Powerwall is a rechargeable lithium-ion battery with a liquid thermostat. Tesla is one of the few companies in the energy storage market in homes that produces compact batteries for storing energy at home. The battery is designed to save energy for domestic use, shift load consumption, as well as backup power.

Tesla battery packs are an ideal pairing for solar panel systems, especially in the case of off-grid projects where homeowners need or want to become fully independent of their utility. A solar storage solution like the Tesla Powerwall allows you to maintain a sustained power supply during the day or night.

Normally, this process happens over the course of a day: when the sun is high in the sky and your solar panels are producing more electricity than household can use, the surplus energy is stored in your Tesla Battery. As the sun goes down and your solar panel production decreases, you draw on the electricity that you stored during the sunniest part of the day. Essentially, the Powerwall helps you balance out your electricity production and usage over the course of the day.

Source:Tesla

Tesla enthusiast, owner of Model 3 and owner of Tesla Powerwall, TeslaStraya / Twitter, shared a blog post about his January electricity bill. He lives in Central Coast, New South Wales, Australia. This is one of the the states where Bushfire raged that destroyed hundreds of houses. Many settlements were covered in strong smoke. In the settlements it was so dark because of the smoke that during the day it was necessary to turn on street lighting. Residents of the affected areas had to survive in very difficult conditions.

So, my January 2019 energy bill arrived, I dug into the data and posted this blog post. In summary, all I paid was $17 thanks to Solar and @Tesla Powerwall 2's. @elonmusk is correct, solar is a license to print money! @SolarayEnergy #tesla #powerwall2https://t.co/RE74UHLFKu

— TeslaStraya (@TeslaStraya) February 5, 2020

For TeslaStraya's family, January is the month when electricity consumption increases. This is primarily due to the heat, and this year the temperature in this region reached 104 ° F. Other factors of increased energy consumption include the fact that at this time TeslaStraya and his children usually are at home. Must be noted, that feed in for this month was low, due to many days of low solar production due to Bushfire smoke/haze.

So, his feed in tariff is 21c/kWh which arguably reduces the benefit of having battery storage. He is on a TOU plan with AGL but the data isn’t easy to split based on TOU rates so he will work on AGL’s single rate plan of 29c/kWh. Daily supply charge is not factored in but GST is.

Powerwall Monitor Data

Source: TeslaStraya's blog post

Ignore utilization figure, that’s designed for day use. Utilization for month was $49%.

• Consumed on average 38.7kWh per day.
• Powerwall efficiency remains at 87%.
• If they didn’t have solar, they would have spent $343.12 for the month or $11 a day for power!
• Thanks to solar and battery storage this dropped to $27.01 for the month or 87c per day!
• If we look at pure battery only savings, factoring in his high feed in tariff and efficiency losses it contributed to $19.09 in direct savings.
• Roughly a third of energy came from solar/battery/grid.

TeslaMate Charging Data 

(TeslaStraya's Model 3)

Source: TeslaStraya's blog post

TeslaMate charging stats for same time period:

• 183kWh of Model 3 charging was done at home during this billing period or approximately 15% of entire consumption.
• All charging done in off peak period (Powerwalls are configured for TOU rates so discharge rarely in off peak period).
• Costs of Model 3 charging in January was $28.49.
• This will inevitably rise when free supercharging is exhausted.
• During this time he made 78 trips for a total of 1765 miles.

Actual AGL Bill

Actual AGL bill for the month of January:

• Total bill for the period of January was $17.28.
• His account remains in credit of $347.75.

TeslaStraya said:

"Overall, I am super happy with having to “pay” just over $17 for what was over a megawatt hour of usage for the month. Solar really does save you money and I did see some benefit in battery storage during January!"

Tesla's mission is to accelerate the transition of the world to sustainable energy. Tesla Solar, like the Tesla electric cars, is a powerful tool to achieve this.

 Featured image: TeslaStraya