Happy With Our System

[SolTex]

We are total newbies to the solar world, but I have learned a lot from reading on this forum. We installed a system behind our house that turned out pretty good in spite of our ignorance. Thought I would share a graph of our recent production. We are very happy with the performance of our Enphase system. It has met all design goals, and is operating optimally. System is located in West TX where we have excellent solar production conditions. Our 15kW ground mount system was installed facing 180 degrees true south and with a 23 degree tilt. It includes 40 LG 380W panels, IQ7+ inverters, and two 10T batteries. We run the "Self Consumption" battery profile with reserve set at 30%. In the graph below (from Oct 13, 2022) battery SOC at both ends of 24hr period is identical at 46%. The inverter clipping in the middle of the day occurs at the 11.8kW level, which corresponds to the max combined output of our IQ7+ inverters (40 x 295W = 11,800W).

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[Bob Moffit]

Hi SolTex, that is an impressive generation and export curve. Just curious, how does the utility manage your excess? We are in central OH and under AEP. Here, they balance grid import and grid export at the end of each billing month and any excess is credited at about 1/3 of the standard purchase price (about $0.05 / KWh vs $0.15 / KWh). We've only had our system since mid February 2022, and we have been net positive each month - but our days are getting short, so I expect we will break this streak in November.

[SolTex]

Bob,

We are in the Oncor service area, in a de-regulated part of TX, where we have a choice...although none of the providers are particularly solar friendly. We have been operating our system for about 5 months. The best deal I could find is with Chariot Energy. We pay a fixed price of about 16 cents per kWh for imported energy, and receive credit equal to 9.15 cents per kWh on whatever we export. Our unused credits carry over month-to-month for the duration of the contract. Credits can be used to offset the total monthly charges including all fees and taxes. Because we generate excess power almost every day, we have accumulated a decent "credit" account and we (so far) have ended up with zero due on our monthly bills. There is no provision for converting credits to cash, so it's "use them or lose them".

[Srrndhound]

The inverter clipping in the middle of the day occurs at the 11.8kW level, which corresponds to the max combined output of our IQ7+ inverters (40 x 295W = 11,800W).

I think the 11,800W clipping point makes sense, but why does the y-axis of the graph show it as 3 kW?

[SolTex]

Actually, it shows a value of about 3 in units of kWh. The vertical axis scale is a continual source of confusion to new Enlighten users (like me). Here is the best explanation I have found. If I hold my cursor over any one of the blue bars in the middle of the plot, it pops up a little box with the data for that bar. See expanded presentation below. Each bar shows a "produced" value of 11.8kW which is the clipping level of the system. 11.8kW produced for one hour would equal 11.8 kWh. But since each bar only represents 15 minutes (1/4 of one hour), the kWh value of that bar which is displayed on the "Y" axis is 11.8 divided by 4 which equals 2.950 kWh.

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[Srrndhound]

Actually, it shows a value of about 3 in units of kWh. The vertical axis scale is a continual source of confusion to new Enlighten users (like me). Here is the best explanation I have found. If I hold my cursor over any one of the blue bars in the middle of the plot, it pops up a little box with the data for that bar. See expanded presentation below. Each bar shows a "produced" value of 11.8kW which is the clipping level of the system. 11.8kW produced for one hour would equal 11.8 kWh. But since each bar only represents 15 minutes (1/4 of one hour), the kWh value of that bar which is displayed on the "Y" axis is 11.8 divided by 4 which equals 2.950 kWh.

Thanks much for the explanation -- that clears it up. I kept thinking it was watts like in the SolarEdge monitor, even when I read "kWh" -- it just didn't register.

All good...