- We hear a lot about a clean green energy transition these days, with experts saying, "We need to electrify everything and green the grid as quickly as possible to stop climate change."

But most of those renewables rely on weather, which is getting so extreme that it's contributing to a sharp increase in blackouts.

And of course, it's not always sunny or windy.

So we started to wonder if this transition is even possible with all this weather.

Remember the 2020 heat wave-induced blackouts in California?

Followed by Winter Storm Uri, which knocked out power to 4.5 million homes in Texas, and then the extended outages in Louisiana caused by Hurricanes Ida and Nicholas the very next summer.

Plus, our electrical grid is already long past its prime.

So how will it be able to handle the additional draw of all the vehicles, stove tops, heating, air conditioning, industrial energy, everything switching from fossil fuels to plugging in?

So make sure to watch the whole episode because we'll show you which states are the furthest along in this transition, and we're gonna ask some hard questions that not everyone agrees on, but it seems like there's a lot of agreement on this.

- Our current grid is not sufficiently hardened even for our current climate, and people need electricity to keep their homes heated, to keep medical devices operating.

Grid of reliability is a matter of life and death.

(pensive music) - So in this episode, we wanted to determine if getting to net zero carbon emissions by 2050, the date the climate community has set as their target, is at least theoretically possible because if not, the alternatives look pretty bad.

If you've been watching "Weathered," I probably don't need to tell you why, but you can check out these episodes to review.

So let's start by taking a look at our energy makeup today.

About 16% of the world's final energy, which is energy that's actually used, is considered low carbon.

And of this, about 5% is solar, wind, and other renewables; 4.3% is nuclear; and 6.8% is hydropower.

But the rest is still considered high carbon fossil fuels.

And to reach net zero, while the experts tell us that the vast majority of our energy needs to come from clean renewables, mostly wind and solar.

This means we'll need to find ways to keep this energy flowing to customers, even when the weather's not cooperating.

- People often worry about wind or solar in isolation because the wind doesn't always blow or the sun can't shine at night.

But the thing is, wind and solar actually compliment one another fairly well, and that the wind is often stronger at night, and then the sun, of course, is out there during the day.

- That's because the atmosphere tends to be more stable at night, which allows for a more uniform wind speed and direction.

But that's not true everywhere all the time.

And renewable generation isn't always close to demand.

- Have a lot of wind, we have a lot of solar in areas that are already surpassing the level of demand in those areas, and we just can't pipe that energy to where it needs to go.

- At least not yet.

And if our goal is to increase the amount of renewable energy on the grid as quickly as possible, we have to build solar where it's sunny and wind where it's windy, but we don't necessarily live in those places.

For example, the middle of the country has the greatest potential in the US for wind energy generation, but most people live near the coast.

We'll discuss which state produces the highest portion of its energy from renewables, but for now, I'll tell you it's not where I expected.

- So we can fix a lot of these problems just by having more pathways for those electrons to flow.

- [Maiya] And that means more transmission.

Like, a lot more.

- The scale of that buildout is enormous.

We're talking about roughly doubling, I think, at least our transmission system.

We're about at 200,000 miles of transmission today, so that's adding quite a lot of high-voltage transmission.

- This idea of expanding the country's transmission network to facilitate the flow of renewable energy is often called the megagrid, and it won't be cheap.

Estimates for new high-voltage transmission lines in the US are somewhere between 1.5 and $10 million per mile.

To be fair, mining, shipping, and buying fossil fuels is also expensive.

And once we build renewable infrastructure, the actual energy from the sun and wind is free.

Still, even after the megagrid is built, there is likely to be a mismatch between peak energy demand and peak renewable generation.

- If you add on even a small bit of electricity storage, you can balance out some of the moment-to-moment fluctuations in wind or solar because of clouds or changing winds, and get a fairly smooth curve that often matches fairly well with the daily generation profile.

- [Maiya] And we see this already happening.

California, which gets around 17% of its energy from solar, leads the country in battery installations on the grid.

- In California, during the last three months, during the peak demand times, which are before sunrise and after sunset, the batteries that have been installed on California's grid have provided seven to 8% of California's electricity during these peak times.

That's the same amount of electricity as the Diablo Canyon Nuclear Power Plant has been providing, and that's just within a couple years we've installed all these batteries.

- The outlook for the future growth of battery installations is excellent.

In 2022 alone, the US nearly doubled its battery capacity from 4.7 to 8.7 gigawatts.

Battery cost is dropping, and unlike traditional power plants, battery power output can respond quickly to changes in demand, which actually increases reliability.

- This is going to require a lot of investment, a lot of policy, and a lot of effort.

It's gonna be a very complicated process, but also a very necessary one.

And at the end of the day, we needed to upgrade this system anyway.

It was aging, it was becoming increasingly unreliable.

And by doing all this work for the clean energy transition, we're going to modernize the grid along the way.

- Okay, so we've been painting a pretty rosy picture here of the megagrid so far, but it's not without its problems.

Beyond the environmental and humanitarian concerns, like mining all the raw materials for such a large buildout, one enormous centralized grid may, in fact, have an Achilles' heel.

- So you can have infinite generation at the transmission grid, but the largest percentage of outages happen in distribution.

So the distribution is really some of the weakest points in the grid.

These are the low-voltage points, these are the power poles outside your house.

- As opposed to the high-voltage lines that transport energy from power stations.

And these low-voltage points are where the grid is most susceptible to the elements like high winds, freezing, lightning strikes, and wildfire.

And the risk of inclement conditions like these have to be taken seriously as climate change continues making our weather more and more extreme.

So it may be wise to consider an additional strategy for getting us to net zero.

While the megagrid connects the country's resources by pumping energy across vast distances, what if we generated more of our energy closer to home?

- So distributed energy resources provides power to your house without having to rely on the power grid as a piece of infrastructure.

There's the benefit of just being able to protect your own family, and being self-sufficient, and not relying on larger infrastructure.

People stock up eggs, milk, bread before a storm 'cause they know they're not gonna be able to rely on the grocery store being open or being able to get to the grocery store.

We're already thinking about self-sufficiency, so why don't we think about that in terms of energy?

- These distributed energy resources, like rooftop solar, mini EVs, and local storage, can be operated independently like the diesel generators of today.

But, with some hardware upgrades, they can also be connected to a more localized microgrid, enhancing resiliency at the community level.

- There's also efficiency gains when you generate power closer to consumers.

There's ways that you can share energy among the communities, so it's not just like you as a single house can provide power for your family.

You could also potentially spread that throughout your community to help your neighbors.

There's a lot of benefits to these distributed energy resources that go beyond just the larger countrywide transmission scale goals.

- There are also benefits, such as locating solar panels already on disrupted areas like roofs, parking lots, or even reservoirs, instead of disrupting important habitats.

But how much power can we generate like this?

- As much as 1/5 of our energy resources could come locally, but that still leaves at least 4/5 to get from a larger scale and greatly expanded grid.

So it's definitely not either/or.

- So back to our original question, how much energy can we produce by using existing technologies for renewables?

Can we count on water, wind, and solar alone?

Most of the experts we talked to said, "No," but keep watching because this is where it gets really interesting.

- My team has done some modeling work for the United States that would suggest that you could use a mix of somewhere between 50% to 80% of variable renewable sources, like wind and solar, backed with firm clean generation sources, like hydroelectricity, nuclear, and geothermal.

Now, that's for the United States, and different countries have different circumstances and would have different optimal percentages of those energy sources.

- A diversity of resources is really good for the grid.

Most of it should be wind and solar, but 100% decarbonization is just extremely expensive.

Is it doable?

Absolutely.

We need a lot of transmission lines.

We need a lot of stuff that's gonna be built.

We need a lot of energy storage or flexible demand.

But a more realistic solution is to have a little bit of base load, nuclear, wind, solar, and a little bit of natural gas.

It can definitely help with some of those peak times or some of those emergency times and keep those plants running.

- But not everybody agrees.

Mark believes that going 100% renewable isn't just possible, it's necessary.

- Like, 10 years ago or even 15 years ago, utilities claimed, "Well, we can't put more than 20% renewables on the grid."

And that turned out to be not true entirely because since then, there are many locations that have large penetrations of renewables.

California's about 50% renewable.

- And several states are already over 50%, including Montana, Maine, Iowa, Oregon, Idaho, Washington.

And the highest percentage of its own energy?

Well, that's South Dakota, which gets most of its energy from wind.

And there are many other places around the world.

In Australia last summer, the Tasmanian and South Australian grids were a 100% and 70% renewable, respectively, and they were also the two most reliable grids in the country.

At this point, nearly all of these examples are grid connected to some form of fossil fuel or nuclear energy, even if they generate more than 100% of what they use regionally from renewables.

But, is that necessary in the near future?

- There was a recent review paper that looked at over 700 papers that were evaluating energy in different parts of the world that found that we can go to 100% renewables in the electric power sector or all sectors with just clean renewable energy.

No nuclear power, no fossil fuels, no carbon capture, no biofuels in many cases.

There's no limit to how much renewables we can put on the grid with sufficient storage.

And so when we account for the health cost savings, the climate cost savings, and the energy cost savings, we get what's called this total social cost.

We get a 92 to 93% reduction in the social cost of energy by transitioning to wind, water, solar and a 63% in the direct cost of energy.

- Mark also explained that if we did choose to go 100% wind, water, and solar, it would cut our total energy needs in half because all of the increased efficiency.

For example, combustion engines and cars use energy less efficiently than electric motors.

And running gas-powered plants is only carbon-neutral if you also do carbon capture.

But you have to generate additional energy to run the carbon capture itself.

So while the importance of reaching net zero by 2050 is widely accepted, exactly how we get there is not yet clear, but it is possible with existing technology and how quickly we choose to make the change determines how much we change the climate.

(pensive music)