My home powered by Tesla
by Chase Ogoshi | March 11, 2020
What is PV? How can you keep the power on during an outage? These are questions I had during my first few months working at Hawaiian Electric.
When I landed back home in the summer of 2018 after living in San Francisco, my parents uttered these unforgettable words: “We got a Tesla.” Being the millennial that I am, I screamed with excitement and shock. I could not believe it! My parents bought my dream car. This was a brand that I saw every day in the Bay Area. And while I was attending the University of San Francisco, I also worked on two major projects focusing on the new Tesla.
I anxiously awaited the big reveal in my driveway outside the garage door. As it opened, I saw no Model S, Model X, or even a Model 3. But here’s the thing, I did see something with the word “Tesla” on it. It was a big white box with a green light on the side. I thought to myself, “Is that a Tesla car charger, but with no car?”
That white box is called the “Powerwall” and it is one of the most advanced residential energy storage systems in the world because of its batteries. The one in our garage is a second-generation version. According to Tesla’s website, the Powerwall 2 is a DC Battery system that has a usable capacity of 13.5 kilowatt-hours that can be extracted at a 7kW peak or 5kW continuous rate. Because most homes run on AC power, Tesla has planted an inverter on top of the battery pack that diverts stored DC power from the battery into AC power that all the appliances in the house can use. Then, when it comes time to charge, the inverter can turn AC power back into DC power that is stored in the battery.
Having a self-powered home means the combination of solar energy from photovoltaic (PV) panels and a Powerwall battery storage system is able to independently power your home all day and all night. During the daytime, solar panels may produce more energy than your home uses so the Powerwall stores that excess solar energy and makes it available on demand — even after the sun sets — at night.
So how does a Powerwall work during an outage? Tesla’s website states that “Powerwall can detect an outage, disconnect from the grid, and automatically restore power to your home in a fraction of a second. You will not even notice that the power went out. Your lights and appliances will continue to run without interruption. If you have solar and Powerwall, then solar energy will continue to power your home and recharge Powerwall. Without Powerwall, solar will shut down during an outage.”
After reading this, I had a conversation with my dad and an operations supervisor from SolarEdge. I learned that we had the option to choose which appliances or areas of the house that will stay powered on during an outage when the Powerwall was installed. Not only that, but there is this cool mobile app that we can use to manage our Tesla products from anywhere. Specifically, for the Powerwall, the app can monitor energy consumption, switch modes (self-powered, backup-only, and even time-based) and receive updates.
Tesla CEO Elon Musk has been quoted as saying, “When Henry Ford made cheap, reliable cars, people said, ‘Nah, what’s wrong with a horse?’ That was a huge bet he made, and it worked.” Tesla is a leader in solar-plus-storage technology, and Powerwall and PV panels are the way of the future.
And even though I was hoping for a sleek Model 3 in the garage, Tesla’s Powerwall does not disappoint — especially during power outages.
Chase Ogoshi is a digital communications and social media specialist at Hawaiian Electric Company.
