Newbie, just got Powerwall installed

[rjdunn]

Hi all,

I’m a newbie here. Just got my Powerwall installed this week. So far so good. I have a modest solar system, 4.35 kW and one Powerwall, located on the North Carolina coast. I’m 100% self consumption (but with a grid connection), as my utility (a coop) doesn’t do net metering. I’ve got very low power costs, and my motivation is more altruistic than financial (my average power cost is under 10 cents per kWh). I’ve been reading a number of threads and have already learned a lot, thanks! I currently have my system (Powerwall running 1.17.2) set in self-powered mode with a 25% backup reserve. I may reduce that but it was a place to start. Reading the issues with delivery, I feel fortunate that my installer got me a Powerwall allocated in only 4 months after ordering (in mid-February).

Y’all don’t kick me out, now, but my EV is a Chevy Bolt

-Joel

 

[Babaron]

Congratulations Joel and welcome to the forum! I am also getting a Tesla set up with Powerwall . I am in the early stages of waiting for final blue printing and contract. I expect the install will take place in September. I don't expect to get my power wall for some months but hopefully my advisor can do magic like yours did.

I love the idea of going solar just because it's the right thing to do for the planet. But also, here in West Central Florida, the financial incentives are there as well.

I hope all works well for you and please keep us updated.

Ron

 

[gavine]

How do you like your Chevy Bolt?

 

[rjdunn]

Love the Bolt, Gavine. Good performance, range is about 275-300 in the summer, about 210-220 in the winter. I’m 6’5” and 230 pounds, and have no trouble sitting in the front or back seats. I like the hatchback style.

I started looking seriously at EVs when Tesla announced the Mod 3, but it became pretty clear to me I’d be waiting a long time, so I jumped on the Bolt. Paid $36K out the door, so that’s $28.5K after tax. Took the left over $ to buy my solar and Powerwall ;-)

-Joel

 

[rjdunn]

Following up on my first full day in self-powered mode, here’s an interesting annotated shot from the Tesla app. Today is a cloudy day, poor solar output. Still had 37% charge added to Powerwall (over 25% backup reserve) over the house usage (cool day, no air conditioning). The Powerwall should have enough energy stored to run the house until midnight or so. If it had a 100% full charge, should be close to enough to get to daylight tomorrow.



-Joel

 

[rjdunn]

One question that I’d had when I started the Powerwall installation was whether the max power supplied to the house would be the 5 kW from the Powerwall or the combination of the instantaneous output from the panels and the Powerwall. I was pleased to learn it was the latter. Here are two pictures, one showing the 5 kW plus solar plus grid, and another showing 4.5 kW plus solar.

Hope this helps someone!

 

[Rockster]

I'm envious. I really want a Powerwall, just because they're cool. I have a 10k system but with two EVs and two air conditioner units in Texas, the 10k system only offsets about 2/3 of our electricity usage. The fact that I rarely produce surplus and our cost per kWh is an average of $0.10 with no TOU, it's hard to justify adding a Powerwall to the system.

 

[rjdunn]

I'm envious. I really want a Powerwall, just because they're cool. I have a 10k system but with two EVs and two air conditioner units in Texas, the 10k system only offsets about 2/3 of our electricity usage. The fact that I rarely produce surplus and our cost per kWh is an average of $0.10 with no TOU, it's hard to justify adding a Powerwall to the system.

Agreed, it’s cool, Rockster and my wife and I say that watching the power flow is like a video game, but also, like you it’s a loooong payback for us if at all. My power cost averages less than $.10 with no TOU. I need more panels on my system as I have 3 HVACs; maybe next year. However, what the Powerwall does is in those intervals when 0 or 1 HVAC is running and there is momentarily extra capacity, I capture that power and use it on the next HVAC cycle. In the fall and spring, with no heat or A/C, the Powerwall will run the house all night, insofar as I can tell from the couple of “open windows” days we’ve had recently.

It’s a good thing to do, tho, and helps to move the industry and pices will drop.

-Joel

 

[nwdiver]

Following up on my first full day in self-powered mode, here’s an interesting annotated shot from the Tesla app. Today is a cloudy day, poor solar output. Still had 37% charge added to Powerwall (over 25% backup reserve) over the house usage (cool day, no air conditioning). The Powerwall should have enough energy stored to run the house until midnight or so. If it had a 100% full charge, should be close to enough to get to daylight tomorrow.

View attachment 315600

-Joel

Have you looked into heat pump water heaters? Their peak draw is ~500w and they use ~70% less energy overall. I know Rheem is wifi connected and you can schedule it to heat during solar hours to maximize self-consumption.

Rheem @ Home Depot

My local utility currently has a $500 rebate for these... yours might offer something too...

 

[rjdunn]

Agreed, it’s cool, Rockster and my wife and I say that watching the power flow is like a video game, but also, like you it’s a loooong payback for us if at all. My power cost averages less than $.10 with no TOU. I need more panels on my system as I have 3 HVACs; maybe next year. However, what the Powerwall does is in those intervals when 0 or 1 HVAC is running and there is momentarily extra capacity, I capture that power and use it on the next HVAC cycle. In the fall and spring, with no heat or A/C, the Powerwall will run the house all night, insofar as I can tell from the couple of “open windows” days we’ve had recently.

It’s a good thing to do, tho, and helps to move the industry and pices will drop.

-Joel

The other thing I didn’t add on the value prop, tho, is that there is value in having the whole house backup for the fridges, etc. Gotta keep the beers cold in the south! Do you compare that against a wired standby generator with an automatic transfer switch. The first night I had it online, I had a short power interruption and the Powerwall kicked in.

 

[rjdunn]

Have you looked into heat pump water heaters? Their peak draw is ~500w and they use ~70% less energy overall. I know Rheem is wifi connected and you can schedule it to heat during solar hours to maximize self-consumption.

Rheem @ Home Depot

My local utility currently has a $500 rebate for these... yours might offer something too...

I’ve looked at that, but with just two of us at the house now, we usually only have 2 or 3 short cycles with the water heater. My utility does offer a rebate on them, but I’d actually be more likely to think about direct solar water heating if I do anything...

The HVACs are my biggest power hog. I need to put in new ones that hopefully will be more efficient. By 2020 I need to replace as I’m using R22 refrigerant in them...

The attached snapshot is my more normal consumption pattern. Most of the load is HVAC with the water heater lost in the noise ;-)

-Joel

 

[rjdunn]

I’ve looked at that, but with just two of us at the house now, we usually only have 2 or 3 short cycles with the water heater. My utility does offer a rebate on them, but I’d actually be more likely to think about direct solar water heating if I do anything...

The HVACs are my biggest power hog. I need to put in new ones that hopefully will be more efficient. By 2020 I need to replace as I’m using R22 refrigerant in them...

The attached snapshot is my more normal consumption pattern. Most of the load is HVAC with the water heater lost in the noise ;-)

-Joel

If you look carefully you can see the pattern with one, two, or three HVACs. In the morning from 9-11 I also put about 6 kW into the car...

 

[nwdiver]

I’ve looked at that, but with just two of us at the house now, we usually only have 2 or 3 short cycles with the water heater. My utility does offer a rebate on them, but I’d actually be more likely to think about direct solar water heating if I do anything...

The HVACs are my biggest power hog. I need to put in new ones that hopefully will be more efficient. By 2020 I need to replace as I’m using R22 refrigerant in them...

The attached snapshot is my more normal consumption pattern. Most of the load is HVAC with the water heater lost in the noise ;-)

-Joel

True; Heat pump water heaters just tend to come out on top in the cost/benefit calculation but if hot water is rarely used it's not as beneficial. It's usually a quick install and they aren't too expensive. Solar water heating tends to be cost prohibitive when compared to a heat pump.

Looks like you're already pretty much self-sufficient so any further improvements would just be for 'bragging rights'