What You Should Know About the Tesla Powerwall 2 Energy Storage System
Tesla’s Powerwall 2 Battery System is a residential energy storage solution. It utilizes the company’s advanced lithium-ion battery technology as well as internet connectivity to deliver customers with a robust energy solution with wide applications in the smart home.
Most people know about Tesla from their pioneering work in electric vehicles. Beyond their automotive products, the company has expanded the applications of their battery technology to include residential and commercial energy storage products. Founded in 2003, the company continues to make strides towards its mission, which is “to accelerate the world’s transition to sustainable energy.” As the market for solar energy continues to grow, Tesla has also positioned itself and its products to maximize this clean and renewable energy source to solve energy problems around the world.
What is the Powerwall 2?
The Powerwall 2 Battery System or Powerwall 2 is the residential version of Tesla’s Powerpack energy storage product for commercial use. The pilot of the product was released in 2015 and the second generation was announced in 2016. Production takes place at the Gigafactory 1 in Nevada, USA.
The Powerwall 2 is an energy storage unit that can be mounted to a wall or to the ground. It is suitable for outdoor installation as it can handle temperature extremes on either end in the range of -20°C to 50°C, although the optimal range is between 0°C and 30°C. The unit is also water-proof. As you would expect from a Tesla product, the unit itself is designed very well and is also modern-looking. The slim product measures 1150 mm x 755 mm x 155 mm and weighs 122 kg.
The Powerwall 2 contains rechargeable lithium-ion batteries allowing the unit to store electricity from the grid or from an installed solar PV system. The applications of this product include solar self consumption, a backup power source during outages and for off the grid use.
Solar self-consumption is the act of using your solar energy to run devices within your home or business. Provided you have a net (aka bi-directional) energy meter, this will happen automatically when appliances are switched on in your home while your solar system is producing energy.
Lithium-ion batteries have a number of important advantages, making them the fastest growing battery technology on the market. For one, they are rechargeable. They have potential for high storage capacity and require very low maintenance. When new, these batteries do not require much priming. Compared with the widely used nickel-based batteries, lithium-ion batteries have half the self-discharge rate, meaning lower energy losses.
Energy is stored as DC power in the Powerwall 2 batteries and must be converted to AC power by the built-in inverter before it can be used by devices in the home. Each Powerwall has a usable capacity of 13.5 kilowatt-hours per unit, and for additional storage capacity, multiple units can be purchased and connected in parallel. The inverter also functions in the reverse to convert AC to DC power when the batteries are being charged. With a round-trip inverter efficiency of 90%, power lost in the trip to be stored in the unit and back out for usage equates to 10%. The full owner’s manual contains the details of the product and its operation.
Connectivity and the Mobile App
Along with the battery unit, comes the Powerwall Backup Gateway 2 which is the energy storage unit’s connection to the internet. This stays up-to-date with what is happening in the news, the area, and the weather concerning prices, policies, and any other factors that impact residential energy storage, particularly from solar PV systems. In the Tesla app, users of any of the company’s products from electric vehicles to storage units can keep track of key metrics and change a wide range of settings around how the product is used.
The Tesla app has impressive visuals and allows owners of the Powerwall 2 to:
- View the current state of charge
- Monitor energy flow (this happens between the Powerwall 2 and the rooftop solar PV units, the grid and the home appliances)
- See detailed metrics and graphics for each energy source
- Select between the different operating modes (Self-powered, Backup Only, Advanced Time-Based Control as well as special modes such as Grid Services, Storm Watch, and Preconditioning)
Advantages of the Powerwall 2
The Powerwall 2 is the energy-conscious resident’s answer to a self-powered home. There are a number of comparative energy storage solutions already on the market. With more and more people looking for backup solutions to withstand power outages and loadshedding, generators and other battery storage solutions are often used.
The Powerwall 2 is an investment that comes with some notable benefits. These include:
- High energy storage capacity that can be combined with a solar PV system to reduce reliance on the grid in a self-powered home.
- Energy stored from solar during the day is a great backup to power home at night or during loadshedding or an outage
- The unit is well-designed and compact. It is safe for indoor or outdoor installation and allows easier integration because of its built-in inverter.
- Although there is a high initial investment, it is worthwhile. You can reduce your monthly electricity bill.
- Connectivity allows for over-the-air updates for new features and functions.
- The Tesla app gives you more control and insight into your home energy use in real-time.
With the Powerwall 2, home owners can enjoy greater control over their energy use and withstand fluctuations in the grid power supply. Combining this storage unit with a solar PV system is a great choice that ultimately leads to monthly electricity bill savings as well.
As a Tesla Powerwall 2 certified Installer, use our free online Tesla system sizer and cost estimator here, or contact the Zero Point Energy team to see how best we can help you make the move to reliable, renewable and self-sufficient energy.
Zero Point Energy (Pty) Ltd is a proudly South African sustainable engineering company that provides professional engineering consulting & turn-key solutions in the areas of energy efficiency, renewable energy, off-grid and energy storage solutions, water efficiency and responsible waste management. The company is a 100% black youth-owned, 30% black female-owned company achieving a Level 1 BBBEE Contributor status, and has a passion to transform the energy industry without compromising on safety, quality and client satisfaction. Learn more about the company’s team here