Russell Muren – TRANSCRIPT
All right. When we talk about climate change, we tend to focus on the big solutions. Large wind farms, giant solar panels, and huge batteries. These are the sexy technologies that have always promised, but never quite solved our energy problems.
Today, I want to tell you a story of a slightly less sexy technology that specifically does not have the potential of addressing all of our energy problems. But instead, it highlights a new of thinking about climate change that just might. This story starts with grocery stores.
Within five miles of this conspicuous, big red dot there are 20 grocery stores. Now, it might not look like it, but I get about half of my calories from ice cream. And if you’re like me, you’re very familiar with what the frozen food section at these grocery stores looks like. What you might not be as familiar with is the impact that that small section has. Of the 20 or so aisles of the typical grocery store, the two that contain frozen food, account for more than 30% of the energy load of that building.
That load can add up to more than $60000 a year in energy costs. But what’s worse is that each store requires 4,000 pounds of refrigerant just to keep those aisles cold. This gas is incredibly non-toxic, but very leaky. And over the course of a year, more than a 1,000 pounds of gas can leak out of tiny holes and loose connections from each store.
The issue is that this gas is an incredibly potent global warming agent, and warms our atmosphere more than 3,000 times faster than CO2. Now, all those numbers can be very hard to understand, so let me put it in a different way. In the time that we are all at TEDx today those grocery stores, within just five miles of this spot, will create the same climate impact as a road trip around the equator five times. Now, there’s a risk here in this part of the story. That the grocery stores are going to sound like the villains. And they’re not.
Grocery stores try so hard to keep their frozen food aisles as efficient as possible. But the simple truth is they just don’t have very many options. It’s hard enough to find really good thermal engineers to work on the sexiest thermal energy systems. Like this concentrated solar power tower. I mean, that’s sexy. It is even more difficult to find thermal engineers to work on the technology whose sole responsibility is to keep this frozen. Now, I would also love for this to be part of this story. Where I get to stroll out on this stage and tell you how brilliant we were to see this problem and move in and solve it. But that’s not what happened at all.
When Kevin Davis, my co-founder, and I started, we wanted to create the silver bullet energy storage technology that would allow more renewables on the grid, just like a battery. We didn’t know anything about grocery stores, their frozen food aisles or the carbon footprint of frozen burritos. And we had some great ideas, sure. But they were right in line with the other big solutions. Make a technology that can work anywhere, and make it solve as much of the problem as humanly possible.
We started by writing code on my five year old MacBook. Now, if there’s anything less sexy than grocery store freezers, it’s computer code that predicts the performance of grocery store freezers. But still, we’ve modeled a little over 100 energy storage systems. And in doing so, solved roughly six million equations. And when we first started our system costs a fortune, but it could work anywhere.
Over the course of several iterations, the costs came down as we integrated the system directly into low temperature freezers, the technology that our target costumers were already using. Now, the system is downright affordable and is fully integrated into those systems. Now let me walk you through what our technology actually looks like. The best way to think about it is like an old fashioned ice cream maker. We mix ice and salt water together to lower the freezing point of that ice.
This allows us to absorb heat at a low temperature by melting that ice. Additionally, we use high temperature heat to maintain the salt concentration and create a continuous cycle of cooling. Now, when we first started, this core cooling system relied on peripheral equipment to help it actually store electricity. This allowed our system to work anywhere, but it came at a sizable cost. Over the course of a year, and several iterations on the technology and conversations with amazingly helpful individuals, we were able to slowly replace this technology, with the technology that already existed in the supermarket.
Now the supermarket is allowing our core system to store the electricity. And we’re able to provide community-based energy storage at a fraction of the cost. Once we had an idea of what our technology was actually going to look like, we started doing some simple demonstrations. In line with our bootstrapping approach, we set up a budget of about $500 for our first test. And in this test, we wanted to show that we could heat and absorb energy at our low temperature.
Here, you can see some data from that first test that shows just that. We’re able to heat about -30 F, which is right where the low temperature freezers of your grocery store operate. And we’re able to absorb heat there for about twenty minutes. Now, I deliberately showed you this graph before a picture of the device that produced this graph because one is significantly prettier than the other.
Here, on the left, you can see the parts we used to make the final device that took that data, on the right. Now I have to be very clear. This is not like, ground-breaking science. Nobody is going to bust in the doors and be like, “This is amazing!” That’s not really the point. The point is that as we iterated towards these simple, integrated systems we found that testing them was becoming easier and easier. It would’ve taken us a very large funding round to test our first system.