Tesla Powerwall

The **Powerwall** and **Powerpack** are rechargeable lithium-ion battery stationary energy storage products manufactured by Tesla, Inc. The Powerwall is intended to be used for home energy storage and stores electricity for solar self-consumption, time of use load shifting, backup power, and off-the-grid use. The larger Powerpack is intended for commercial or electric utility grid use and can be used for peak shaving, load shifting, backup power, demand response, microgrids, renewable power integration, frequency regulation, and voltage control.

Announced in 2015, with a pilot demonstration of 500 units built and installed during 2015, production of the product was initially at the Tesla Fremont factory before being moved to the under-construction Gigafactory 1 in Nevada. The second generation of both products was announced in October 2016.

## History

Tesla started development in 2012, installing prototypes at selected industrial customers. In some cases, PowerPacks have reduced the electrical bill by 20%. Tesla originally announced the Powerwall at the April 30, 2015 product launch with power output of 2 kW steady and 3.3 kW peak, but Elon Musk said at the June 2015 Tesla shareholders meeting that this would be more than doubled to 5 kW steady with 7 kW peak, with no increase in price. He also announced that Powerwall deliveries would be prioritized to partners who minimize the cost to the end user, with a Powerwall installation price of US$500.

When originally announced in 2015, two models of Powerwall were planned: 10 kWh capacity for backup applications and 7 kWh capacity for daily cycle applications. By March 2016, however, Tesla had "quietly removed all references to its 10-kilowatt-hour residential battery from the Powerwall website, as well as the company's press kit. The company's smaller battery designed for daily cycling is all that remains." The 10 kWh battery as originally announced has a nickel-cobalt-aluminum cathode, like the Tesla Model S, which was projected to function as a backup/uninterruptible power supply, and had a projected cycle life of 1000–1500 cycles.

In October 2016, Tesla announced that nearly 300 MWh of Tesla batteries had been deployed in 18 countries. The **Powerwall 2** was unveiled in October 2016 at Universal Studios' Colonial Street, Los Angeles, backlot street set and is designed to work with the solar panel roof tiles to be produced by SolarCity.

## Powerwall specifications

Since March 2016, there was only a single model: the 6.4 kWh version for daily cycle applications, before the Powerwall 2 was introduced:

1. ↑ Installation cost not included
2. ↑ 2.0 2.1 2.2 Includes inverter.

## Powerpack specifications

### Examples of Powerpack installation

Tesla installed a grid storage facility for Southern California Edison with a capacity of 80 MWh at a power of 20 MW between September 2016 and December 2016. As of January 2017[update] the storage unit was one of the largest accumulator batteries on the market. Tesla installed 400 Powerpack-2 modules at the Mira Loma transformer station in California. The battery storage serves to store energy at a low network load and then to feed this energy back into the grid at peak load. The principal way of adding peak generation capacity prior to this was the use of gas-fired power stations. As of 2019[update], the 100MW/129MWh Hornsdale Power Reserve in Australia is the world's largest lithium-ion battery.

## Versions

The first generation Powerwall has a 6.4 kWh capacity for daily cycle applications. Users with larger energy needs can connect multiple Powerwalls to expand the capacity even higher. In March 2016 Tesla quietly discontinued a previously announced 10 kWh capacity model designed to produce backup power as the 6.4 kWh version can also be configured to act as backup power.

The Powerpack is a bigger unit with 100 kWh (first generation) and 210 kWh (2nd generation) of storage for commercial and utility grid use. To meet the variety of energy needs in industry, "Powerpack is infinitely scalable", said Elon Musk. Tesla's objective is to "fundamentally change the way the world uses energy" by "fostering a clean energy ecosystem and helping wean the world off fossil fuels" using backup energy storage for renewable energy. The Powerpack 2 has 200 kWh of storage, probably using the 21700 cell type by the end of 2016. Tesla deployed the containerized Megapack in Canada in 2020.

## Technology

The Powerwall is optimized for daily cycling, such as for load shifting. Tesla uses proprietary technology for packaging and cooling the cells in packs with liquid coolant. Elon Musk, the chairman, CEO and product architect of the Tesla company, promised not to start patent infringement lawsuits against anyone who, in good faith, used Tesla's technology for Powerwalls as he had promised with Tesla cars.

The daily cycle 7 kWh PW1 battery uses nickel-manganese-cobalt chemistry and can be cycled 5,000 times before warranty expiration. The Tesla Powerwall has a 92.5% round-trip efficiency when charged or discharged by a 400–450 V system at 2 kW with a temperature of 77 °F (25 °C) when the product is brand new. Age of the product, temperatures above or below 77 °F (25 °C), and charge rates or discharge rates above 2 kW would lower this efficiency number, decreasing the system performance.

First-generation Powerwalls include a DC-to-DC converter to sit between a home's existing solar panels and the home's existing DC to AC inverter. If the existing inverter is not storage-ready, one must be purchased. The second generation Powerwall incorporates a DC-to-AC inverter of Tesla's own design. Production of the 21700 cell type (Tesla names them **21-70**) for the PW2 and PP2 began at Gigafactory in January 2017.

The National Fire Protection Association conducted two worst-case scenario tests in 2016, igniting Powerpacks to initiate thermal run-off. The design contained damage to the structures.

When the 750 MW Kogan Creek Power Station in Queensland tripped in October 2019, system frequency fell and the hundreds of Powerwalls in South Australia combined in a virtual power plant responded to assist in keeping up the frequency.

## Market

### Powerwall

The Powerwall was unveiled on April 30, 2015, with a 7 kWh Powerwall model that would retail for US$3,000 and a 10 kWh model at US$3,500. Shipments of 500 pilot units were planned to begin in the late summer of 2015. Musk indicated that he believed the low Tesla price would cause other storage producers to follow. Before the April 30, 2015, unveiling, some existing solar-panel users participated in a demonstration program and paid up to US$13,000 for a 10 or 15 kWh Tesla battery.

As of May 2015[update], Powerwalls were sold to companies including SolarCity and OUXO Energy for installation. SolarCity was running a pilot project in 500 California houses, using 10 kWh battery packs. In 2016 in Vermont, Peck Electric Company partnered with Green Mountain Power to install hundreds of Powerwalls in Vermont homes as part of a distributed storage pilot program. A market overview calculates Powerwall 2 at 0.23 Australian dollars per warranted cumulative kWh discharged.

#### Volume tendency

As of May 2015, Tesla Powerwall had already sold out through to the middle of 2016. Reservations within the first few weeks were over 50,000 units for the Powerwall (US$179 million), and 25,000 units for the Powerpack (US$625 million), therefore combined orders of US$800 million.

During the first quarter of 2016, Tesla delivered over 25 MWh of energy storage to customers on four continents. Over 2,500 Powerwalls and nearly 100 Powerpacks were delivered in North America, Asia, Europe, and Africa. The first Powerwall in Portugal has been sold by OUXO Energy. As of October 2016[update], nearly 300 MWh of Tesla batteries had been deployed worldwide.

### Powerpack

At the announcement, a larger battery called Powerpack—storing 100 kWh of electrical energy—was projected to be available for industrial consumers, reaching a price point of $250/kWh. The Powerpack was projected to comprise the majority of stationary storage production at Gigafactory 1 while Powerwall would play a smaller part, giving Tesla a profit margin of 20 percent.

#### Price tendency

In September 2016, Tesla priced the Powerpack at $445/kWh, and a system with 200 kWh of energy and 100 kW of peak power was the cheapest available priced at $145,100. A bi-directional 250 kW inverter costs $52,500. By October 2016, a limited system of Powerpack 2 cost $398/kWh. A 22 MWh system can cost €15 million.

#### Volume tendency

Musk predicted in 2016 that the utility power will need to increase to supply more electric vehicles, eventually reaching an equilibrium with about 1/3 of power coming from distributed energy and 2/3 from utilities. Battery storage is one of the ways to mitigate the increasing duck curve, particularly in California.

## Return on investment calculations

A May 2015 article in *Forbes* magazine calculated that using a Tesla Powerwall 1 model combined with solar panels in a home would cost 30 cents/kWh for electricity if a home remains connected to the grid (the article acknowledges that the Tesla battery could make economic sense in applications that are entirely off-grid). US consumers got electricity from the power grid for 12.5 cents/kWh on average. The article concluded the "...Tesla's Powerwall Is Just Another Toy For Rich Green People." Bloomberg and Catalytic Engineering also agreed that the Tesla system was most useful in places where electricity prices are high.

There are however a number of such locations, including Hawaii and other remote islands that generate electricity with shipped-in or flown-in fuels. Residential California PG&E customers pay as much as 40 cents/kWh if they reach Tier 3 in electrical usage.
Arctic and sub-Arctic locations with high energy prices cannot generate sufficient solar energy in the winter due to little or no sunlight.

The Swiss bank UBS said that the Powerwall makes sense in Australia and Germany where electricity is very costly but solar panels are well distributed.

As of October 2019, the Tesla Powerwall 2 costs $14,600 for the recommended two units (plus $2,500 to $4,500 for installation) in the US; this price does not include the cost of solar panels.

## Competition

### Home

Energy technology company Enphase Energy, based in California, has announced it will release its lithium iron phosphate battery as part of a complete alternating current Enphase Home Energy Solution starting in winter 2016 in Australia and New Zealand with Genesis Energy conducting trials. The system, which includes monitoring and control of solar generation, home energy consumption, and battery storage, will be sold at wholesale through solar distributors, who sell to solar installers. Enphase's modular 'building block' batteries are more efficient than the Tesla Powerwall (96% compared to Tesla's 92% round-trip efficiency). The Enphase AC Battery also includes an inverter inside the casing and works with all existing solar systems or alternatively, in homes without solar. Lithium iron phosphate batteries are known to be the most stable and safe of the various lithium batteries.

LG Chem announced RESU10H(Type-R)\_Expansion system as part of their Energy Storage System product portfolio and are compatible with SolarEdge inverters. Tesla announced that it will be installing its Powerwall home storage batteries in Japan by 2020.

### Industrial

BYD's energy storage system is another competitor of Tesla's Powerpack. UC San Diego installed this system, which has 5 megawatt-hour (MWh) capacity—enough to power 2,500 homes—in September 2014. BYD is a large supplier of rechargeable batteries, and is also known for its leading position in electric buses.

Sonnen and AutoGrid collaborated on combining house batteries into a large-scale utility-level grid storage system. Eos claimed a battery price of $160/kWh in 2017, before the cost of integration by Siemens.