Our mix of energy choices today is in a state of transition, from a system based on cheap oil and coal to a broader energy spectrum. Science and technology have a big role to play in our energy future by addressing inefficiencies in the ways we find, process and use energy, and by finding innovative ways of scaling up successful energy systems. Scott Tinker is the Director of the Bureau of Economic Geology at the Jackson School of Geosciences, University of Texas, Austin. He worked in the oil and gas industry for 17 years in research, exploration, and development, prior to coming to The University of Texas in 2000. He told EarthSky that future energy choices will likely be based on both economic realities and environmental concerns. This interview was made possible in part by the Bureau of Economic Geology at the University of Texas at Austin.
Describe the big picture of energy choices today — fossil fuels, wind, solar, nuclear — in the U.S. and the world at large.
It’s still a fossil-fuel-dominated world. Within the fossil fuel mix, the transition has been away from oil and coal to more natural gas.
Let’s talk about U.S. electricity first. Coal – which has been king in the past for making electricity – has been slowly declining. In fact, in the last few years, it’s come down quite a bit. It now represents about 35% of the fuel used to make electricity. Meanwhile, natural gas use has been increasing. Natural gas now represents about 30% of the fuel we use for electricity, approaching parity with coal for the first time in history. Unlike coal, natural gas is also used directly for heating and cooling industrial, commercial and residential buildings.
Now consider U.S. transportation. Oil has been the traditional fuel of choice for transportation. We’re starting to see a few other things, such as as biofuels, CNG and electric vehicles, but, for transportation, it’s still mostly oil. And oil represents about 35% of our total energy mix.
Considering all the ways we use energy, overall we’re still using about 82% fossil fuels. Most of the rest is nuclear fuel, which makes about 20% of electricity alone. Nuclear represents about 8% of the total mix.
Hydro – energy taken from water and converted to electricity, mostly from dams – is another 3% or so. Biomass is 4%, and the remaining 3% percent are what we call alternative or renewable resources, such as wind, solar, waves, tides, and the like.
You’ve spoken of a transition in the kinds of energy the world uses. Tell us about it.
That transition has been very predicable for over a century – a very linear decarbonization, as my friend Jesse Ausubel terms it.
In other words, as we look back in history, our energy mix was all carbon-based. Today, and out into the future, carbon decreases and hydrogen increases in the mix. If you go back to the 1800s, for example, we were a carbon-based world in terms of energy. We used hay as fuel for transportation, because that’s what we fed to animals. We used wood – which is also carbon-based – for heat. Then coal came along. Coal is just the carbon from plants and animals that has been solidified by pressure and geologic time. Coal was burned for heat, and also used for transportation in the steam combustion engine of trains and transoceanic steam liners.
In 1909, when the first Model T rolled off of a production line here in the United States, it had a combustion engine that ran on liquid: oil. After that came the explosion of the oil economy.
Oil peaked globally as a percentage of the mix in 1979. In that year, just under half of all energy came from oil. That percentage been slowly coming down since 1979. It’s just over 30% now.
In recent years, natural gas use has been rising. Natural gas is a very simple hydrocarbon – one carbon, four hydrogens – CH4. That’s compared to oil, which is a complex hydrocarbon consisting of chains of hydrogen and carbons. That’s what I mean when I say the hydrogen component of fuel we’re using is increasing, and the carbon component is decreasing. It’s that idea of decarbonization that I mentioned earlier.
Natural gas – methane – is a versatile fuel. You can use it to make electricity. You can use it to put in cars as a fuel. Most of us use it in our homes for cooking and heating and other kinds of things.
Nuclear energy is another part of our fuel mix and our energy transition. Nuclear is not a source from fossil fuels. Its source is radioactive elements – mostly uranium – but others as well. The heat from that radioactivity is used to boil water and make steam, turn a turbine, and make electricity.
Nuclear took off in the 1970s. The U.S. is the leader in nuclear power generation. We have 104 reactors in this country. But they’re all 1970s technology. We’ve added capacity, but we haven’t started new construction on a nuclear reactor in several decades.
Personally, I think nuclear energy has to be a very important part of our energy future. It’s extremely efficient. Though building a nuclear plant is expensive, once the plant is built the kilowatt hours are affordable. And there are no air emissions. It is clean. The main challenge with nuclear is handling the radioactive waste and making sure the plant is safe from human and natural disasters. And there are some interesting technologies now that are improving for that.
As for hydroelectric energy, we’ve built pretty much all the dams that topography and available water provide. There are a few new ones being built. Three Gorges in China – which has been mostly completed this year – is a giant facility; the largest power plant in the world. But, Three Gorges notwithstanding, most of the rivers have been dammed. In fact, a few dams are being taken down now, so hydro energy is transitioning, slowly, to be a smaller percentage of the energy mix over time.
Wind energy is growing. In Texas we have over 10 gigawatts – 10,000 megawatts – of installed wind capacity, which is more than any other state. The turbines are simple and affordable and there are no emissions. The big challenge with wind is that it is intermittent: the wind doesn’t blow all the time. It can stop and start very quickly. That is not a trivial problem.
Solar energy has the same issue. The sun doesn’t always shine. There is nighttime, of course, and cloud cover. So solar, too, is intermittent.
When you’re trying to manage an electric grid with renewable sources like solar and wind, you have to be able to replace the wind capacity, for example, with something else very quickly. That’s called backstopping. It means you have to bring some other form of electricity on when the wind slows down, or when the sun isn’t shining. Then, you have to take that system down when the wind comes up again. A power grid based on renewable energy sources has to have almost a complete backstopping capacity for the demand load put it on it by the public today. Along with long distance transmission, intermittency is one of the great challenges of bringing these sources along more quickly.
You’ve described the close linkage of energy, economy, and the environment as a dance where when one moves, the other follows. Why is it useful to think about these ‘Three Es?’
If you look at the ‘Three Es’ – energy, economy and environment – energy underpins all major economies. In fact, six of the last last seven global recessions were preceded by a spike in the price of oil. When oil, as a proxy for energy, price goes up significantly and quickly, the economy reacts. There’s a lot more that influences the economy than just the price of oil, such that correlation is not causation, but you see a consistent correlation between oil price and the economy because so many things depend on energy. The economy counts on available, affordable, reliable energy.
Now, we also want and need our energy production to be environmentally sensitive to our water, land, and atmosphere. When the economy is healthy, we can afford to invest in the environment. We can put more efficient things in place that will eventually save money, although they don’t upfront. The public is more likely to accept protocols for emissions and other kinds of things.
When the economy is not healthy, we tend to have other things on our minds – jobs and school and food and other basic needs. Without a healthy economy, it’s tougher to invest in the environment.
You can see that time and time again. It’s a waltz, with the energy underpinning the economy, and the economy helping to invest in the environment. It’s very elegant when it’s working well.
But if you go too far toward any one of the three, then the others get left behind and suffer. Too much on the energy side of things, and you’ll see some environmental impacts. Too much on all renewables and you’d see an economic impact because of issues of affordability, availability, or reliability. And accordingly investment in the environment suffers.
The “Three E” dance with public education at its core.
Why do you sometimes say that efficiency and scale are crucial for shaping people’s energy choices?
It’s hard for us to fathom the scale of our own demand for energy. We don’t really recognize it. We recognize that we have lights and that there is electricity coming from somewhere – that we get in a car and turn on a switch and an engine fires up that burns gasoline.
But we don’t really recognize that everything in the world has energy involved.
We’re sitting here in a room right now surrounded by furniture. That needed energy. We have clothes on. Every pair of blue jeans made takes the equivalent of about three gallons of gasoline to manufacture, ship, market, and keep clean.
I just had lunch. A grocery cart full of groceries each week is the equivalent of about 22 gallons of gasoline. From growing, harvesting, transporting, processing, packaging, and transporting to the grocery store, my buying it and bringing it home, cooking, that’s four of those big red five-gallon cans of gasoline in your grocery cart every time you walk out of the grocery store. The roads, everything depends on energy. The scale is hard to fathom.
I can throw out numbers that won’t mean anything to anybody. In the US, we consume about 90 million watt-hours of energy per person every year. The scale of our demand in modern economies has become something that no one can really process.
What that means is we have to be able to have systems that can meet the scale. It’s not just the volume or amount of energy. It’s when we want it, and where we want it but I don’t want my power bill to be too high.
So you have to have things in place that allow for the right level of supply to fuel the world. It takes smart people. It takes a lot of systems working together. It takes huge investments. It takes governments and industry and academics working together to make sure that this all is done in a way that can meet those demands.
We built the global energy system to meet the human demand for energy; we are the only users. And so efficiency and conservation – smarter use of energy – have many benefits. Efficiency saves energy, lowers emissions, uses less water, requires less infrastructure and less land, and can even save money! The biggest challenge to efficiency is cultural. How can we save energy if we rarely think about energy, and don’t really understand it? It’s time to make efficiency a habit.
Any last thoughts?
I’d like people to understand – as we look out into the future – that it’s going to be okay. The combination of science and technology, thoughtful policy, and educated public will come together and solve some of these big challenges. I’m an optimist. I think this will happen.
But it can’t be done without some level of understanding. We need to become educated and start to think about and read about what this is going to require and what that transition really looks like as we move forward.
The facts, not the dramatic, and often misleading, fiction.
And if the world begins to do that, then I believe we’ll move to an energy future that’s very positive for our kids, for the environment and for the economy.
So our energy future is a very solvable challenge, if we each engage and participate in it.
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