Separate company for Solar -vs- Powerwall

[jjrandorin]

Question. In the event of a power loss from bad weather or what have you; if you have solar panels and a Powerwall setup do you still store power during the outage? I know that in many states when the grid goes down those who have solar panels loose power as well. I am hoping this is not tru for those who pay a premium for Powerwall solar energy storage.

Yes, you still "store power" during an outage if you have solar power (PV) and battery storage (powerwalls). Your home becomes its own "microgrid". Your solar will still generate power, and power your home, and fill your powerwalls until they are full. When the powerwalls are full, the powerwalls will shut down the solar (because the power has no place to go). The powerwalls will continue to power the home, draining some battery power, and then when they have drained a bit of battery power, if there is still sun the powerwalls will let the PV (solar) turn back on.

That off / on of solar will repeat if powerwalls are full. If they are NOT full, the solar will power the home and fill the powerwalls until they are full, or until there is no sun.

The short answer is, you become your own grid when you have powerwalls and PV, and the solar fills the PV until its full or there is no more sun. if you have enough sun, and sized your system appropriately (have enough storage) you can run for quite a while that way (measured in days)... again depending on system size, and sun, and home loads, and number of powerwalls.

 

[Madjawa889]

Awesome ! The answer I was looking for; the only other question I have to sort out is compatibility with local solar company I.e. the solar panels I inherited when I purchased my house. My house was built in 2001 and the previous owners leased out solar two years prior to my purchasing the property. All I am saying is if I can tap into my solar panels and store my own enegery with powerwalls “micro grid” I am all for it!

 

[holeydonut]

Yes, you still "store power" during an outage if you have solar power (PV) and battery storage (powerwalls). Your home becomes its own "microgrid". Your solar will still generate power, and power your home, and fill your powerwalls until they are full. When the powerwalls are full, the powerwalls will shut down the solar (because the power has no place to go). The powerwalls will continue to power the home, draining some battery power, and then when they have drained a bit of battery power, if there is still sun the powerwalls will let the PV (solar) turn back on.

That off / on of solar will repeat if powerwalls are full. If they are NOT full, the solar will power the home and fill the powerwalls until they are full, or until there is no sun.

The short answer is, you become your own grid when you have powerwalls and PV, and the solar fills the PV until its full or there is no more sun. if you have enough sun, and sized your system appropriately (have enough storage) you can run for quite a while that way (measured in days)... again depending on system size, and sun, and home loads, and number of powerwalls.

Adding to this post... Madjawa889 you're right if you only had PV (with no isolated micro-grid in your home) then when the utility fails your PV is automatically de-activated and cannot power your home. This ensures the public lines are de-energized since the cause of the outage may be local, and crews need to be able to work on the grid without worrying about getting electrocuted by your solar array.

Even if you had a monster PV array that could energize a few circuits in your home during a daytime outage, your typical PV-only installation would be out of luck.

As jjrandorin said, the battery backup solutions create a "microgrid" that is basically disconnected from the main grid when the utility fails. Assuming your PV + Battery combination is sized correctly to your usage, you should be able to generate enough energy with your solar in the daytime to run your microgrid; and then have some left-over energy to operate select items after sunset. Most people would probably curtail their energy use if the outage were to last a long period of time.

Also, backup generators could help provide extra juice after the sun sets if your PV can't generate enough during the daytime to prevent your microgrid from having a deficit per 24-hour cycle. Tesla lets you run PV + Powerwall + Generator. As you'd imagine, you can't charge the Powerwall with a Generator during an outage, but the Generator can power your house to give the Powerwall more time to recharge from the PV.

 

[DrSmile]

You can run completely off grid with solar and Powerwalls assuming they are properly size matched, meaning the solar doesn't overrun the charging rate of the Powerwalls. The gateway will shut down the solar when the Powerwalls get full and turn the solar back on when they start to deplete (usually around 90% full, so it cycles pretty rapidly if you're using some electricity). You can throw a breaker in the Gateway and run this way even when the grid is up. It's a pretty perfect setup when working.

 

[Madjawa889]

So if I am tracking; theirs a difference between the acquisition and utilization of solar power (PV)? My solar panels are connected to the grid; as we speak I am sitting in a dark house because we lost power do to that tropical depression moving up the east coast. In this situation in my understanding would I have to have separate panels to power the Powerwall? Ultimately excluding the panels I am currently leasing from my solar company?

 

[holeydonut]

So if I am tracking; theirs a difference between the acquisition and utilization of solar power (PV)? My solar panels are connected to the grid; as we speak I am sitting in a dark house because we lost power do to that tropical depression moving up the east coast. In this situation in my understanding would I have to have separate panels to power the Powerwall? Ultimately excluding the panels I am currently leasing from my solar company?

Yeah unfortunately for you the PV system is in effect disconnected from your home since you're grid-tied to your public utility and you have no "micro-grid" for your home.

You'll have to check with your solar lease to see if they will allow you to install a battery solution whereby the PV can be used to charge your batteries or run your house. But assuming the lease isn't too strict; qualified installers should be able to create the micro-grid that jjrandorin talked about. So when the utility goes offline you can then power your house using PV + Battery or use PV to charge your batteries.

With the Tesla Gateway your house will switch seamlessly between these two conditions.

 

[jjrandorin]

So if I am tracking; theirs a difference between the acquisition and utilization of solar power (PV)? My solar panels are connected to the grid; as we speak I am sitting in a dark house because we lost power do to that tropical depression moving up the east coast. In this situation in my understanding would I have to have separate panels to power the Powerwall? Ultimately excluding the panels I am currently leasing from my solar company?

My solar is leased... it is through solar city (which tesla bought). As long as you still are making your payments and the solar leasing company can see your production, they likely wont care.

While my solar is leased, I purchased the powerwalls outright.

One of the most frustrating things that happened to me last year (home related anyway), was the couple of power outages I had last year, one for just under 3 days total time (food spoiled, etc) when the days were bright and sunny, and I knew I had solar on my home that "could have been" powering my home, but could not because of the danger to the linemen repairing, etc.

So, I feel your pain... Now that I have powerwalls I would never personally have solar without them again, by choice.

 

[DrSmile]

So if I am tracking; theirs a difference between the acquisition and utilization of solar power (PV)? My solar panels are connected to the grid; as we speak I am sitting in a dark house because we lost power do to that tropical depression moving up the east coast. In this situation in my understanding would I have to have separate panels to power the Powerwall? Ultimately excluding the panels I am currently leasing from my solar company?

I don't see why the lease holders wouldn't allow you to use the panels for the Powerwall. The panels will produce more power than before because without the Powerwall the system would be off. But obviously that's up to them. Leasing panels seems like a bad idea, financing them makes a little more sense.

 

[jjrandorin]

I don't see why the lease holders wouldn't allow you to use the panels for the Powerwall. The panels will produce more power than before because without the Powerwall the system would be off. But obviously that's up to them. Leasing panels seems like a bad idea, financing them makes a little more sense.

I agree buying them makes more sense. In 2015 when I was looking at this, I didnt have the money to buy them, and really wanted solar. While I would prefer to have purchased it back in 2015, having solar (even on a lease) saved me a ton of money every month, even from install. The way I looked at it back then was, I was just swapping power companies, with a guaranteed price per kWh for the solar I generated.

I am going to look to either buy the system out next year or see if they will let me out of the lease early to put up a new larger system I purchase. My current system covers about 90% of my yearly needs including the car, but I didnt get the EV until the end of 2018 and previous to that it generated about 110% of my yearly usage.

 

[jjrandorin]

So if I am tracking; theirs a difference between the acquisition and utilization of solar power (PV)? My solar panels are connected to the grid; as we speak I am sitting in a dark house because we lost power do to that tropical depression moving up the east coast. In this situation in my understanding would I have to have separate panels to power the Powerwall? Ultimately excluding the panels I am currently leasing from my solar company?

If I am understanding the question you are asking, no, you would likely NOT "have" to get new solar panels to purchase tesla powerwalls. One of the big draws of tesla powerwall batteries is that they have their own inverter inside of them, which in laymens terms means that they can be connected to most solar systems that are "grid tied". "Grid Tied" means "connected to the electrical grid, which most homes are. People that are not grid tied, know it.

If you pay an electrical bill to some company, you are grid tied, thus powerwalls should work for your existing system. You still need to know how much power your current system generates, whether that is "enough" to run your home the way you would like to in a power outage, and how many powerwalls you need to go with it.

In general, 1 powerwall = a backup to run your refrigerator and regular outlets in a typical home (regular outlets you plug things into like phones, etc). 1 Powerwall is likely not running any electric oven, dryer, heater, etc.

Anyway, you should be able to purchase powerwall or powerwall(s) and connect them to your existing solar, whether its leased or not shouldnt matter because you will still be making payments on the solar in either case.

 

[Madjawa889]

If I am understanding the question you are asking, no, you would likely NOT "have" to get new solar panels to purchase tesla powerwalls. One of the big draws of tesla powerwall batteries is that they have their own inverter inside of them, which in laymens terms means that they can be connected to most solar systems that are "grid tied". "Grid Tied" means "connected to the electrical grid, which most homes are. People that are not grid tied, know it.

If you pay an electrical bill to some company, you are grid tied, thus powerwalls should work for your existing system. You still need to know how much power your current system generates, whether that is "enough" to run your home the way you would like to in a power outage, and how many powerwalls you need to go with it.

In general, 1 powerwall = a backup to run your refrigerator and regular outlets in a typical home (regular outlets you plug things into like phones, etc). 1 Powerwall is likely not running any electric oven, dryer, heater, etc.

Anyway, you should be able to purchase powerwall or powerwall(s) and connect them to your existing solar, whether its leased or not shouldnt matter because you will still be making payments on the solar in either case.

Awesome thank you kindly for your insight!