It took just two-and-a-half hours a day from start to finish to build the solar panels that power the company’s massive Palo Alto plant.
As they build those SolarCity solar panels, Tesla’s engineers at the factory at the time make sure they have enough power stored so the factory can quickly ramp up production. This is a critical component for Elon Musk’s Tesla electric-car company. It helps avoid expensive downtime.
In September, the U.S. Energy Department ordered that Tesla stop building solar panels at its gigafactory in Sparks, Nevada. It has only been operating a few hundred megawatts of solar power since the beginning of 2013 and is only building a few gigawatts of battery storage at this time. (In fact, Tesla now has only a few gigawatts of battery storage.) But by using the free energy, Tesla has a way of keeping the factory humming.
Here’s how it works. Tesla uses the energy stored in the batteries to power its computers. When you look at the Tesla website, you can see the data that goes into building these super-efficient cars. But what you don’t see is the data the automaker uses to optimize the battery’s operation. To see just how much this optimized data is used, I ran their numbers for a number of different conditions, including temperature, speed, and a range of power output:
The first chart shows the amount of time that Tesla was able to build an electric car every day while using the free energy. The second chart looks at how fast its car was turning with respect to every other car in the field, which is an example of pure computing. Here, the first chart shows that the car was able to turn 100 miles per hour with about the same amounts of energy put into it. The second charts shows how quickly it was able to turn 400 miles per hour.
The results, again, speak for themselves. The battery cars that use the free energy were able to travel 40 miles on a charge in around 30 minutes, compared to 80 minutes for a Tesla Model S sedan that used the energy. The Tesla Model S was so fast in fact, Tesla CEO Elon Musk said he thought he was driving a Hummer.
Tesla uses this energy when it is charging its batteries. Musk calls this a “cold-stacking” system, which, you guessed it, means that it is powering itself with electricity, not stored energy. And while the free energy is always in use during this time, it