[KSchneider]

We have 15 solar panels on our garage that are rated at 5.4 kW. For the past 4 years they have made our house Net Zero. The Solterra will change the dynamics. There is lots of interest in this forum on data so I am sharing some solar data on a sunny day.

Pink = imported kW's / Blue = Self-Consumption kW's / Green = Exported kW's.
X-axis = time
starting at midnight at the left end of the X-axis is imported kW. The surge around 7 am is when i turned on my espresso machine. At 1:15 the 1.79 kW consumption is the clothes dryer and 2.5kW export. The pink spike to the right is the beginning of charging at 2 pm.

1:45 dryer done and 4+ kW export.

At 2:30 7.75 kW consumption. Almost all is battery charging minus ca. 300 W for the house. The Solterra charger is eated at 6.6 kW. I do not have a smart app to report actual charging data.

One goal is to use as much of formerly exported kW's as possible for charging. Pre-Solterra the self-consumption / export has been 37/63.

 

[Ducatista]

Love this. Thanks for sharing!

 

[KSchneider]

In ca. 2.75 hours ca. 18.6 kWh / 26% were added. That is ca. 6.6 kWh / hour. The ambient temp. was 54ºF at the end of charging.

 

[JayEM]

Your SolarEdge app shows you all that detail? You must have a newer/smarter inverter than we do.

 

[KSchneider]

Your SolarEdge app shows you all that detail? You must have a newer/smarter inverter than we do.

We have a 2018 Solar Edge inverter. It also has a 9.8 kW LGbattery back-up supporting a drainage system for our basement. Our data comes through a cell phone connection that posts every 15 mins. The house was newly built in 2018 and meets the German Passive House standards. It is unquestionably a high-performance house using 10% tje eergy of new construction today. The Solterra is just the latest step in having a carbon "toe-print".

 

[KSchneider]

More data from today.

Here is the whole day so far. The blue is what we want to see.

This is yesterday. The green is great but it would be better as blue (self-consumption).

 

[JayEM]

We have a 2018 Solar Edge inverter. It also has a 9.8 kW LGbattery back-up supporting a drainage system for our basement. Our data comes through a cell phone connection that posts every 15 mins. The house was newly built in 2018 and meets the German Passive House standards. It is unquestionably a high-performance house using 10% tje eergy of new construction today. The Solterra is just the latest step in having a carbon "toe-print".

Hmm, our inverter is 2018 too, but we don't have any battery backup.

Our 24 modules/6.0 kW inverter provides about 90% of the electricity used by our 1991 "high efficiency" home, 80% when including EV charging. But we're not all electric, that wasn't really a thing in the late 80s/early 90s when we were planning the home.

 

[KSchneider]

Our house is all-electric. 1500 sq. ft. plus full basement (wine cellar +). The whole uses only 6 mWh / year and 5.4 kW panels make 7 mWh / year. I estimate our use of the Solterra will need an additional 3.5 mWh (= half as much as the whole house). High perormaance house tech inproves as do computers. Our previous 1904 farmhouse in 2011 had 54 solar panels = 12.09 kW and with a geothermal was close to Net Zero. What you did in 1991 was amazing.

 

[JayEM]

Our house is substantially larger than yours, close to double the sq. ft. in fact (so not "green" in that sense), + 1500 sq. ft. basement + 3 car heated garage (radiant floor heat, as in the rest of the house). We're far from net zero, but our house uses substantially less MMBTU of gas and kWh of electricity than any of our neighbors. Annual energy use is about 80 MMBTU on the gas side (800 therms) and gross electricity use is around 10 MWh (including EV charging at 1.5 MWh, and pool pump in the summer). Total annual solar production is around 8 MWh, hence the 80% solar. If our gas use (water/space heating + clothes dryer) was kWh (assuming no efficiency gain from e.g. heat pumps) that would add another 23 mWh to the equation, for a total of 33 Mwh... so our solar % on that basis drops to just 25%. This just illustrates what a huge mountain we have to climb to get our entire economy to anywhere near net zero. It's a real challenge, but we can move in only one direction. Or, I should say, we NEED to move in only one direction.

 

[KSchneider]

This just illustrates what a huge mountain we have to climb to get our entire economy to anywhere near net zero. It's a real challenge, but we can move in only one direction. Or, I should say, we NEED to move in only one direction.

Yes it is a huge mountain. Fortunately we can do the climbing one step at a time. We started replacing the 100 year old windows in our farmhouse. When that was done we wanted to get rid of the propane heat (natural gas not available). Replaced propane with geothermal, But the geothermanl needed beletric backup for really cold days. That led to installing solar panels. When we left that house it was close to net zero. Built the current one from the start with the top priority as net zero. German passive house standards and only 15 solar panels and a tiny heat pump (12,000 btu's) do that. In the process had the opportunity to make a passive wine cellar in the basement that uses coolness from ground below and no power other than light. The Solterra is the latest big step.

 

[Greg M]

We have 15 solar panels on our garage that are rated at 5.4 kW. For the past 4 years they have made our house Net Zero. The Solterra will change the dynamics. There is lots of interest in this forum on data so I am sharing some solar data on a sunny day.
View attachment 1883

Pink = imported kW's / Blue = Self-Consumption kW's / Green = Exported kW's.
X-axis = time
starting at midnight at the left end of the X-axis is imported kW. The surge around 7 am is when i turned on my espresso machine. At 1:15 the 1.79 kW consumption is the clothes dryer and 2.5kW export. The pink spike to the right is the beginning of charging at 2 pm.



View attachment 1885

1:45 dryer done and 4+ kW export.

View attachment 1886

At 2:30 7.75 kW consumption. Almost all is battery charging minus ca. 300 W for the house. The Solterra charger is eated at 6.6 kW. I do not have a smart app to report actual charging data.

One goal is to use as much of formerly exported kW's as possible for charging. Pre-Solterra the self-consumption / export has been 37/63.

Ahahaha! My reasoning exactly!

 

[KSchneider]

The charging from home solar is working very well. A short top up of battery yesterday. At 11:45 7.664 kW was being used. Of that all 4.523 kW from panels (blue) was being used plus 3.141 kW (pink) from the "grid". Non-charging uses at that period would be 300W or fewer. The panels are rated at 5.4 kW. The max. I have seen is 5.983 kW. 5 kW or higher is rare.

 

[md.]

The charging from home solar is working very well. A short top up of battery yesterday. At 11:45 7.664 kW was being used. Of that all 4.523 kW from panels (blue) was being used plus 3.141 kW (pink) from the "grid". Non-charging uses at that period would be 300W or fewer. The panels are rated at 5.4 kW. The max. I have seen is 5.983 kW. 5 kW or higher is rare.

Would there be any advantage to limiting your charging amps to 16 to more closely match your production?

 

[KSchneider]

I thought about that option. I think the L1 EVSE that comes with the car would produce ca. 2 kW/h instead of the 66.kW/h of my L2. That would triple the charging times for the same kW added. In summer when the sun shines for many hours thay would be OK as long as I could wait. For the moment speed at L2 levels seems preferable. I am not really trying to minmize cost. The difference is small and our electric utility provides most of its power from renewable sources (including ying them from home solar in our village).

 

[md.]

Can't you limit the L2 charge to 16A in the vehicle? Or does that setting only apply to L1? A lot of L2 EVSEs have that option, too.

 

[KSchneider]

Thank you for this question!!! Yes onne can set charging in the vehicle to MAX or 16A or 8A. On p. 571 Owner's Manual. Had read that but did not remember. That would be far easier than using the Subaru L1 EVSE. I have the Grizzl-E L2 EVSE and one cab set it to any of 40A, 32A, 24A, 16A. Making a change however requires opening the box on the wall and flipping switches. I leave it on 40A since that is the circuit I have. The car determines the actual A amount. This will likely encourage me to try charging at 16A on appropriate low solar power production days. Lots of details to learn and understand with these EV's.

 

[KSchneider]

Can't you limit the L2 charge to 16A in the vehicle? Or does that setting only apply to L1? A lot of L2 EVSEs have that option, too.

Would there be any advantage to limiting your charging amps to 16 to more closely match your production?

I replied earlier to this good question saying my L1 EVSE would only produce ca. 1.9 kW/h which is less than 1/3 as fast as my L2 @ 6.6 kW/h. Then you mentioned setting the car to use only 16a from my L2. It just dawned on me that the L2 would produce 240v x 16a = 3.8 kW/h. Assuming my calculation is correct 3.8 kW/h is much closer to the regular solar panel output on most sunny days. And 60% as fast as 6,6 kW. Very tempring. So far have never needed to be in a hurry to charge.

 

[KSchneider]

First charge with L2 240v EVSE + current set in car to 16a is working perfectly as desired.

Panels making 4.45kW / charging using most of the 4.27 kW / .18kW to grid.

X-axis = 4 hour time segments / Y-axis - 1 kW segments. Charging started before noon. Using all of 4 + kW produced by panels and sending rest to grid.

 

[n6nl]

Yep, I try to do the same thing with my (rated gross) 5.9kW array, which produces a peak of about 4-4.5kVA because it’s mounted horizontally. But yeah, self consumed is pretty much what we aim for when charging. My panel orientation peaks within a few minutes of local Solar noon, which makes it easy to estimate a reasonable charge time, split each side of that. Or, if charging after short trips back to 80%, it sometimes won’t matter, as long as we start near that peak point and finish up quickly.

Limiting the charge to 16A is also our method for Spring, Summer and Fall, and limiting to 8A is our method for deep Winter, when we still get good production on overcast days, but not enough for household load plus charging at 16A.

 

[FelineFreddie]

I am really jealous of you guys with solar panels. I live in a great area for them (upstate SC), but at almost 70 years of age, I can’t seem to make it work for me financially. If I was 20+ years younger, I’d be all over adding them.