Name: 这种被忽视的能源可以提供50％的电力（This Overlooked Energy Source Could Supply 50% Of Electricity）
Uploaded: 2021-05-09T09:44:15.000Z
Duration: 15 min 42 s
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Miles below the Earth's surface, there's a source of renewable energy that could sustain all of humanity for the foreseeable future.

程度副詞

Just 0.1 percent of Earth's total heat content could meet our energy needs for two million years, according to ARPA-E, the government agency that

funds R&D efforts for advanced energy technologies.

It's more than we could use in our entire arc of civilization, thousands and thousands of times over.

It's called geothermal energy and in some ways it's old news.

It's been used to heat buildings since the late 1800s and to provide electricity since the 1900s.

has the most installed geothermal capacity in the world, it still only accounts for about 0.4 percent of our total electricity mix.

Because geothermal has been around for over 100 years, it just doesn't have the same kind of cachet that some new energy source

Though newer geothermal technologies are essentially emissions-free, it's expensive and technically challenging to drill geothermal wells.

The hotter and drier the rocks are, the more difficult it is.

And now that natural gas, wind and solar are so cheap, there just hasn't been much economic motive to scale geothermal in more difficult

Fast forward a few years and it's a very different world.

I think the volatility of the oil and gas sector, as well as this increased focus on climate change and the environment and sustainability,

have really caused these companies to wake up and realize that the energy transition is going to totally change how business is done.

Now oil and gas majors like Chevron and BP are getting into the game, making investments in the geothermal space.

It's a natural fit, as the skills required for drilling oil and gas wells are quite similar to drilling for geothermal, and technical innovations

from the shale revolution are making the economics more feasible.

Most of the heavy lifting was already done by the oil and gas industry in the last five or 10 years.

We're sort of riding on the coattails of their advances in directional drilling and speeding up drilling.

We spoke to a number of startups in the geothermal space, gearing up to demonstrate their tech or developing their first commercial projects, all

hoping that their approach will help get the world to 100 percent renewable energy.

I feel like geothermal is where mobile phones were in the 1990s with these big clunky models that nobody could afford.

Whereas now, there's a mobile device in everybody's hand.

You can just feel that we're in early innings of something that people are just recognizing what a transformative impact it's going to have on the

The most obvious sign of geothermal energy is when it breaks the surface, creating hot springs or geysers.

The first geothermal power plants that were developed over 100 years ago were put in places that were so hot that the steam was literally coming

Today, there are over 60 geothermal power plants in the U.S.

But technology and costs have limited where we can build geothermal plants.

Right now, it's mostly confined to very specific geographies where naturally porous, fractured rock creates a reservoir of hot water, allowing

the heat from the Earth's core to rise to the surface.

All geothermal essentially works the same way.

You drill deep wells down to access this hot part of the Earth and you pump cold water down.

It goes through the hot part of the Earth and returns back as hot water or steam.

And that's captured at the surface to turn a turbine and create electricity.

The challenge for geothermal power has always been, how do you get it to work in places where you have to drill deeper or where the geology is less

Basically, unless you can see a geothermal feature like a hot spring or a fumarole, there's no way to be certain that there's a reservoir of hot

water below. Another challenge is the high upfront cost, which dwarfs that of a solar or wind farm.

But if you can figure out how to finance it and where to build it, geothermal has some major advantages over other renewables.

We always talk about electrical power, but of course there's this massive other market that wind and solar don't play in at all, and that's heat.

Geothermal can be used to heat buildings much more cost-effectively and directly than solar or wind power, which needs to be converted into

And you can build geothermal plants close to population centers.

So you can fit us in urban areas, put us on tiny islands.

You don't have to blanket entire valleys with solar panels.

Perhaps most importantly though, geothermal is a renewable source of baseload power.

So it's available 24 hours a day, seven days a week, 365 days out of the year.

Whereas solar and wind are dependent on the sun shining and the wind blowing.

When you consider that wind and solar need massive amounts of battery storage to attain the same degree of always-on reliability, the economics

of geothermal definitely start to look better.

Now, many experts think that it's just a matter of incremental technological improvements that will bring the cost of exploration and

drilling down, hopefully one day allowing us to build geothermal power plants anywhere in the world.

It's been estimated that 98 percent of the world's geothermal resource cannot be adequately harvested with conventional geothermal

technology. So our goal is to go for the 98 percent.

No matter where you are in the world, if you dig down deep enough, you'll hit hot rocks.

Today, geothermal startups are taking advantage of technologies pioneered by the oil and gas industry to help harvest that heat, such as horizontal

drilling. While most wells used to be drilled straight down, technical advances in horizontal drilling now allows for much greater access to oil,

gas and geothermal resources, which usually occupy a subsurface area that is wider than it is deep.

Drilling has also simply gotten faster, as drilling rigs and drill bits have improved.

Drilling productivity for oil and gas in the United States has increased by a factor of 10 in the last 10 years.

Latimer, who used to work as a drilling engineer in Houston, founded his company Fervo Energy in 2017.

Fervo uses a technology known as EGS, or Enhanced Geothermal Systems.

While conventional geothermal relies on preexisting reservoirs of steam or hot water, EGS creates a reservoir where one did not previously exist.

It's basically a version of what we know as fracking.

That is, drilling down and injecting water at high pressure such that the hard rock fractures.

This allows water to flow through, creating a reservoir.

The water is then heated by the hot rocks and brought back to the surface through the production well, where it's converted to steam that turns a

turbine. What sets it apart from oil and gas fracking, of course, is that the final product is renewable energy, not fossil fuels.

We can get up to four times more flow rate out of a geothermal well than using traditional technology.

That means we can develop geothermal in way more places, make it economic and connect to the grid in many more locations.

The Department of Energy says that EGS has the potential to generate over 100 gigawatts of electricity in the U.S., over 25 times the current

geothermal production and enough to power about 100 million American homes.

Right now, Fervo is focusing on commercializing its tech in the western U.S., where both the geology and the renewable policy incentives are

So we're very excited about those markets, places like California, Nevada and New Mexico that both have the know-how and geology to develop

geothermal and have put in the right market structures to allow geothermal as a technology to flourish.

Then there are the companies pursuing Advanced Geothermal Systems or AGS.

These include GreenFire Energy and Eavor Technologies ,founded in 2015 and 2017, respectively.

These technologies don't rely upon a preexisting reservoir, like traditional geothermal or on fracturing the surrounding rock to create a

Instead, it's basically a subsurface heat exchange system.

The way it works is two wells are connected by a sealed pipe or in Eavor's case, many lateral sealed pipes.

A highly conductive fluid, perhaps water, perhaps something more specialized, is circulated throughout the pipes, picking up heat from the

surrounding rocks and carrying it to the surface.

There's no water going out of the rock or into the rock, no contamination, no fracking, no seismicity risk

Eavor made headlines in February after receiving backing from BP and Chevron in its 40 million dollar funding round.

Now it's looking to commercialize, a costly endeavor for them and any company in this space.

That first commercial implementation in Bavaria, phase one of that is 200 million euro.