plants that are trying to cut their sulfur dioxide emissions in response to pollution regulations. What's more, Appalachian states like Kentucky and West Virginia have already mined much of their easiest-to-reach coal seams — and many areas are seeing a decline in production.

Coal mining is expected to take a further hit in the future as the EPA's new climate rules lead to a decrease in coal-fired electricity. Some of the coal from Wyoming and elsewhere may start to get exported abroad, though environmentalists have been working to block that export infrastructure, arguing that it's detrimental to climate efforts.

9) The US produces about 62 percent of the oil it needs

This map shows every oil well in the lower 48 states. Not shown are oil wells in Alaska, responsible for about 5 percent of US production:

So far we've been looking at electricity, but that's only part of the energy story. The United States also uses about 19 million barrels of oil per day, mainly turning it into fuel for our cars, trucks, and airplanes. That all has to come from somewhere. And, increasingly, it comes from within our own borders. The biggest oil states, by production, are Texas, North Dakota, California, Alaska, and New Mexico. (Note that not all wells are equally productive — Kansas has a lot of wells on this map but only ranks 10th in output.)

Overall, US oil production has been growing at a staggering rate in recent years. Back in 2010, the country was producing just 5.4 million barrels of crude oil per day. By April 2015, that had soared to 9.7 million barrels per day — the most since the 1970s

The reason for the surge: fracking and horizontal drilling techniques allowed oil companies to extract more crude from shale rock and other difficult formations in states like North Dakota and Texas. Advances in offshore drilling, particularly in the Gulf of Mexico, have also helped. Meanwhile, as all this was happening, the US economy was also becoming more oil-efficient, thanks in part to stricter fuel economy rules for cars and light trucks. Add that all together, and oil imports from abroad have been plummeting.

The recent US boom also helped trigger the recent crash in oil prices worldwide. And that, in turn, has put pressure on American drillers. So far, they've managed to slash costs and continue pumping even in the face of low prices. We'll see how long that can last.

10) But that oil first has to make it to refineries to be useful

Once crude oil is drilled out of the ground, it has to be sent off to refineries that can turn it into usable fuel for our cars and trucks. This map shows all the major pipelines and rail terminals that take oil to refineries (the brown squares):

This map is crucial for understanding a number of contemporary energy disputes.

For instance, a lot of oil is being dug up from the tar sands in Alberta, Canada. But there arguably aren't enough pipelines to bring all that oil to refineries. That's why Canada and various oil companies want to build the Keystone XL pipeline — to bring that tar sands oil down to Texas refineries. Environmentalists have opposed that project, arguing that boosting tar sands production is incompatible with dealing with climate change. Obama, in turn, has wavered on a decision for years.

Separately, oil companies have also argued that there's not enough refining capacity down in Texas to handle the recent boom in US oil production. They'd like to lift the longstanding ban on exporting crude oil from the United States to other countries abroad — so that they can reach more customers.

Meanwhile, check out North Dakota. That state has recently become the epicenter of the US oil boom — thanks to fracking. But because this was so recent, there still aren't enough oil pipelines running out of the state. Instead, oil companies have been shipping their crude out via trains (which is why you see all those rail terminals). The problem? Every now and again, one of these oil trains will get into an accident, causing leakages or, worse, a massive explosion. Policymakers in Washington have been fighting for some time over how to improve oil-by-rail safety.

11) The shale boom is upending the US energy landscape

This final map shows shale plays of oil and gas (in brown), as well as tight gas plays (in blue):

I've discussed fracking and horizontal drilling a lot above. Well, here's where it's all happening. There are currently more than 63,000 shale oil wells and shale gas wells around the country. Much of the activity is concentrated in Texas, North Dakota, Louisiana, and the Marcellus Shale region in the East.

The shale boom has undeniably reshaped the American energy landscape — it's easily the energy story of the past decade. Domestic production of oil and natural gas has risen sharply, leading to lower energy costs and a reduced reliance on imports.

But fracking has also created plenty of controversy. Advocates argue that the shale boom has created jobs and boosted manufacturing, and can help tackle global warming by reducing the amount of coal we use. Opponents often argue that the industry is poorly regulated, the global warming benefits are overhyped (because of methane leaks from natural gas infrastructure), and that fracking has led to increased air and water pollution around the country.

You can read about the shale boom — and its consequences — in much more detail in our fracking card stack.

Note: This piece is an update of a similar piece I did back in 2014. There have been some subtle changes and developments in the past year (particularly the oil price crash and further coal plant closures). So, rather than simply repost the old piece, I did a brand new one. It might be interesting to follow these changes over time, year by year.