Energy
A Tesla Powerwall-powered Home: Will it Pay Off?
We’ve all heard by now that the Tesla Powerwall home battery is designed to store electricity, generated from solar panels and electricity captured from utility companies during off-peak rates, and provide overall independence from the grid.
It sounds like an amazing product, and I’m sure it is, but will it pay off to own one?
Understanding the Powerwall
The Powerwall is an energy storage unit otherwise known as a battery. It comes in two sizes today (although they can be stacked/expanded), 7kWh and 10kWh (what’s a kWh?) and costs $3,000 and $3,500, respectively. Note that the cost excludes an inverter and installation, both of which can be quite expensive to the point it can double the total out-of-pocket cost. The specs for the Powerwall come in at a whopping 220 lbs / 100 kg (unclear as to which capacity this represents) and 52.1″ x 33.9″ x 7.1″ or roughly 3.5 x 3 feet in dimension.
The concept is simple, the Powerwall battery stores energy generated through your utility company when rates are the lowest (or through solar panels) and ready on tap when you need it.
Installation
Tesla notes that the cost of the Powerwall does not include the inverter or installation. An inverter alone such as the one SolarCity uses can cost around $2,000 which does not include a separate installation cost.
Installation will vary depending on the following:
- Does your residence have an existing net metering?
- Is it already wired for a generator?
- What is the distance between the photovoltaic solar panel hardware and the location to where Tesla’s Powerwall would be mounted? The shorter the distance, the less cabling to run and thus a lower installation cost.
At 200+ pounds in weight, you’ll need to ensure that there’s ample space and structural support to where the Powerwall will be installed. There also needs to be sufficient cooling space and ventilation in the mounting location.
Primary Use Cases for the Tesla Powerwall
Tesla proposes two primary use cases for the Powerwall:
- Time of Use (TOU) offset
- Backup power
Let’s explore each of these options.
Powerwall provides a Time of Use offset
In many states and countries from around the world, a Time of Use (TOU) electricity rate is available through the local utility company. The concept is simple: you pay different rates at different times of the day. During peak hours the rates are higher than they are during off hours. Many Tesla owners that live in these areas that have TOU pricing will charge their cars during the evenings when rates are typically the lowest.
Unfortunately TOU pricing is not widespread here in Massachusetts but if you’re able to take advantage of it in your area, then the Powerwall may bring some value although it would take quite awhile to recoup the initial investment.
Taking a look at TOU rates from Southern California Edison, we can see that their off-peak rate is $0.11 while peak rate comes in at $0.46 for a difference of $0.35 per kWh. The large Powerwall unit is capable of storing 10kWh. Assuming you are able to fully charge the battery during off-peak hours each and every day, you would save approximately $3.50 per day.
Since the unit itself (without install) costs $3,500, it would take approximately 1000 days or just shy of 3 years before you “broke even”. This is assuming the utility company continues to offer off-peak rates throughout the year. Add in the installation costs and you’re looking at closer to 5 years before breaking even on the Tesla Powerwall investment
Of course, there’s the argument that having a solar panel system would allow you to charge the Powerwall battery for free through sunlight, but only if you fully ignore the cost of the solar system itself.
RELATED >>> My journey to installing a SolarCity system
Owning or leasing a solar system comes with its own break-even calculations so you’ll have to factor that into the equation with the Powerwall.
Powerwall provides backup power
The other stated potential use case for the Powerwall is to use it for backup power in the event your home power is completely cut off from the grid.
Source: SolarCity
Don’t expect to power your entire house with just a single 10kWh Powerwall. Tesla’s site provides some good examples of how much power common home appliances draw. For instance the Powerwall would be able to power a typical refrigerator for 2 days. This time would of course be extended if you were able to replenish the battery through a solar system.
In the case of an extended power outage (think Zombie apocalypse), you may be able to power essential home services indefinitely with a properly sized battery and solar system.
The ability to re-fill from solar is a nice benefit, but the alternative would be a noisy gasoline powered generator.
A 6.5kW generator can be had for for as little as $800. That generator can output 32,500kWh (50% load x 10 hours according that link). That’s 3x the power at less than 25% of the cost of Tesla’s offering. The cost for that power? About $15. The generator, unlike the Powerall, is mobile and can go anywhere you go. Generators typically have very low maintenance and can be re-filled quickly regardless of weather conditions (hurricanes, snow storms, etc – all likely conditions that will cause loss of power).
I have a Honda 6.5kW generator. My house has its own well, septic etc. When power goes out I fire up the generator and power the things I need. I have water, hot showers, heat (oil, fired by electric which is powered by the generator), lights etc. I have run for days off that generator in some of the worst weather conditions New England can throw at me. I’d argue if you’re serious about backup power, then a generator is still the best option.
Powerwall, as a backup power option and also from a pure cost-perspective, I feel is only a good fit for those who have a solar system installed and live in an area where the climate is more stable.
Tesla Energy has become the undisputed dark horse of the electric vehicle maker. This was highlighted by Tesla Energy’s growing role in the company’s overall operations in the past quarters.
And as per Tesla’s year-end milestone posts on X, Tesla Energy had a blockbuster 2024.
Tesla Energy’s 2024 milestones:
- As per Tesla on its official social media account on X, the company has hit over 800,000 Powerwalls installed worldwide.
- From this number, over 100,000 Powerwall batteries have been enrolled in virtual power plant (VPP) programs.
- The Powerwall 3 has officially been launched in the United States, Canada, Puerto Rico, the U.K., Germany, Italy, Australia, and New Zealand.
- The Tesla Megapack hit over 22 GWh in operation across more than 60 countries across the globe.
- The Lathrop Megafactory, which produces the Megapack, has been ramped to 40 GWh per year.
- The Lathrop Megafactory has also produced its 10,000th Megapack battery.
- The Shanghai Megafactory was completed in just seven months, and it is ready to start Megapack production in Q1 2025.
Hit 800k Powerwalls installed worldwide
— Tesla (@Tesla) December 31, 2024
Also:
– Over 100k Powerwalls are now enrolled in VPP programs
– Launched Powerwall 3 in the US, Canada, Puerto Rico, UK, Germany, Italy, Australia & New Zealand
– Megapack hit 22+ GWh in operation across 60+ countries
– Ramped… pic.twitter.com/bE88DpeyTg
Powerwall owners’ 2024 impact:
- As per Tesla Energy, Powerwall owners generated a total of 4.5 TWh of solar energy globally in 2024. This was equivalent to powering a Model 3 for more than 17 billion miles.
- A total of 1.1 TWh of energy was stored in Powerwalls in 2024. This protected homes from over 5.8 million outages during the year.
- Tesla’s Storm Watch feature for Powerwall batteries covered 2.8 million severe weather events over the year.
- Powerwall owners saw collective savings of over $800 million on utility bills.
- Virtual Power Plants contributed over 2.2 GWh of power to the grid. This reduced the need for 2,200 metric tons of fossil fuel peaker plant emissions.
Don’t hesitate to contact us with news tips. Just send a message to simon@teslarati.com to give us a heads up.
Utah-based rPlus Energies recently held the groundbreaking ceremony for the Green River Energy Center, a 400 MW solar PV and 400 MW/1,600 MWh battery storage project in Eastern Utah. Tesla Megapacks will be used as the upcoming facility’s battery storage solution.
At 400 MW/1,600 MWh, the Green River Energy Center is expected to become one of the largest solar-plus-storage projects under development in the United States. Once operational, the facility would supply power to PacifiCorp under a power purchase agreement, as noted in a press release.
Utah Gov. Spencer Cox shared his excitement for the project during the Green River Energy Center’s groundbreaking event. As per the Utah Governor, the solar and battery storage system represents a notable step forward for the state’s sustainable energy efforts.
NEWS: rPlus Energy has just broken ground on a new $362 million @Tesla Megapack battery energy storage system in Utah.
— Sawyer Merritt (@SawyerMerritt) September 24, 2024
This 400 MW solar PV and 400 MW/1,600 MWh battery storage project is one of the largest solar-plus-storage projects under construction in the nation. The entire… pic.twitter.com/ubPOUnPWEf
“This project is being built in rural Utah, by rural Utahns, and for all of Utah. When rural Utah thrives, the entire state prospers. Today, we’re not just breaking ground—we’re building a future of affordable, abundant energy in Utah,” the official noted.
The Green River Energy Center secured over $1 billion in construction debt financing earlier this year. The facility is also expected to create about 500 jobs, many of which will be filled by local workers. With this in mind, the solar and battery farm would likely prove to be a boost to Emery County’s economy, enhancing tax revenue, strengthening public services, and offering long-term employment opportunities for the area’s residents.
Sundt Construction will serve as the project’s contractor, EliTe Solar will supply the solar modules, and Tesla will provide the battery storage system for the project. Luigi Resta, President and CEO of rPlus Energies, noted that the Green River Energy Center is special because of the entities that have worked together to make the facility a reality.
“It’s the partners that make this project special, that have made this monumental project possible. From our equipment providers to the onsite talent, and the support of the local and regional community, we owe this project’s success to each of you,” he stated.
Don’t hesitate to contact us with news tips. Just send a message to simon@teslarati.com to give us a heads up.
Tesla Energy is losing a director who brought Autobidder, a real-time trading and control platform that provides value-based asset management and portfolio optimization, to the company.
Rohan Ma, who has been at Tesla for just under eight years, announced he would depart the company on LinkedIn, aiming to take on a new opportunity elsewhere.
Ma posted:
“After eight years at Tesla, this will be my last week. It was a ride of a lifetime! Today, Tesla Energy is thriving and I can confidently say it’s in the best position it has ever been in to drive impact toward the original mission I signed up for. I’m proud to have contributed over the years to where it is now, and will be cheering the team on from the sidelines as they carry the torch forward and continue to relentlessly solve problems at the frontier of the energy transition.”
Ma started as the Senior Manager of Energy Optimization at Tesla back in November 2016. After four-and-a-half years at the position, he then moved on to a new role as the Director of Energy and Software Optimization. He has been in that role for over three years.
The exit of Ma is the latest in Tesla’s tough year in terms of losing high-level employees.
Earlier this year, as a part of widespread layoffs, Tesla eliminated up to 20 percent of its workforce and people like Rebecca Tinucci, who was the company’s Senior Director of EV Charging.
Tesla also lost Rohan Patel, Vice President of Global Public Policy and Business Development, and Martin Viecha, who was Head of Investor Relations, are just a few notables to depart.
Autobidder
Tesla’s Autobidder platform helps owners and operators make money by autonomously monetizing battery assets. It is a real-time trading and control platform that maximizes revenue according to business objectives and risk preferences.
Tesla Megapack, Autobidder to be deployed in big battery project in Queensland
Autobidder already has hundreds of megawatt-hours under management and continues to scale. It is hosted on Tesla’s secure cloud infrastructure that is engineered to handle large and complex computations.
Without Ma’s expertise, Autobidder would likely not be involved in Tesla’s Energy division at all, and although it is not frequently discussed, it is still a major part of the business’s growth over the past several years.
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