Ampster
Renewable Energy Hobbyist
I have had an Outback Skybox for several years but recently decided to finally rewire my GT Inverter to take advantage of the new battery pack I recently installed. Details of that build are here.
My GT system is a 3.8 kW Solaredge inverter with 19 Hanwha cells for a total DC capacity of 5.7kW. It is on a NEM 2.0 aggreement with PG&E. What NEM 2.0 means is that I am charged Non Bypassable Charges (NBCs) for every kWh that I am using the grid. It adds about $0.01 to 0.015 the the applicable TOU rate. I think last year I paid less than a $100 in NBCs last year, in addition to fixed month Minimum Delivery Charges (MDCs). I can go into details about my rate structure if anybody is interested.
One of my long term goals has been to be self sufficient in terms of Energy as far as practical with two EVs. For that reason and to increase my backup capacity I upgraded my pack. After doing that I was finally ready to swing the GT inverter over to my critical loads panel that is controlled by the transfer switch in my Skybox. The other motivation was that during fire season in Northern California we have Public Safety Power Shutoffs. (PSPS) I was able to limp through them last year but my old Frankenpack of Nissan Leaf Modules was barely able to make it through the night and the only solar I had connected to the Skybox was some west facing used Sunpower panels and they didn't even start producing until afternoon. So now with a 28 kWh pack of 28 kWh of thirty two LF280 cells I wanted to get the full benefit of AC coupling my GT inverter so I could charge from the sun in the morning and use some of that solar to charge my EVs during the afternoons.
A few days ago I completed the rewiring of the GT inverter and now it runs through the Skybox. I have several modes on the Skybox and the one I chose to use was Self Consumption because it charges the batteries and covers the loads as its first priority then sells any excess to the grid. The Skybox has a coulomb counter so I can describe things in terms of percentage of SOC. By morning the pack is down to about 70% of SOC and begins charging by 9AM ramping up the Amperage to about 40 Amps by 10:30 to 11:00 AM. Usually it is done my 1:00 PM. The last hour is in the ramp down of current in the Constant Voltage stage so it begins sell to the grid. What I like about the Skybox is that I can set the maximum kW that I sell to the grid. That is important because my NEM agreement limits me to 4.8 kWs so that is the setting on my Skybox.
It will take me a year to see the financial impact of all of this and I did not do it with a particular payback in mind. Part of that is because I have two EVs that I can charge with any excess solar or by using the credits I have built up in my NEM arrangement with PG&E
NOTE: As of July I sold that house and am moving the Skybox to the new home and installing a 23 panel system with Enphase micros.
My GT system is a 3.8 kW Solaredge inverter with 19 Hanwha cells for a total DC capacity of 5.7kW. It is on a NEM 2.0 aggreement with PG&E. What NEM 2.0 means is that I am charged Non Bypassable Charges (NBCs) for every kWh that I am using the grid. It adds about $0.01 to 0.015 the the applicable TOU rate. I think last year I paid less than a $100 in NBCs last year, in addition to fixed month Minimum Delivery Charges (MDCs). I can go into details about my rate structure if anybody is interested.
One of my long term goals has been to be self sufficient in terms of Energy as far as practical with two EVs. For that reason and to increase my backup capacity I upgraded my pack. After doing that I was finally ready to swing the GT inverter over to my critical loads panel that is controlled by the transfer switch in my Skybox. The other motivation was that during fire season in Northern California we have Public Safety Power Shutoffs. (PSPS) I was able to limp through them last year but my old Frankenpack of Nissan Leaf Modules was barely able to make it through the night and the only solar I had connected to the Skybox was some west facing used Sunpower panels and they didn't even start producing until afternoon. So now with a 28 kWh pack of 28 kWh of thirty two LF280 cells I wanted to get the full benefit of AC coupling my GT inverter so I could charge from the sun in the morning and use some of that solar to charge my EVs during the afternoons.
A few days ago I completed the rewiring of the GT inverter and now it runs through the Skybox. I have several modes on the Skybox and the one I chose to use was Self Consumption because it charges the batteries and covers the loads as its first priority then sells any excess to the grid. The Skybox has a coulomb counter so I can describe things in terms of percentage of SOC. By morning the pack is down to about 70% of SOC and begins charging by 9AM ramping up the Amperage to about 40 Amps by 10:30 to 11:00 AM. Usually it is done my 1:00 PM. The last hour is in the ramp down of current in the Constant Voltage stage so it begins sell to the grid. What I like about the Skybox is that I can set the maximum kW that I sell to the grid. That is important because my NEM agreement limits me to 4.8 kWs so that is the setting on my Skybox.
It will take me a year to see the financial impact of all of this and I did not do it with a particular payback in mind. Part of that is because I have two EVs that I can charge with any excess solar or by using the credits I have built up in my NEM arrangement with PG&E
NOTE: As of July I sold that house and am moving the Skybox to the new home and installing a 23 panel system with Enphase micros.
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