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FYI - Managing Power during an Outage

Randy Spencer

Active Member
Mar 31, 2016
3,287
3,183
Alameda, CA
We have a neighbor with one at our cabin in the Sierras. Always fun when the power goes out at midnight. I could just as happily slept until dawn before discovering the power is out. I don't need his generator cranking on the second the power fails waking us up. Sheesh. That said, it sure has helped them in the last two years of PSPSs and that big snow storm from January the power was off for more than 4 days, we just went home, but that is his home. Hopefully he got more propane after the outage, as it's also all he has for heat.
 
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Dukeybootie

Member
Nov 12, 2015
201
119
United States
we had natural gas throughout the crisis... our neighbors generacs worked well..

Good to know. I wonder if this was true throughout the state as well. When I lived on the East Coast and got an estimate for a Generac after Hurricane Irene, I was told our cul-de-sac did not have a large enough natural gas line for more than one house to have such a standby generator installed. Apparently the startup demand surge would have not been handled well in such a situation, leading to generator stalling and possible malfunction. These were homes built around 1900.

Anyway, I'm glad the Powerwalls exist now. If I lived on a larger property in a disaster prone area, I would definitely look into getting both PW and a Generac.
 

bob_p

Active Member
Apr 5, 2012
3,669
2,791
We moved to the Houston area last summer and had not yet looked into solar/powerwalls... Needless to say, I initiated the process yesterday -- so appreciate reading your experience. We don't have a pool (although we are considering putting one in).

The pool installer used by our builder did not understand variable speed pumps - we had to push hard to get them to use one of the main pool pump (which is used by the pool, spa and cleaner). But they went ahead and installed a fixed speed pump that runs continuously at the maximum speed of the main variable speed pump - so it sucks A LOT OF POWER.

At the time we designed the pool, we weren't considering solar - and didn't pay that much attention to the power consumption. We did make an investment in sprayed foam insulation for the house (which increases the insulation for the entire house, plus insulates the attics) - and we installed a zoned HVAC system in the upstairs, so we would only condition the rooms we were actually using. And both of those investments reduced energy costs.

But we didn't look as closely at the pool - and it turned out our pool pumps were using 30% of our electricity! Just the decorative waterfall fixed speed waterfall pump was using 15% of the electricity for our entire house - including charging a Tesla Model S and X!

If you are planning to install solar/PowerWalls - also do an assessment of where your power is going - and if you're planning to add a pool, you should factor that into planning for your solar/PowerWall system (since that will increase your energy consumption) and make sure the pool installer is being energy efficient in their choices for your equipment...
 

flywithdan

Member
Aug 12, 2019
5
2
Wisconsin
During this week's Texas power outage, we were fortunate to lose power only for 2.5 hours.

Though when the power went out, because it might be days before power was restored, and we may not have much sun for the next 36 hours, we immediately turned off everything we could in the house to reduce power consumption.

And we were able to get the power down to only 400W... We left our two large refrigerators running (with food in the freezers) along with our internet and network gear. I used the breaker panels to turn off the circuits that we weren't going to be using - and it was surprising how much power those circuits were using for devices that were plugged in but not being used.

Our pool pumps are the major power consumer at the house. The main pump is variable speed and usually uses around 800W. But the second pump that powers a decorative waterfall is fixed speed - and uses 2500W. And because the freeze protection is activated when temperatures are below 40 degrees (which has been the case for the past 4 days), we were getting a constant 3300W draw from just the pool equipment.

If the power outage had lasted longer, we would manually turn on the main pump only during overnight freezing temperatures.

For the waterfall pump, I turned off the power and drained it and covered it - and will be turning it on since the Texas grid appears to be working again.

We had planned for our system to handle extended outages after a hurricane - when it would be warm and we'd likely have sun (skies typically clear after a hurricane passes). What we didn't plan for was an extended outage in the winter - when heat would be needed - and the pool pumps need to run. And with the increased energy usage, without taking additional steps, our PowerWalls may not have had enough power to get us through an extended outage (due to cold temperatures and little solar power until skies cleared).

Lessons learned:
  • We'll replace the fixed speed pool pump with a variable speed pump that should be able to reduce power consumption by at least 2/3 - not only helping during an outage - but also when the pump is running normally.
  • In preparation for an extended outage, I'll mark the circuits in the breaker boxes that should be left on for essential systems - so it'll be easier to turn off the circuits with non-essential devices.
It also helped that we have an RV with it's own power generation (solar panels, lithium batteries, diesel generator) - which we could use in an emergency and evacuate from the house to the RV on the driveway, allowing us to drastically reduce power consumption inside the house.



we have the exact same pentair pump here in Seabrook. With a flow meter we found were pushing 38gpm at 1100rpm and 84watts. Running 247 at that speed keeps the pipes from freezing and our freeze protection is at 40F. Never had an issue during this past week. You may be pushing too much if you don’t have a flow meter. Before we installed a flow meter we were overestimating need. Hope this helps d
 

DuaneCastles

New Member
Feb 22, 2021
3
3
Selah, Washington
Here are some insights i did not know about the Texas energy market.
Five things to know about Texas's strained electric grid
They do not belong to any national interconnect. Only El Paso belongs to the Western Interconnect and they had less issues in El Paso because the got supplemental power from other states.
We are in eastern Washington State and have 82 panels and a Generac 24kw natural gas generator with a few limiters and we do the whole house. We went with this instead of Powerwalls as I am told our solar has to shut off in a power outage so not to send power back into the grid during repair efforts. So the powerwall wouldn’t recharge during an outage. Is that not the case in Texas? I called our gas provider and they said, duh, their pumping stations are all on gas no electricity, so baring an earthquake, which we have from time to time, we should be fine. So far so good. We get colder weather than Seattle in winter and hotter in summer and so far so good. Wind usually knocks out power. We have a Model X and S.
 
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KenC

Active Member
Sep 4, 2018
3,496
3,179
Maine
We have a neighbor with one at our cabin in the Sierras. Always fun when the power goes out at midnight. I could just as happily slept until dawn before discovering the power is out. I don't need his generator cranking on the second the power fails waking us up. Sheesh. That said, it sure has helped them in the last two years of PSPSs and that big snow storm from January the power was off for more than 4 days, we just went home, but that is his home. Hopefully he got more propane after the outage, as it's also all he has for heat.
Yeah, when we have an outage after midnight, having the standby generator turn automatically on seems a bit unnecessary. Would be nice to have a programmable option not to run between say 2am and 5am. In a long outage, I turn it off before going to bed, just to extend the fuel in my LP tanks, since you never know when a few days turns into 2 weeks.

As for the sound, I can't hear my standby generator when it turns on. I have a 12k GE model. I actually have to look at the UPS connected to my computer to see what the frequency is. If it's 60.0Hz, then it's utility power, if it's fluctuating, then it's my generator.
 
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jjrandorin

Moderator, Model 3, Tesla Energy Forums
Nov 28, 2018
8,232
9,081
Riverside Co. CA
We are in eastern Washington State and have 82 panels and a Generac 24kw natural gas generator with a few limiters and we do the whole house. We went with this instead of Powerwalls as I am told our solar has to shut off in a power outage so not to send power back into the grid during repair efforts. So the powerwall wouldn’t recharge during an outage. Is that not the case in Texas? I called our gas provider and they said, duh, their pumping stations are all on gas no electricity, so baring an earthquake, which we have from time to time, we should be fine. So far so good. We get colder weather than Seattle in winter and hotter in summer and so far so good. Wind usually knocks out power. We have a Model X and S.

You were told, or understood incorrectly. One of the whole points of having powerwalls (or other batteries) when you have solar is so that solar power has someplace to go when there is no grid. Powerwalls absolutely postivitely 100% do charge from solar during a power outage.

Thats the way the system works everywhere (not just texas).

I am not making any judgement at all about which backup technology is better because its a personal choice for each person, and both have their pros and cons. I just wanted to provide you with correct information about solar + powerwalls and charging during an outage.
 

KenC

Active Member
Sep 4, 2018
3,496
3,179
Maine
Will see.

But we are hearing that Generac installs in this area now have a 6+ month wait...
Where I live, you can order a wholehouse standby generator from HD or Lowes, and have your local electrician and plumber do the connections. I ordered mine from HD, over 10yrs ago, and helped my electrician buddy to do the wiring, and my local fuel company to do the gas connection. The install cost was about $750 in total.
 
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Bruce Person

Red Rover
Mar 2, 2020
41
15
95437
During this week's Texas power outage, we were fortunate to lose power only for 2.5 hours.

Though when the power went out, because it might be days before power was restored, and we may not have much sun for the next 36 hours, we immediately turned off everything we could in the house to reduce power consumption.

And we were able to get the power down to only 400W... We left our two large refrigerators running (with food in the freezers) along with our internet and network gear. I used the breaker panels to turn off the circuits that we weren't going to be using - and it was surprising how much power those circuits were using for devices that were plugged in but not being used.

Our pool pumps are the major power consumer at the house. The main pump is variable speed and usually uses around 800W. But the second pump that powers a decorative waterfall is fixed speed - and uses 2500W. And because the freeze protection is activated when temperatures are below 40 degrees (which has been the case for the past 4 days), we were getting a constant 3300W draw from just the pool equipment.

If the power outage had lasted longer, we would manually turn on the main pump only during overnight freezing temperatures.

For the waterfall pump, I turned off the power and drained it and covered it - and will be turning it on since the Texas grid appears to be working again.

We had planned for our system to handle extended outages after a hurricane - when it would be warm and we'd likely have sun (skies typically clear after a hurricane passes). What we didn't plan for was an extended outage in the winter - when heat would be needed - and the pool pumps need to run. And with the increased energy usage, without taking additional steps, our PowerWalls may not have had enough power to get us through an extended outage (due to cold temperatures and little solar power until skies cleared).

Lessons learned:
  • We'll replace the fixed speed pool pump with a variable speed pump that should be able to reduce power consumption by at least 2/3 - not only helping during an outage - but also when the pump is running normally.
  • In preparation for an extended outage, I'll mark the circuits in the breaker boxes that should be left on for essential systems - so it'll be easier to turn off the circuits with non-essential devices.
It also helped that we have an RV with it's own power generation (solar panels, lithium batteries, diesel generator) - which we could use in an emergency and evacuate from the house to the RV on the driveway, allowing us to drastically reduce power consumption inside the house.
I live in northern California along the coast and we lose power quite frequently due to all our trees. Now with planned outages due to wildfire prevention efforts it seems that it can happen at any time during fire season. When we first moved here we were made aware of this and so we installed a 16kw Generac generator with a 500 gallon propane tank (400 gallons useable) to feed it which is good for 24/7 for between 2 to 3 weeks. We pump our water and that is also used for our hot water heating system so no water, then no heat (in addition to no toilets, no showers, or other normal water usage). Question: Do some areas in Texas allow for generators? They don't bother us but they do make noise. As far as propane costs, we have never used more than 20% to 30% on any one outage so far. If I was to buy one now, I would probably buy the 20 or 22kw which is the smallest air cooled one since I now own a Tesla. However, I can simply change the charge current on the car and that would handle the car and still have enough for computers, fridge, and water pumps/filtration systems. On the news, I didn't hear any mention of propane fed generators. Our hospital uses these as well as many houses in our area.
 
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h2ofun

Active Member
Aug 11, 2020
2,212
342
auburn, ca
I live in northern California along the coast and we lose power quite frequently due to all our trees. Now with planned outages due to wildfire prevention efforts it seems that it can happen at any time during fire season. When we first moved here we were made aware of this and so we installed a 16kw Generac generator with a 500 gallon propane tank (400 gallons useable) to feed it which is good for 24/7 for between 2 to 3 weeks. We pump our water and that is also used for our hot water heating system so no water, then no heat (in addition to no toilets, no showers, or other normal water usage). Question: Do some areas in Texas allow for generators? They don't bother us but they do make noise. As far as propane costs, we have never used more than 20% to 30% on any one outage so far. If I was to buy one now, I would probably buy the 20 or 22kw which is the smallest air cooled one since I now own a Tesla. However, I can simply change the charge current on the car and that would handle the car and still have enough for computers, fridge, and water pumps/filtration systems. On the news, I didn't hear any mention of propane fed generators. Our hospital uses these as well as many houses in our area.
I got a 22K last year. They now make a 24K which I would have gotten. What is nice with the larger units, is not matter what load you put on them, then do not bog down. My installer will not install 16K's anymore since he has seen them bog down.

Mine is also connected to a 500 gallon propane tank. Once I get batteries, I am ready for anything northern calif can throw at us. And yep, wife wants power. Now power, our sewer up the hill pump does not work, even though we have water pressure. Cheap, nope. But happy wife, happy life.
 
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DuaneCastles

New Member
Feb 22, 2021
3
3
Selah, Washington
You were told, or understood incorrectly. One of the whole points of having powerwalls (or other batteries) when you have solar is so that solar power has someplace to go when there is no grid. Powerwalls absolutely postivitely 100% do charge from solar during a power outage.

Thats the way the system works everywhere (not just texas).

I am not making any judgement at all about which backup technology is better because its a personal choice for each person, and both have their pros and cons. I just wanted to provide you with correct information about solar + powerwalls and charging during an outage.
So the solar array is just cut off from the grid during an outage but charges the powerwalls?
 

Bruce Person

Red Rover
Mar 2, 2020
41
15
95437
I got a 22K last year. They now make a 24K which I would have gotten. What is nice with the larger units, is not matter what load you put on them, then do not bog down. My installer will not install 16K's anymore since he has seen them bog down.

Mine is also connected to a 500 gallon propane tank. Once I get batteries, I am ready for anything northern calif can throw at us. And yep, wife wants power. Now power, our sewer up the hill pump does not work, even though we have water pressure. Cheap, nope. But happy wife, happy life.
We got our generator once we had an outage and my wife couldn't open the garage door to get to Starbucks. Enough said.
 

Ampster

Active Member
Oct 5, 2012
1,758
472
Sonoma, California
So the powerwall wouldn’t recharge during an outage.
As others explained earlier, the Powerwalls are AC coupled to a grid tie solar system and the gateway isolates from the grid so the Powerwalls would be charged from the solar system.
The problem in Texas was that the supply of natural gas was reduced significantly because moisture in the gas lines froze and restricted or shut off the flow of gas to the generating stations. Some of thee wind turbines also froze because they were not winterized. Wind turbines that are winterized work fine in Vermont, Antartica and other places that get colder than Texas. If anybody had Powerwalls in Texas all they would have had to do is clear off the snow from the panels and they should have had power and been able to charge Powerwalls.
 

h2ofun

Active Member
Aug 11, 2020
2,212
342
auburn, ca
We got our generator once we had an outage and my wife couldn't open the garage door to get to Starbucks. Enough said.
Yep. They changed code in like July 2019 that states any new garage door or opener installed, MUST have battery backup included. During the fires, many could not get their garage doors open. Now was not planning on changing my 3, but when the wife just ran into one that did not open all the way, well, we are now getting 3 new garage doors and new openers. So we will be covered whether the generator, powers, grid are running or not. :(
 
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MorrisonHiker

S 100D 2021.4.15
Mar 8, 2015
9,582
8,796
Colorado
So the solar array is just cut off from the grid during an outage but charges the powerwalls?
The solar can charge the Powerwalls and power the house when the grid is down. Our Powerwalls have gotten us through several multi-day outages and an 8 day off-grid test, no problem. During the 8 day off-grid test, we had a snowstorm with over 8" of snow. Once I cleared off a few of the panels, the solar system worked fine to charge the Powerwalls back up.
 

bob_p

Active Member
Apr 5, 2012
3,669
2,791
When the Tesla Gateway detects the grid is down, excess solar power is used only to charge the PowerWalls. And when the PowerWalls get near to full, the Gateway changes the power frequency above 60Hz, which causes the solar power inverters to shut off, so no power from the solar panels will even be sent into the Gateway.

During an outage - no power is sent to the grid.

---

We live in the Houston area. Generators will usually run off the same gas lines that go into the houses for use in appliances and HVAC systems.

We have the only solar panels on our street. Two houses next to us have gas generators. When we lost power, we switched over to our PowerWalls - and for those houses, their generators kicked on - and you can definitely hear them running.

As far as I know, our area did not have any problems with natural gas lines.

Our concern was that when our power went out, the "authorities" were indicating new outages could last days - and with the prospect of little sun for the next day, we took steps to drastically reduce consumption, just in case we needed to run off the PowerWalls for more than 24 hours. Our neighbors with the generators were fine and only had to worry if the natural gas lines went down - which haven't happened as long as I can remember in our area - even after hurricanes, the natural gas lines have worked.
 

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