Published on June 16th, 2020 | by Kyle Field0
Tesla Powerwall Saves The Day In SCE Power Outage
June 16th, 2020 by Kyle Field
Tesla’s Solar + Storage Makes Grid Outages A Non Issue
Our local utility notified us that a power outage with an 8-hour outage window spanning from 9am to 5pm was scheduled for June 3rd. For most people, in a non-pandemic world, that would not be a problem. People are normally at work during the day, so the outage passes by unnoticed.
We are not most people. In the pre-coronavirus world, that honestly still feels a bit like a fiction right now. I work from home, writing articles, doing consulting work, and other random bits of helpfulness. The kids normally go to school for most of the day, and my partner goes to work, but that world is no more. I still work from home, but the landscape we live in has changed completely.
Now, we have two kids thrown into the mix attempting to acquire an education from their Chromebooks and iPads. In just a few short days, they were more fluent than I in Zoom and Google Docs. We live, eat, breathe, sleep, and recreate in and around the house. We learn, work, and play from home nearly 24/7. These changes have made our home and the electricity that powers it essential for our day-to-day functions.
Thankfully, Tesla installed 2 Powerwalls in our garage along with a Tesla Solarglass system. These two systems work together to effectively create a minigrid for our home. In normal operations, the systems operate in tandem with the electric grid, pushing power to the Powerwalls until they are full, with any excess spilling over onto the grid. When the grid goes down, the dynamic shifts.
Related: Check out our comprehensive Powerwall article here for a deeper dive into its operation.
We were notified of the outage 1 week in advance and, to be honest, I was a little bit excited. Having moved into our home in mid-January, the past few months had been so full with us moving in, adjusting to new schedules, hanging the requisite pictures on the wall, and stocking the pantry that we simply have not carved out time to play much with our new house. Oh, and that COVID thing.
On a typical day, the Powerwalls store up excess power produced by our 10.6kW Tesla Solar Roof system and push it back to our home when the sun goes down. The 27kWh stored by the Powerwalls is far more than our home uses in a day, but we also have two electric vehicles that gulp down a big chunk of our daily power production. Sheltering at home these past few months translates to less driving, so we tend to overproduce power day to day.
On the fateful day of the scheduled outage, I was downstairs getting a snack when the power first went out. I didn’t even notice, as nothing changed. As I shmeared peanut butter on a piece of toast, grid power to our house was cut and the automatic transfer switch, detecting the change, disconnected the home from the grid. After the physical disconnect from the grid, the Powerwalls would normally begin feeding their power to the home. In our case, that didn’t happen.
When grid power went down that morning, our rooftop solar system was already at 5.9kW, far more power than our home was consuming (600 watts). As a result, nothing changed. Our home continued to be powered by the rooftop solar system, with the 5.3kW of excess power still getting pushed to the Powerwalls.
The morning outage only lasted 24 minutes, with another 16 minute outage later in the afternoon. As uneventful as it may sound, the exciting part is exactly how uneventful it was. I was able to continue working without losing internet connectivity or power to any of my devices. On the other side of the house, our two boys were able to continue their COVID-induced remote schoolwork. We didn’t have to reset any clocks or worry about our refrigerated goods spoiling.
It’s not the most interesting story and that is exactly the beauty of the system. When paired with an appropriately sized solar system, a home energy storage unit enables life to continue unaffected in the face of power outages big or small. If the outage would have lasted hours or even a few days, the situation wouldn’t have changed all too much. We would pay a bit more attention to when we charge our vehicles, run the electric dryer, oven, and heat pump, but life would continue largely unaffected.
Adding a rooftop solar system to a home typically comes with an attractive return on investment, but residential energy storage systems often lack the same allure. The lack of net metering schemes in many states impact the payout of a rooftop solar system and provide an incentive for homeowners to add local energy storage to prevent excess power from flowing onto the grid. They also enable the home to run off of the power generated by a rooftop solar system in the event of a grid outage.
If CleanTechnica has helped you learn about Tesla or Tesla’s Energy products, feel free to use my Tesla referral code — https://ts.la/kyle623 — to get 1,000 free Supercharging miles with the purchase of a new Tesla vehicle or a $250 award after activating a new Tesla solar system.