Clarity, Soul and Solar

[Landshark]

On your system do the DC Panels pass through a charge controller, charge the batteries and then the inverter is on the battery side of things?

The inverter (Outback Radian) has inputs from the batteries, (post charge controllers), grid and generator, yet to be installed. Output goes to “essential loads” through a sub-panel. It is not a whole house back up. We have net metering, so we don’t “sell” to the power company. Any and all surplus will be a credit on future bills.

 

[David Towle]

It was for backup and self sufficiency and its all of the above type of thing and Independence isn’t free

But it just seems like a huge waste of valuable resources to not use the same batteries for both your car (which cycles near daily) and backup (which gets 0-2 uses per year or so)

 

[LegoZ]

But it just seems like a huge waste of valuable resources to not use the same batteries for both your car (which cycles near daily) and backup (which gets 0-2 uses per year or so)

Seems like a waste to get a car I don’t want to haul around a much larger battery than needed and use more energy per mile all for a solution that isn’t even widely available yet. All while still not fulfilling all use cases or dealing with the fact that there are no plans currently being offered that are full net metering currently in the Oncor service area here in Texas. So in 2023, unless something changes, the best case will be credit for exported energy capped at my monthly usages (no rollover at at) and worst case will be no credit whatsoever. Also using the truck as energy storage to power my home during Peak and at night would leave me with a depleted battery in the morning when I would need a vehicle. Yes V2G/V2L/V2G is an important part of the solution but it is not a solution for everyone or all use cases. I AM definitely keeping my eye on Quasar 2 for V2G/V2L/V2G for my future vehicles.

 

[Landshark]

But it just seems like a huge waste of valuable resources to not use the same batteries for both your car (which cycles near daily) and backup (which gets 0-2 uses per year or so)

Without batteries the house has no backup. Using a car battery would require the car to be at the house, at all times, during a power outage. That isn’t always convenient.

 

[LegoZ]

I think a cool idea would be to have a system where you could stow part of the pack at home as additional home backup and grid storage for peak offloading. You can day to day have something like x miles range and way less weight and then if you go in a trip push a button and the pack gets installed in the car.

 

[Landshark]

So in 2023, unless something changes, the best case will be credit for exported energy capped at my monthly usages (no rollover at at) and worst case will be no credit whatsoever.

At a quick glance it looks as though your system would allow you to remain off-grid for at least 8 months, Mar-Oct, at your current power consumption levels. Perhaps all year if you have a “survival mode” at the ready for the lower solar production months in winter. If the power company does go the no credit route, you can always play the off-grid game and give them none of your electricity and use none of theirs.

You do use a bit of juice. What is your primary source of heat? Do you have alternative heating options?

 

[LegoZ]

At a quick glance it looks as though your system would allow you to remain off-grid for at least 8 months, Mar-Oct, at your current power consumption levels. Perhaps all year if you have a “survival mode” at the ready for the lower solar production months in winter. If the power company does go the no credit route, you can always play the off-grid game and give them none of your electricity and use none of theirs.

You do use a bit of juice. What is your primary source of heat? Do you have alternative heating options?

Gas for heat, cooktop (that I try to keep my wife from using) and hot water. Electric dryer, oven, two of us full time work from home, two car I shove electrons into as soon as the powerwalls are full and heavy AC usage (68°F at night). Also with bad allergies in the house have a bunch of hepa running and a dehumidifier to keep humidity below at or below 50%.

When my central dies I am looking to go variable speed setup heat pump that hopefully will allow me to ditch the dehumidifier. Also ventilation in my house is fresh air intake only not an ERV/HRV which I eventually plan to change.

There are still a few option although not as good as I have it now, if octopus reenters the market in October they have a real time wholesale buyback that is a refundable credit with no caps with a fixed buy amount. If not I may go with a free nights 8p-5:59a and let the Tesla system manage that. Some of the REP are getting wise though and blocking customers with on-site generation. So we will have to see how long that lasts.

 

[Landshark]

heavy AC usage (68°F at night).

Holy smokes! We cool to 78F and sometimes allow the house to hit 80F. Southern Oregon summers are relatively dry. Typically, we don’t even run the A/C until daytime temperatures are consistently above 90F and even then, the house won’t hit 80F until late afternoon. Morning temperatures will be upper-50’s to low-60’s, so we open windows and “icebox” the house until we hit equilibrium, maybe 70-72F inside and out, then close the windows.

When temperatures top 100F, or wildfire smoke is present, we seal it up and run the A/C as needed.

 

[LegoZ]

74-76° here daytime. 78° way too hot my son’s fish tank overheats. While more dry than IL it’s still too humid to not run AC and be comfortable. We also have to deal with the air quality in the metroplex so things are usually sealed up. I also have a enough solar and batteries to basically be able to do whatever I want without touching the grid lol.

now on the heat side we are at 63° at night and used to be 68° during the day but that has crept up to 72° since I’m on my butt for work.

 

[Landshark]

We’re looking at 10 more days of no A/C, maybe a little heat at night. With this weather the house would probably stay between 64-72 with no HVAC.
Our highest usage is Dec-Jan, around 1000kWh’s/month, with a 14 year old heat pump being the largest single load. Of course those are the lowest solar production months as well. The heat pump won’t run off the batteries, but once the propane generator goes in we could dial up the heat for an hour or two while simultaneously charging the batteries and then revert to battery power. Rinse and repeat.

 

[LegoZ]

We’re looking at 10 more days of no A/C, maybe a little heat at night. With this weather the house would probably stay between 64-72 with no HVAC. View attachment 16619
Our highest usage is Dec-Jan, around 1000kWh’s/month, with a 14 year old heat pump being the largest single load. Of course those are the lowest solar production months as well. The heat pump won’t run off the batteries, but once the propane generator goes in we could dial up the heat for an hour or two while simultaneously charging the batteries and then revert to battery power. Rinse and repeat.

That’s really nice.

 

[David Towle]

When my central dies I am looking to go variable speed setup heat pump that hopefully will allow me to ditch the dehumidifier. Also ventilation in my house is fresh air intake only not an ERV/HRV which I eventually plan to change.

Yes we have a variable speed heat pump and it does much better for dehumidifying than single speed. In Florida we use 79F at night and 81F in the day and humidity never leaves 40-50% in season. It runs pretty much constantly all day in the summer so you have constant air movement too.

 

[LegoZ]

Yes we have a variable speed heat pump and it does much better for dehumidifying than single speed. In Florida we use 79F at night and 81F in the day and humidity never leaves 40-50% in season. It runs pretty much constantly all day in the summer so you have constant air movement too.

Oh that’s awesome! Humidity loading is more than likely much higher there so if it is working well there it should be able to handle here.

 

[David Towle]

Oh that’s awesome! Humidity loading is more than likely much higher there so if it is working well there it should be able to handle here.

I assume you realize you could get lower humidity with your existing system by slowing down the air blower? Many you can do by connecting the blower leads to different terminals on the control board, or changing switch settings, or if that's not available you maybe can change v-belt drive pulleys if its not direct drive. They sell adjustable size pulleys to fine tune it.

 

[LegoZ]

I assume you realize you could get lower humidity with your existing system by slowing down the air blower? Many you can do by connecting the blower leads to different terminals on the control board, or changing switch settings, or if that's not available you maybe can change v-belt drive pulleys if its not direct drive. They sell adjustable size pulleys to fine tune it.

I'll have to look into this more I believe the fan speed for ac is set to the highest setting. Thanks for bringing this up as I never knew this!

 

[David Towle]

I'll have to look into this more I believe the fan speed for ac is set to the highest setting. Thanks for bringing this up as I never knew this!

The slower the air moves, the closer it gets to the coil temperature (about 38F), the more water drops out, and the lower the outgoing air dew point becomes. You will sacrifice a small amount of cooling capacity but its worth it, you will feel cooler at the lower humidity, you might even be able to increase the temperature a bit and feel fine. The main potential disadvantage is distribution, you may have to close some vents a bit to force the air to the furthest reaches of the system.