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EcoWatch is a community of experts publishing quality, science-based content on environmental issues, causes, and solutions for a healthier planet and life.
A wind-solar hybrid photovoltaic power station on Sept. 12, 2020 in Zaozhuang, Shandong Province of China. Li Zongxian / VCG via Getty Images

A group of governments and the private sector on Friday collectively promised more than $400 billion (just over €340 billion) at a high-level summit that called for more urgent action to curb catastrophic climate change.

Read More Show Less
EcoWatch Daily Newsletter

The youth-led Mock COP26 virtual conference concluded Tuesday with a treaty they hope world leaders will sign ahead of the official COP26 in November 2021.

Read More Show Less
Courtesy of Tesla, Inc.

The Tesla Powerwall is arguably the best-known solar battery for homes, but does it live up to the hype? In this Tesla Powerwall review, we'll discuss the main features of this popular energy storage system and compare it with some competing battery backup devices.

What Is the Tesla Powerwall, and How Does it Work?

The Tesla Powerwall is a lithium-ion battery that's most often associated with storing energy generated by Tesla solar panels. However, you can actually charge these batteries with any electricity source to use as a backup during a power outage. You can also connect up to 10 Powerwall units as a single energy storage system, making them viable for small and medium businesses as well as homes.

You can currently purchase a Tesla Powerwall 2 or Powerwall+. The Powerwall 1 has been discontinued since 2016, but the newer versions are much better products: a single Powerwall 2 or Powerwall+ can store 13.5 kilowatt-hours of power, while the Powerwall 1 only had 6.4 kWh of usable capacity. The newer versions also have a higher power output (5.6 kW vs 3.3 kW), which means they can provide electricity for more devices at once.

The Powerwall 2 and Powerwall+ have the same storage capacity, but the Powerwall+ includes an inverter for easier integration with solar PV panels. The Powerwall+ can also deliver more kilowatts when panels are in full sunshine, while the Powerwall 2 offers the same output regardless of solar generation.

Here's a summary of Tesla Powerwall output:

  • Originally, the Powerwall 2 offered 5 kW of continuous power and 7 kW of peak power.
  • The Powerwall+ and later versions of the Powerwall 2 have 5.8 kW of continuous power and 10 kW of peak power.
  • When solar panels are under full sunshine, the Powerwall+ reaches 7.6 kW of continuous power and 22 kW of peak power.

If you already have a home solar energy system with its own inverter, the Powerwall 2 is a great option to add energy storage without modifications. However, the Powerwall+ is easier to install with new solar panels, since there is no need to add a separate inverter. In this article, we refer to the Tesla Powerwall 2 as simply the Powerwall, since the first version is no longer available.

How Powerwall Batteries Work

All batteries store DC (direct current) power, and solar panels produce DC power. But home appliances use AC (alternating current) power. This is where inverters and rectifiers come into play.

When solar panels produce DC power, it runs through an inverter, where it's converted to AC, then flows through your house. If you have a backup power system, excess energy that's not used in the home will keep flowing to charge your battery. It will need to run through a rectifier to be converted back to DC power in order to be stored in the battery.

The Powerwall 2 and Powerwall+ both have an internal inverter and rectifier to convert electricity between AC and DC. The inverter in the Powerwall 2 is only for the battery, and an external inverter is required for solar panels. On the other hand, the Powerwall+ includes a solar inverter. Both models can also charge from the grid when solar panels are not producing electricity.

The energy stored in a Tesla Powerwall can be used at any time. However, there are certain times of the day when stored electricity is more valuable. For example, many electricity providers charge expensive peak tariffs after sunset, when homes tend to use more power. By pulling from your Powerwall instead of the grid at this time of the day, you can maximize your electricity savings.

The number of solar panels needed to fully charge a Tesla Powerwall will depend on how much sunshine you get. Consider that the Powerwall has a 90% round-trip efficiency when charging and discharging — to get the usable capacity of 13.5 kWh, you must have 15 kWh available from your solar panels.

Here's how that breaks down in a typical solar panel system:

  • Assuming a solar panel capacity of 330 to 360 watts, you will need around 10 to 14 panels to generate 15 kWh of usable energy per day.
  • The exact number of solar panels needed to charge a Tesla Powerwall will depend on the specific model and local sunshine conditions.

Keep in mind that your home uses some solar electricity during the day, while the Powerwall is charging. You must have enough solar panels to cover your daytime consumption and charge the battery as well.

Tesla Powerwall Specs

The Tesla Powerwall has some of the best specifications in the home battery market. There are many energy storage systems with excellent performance, but the Powerwall is among the top products in terms of storage capacity and power output.

This is in part because the batteries use a lithium nickel manganese cobalt oxide chemistry, or NMC for short. Lithium-ion batteries with NMC technology are characterized by their high power and storage capacity relative to their size.

Here's a snapshot of key Tesla Powerwall specs:

  • Energy storage capacity: 13.5 kWh
  • Continuous power: 5.8 kW (5 kW on earlier Powerwall 2 units)
  • Peak power: 10 kW (7 kW on earlier Powerwall 2 units)
  • Size: 45.3 in x 29.6 in x 5.75 in
  • Weight: 251.3 pounds
  • Operating temperature range: -4°F to 122°F
  • Warranty: 10 years

If you have a Powerwall+ connected to solar panels or solar roof shingles, it can achieve a higher output with full sunshine. The Powerwall+ is also larger and heavier than the standard unit since it includes a solar inverter:

  • Energy storage capacity: 13.5 kWh
  • Continuous power with no sun: 5.8 kW
  • Peak power with no sun: 10 kW
  • Continuous power with full sun: 7.6 kW
  • Peak power with full sun: 22 kW
  • Size: 62.8 in x 29.7 in x 6.3 in
  • Weight: 343.9 pounds
  • Operating temperature range: -4°F to 122°F
  • Warranty: 10 years

The solar inverter on the Powerwall+ has an efficiency of 97.5% and four Maximum Power Point Tracker (MPPT) circuits. This means you can group solar panels with up to four different orientations and connect each group to a different MPPT circuit to maximize power generation.

Home with Tesla solar panels and Tesla Powerwall+ Batteries Courtesy of Tesla, Inc.

Tesla Powerwall Cost

The Tesla Powerwall has a higher price than many other battery systems, but you also get a high storage capacity and power output. The price is calculated based on how many units you order: a single Powerwall sells for $10,500, but two units will cost $17,000 ($8,500 each). They can be purchased directly from Tesla, but you can also get them from third-party providers and solar installers near you.

Powerwalls and other battery systems qualify for the 26% federal solar tax credit, which effectively reduces the price of a single unit to $7,770 (down from $10,500). However, you must meet some requirements to be eligible:

  • The Powerwall must be used with solar panels (or another renewable energy system) to get credit. In other words, a stand-alone unit that only pulls charge from the grid does not qualify.
  • If you're using the Powerwall in a home, it must get 100% of its charge from solar panels.
  • If you're using it in a business, it must get at least 75% of its charge from solar panels.

Depending on where you live, there may be additional solar tax exemptions or other financial incentives from your state government or utility company. Before installing a Tesla Powerwall, look for information about local incentives and their eligibility requirements.

If you're interested in buying a Powerwall, there are a few additional things to keep in mind:

  • Since the Powerwall has become very popular, there are often long wait times to get products in after ordering them.
  • Tesla is no longer selling Powerwalls individually — they can only be purchased with new solar roof shingle or panel installations.
  • If you want to add a Powerwall to an existing solar array, or you want to use solar panels and inverters from another manufacturer, you will need to contact a third-party provider.

Many top solar companies are authorized Tesla Powerwall retailers. To connect with a certified installer near you and get a free quote for a Powerwall or other installation, fill out the 30-second form below.

Is Tesla's Battery Really Better Than Competitors' Products?

Without a doubt, the Tesla Powerwall is ahead of the competition in terms of market share, and Tesla Powerwall reviews from customers consistently give the batteries high marks. However, when you compare technical specifications, there are many home batteries with excellent performance out there.

Here's how two other market-leading batteries — the Enphase Encharge 10 and the Generac PWRcell — stack up against the Powerwall:

Tesla Powerwall Enphase Encharge 10* Generac PWRcell
Price $10,500 $18,000+
($6,000+ for a single Enphase 3)
$9,999+
(modular design, price increases based on capacity)
Storage Capacity 13.5 kWh 10.08 kWh
(3.36 kWh with a single Enphase 3)
9+ kWh
Continuous Power 5.6 kW 3.84 kW
(1.28 kW with a single Enphase 3)
3.4+ kW
Warranty 10 years 10 years 10 years
Size 45.3 x 29.6 x 5.75 in 42.13 x 26.14 x 12.56 in 22 x 10 x 68 in
Weight 251.3 pounds 341 pounds 287+ pounds
Monitoring Tesla app Enlighten Manager and MyEnlighten app PWRview app

*The Encharge 10 is an integrated AC system that uses three smaller Enphase 3 units.

As you can see, the Powerwall's storage capacity and continuous power output beat out the competition, as does its straightforward pricing. Lower-end batteries may save you money in the short term, but over the lifetime of your solar system, you'd be hard-pressed to find a model as cost-effective as the Powerwall.

FAQ: Tesla Powerwall

How much does a Tesla Powerwall cost?

A single Tesla Powerwall has a price of $10,500. The system price increases based on how many units are connected together (up to 10), and the price per Powerwall is lower when installing two or more.

Can a Tesla Powerwall power a home?

Yes, a Tesla Powerwall can power a home during a short-term blackout or overnight, but you will normally achieve a better return on investment by staying connected to the grid.

An on-grid Powerwall with solar panels can greatly reduce your electricity bills, covering a large part of your consumption during the day and night and pulling from your utility grid if you need more power. However, if you're planning to go off-grid, you'll need at least two (but most likely more) Powerwalls to power your home continuously when the sun isn't shining.

How long does a Tesla Powerwall last?

The Tesla Powerwall comes with a 10-year warranty, which ensures the battery will keep at least 70% of its rated storage capacity after 10 years (equivalent to 9.45 kWh). When used only for solar self-consumption and backup, the Powerwall warranty does not have a cycle limit during the warranty period.

When the Powerwall is used for other applications beyond solar self-consumption and backup, the warranty covers a battery throughput of 37.8 megawatt-hours. In other words, the warranty ends when the battery has stored and provided a total of 37,800 kWh.

Will a Tesla Powerwall save me money?

A standalone Powerwall can save money if your electricity provider charges time-of-use prices. You can charge the Powerwall when grid electricity is cheap, and you can use it when grid electricity is expensive. If your utility company has demand charges, you can also use the Powerwall to cut the peak demand measured by the power meter, and this will be reflected as a lower demand charge on your next bill.

A Powerwall with solar panels or roof shingles can achieve greater savings, as it charges locally with solar power. Instead of exporting your surplus generation to the grid, you can store that energy in the Powerwall and use it when its value is higher. Like in the previous case, you can use the Powerwall to avoid peak tariffs or reduce demand charges.

Leonardo David is an electromechanical engineer, MBA, energy consultant and technical writer. His energy-efficiency and solar consulting experience covers sectors including banking, textile manufacturing, plastics processing, pharmaceutics, education, food processing, fast food, real estate and retail. He has also been writing articles about energy and engineering topics since 2015.

A new "Climate Clock" is displayed in New York City on September 20, 2021. Ben Wolf via Climate Clock

By Jake Johnson

As the United Nations General Assembly kicked off in New York City on Monday, activists unveiled a new version of their digital "Climate Clock" to spotlight the extent to which rich countries are reneging on their vow to invest $100 billion a year in a global green energy fund designed to assist developing nations.

Read More Show Less
Trending
Newly constructed buildings on Hulhumale, an artificial island built up to 10 feet above sea level in anticipation of rising seas, on Dec. 13, 2019 in Male, Maldives. Carl Court / Getty Images

Some of the nations most vulnerable to the climate crisis are calling for an "emergency pact" to limit global temperature rise.

Read More Show Less
Kunming Declaration: Nature Defenders Warn Global Biodiversity Pledge Lacks Urgency

While welcoming a pledge by more than 100 countries to make "transformative change," conservationists say governments must turn "words into reality."

Animals
Red pandas are listed as endangered on the International Union for Conservation of Nature's Red List. Mathias Appel / Flickr

By Jessica Corbett

More than 100 countries on Wednesday concluded a round of negotiations on global efforts to restore and protect the variety of life on Earth by pledging "urgent and integrated action" to achieve "transformative change, across all sectors of the economy and all parts of society."

While conservation advocacy groups worldwide welcomed the "Kunming Declaration" on biodiversity, they also made clear that its 17 specific commitments must be met with immediate, bold, and concrete steps to fully address the existential crisis the natural world now faces from human activity.

Read More Show Less
President Joe Biden delivers remarks on the September jobs report in the South Court Auditorium at the White House on Oct. 8, 2021. Demetrius Freeman / The Washington Post via Getty Images
The outcome of the global climate negotiations in Glasgow this month hinges in part on the Biden administration's efforts to pass domestic legislation and to spur other nations' commitments.
Read More Show Less
Secretary-General António Guterres delivers a speech at the United Nations Climate Ambition Summit 2020 taking place virtually with world leaders invited to make pre-recorded statements outlining their new and ambitious commitments. UN Photo / Mark Garten

World leaders should declare a "climate emergency" in their countries to spur action to avoid catastrophic global warming, UN Secretary-General Antonio Guterres said in opening remarks at a climate summit on Saturday.

On the fifth anniversary of the 2015 Paris Agreement, more than 70 world leaders are due to address the one-day virtual meeting in the hope of galvanizing countries into stricter actions on global warming emissions.

Read More Show Less
Trending
A sea turtle and tropical fish swim in Oahu, Hawaii. M.M. Sweet / Moment / Getty Images

By Ajit Niranjan

Leaders from across the world have promised to turn environmental degradation around and put nature on the path to recovery within a decade.

Read More Show Less
Extensive meetings in preparation for IPCC's Sixth Assessment Report have been happening online. Intergovernmental Panel on Climate Change / YouTube

By Kenny Stancil

Amid an ongoing wave of extreme weather disasters and ahead of a major United Nations climate conference this fall, top scientists from nearly 200 countries began meeting Monday to finalize a landmark report detailing how the fossil fuel-driven climate emergency is already wreaking havoc around the globe and what society must do to avert its most catastrophic consequences.

Read More Show Less
Trending
The Drax coal-fired power station near Selby, North Yorkshire, England. Warwick Sweeney / Photographer's Choice / Getty Images Plus

Thirty of the world's largest investors, who together control $5 trillion in assets, have pledged to cut the greenhouse gas emissions of their portfolios by as much as 29 percent in five years.

Read More Show Less
Leading Glasgow club and music venue SWG3 will use dancers' body heat as a renewable energy source to power the building and reduce carbon emissions. Michael Hunter

We've heard of wind, solar, thermal and tidal — but dance energy? Apparently, yes! Legendary nightclub SWG3 in Glasgow, Scotland will trial an innovative scheme to trap body heat from the dancers on its dance floor to heat and cool various parts of its complex.

Dubbed BODYHEAT, the system captures and converts human body heat created by staff and partiers inside the venue into a renewable energy source for the club to use, TimeOut reported. Importantly, the energy generated can also be stored for months until needed, long after the party is over.

Read More Show Less
Earth Overshoot Day Moves Forward By Nearly a Month

The COVID effect didn't last. Earth Overshoot Day, the day humanity exceeds its yearly allotment of the planet's biological assets, is nearly back to its record high. What can be done to ease the burden?

Climate
Pexels

By Martin Kuebler

After a temporary reprieve due to the COVID-19 pandemic, Earth Overshoot Day — the day humanity is projected to have used up all the planet's biological resources regenerated in one year — has shifted forward again, this year landing on July 29.

"With almost half a year remaining, we will already have used up our quota of the Earth's biological resources for 2021," said Susan Aitken, leader of Glasgow City Council, where world leaders will gather later this year for the COP26 climate summit in November. "If we need reminding that we're in the grip of a climate and ecological emergency, Earth Overshoot Day is it."

Read More Show Less
EcoWatch is a community of experts publishing quality, science-based content on environmental issues, causes, and solutions for a healthier planet and life.
A wind-solar hybrid photovoltaic power station on Sept. 12, 2020 in Zaozhuang, Shandong Province of China. Li Zongxian / VCG via Getty Images

A group of governments and the private sector on Friday collectively promised more than $400 billion (just over €340 billion) at a high-level summit that called for more urgent action to curb catastrophic climate change.

Read More Show Less
EcoWatch Daily Newsletter

The youth-led Mock COP26 virtual conference concluded Tuesday with a treaty they hope world leaders will sign ahead of the official COP26 in November 2021.

Read More Show Less
Courtesy of Tesla, Inc.

The Tesla Powerwall is arguably the best-known solar battery for homes, but does it live up to the hype? In this Tesla Powerwall review, we'll discuss the main features of this popular energy storage system and compare it with some competing battery backup devices.

What Is the Tesla Powerwall, and How Does it Work?

The Tesla Powerwall is a lithium-ion battery that's most often associated with storing energy generated by Tesla solar panels. However, you can actually charge these batteries with any electricity source to use as a backup during a power outage. You can also connect up to 10 Powerwall units as a single energy storage system, making them viable for small and medium businesses as well as homes.

You can currently purchase a Tesla Powerwall 2 or Powerwall+. The Powerwall 1 has been discontinued since 2016, but the newer versions are much better products: a single Powerwall 2 or Powerwall+ can store 13.5 kilowatt-hours of power, while the Powerwall 1 only had 6.4 kWh of usable capacity. The newer versions also have a higher power output (5.6 kW vs 3.3 kW), which means they can provide electricity for more devices at once.

The Powerwall 2 and Powerwall+ have the same storage capacity, but the Powerwall+ includes an inverter for easier integration with solar PV panels. The Powerwall+ can also deliver more kilowatts when panels are in full sunshine, while the Powerwall 2 offers the same output regardless of solar generation.

Here's a summary of Tesla Powerwall output:

  • Originally, the Powerwall 2 offered 5 kW of continuous power and 7 kW of peak power.
  • The Powerwall+ and later versions of the Powerwall 2 have 5.8 kW of continuous power and 10 kW of peak power.
  • When solar panels are under full sunshine, the Powerwall+ reaches 7.6 kW of continuous power and 22 kW of peak power.

If you already have a home solar energy system with its own inverter, the Powerwall 2 is a great option to add energy storage without modifications. However, the Powerwall+ is easier to install with new solar panels, since there is no need to add a separate inverter. In this article, we refer to the Tesla Powerwall 2 as simply the Powerwall, since the first version is no longer available.

How Powerwall Batteries Work

All batteries store DC (direct current) power, and solar panels produce DC power. But home appliances use AC (alternating current) power. This is where inverters and rectifiers come into play.

When solar panels produce DC power, it runs through an inverter, where it's converted to AC, then flows through your house. If you have a backup power system, excess energy that's not used in the home will keep flowing to charge your battery. It will need to run through a rectifier to be converted back to DC power in order to be stored in the battery.

The Powerwall 2 and Powerwall+ both have an internal inverter and rectifier to convert electricity between AC and DC. The inverter in the Powerwall 2 is only for the battery, and an external inverter is required for solar panels. On the other hand, the Powerwall+ includes a solar inverter. Both models can also charge from the grid when solar panels are not producing electricity.

The energy stored in a Tesla Powerwall can be used at any time. However, there are certain times of the day when stored electricity is more valuable. For example, many electricity providers charge expensive peak tariffs after sunset, when homes tend to use more power. By pulling from your Powerwall instead of the grid at this time of the day, you can maximize your electricity savings.

The number of solar panels needed to fully charge a Tesla Powerwall will depend on how much sunshine you get. Consider that the Powerwall has a 90% round-trip efficiency when charging and discharging — to get the usable capacity of 13.5 kWh, you must have 15 kWh available from your solar panels.

Here's how that breaks down in a typical solar panel system:

  • Assuming a solar panel capacity of 330 to 360 watts, you will need around 10 to 14 panels to generate 15 kWh of usable energy per day.
  • The exact number of solar panels needed to charge a Tesla Powerwall will depend on the specific model and local sunshine conditions.

Keep in mind that your home uses some solar electricity during the day, while the Powerwall is charging. You must have enough solar panels to cover your daytime consumption and charge the battery as well.

Tesla Powerwall Specs

The Tesla Powerwall has some of the best specifications in the home battery market. There are many energy storage systems with excellent performance, but the Powerwall is among the top products in terms of storage capacity and power output.

This is in part because the batteries use a lithium nickel manganese cobalt oxide chemistry, or NMC for short. Lithium-ion batteries with NMC technology are characterized by their high power and storage capacity relative to their size.

Here's a snapshot of key Tesla Powerwall specs:

  • Energy storage capacity: 13.5 kWh
  • Continuous power: 5.8 kW (5 kW on earlier Powerwall 2 units)
  • Peak power: 10 kW (7 kW on earlier Powerwall 2 units)
  • Size: 45.3 in x 29.6 in x 5.75 in
  • Weight: 251.3 pounds
  • Operating temperature range: -4°F to 122°F
  • Warranty: 10 years

If you have a Powerwall+ connected to solar panels or solar roof shingles, it can achieve a higher output with full sunshine. The Powerwall+ is also larger and heavier than the standard unit since it includes a solar inverter:

  • Energy storage capacity: 13.5 kWh
  • Continuous power with no sun: 5.8 kW
  • Peak power with no sun: 10 kW
  • Continuous power with full sun: 7.6 kW
  • Peak power with full sun: 22 kW
  • Size: 62.8 in x 29.7 in x 6.3 in
  • Weight: 343.9 pounds
  • Operating temperature range: -4°F to 122°F
  • Warranty: 10 years

The solar inverter on the Powerwall+ has an efficiency of 97.5% and four Maximum Power Point Tracker (MPPT) circuits. This means you can group solar panels with up to four different orientations and connect each group to a different MPPT circuit to maximize power generation.

Home with Tesla solar panels and Tesla Powerwall+ Batteries Courtesy of Tesla, Inc.

Tesla Powerwall Cost

The Tesla Powerwall has a higher price than many other battery systems, but you also get a high storage capacity and power output. The price is calculated based on how many units you order: a single Powerwall sells for $10,500, but two units will cost $17,000 ($8,500 each). They can be purchased directly from Tesla, but you can also get them from third-party providers and solar installers near you.

Powerwalls and other battery systems qualify for the 26% federal solar tax credit, which effectively reduces the price of a single unit to $7,770 (down from $10,500). However, you must meet some requirements to be eligible:

  • The Powerwall must be used with solar panels (or another renewable energy system) to get credit. In other words, a stand-alone unit that only pulls charge from the grid does not qualify.
  • If you're using the Powerwall in a home, it must get 100% of its charge from solar panels.
  • If you're using it in a business, it must get at least 75% of its charge from solar panels.

Depending on where you live, there may be additional solar tax exemptions or other financial incentives from your state government or utility company. Before installing a Tesla Powerwall, look for information about local incentives and their eligibility requirements.

If you're interested in buying a Powerwall, there are a few additional things to keep in mind:

  • Since the Powerwall has become very popular, there are often long wait times to get products in after ordering them.
  • Tesla is no longer selling Powerwalls individually — they can only be purchased with new solar roof shingle or panel installations.
  • If you want to add a Powerwall to an existing solar array, or you want to use solar panels and inverters from another manufacturer, you will need to contact a third-party provider.

Many top solar companies are authorized Tesla Powerwall retailers. To connect with a certified installer near you and get a free quote for a Powerwall or other installation, fill out the 30-second form below.

Is Tesla's Battery Really Better Than Competitors' Products?

Without a doubt, the Tesla Powerwall is ahead of the competition in terms of market share, and Tesla Powerwall reviews from customers consistently give the batteries high marks. However, when you compare technical specifications, there are many home batteries with excellent performance out there.

Here's how two other market-leading batteries — the Enphase Encharge 10 and the Generac PWRcell — stack up against the Powerwall:

Tesla Powerwall Enphase Encharge 10* Generac PWRcell
Price $10,500 $18,000+
($6,000+ for a single Enphase 3)
$9,999+
(modular design, price increases based on capacity)
Storage Capacity 13.5 kWh 10.08 kWh
(3.36 kWh with a single Enphase 3)
9+ kWh
Continuous Power 5.6 kW 3.84 kW
(1.28 kW with a single Enphase 3)
3.4+ kW
Warranty 10 years 10 years 10 years
Size 45.3 x 29.6 x 5.75 in 42.13 x 26.14 x 12.56 in 22 x 10 x 68 in
Weight 251.3 pounds 341 pounds 287+ pounds
Monitoring Tesla app Enlighten Manager and MyEnlighten app PWRview app

*The Encharge 10 is an integrated AC system that uses three smaller Enphase 3 units.

As you can see, the Powerwall's storage capacity and continuous power output beat out the competition, as does its straightforward pricing. Lower-end batteries may save you money in the short term, but over the lifetime of your solar system, you'd be hard-pressed to find a model as cost-effective as the Powerwall.

FAQ: Tesla Powerwall

How much does a Tesla Powerwall cost?

A single Tesla Powerwall has a price of $10,500. The system price increases based on how many units are connected together (up to 10), and the price per Powerwall is lower when installing two or more.

Can a Tesla Powerwall power a home?

Yes, a Tesla Powerwall can power a home during a short-term blackout or overnight, but you will normally achieve a better return on investment by staying connected to the grid.

An on-grid Powerwall with solar panels can greatly reduce your electricity bills, covering a large part of your consumption during the day and night and pulling from your utility grid if you need more power. However, if you're planning to go off-grid, you'll need at least two (but most likely more) Powerwalls to power your home continuously when the sun isn't shining.

How long does a Tesla Powerwall last?

The Tesla Powerwall comes with a 10-year warranty, which ensures the battery will keep at least 70% of its rated storage capacity after 10 years (equivalent to 9.45 kWh). When used only for solar self-consumption and backup, the Powerwall warranty does not have a cycle limit during the warranty period.

When the Powerwall is used for other applications beyond solar self-consumption and backup, the warranty covers a battery throughput of 37.8 megawatt-hours. In other words, the warranty ends when the battery has stored and provided a total of 37,800 kWh.

Will a Tesla Powerwall save me money?

A standalone Powerwall can save money if your electricity provider charges time-of-use prices. You can charge the Powerwall when grid electricity is cheap, and you can use it when grid electricity is expensive. If your utility company has demand charges, you can also use the Powerwall to cut the peak demand measured by the power meter, and this will be reflected as a lower demand charge on your next bill.

A Powerwall with solar panels or roof shingles can achieve greater savings, as it charges locally with solar power. Instead of exporting your surplus generation to the grid, you can store that energy in the Powerwall and use it when its value is higher. Like in the previous case, you can use the Powerwall to avoid peak tariffs or reduce demand charges.

Leonardo David is an electromechanical engineer, MBA, energy consultant and technical writer. His energy-efficiency and solar consulting experience covers sectors including banking, textile manufacturing, plastics processing, pharmaceutics, education, food processing, fast food, real estate and retail. He has also been writing articles about energy and engineering topics since 2015.

A new "Climate Clock" is displayed in New York City on September 20, 2021. Ben Wolf via Climate Clock

By Jake Johnson

As the United Nations General Assembly kicked off in New York City on Monday, activists unveiled a new version of their digital "Climate Clock" to spotlight the extent to which rich countries are reneging on their vow to invest $100 billion a year in a global green energy fund designed to assist developing nations.

Read More Show Less
Trending
Newly constructed buildings on Hulhumale, an artificial island built up to 10 feet above sea level in anticipation of rising seas, on Dec. 13, 2019 in Male, Maldives. Carl Court / Getty Images

Some of the nations most vulnerable to the climate crisis are calling for an "emergency pact" to limit global temperature rise.

Read More Show Less
Kunming Declaration: Nature Defenders Warn Global Biodiversity Pledge Lacks Urgency

While welcoming a pledge by more than 100 countries to make "transformative change," conservationists say governments must turn "words into reality."

Animals
Red pandas are listed as endangered on the International Union for Conservation of Nature's Red List. Mathias Appel / Flickr

By Jessica Corbett

More than 100 countries on Wednesday concluded a round of negotiations on global efforts to restore and protect the variety of life on Earth by pledging "urgent and integrated action" to achieve "transformative change, across all sectors of the economy and all parts of society."

While conservation advocacy groups worldwide welcomed the "Kunming Declaration" on biodiversity, they also made clear that its 17 specific commitments must be met with immediate, bold, and concrete steps to fully address the existential crisis the natural world now faces from human activity.

Read More Show Less
President Joe Biden delivers remarks on the September jobs report in the South Court Auditorium at the White House on Oct. 8, 2021. Demetrius Freeman / The Washington Post via Getty Images
The outcome of the global climate negotiations in Glasgow this month hinges in part on the Biden administration's efforts to pass domestic legislation and to spur other nations' commitments.
Read More Show Less
Secretary-General António Guterres delivers a speech at the United Nations Climate Ambition Summit 2020 taking place virtually with world leaders invited to make pre-recorded statements outlining their new and ambitious commitments. UN Photo / Mark Garten

World leaders should declare a "climate emergency" in their countries to spur action to avoid catastrophic global warming, UN Secretary-General Antonio Guterres said in opening remarks at a climate summit on Saturday.

On the fifth anniversary of the 2015 Paris Agreement, more than 70 world leaders are due to address the one-day virtual meeting in the hope of galvanizing countries into stricter actions on global warming emissions.

Read More Show Less
Trending