How Tesla's Powerwall carried me through Hurricane Ian

Tesla's Powerwall carried me through the post Hurricane Ian power outage

Back in 2017, I was in a home with solar panels, but no battery backup. Hurricane Irma passed overhead, and I found myself without power for 24-48 hours. We lost all of our food as a result.

When the storm passed, I called up the company that installed my solar panels and found that adding in a battery would be cost-prohibitive, as it would require replacing the solar inverter. As my wife and I started shopping for a new home for our family, I kept this information in mind as I had planned on having solar+battery put in at the new house. I worked on finding a home that would be oriented properly to get the best solar collection capacity, and we bought it in 2018.

Once the home was bought I went through the process of getting quotes for solar + battery arrays and ultimately settled on Tesla.

Tesla was largely chosen because, at the time, the Powerwall battery had the shortest cutover time in the event of an outage. It kicks in right away, while the others took 2-3 seconds to switch over.

By the end of 2018, the array and Powerwall were installed and operational. The array has a max output of 9.425 kW using a SolarEdge SE7600H-US inverter, which has a max output of 7.64 kW, and a single Gen 2 Powerwall 2. During the design, I chose not to have the HVAC and car chargers run off the Powerwall.

As Hurricane Ian approached, Tesla's Storm Watch kicked in on the Powerwall.

The Powerwall started charging to 100% about two days before the hurricane made landfall. I debated on letting the Powerwall’s power get used leading up to landfall, but having been through hurricanes before, I opted to let Storm Watch do its thing. As the hurricane approaches it’s not uncommon for the winds to cause power stability issues. Leading up to the hurricane the power blinked numerous times.

By the afternoon of September, 28th people in the Tampa area were already starting to lose power.

At around 4:15-4:30 pm, as the winds outside were getting stronger, my wife and I decided to start making dinner for the kids. For reasons unknown, we decided to cook some things that involved the stove. At 4:42 pm the power blinked, and the Powerwall took over for about 5 minutes, putting us back on the grid at 4:47 pm. Once back on the grid the Powerwall charged back up to 100%.

At 5:03 pm on September 28th, the power went out again. After making dinner, we turned off the appliances and watched Andor on Disney+.When it was over I looked at the Powerwall’s status and found that we were now down to 91%.

There was a notice that said we had about 8.1 hours of power remaining, I started to cycle through the things in the house that consumed power and began shutting them off, either at the breaker box, or by unplugging them, intending to ensure there was enough power to keep our fridge, and a chest freezer in the garage online.

I was able to get us down to about .3-.4 kW of use before going to bed and hoped that was enough. Things that were turned off were the water heater, the dishwashers, computer gear, TVs, etc. Anything that might have vampire drain in the long run, including the internet gear.

At around 7 pm yesterday, two hours after the power had gone out, Tesla sent me an email with the VIN for my new Model Y.

I couldn't help but chuckle at their timing.

I woke up the next morning, September 29th, at around 6:30 am. I had to connect to the Powerwall directly to check the stats since I had powered down the internet gear and Gen 2 Powerwalls don’t have cellular connectivity any longer due to AT&T's 3G network being shut down earlier this year. I found that the Powerwall was down to 46%.

Amount of energy left

By this time the storm had moved beyond my area, and I went outside to start inspecting for potential property damage and such. Thankfully, we were spared property damage. The most we had was a panel that covers the service box for our internet cables get blown off the side of the house. I found it about 4 feet away and put it back on.

Others in the community I live in were less fortunate. Several smaller trees had been tipped over, some homes had shingles blown off their roof, and in at least one case a tree had fallen on top of a vehicle.

At 8 am I checked to see how many people in my neck of the woods were without power and found that the total increased from 21,2000 to 292,247 as the hurricane moved away.

The day after a hurricane is a tricky one, particularly if the hurricane is a big one because there’s still a lot of cloud cover. By around 8:38 am the Powerwall was at 36% charged and the sun was barely peaking out around the clouds, resulting in a lower power generation rate.

About 30 minutes later, at 9:10 am, enough sun was shining through the clouds for the Powerwall to start charging.

35% would be as low as the Powerwall went during this event.

As the day went on, we used power sparingly, mostly trying to ensure our mobile devices were charged. We used a microwave and a toaster oven to make breakfast, and at around 11 am I got a chuckle at my impact card showing 0% grid usage.

Tesla Solar's Impact card

By lunchtime, the Powerwall showed Storm Watch was over, and the Powerwall was charged to 68%.

So we again used the microwave and toaster oven to make lunch and feed the family.

At around 1 pm the Powerwall started to hit around 80-85% charged, and we started running into an issue with generating power. Every time the Powerwall generated more than 5kW of power, we got an error that read “DC VOLTAGE NOT SAFE! DO NOT DISCONNECT! VDC 445.4”

Followed by another “Error code 18x40 AC Freq too high”

Powerwall charging error

And then it would go to “Waking up…” and start a five-minute timer. Once the five-minute timer was done, the cycle would repeat, the array would generate 5 kW, give an error, and reboot.

I tried to open a support ticket with Tesla, first using the Tesla app. I started a chat session with someone who immediately disconnected the chat session saying “Weather-related issue”, as I was not on the grid.

Irritated, I re-opened the chat session and got a different person who worked with me.

Initially, the individual claimed that the issue was related to the overcast sky, however, that wasn’t the case as the inverter *does* shut down when there’s a lack of sunshine. In this case, it was shutting off every time it hit 5 kW generation. While still on chat support I used a different mobile device to call Tesla's solar number. I received different answers from the chat advisor and the representative on the phone.

Chat support said that there did appear to be an issue and advised me to schedule a service ticket, and ended the chat.

The person on the phone took the time to explain to me what was happening, and ultimately resolved the issue. The Powerwalls are limited to 5 kW of intake. As I only had one Powerwall, once the array generated more than 5 kW of Power, the Powerwall was changing the frequency to tell the array “Whoa, stop, you’re giving me too much power”, which would reboot the array for five minutes, and repeat the cycle.

The solution to this issue is rather amusing.

You have to use more power to use the excess energy that the array is generating.

Armed with this new information I turned back on the dishwasher and the water heater, and started doing dishes, taking a shower, and watching TV. We eventually found a happy medium where we were using enough power to have the Powerwall stop shutting off the array and continue charging.

From 2 pm to 4 pm we greedily used power, but at 4 pm the intake wasn’t as good anymore as the sun was starting its trek to go below the horizon.

After the dishwasher finished, I turned the water heater and dishwasher back off and started going back to “low power” mode as we began making an early dinner, again, using the toaster ovens, and an air fryer.

We took some time to eat our food while watching TV, catching up on Paramount+’s Lower Decks, and Disney+’s She-Hulk, and we started turning things off again.

By 6:22 pm the Powerwall reached 98%. The sun finally went low enough on the horizon for power to stop being generated.

By the end of the day when we getting ready for bed, we still had no power.

By 2:15 am, on September 30th, I awoke to go pee, then sat on the edge of the bed and decided to check the Powerwall’s state of charge. I found it to be at 45% and heard a rumbling outside the bedroom door that turned into a roar.

After initially thinking it was an Amazon plane flying overhead, I got up and checked the thermostat to find that the HVAC had turned back on again. After checking the Tesla app again I found that power had been restored.

Tesla Solar's Impact card

Looking at the Impact card to try and see how long the outage was, I realized that Tesla’s app doesn’t seem to know how to handle an outage that’s longer than a day.

The power went out at 5:03 pm on Wednesday, September 28th, and ultimately returned at 2:17 am on Friday, September 30th. A total of about 32 hours being off-grid.

What would I do differently? Tough to say honestly.

Having to go to the garage to flip breakers to reduce or increase the power load was annoying, putting in a Smart breaker panel would’ve been beneficial, but only so long as we had internet access.

A second Powerwall would’ve been very beneficial as it would have allowed me to not have to increase the power load to ensure the Powerwall kept charging properly, as the power would’ve likely been split between them. If and when Tesla sells Powerwalls without requiring solar with it, this is an option I’ll be investigating for sure, as long as it isn’t cost-prohibitive. I’m uncertain if you can mix and match a Gen 3 Powerwall with a Gen 2 under a SolarEdge inverter.

Not having the HVAC, while unpleasant, wasn't a huge deal. After a hurricane clears out of an area, you’re generally left with a lot of cold air, so we just opened the windows for a bit. Having EV chargers was also a non-issue because we didn’t drive anywhere, and the cars only lost about 2-3% charge, mostly from me opening the Tesla app and accidentally waking up the cars while trying to scroll to the Solar card.

Imagining Tesla’s Robotaxi Network Charging Stations

Not a Tesla App

It was a rainy April 1st when a news-searching author went on a delve into the depths of April Fools to find fact from falsehood. And while we found a lot of fantastic jokes, we also found some good ideas.

So, with a shoutout to MarcoRP on X, whose April Fool’s Joke gave us a good run for our money for a couple of minutes, we thought to ourselves - what would a Cybercab Charging Station / Cleaning Hub really look like?

Cybercab Wireless Charging Sites

Now, before continuing, we’d like to point out that the image up top is a joke from Marco - it isn’t an accurate or real site map submission from Tesla. However, it gave us the impetus to think critically about what is required for a Robotaxi fleet, based primarily on the Cybercab, to be able to service a city.

Requirements

Tesla will likely need to charge a small fleet of Cybercabs at a single time and in a single place. That means that the site needs to be large enough to cover a major metro area while also still being compact enough to not cost too much money to build out.

In addition, we need to factor in charge times. The Cybercab is likely to launch with a battery around 50 kWh, which will result in a range of approximately 300 miles. With that much range, the average Cybercab may not need to charge more than once or at all during daytime shifts, so instead, most of the vehicles will charge overnight.

MarcoRP

Math and Charge Times

The overnight charging means that most of these vehicles could be charged slowly. When we did some back-of-the-napkin math last year, we determined that Tesla’s wireless charger will likely peak around 17 kW (for comparison, Tesla’s Wall Connector at 32 amps charges at about 7 kW). If we scale Tesla’s wireless charger down slightly to 10 kW, accounting for some energy loss and the potential size of the site, that means a Cybercab will be able to charge in about 5 hours.

Tesla’s upcoming V4 Supercharger unit can currently handle 1.5MW per cabinet, but this slower-speed charging is A/C, not DC, which means there is a step-down loss of about 3-5%. Let’s make that a comfortable 10% for any other overages, but we can estimate around 1.35MW of power. That 1.3MW will easily handle charging up to 100 Cybercabs at once - all wirelessly, using Tesla’s unique beam-forming and beam-steering technology to keep efficiency high at every single stall.

Within about 5 hours, a whole fleet of 100 Cybercabs could be charged overnight when electricity rates are cheaper and still be out in time for the morning commute.

While this is all just hypothetical, it really does make sense that Tesla will be establishing these sites that won’t require much space or a ton of energy.

Tesla recently curtained off a large section of the parking garage at Giga Texas, as well as some of their chargers on the eastern end of the facility, leading us to believe they may just be testing this at scale internally.

There’s a lot to look forward to with Tesla’s V4 Supercharger deployment coming this year and with Robotaxi launching in just a couple of months.

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Tesla Announces 2025 Q1 Numbers: Lower Than Expected, but the Worst May Be Over

Not a Tesla App

Tesla released its Q1 2025 delivery and production numbers this morning, reporting 336,681 vehicles delivered and 362,615 produced—marking the company’s weakest quarter since 2022. Deliveries declined 13% year-over-year and fell well short of Wall Street estimates, which ranged from 360,000 to 370,000. Some analysts had forecast as many as 407,000 units.

Despite the shortfall, Tesla stock is actually up about 4% this morning, not only suggesting the market had already priced in weaker performance, but that this may be seen as the low point for the company. Tesla began delivering its refreshed Model Y in March, and production across all four Gigafactories was impacted by several weeks of downtime as Tesla retooled lines to accommodate the newer model. However, there’s no doubt that there is some brand impact from Elon Musk.

Comparing Numbers

Most of the deliveries—323,800 units—came from the Model 3 and Model Y lineup, while the “Other Models” category (including the Cybertruck, Model S, and Model X) accounted for 12,881 deliveries. That’s a 31% drop for Model 3/Y and a sharper 45% drop for the Other Models category compared to the previous quarter. However, comparing it to a more applicable Q1 2024, these numbers are only down about 13% for the Model 3/Y and down about 24% for the Model S/X and Cybertruck.

In terms of production, Tesla built 345,454 Model 3/Y vehicles and 17,161 from its “Other Models” line. The company attributed the production drop to the Model Y changeover but said the ramp is “going well.” This still leaves a large gap between production and delivery numbers, although they may not be as large as many had feared.

Cybertruck

One major weak point in Tesla’s numbers seems to be Cybertruck deliveries. While Tesla previously expected the Cybertruck to sell more than 250k units per year, we’re already seeing a decline in numbers. This is likely due to several factors, including the higher-than-expected price point of the truck, the unavailability of the RWD model, and the Cybertruck’s polarizing design, which may attract unwanted attention right now.

While the Cybertruck was ramping up production in 2024, making the lower numbers reasonable, the deliveries for Q1 2025 dropped drastically compared to the previous quarter. Cybertruck deliveries are estimated to be in the 5- 6k unit range for the quarter.

The good news to take away here is that the Single Motor variant of the Cybertruck appears to be nearing release. The price of the RWD version is expected to be about $60k USD before any incentives.

Q1 Earnings Call

Tesla announced their quarterly numbers this morning and posted on social media that they’ll live stream their Earnings Call on April 22nd.

This post was later edited to change “Q1 Earnings Call” to “Q1 Company Update.” It’s not clear whether there’s any significance in this change, but it could mean that Tesla has more to announce during the call.

The Company Update will occur on April 22nd at 2:30 PM PT / 5:30 PM ET. The standard Q&A session with executives and Musk is expected to follow the release of additional financial results for the quarter.

Tesla is set to launch its long-awaited Robotaxi service in June, and a cheaper, mass-market model is also planned for this year. With delivery numbers coming in soft and the refreshed Model Y just hitting the road, all eyes will be on forward-looking commentary during the update.

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