David W Virtue
Member
Thanks for sharing your learning daniel. Fascinating posts to me as a sustainable power fan with no installations except an M3 in the garage.
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Or the powerwalls needed to be discharged a bit to allow soaking up the solar capacity in case your house load decreased. A little hysteresis in the box that is coordinating production to not back feed to grid.
Daniel- ask your installer to submit for grid supply or smart export. MECO still has room on those tariffs and your system will work much better than when it’s set up for non export. The way non export works is that the Pv inverter and the powerwall both use their own zero export mechanisms and they don’t always work that well together. One thing is the delay you see in the Pv ramping up when a big load turns on. And the biggest draw back is that a solar edge inverter set up for zero export will not produce power in offgrid mode. What you will see after the 5 minute wake up is the Pv ramp up and then curtail itself to zero. This is because the Pv inverter only produces when it sees a small amount of import from the grid. The sales people don’t make this very clear but with hurricane season approaching it’s an important thing to be aware of. There is a way your installer can tweak the settings on the solar edge so it will produce offgrid but it typically leads to the Pv exporting too much power than what the utility will allow.
Daniel- ask your installer to submit for grid supply or smart export. MECO still has room on those tariffs and your system will work much better than when it’s set up for non export. The way non export works is that the Pv inverter and the powerwall both use their own zero export mechanisms and they don’t always work that well together. One thing is the delay you see in the Pv ramping up when a big load turns on. And the biggest draw back is that a solar edge inverter set up for zero export will not produce power in offgrid mode. What you will see after the 5 minute wake up is the Pv ramp up and then curtail itself to zero. This is because the Pv inverter only produces when it sees a small amount of import from the grid. The sales people don’t make this very clear but with hurricane season approaching it’s an important thing to be aware of. There is a way your installer can tweak the settings on the solar edge so it will produce offgrid but it typically leads to the Pv exporting too much power than what the utility will allow.
The generation figures shown by the Tesla app and the SolarEdge portal should not be that different. Bring this to your installer's attention and see if he can find the reason. It may be a configuration or measurement problem. If you have more than one inverter, the Solar CTs may only be measuring one of them.
The totals should not be off that much.
It is very common for the CT’s to be set up incorrectly. There are solar edge site CT’s, Tesla site CT’s and Tesla solar CT’s. Each has to be on the right phase and pointing the right direction. Lots of variables and if anything is wrong you’ll see weird stuff.
Smart export has value because it allows you to export from 9-4 with no credit and you do get credit for any export from the Pv after 4. It also saves from needing the 400 dollar solar edge monitor and CT’s. And the Pv produces when the grid goes down. So it’s better than css but they don’t like selling it because it’s either not understood or they don’t like the longer approval process than CSS. Yes some circuits are getting full for zero export but I believe most Maui installers are still getting cgs or smart export approvals. Safe bet is get the css closed out and then ask to apply for smart export.
I guarantee that a zero export system that’s set up properly won’t produce when the grid goes down. So either something is not right or the breaker you are turning off isn’t the main for everything and doesn’t accurately demonstrate an outage. Your installer can ask solar edge or Tesla rep and they will admit it’s a known issue that’s being worked on.
Some days we charge a car or two directly via solar and we did have a long outage during the night where the Powerwalls were drained when the cars charged. We tweeted Elon in May and he replied within minutes confirming that better communication between the Powerwalls and vehicles will be coming in a future update!What Tesla should really do is allow the car to communicate with the gateway and allow us to set the car to charge when there is excess solar, but shut off or dial back when it would be drawing from the Powerwall. Let us charge from the Powerwall if we need the range, but just use solar production otherwise.
As long as you can verify that the solar kW in the Tesla app power flow and the solar inverters themselves show the same instantaneous kW value, then the measurements are set up correctly. If it's just the totals, then don't worry about it.Thanks. I did show it to him. His answer is that Tesla does continual approximation all day, resulting in completely unreliable daily totals. He says the Solar Edge numbers should be correct. In support of this is the fact that the Solar Edge numbers match for production and consumption, and are consistent with my average daily usage for last month from my utility bill, and that Tesla's numbers for production do not match their numbers for consumption. I think Tesla's Power Flow numbers are probably good, since I can see these change in ways that make sense when things turn on and off, but however Tesla is determining daily totals is haywire.
Some days we charge a car or two directly via solar and we did have a long outage during the night where the Powerwalls were drained when the cars charged. We tweeted Elon in May and he replied within minutes confirming that better communication between the Powerwalls and vehicles will be coming in a future update!
As long as you can verify that the solar kW in the Tesla app power flow and the solar inverters themselves show the same instantaneous kW value, then the measurements are set up correctly. If it's just the totals, then don't worry about it.
I would add that I've got an export meter on the output of my SolarEdge inverter and this gives total generation around 3% lower than SolarEdge's numbers. The CT for the PW is also on the AC side of the inverter. I've concluded that the SE total represents the DC production of the panels - the inverter is about 98% efficient near/at full load but the efficiency drops off at part load so expect the Tesla version of the solar output to be slightly lower than SolarEdge's version.Yep. I'm not worried. I'm now taking my daily totals from Solar Edge and my running power flow from Tesla.
I would add that I've got an export meter on the output of my SolarEdge inverter and this gives total generation around 3% lower than SolarEdge's numbers. The CT for the PW is also on the AC side of the inverter. I've concluded that the SE total represents the DC production of the panels - the inverter is about 98% efficient near/at full load but the efficiency drops off at part load so expect the Tesla version of the solar output to be slightly lower than SolarEdge's version.