In the recent Tesla 1st quarter earnings call, an investor asked about whether “vampire drain” in lithium-ion batteries prevents seasonal energy storage from this medium. This led to a much wider explanation of the topic by Elon Musk. Bottom line: Elon Musk believes that current technology can power the world with renewables, and he gave us a nearly complete global recipe for doing it (from a bird’s eye view).
The relevant portion of the quarter 1 call can be found below if you want to listen to it yourself. The embedded video starts at the correct time (1:17:13).
The question that prompted this:
“Proponents of alternative grid storage technologies claim that lithium-ion is unsuited for long-term storage at scale due to vampire drain. Could 4680 cells address these limitations? Is the limitation even relevant for changing the energy equation?”
Lars Moravy, VP of Engineering, jumped in to point out that a good lithium-ion cell loses less than 0.001% of its energy per day to “vampire drain,” so that’s really not a factor in long-term storage.
“As mythical as vampires,” Elon said. He goes on to point out that we have a long way to go before seasonal storage becomes something we need to worry about (presumably because we have bigger fish to fry, like getting more solar and short-term storage on the grid).
Solar Power Is Enough
He then points out that seasonal battery storage probably isn’t even necessary, though. One approach to providing all-season renewables would be to install lots of extra solar and wind capacity at lower latitudes (closer to the equator, where year-round renewables produce a lot more than at places closer to the poles). These sites should be spread out longitudinally (east–west).
For example, in the United States, in theory, all of the power needed for everything could be covered by a 100-mile by 100-mile square covered in solar, which is a very small portion of the overall land area. Doing the math, I found this to be far less than 1% of our land area. Almost any country in the world faces the same situation — very little land actually needed to install solar.
Even more interesting was that if you installed solar on the total footprint of a nuclear power plant, you’d produce more power than the plant. Keep in mind that the plant itself doesn’t take up that much space, but the safety buffer and security zones around the plant (miles in some instances) take up a much larger footprint of area that gets taken out of use. Just using that land for solar gives more power now.
Bottom line, solar is more than capable of providing all the power people need.
No Need For Exotic Transmission Technology Needed To Get It Where It Needs To Go
Getting all that power out to where it’s needed is another matter, though. Many claim that we need power lines made from room temperature superconductors to prevent losses and provide enough power to areas far removed from the solar, but Elon says that’s just not true. “They’re almost irrelevant, in my opinion. Almost irrelevant.”
He says that low-cost long-distance DC power lines are the key, and they can be made with copper or aluminum. Heating and associated losses can be minimized by increasing the voltage so that current can be lowered, which drops the resistance to the point where it’s not a big problem. He estimates a loss of 5–7% with a high-voltage DC (HVDC) power line.
“We Just Need To Scale This Thing Up”
At first glance, it might appear that he strayed pretty far from the original question, but he brings it back at this point. He wants the person asking the question (and the rest of us listening and reading) to realize that we have all of the technology today to provide for the world’s energy needs.
The real challenge is just how big these energy needs are. It can’t be done overnight because the production capacity for solar cells, battery cells, and associated products hasn’t been built up yet. He does point out that we can still accelerate this, possibly with a carbon tax, which he thinks is the most economically supported solution.
The open question is how fast we solve the issue. It’s going to happen, he says, but it’s better if we solve the renewable energy challenge sooner.
“There’s no question in my mind whatsoever that the energy storage problem can be solved with lithium-ion batteries,” he said. “Zero. I want to be clear. Zero.”
Iron-Based Lithium Batteries Will Be A Big Part Of This
While Tesla primarily uses nickel-based lithium-ion batteries for vehicles, Elon says that this is only because that’s better for energy density (to keep the pack from being too large and heavy) and performance. For stationary needs, lithium-iron batteries are perfectly fine, because they don’t need to be as small or light. Unlike nickel, iron is much more plentiful.
Lithium, he says, is only a small percentage of the total mass of a battery. The main part of the cell is the cathode, and makes up most of the mass and cost.
More importantly, there’s no shortage of materials for stationary storage. There is more iron in the world than we could possibly use, and there’s more lithium in the world than we could possibly use. There’s no shortage of either, but the infrastructure needs to be built out to get it from the ground, refine it, build cells, and deploy it all.
In other words, the challenge isn’t getting it, but getting it built into the things we need — quickly.
A Recipe For Powering Everything With Renewable Energy
I could tell from listening to Elon’s answer to this question that he struggles with verbal vs. mental bandwidth. There’s a big image and a lot of information he wanted to convey, and he was thinking fast, but couldn’t get it all out verbally fast enough to keep up with his thinking.
Once he got it all out, though, it’s clearly a basically complete big picture plan for renewables.
- Solar and wind in places where it works year-round.
- High-voltage DC transmission lines carry the energy to places closer to the poles where it doesn’t work seasonally, with no exotic materials needed.
- Battery storage, using readily available materials, helps fill gaps everywhere.
- Challenge is to scale up operations to get the above done.
There’s no way he could have covered every in and out of the plan, and every challenge it would face, in just a couple of minutes, but that’s not the point. It’s damned impressive to see a big plan like that all laid out in just a couple minutes, complete with a rundown of the biggest challenges.
Featured image: the Macho Springs wind and solar farm near Nutt, New Mexico. Photo by Jennifer Sensiba.
