Solar Power with Tesla Battery, the Stats
Just a quick update. I finally got a battery replacement on May 31st. They installed the battery in the afternoon, so it took that day and the next to fully charge the battery.
So now that I have a fully charging Battery (13.8 kwh rated storage) here are some basic stats. I live in Las Vegas for those of you who don’t know, so it gets rather hot here. During a 104 degree day, I used
- 28.6 kwh home usage,
- 35.3 kwh solar generation with a 5.5 kwh system(general peaks at 4.2 to 4.5)
- 13.1 kwh from Powerwall,
- 14.6 to Powerwall.
- .1 kwh from grid,
- 5.2 kwh to grid.
The way it works, the Battery kicks in during the day when solar does not have enough energy to power the house(the air conditioning kicks in) when the air goes off the solar recharges the battery.
Lets start at midnight. From midnight to 6am before the solar kicks in, uses about 3 to 4 kwh. This comes from Battery. The solar panels start receiving sun and it powers the house and charges the Battery. When the power draw is larger then solar generation, the battery kicks in. (this is where the point .1 from grid kicks in, some minute draw while battery switch’s, this happens for micro seconds, but shows up as.1)
During the day the battery charges and supplies extra energy. It generally is fully charged around noon. Then it switches to sending power to the grid. When the Air comes on and draws extra power, the battery gives and takes.
When the sun goes down, the battery kicks in and supply’s the power for the night.
Since the heat began and temps over 100 the Battery basically charges to 100 and drops to 10 percent depending on air conditioning. Some times its only drops to 20 to 25.
My house is 2815 sq foot, Two air conditioners, one down stairs, one upstairs. I do have two Nest Thermostats, with scheduled cool temps. I try to have the air working between 12 and 3pm when solar from panels equals the draw, but our house faces west so sunlight heats around 6 to 8pm so the battery does drain faster about 25% drop till around 9pm when the air stays off for the night.
Since the powerwall has been working at full capacity, The performance is 99 to 100 from solar, and about 5kwh to the grid. About .50 cents a day during these summer months. So I send about $15 a month during the summer, and pay 12.66 a month to NV Energy. I will get back the difference at the end of the year.
I am now calculating about $150 return each year from NV Energy. (Amount is net, what I Pay NV Energy, to what they pay me back)
My payments are 123 for loan, 13 to NV Energy. This would make my Energy Bill $110 a month with solar.
Once the loan is paid off, power costs will be $156 a year to NV Energy(with that amount to be refunded at end of year) will post a year in review with actual numbers. So should be free, with maybe $100 from NV Energy
Those are my real-time numbers as they exist now.
The intangibles: this is the rate for 20 years, no increase. There was no upfront cost.
The rebate from NV Energy will go down, along with the rate they pay once they reach certain caps from people who, install after us. Also the federal rebate will start to go down in 2020. So if you would like solar, do it now.
Tesla seems to be having Powerwall delay Issues(rumored 2019 wait times)we seemed to hit a sweet spot in the process. I would install Solar First, then add the battery. The IRS has ruled that, you can still get the rebate on the battery on a second install.
If you go solar only, your solar generation, along with the energy you send to the grid, will gain you a positive power generation. During the summer months you may have like me, a small amount. The amount I send to powerwall would be sent to the grid.
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