Hybrid Grid-Tie Inverter for Battery storage

[rcoleblack]

Hey y'all long time viewer of Will's YT channel, finally joining in on the forums.

I bought a new house and I'm getting a grid-tie system. It's being engineered right now and then it will move to permitting with the city. This system is by projectsolar.io and I'll be installing it myself. The system will be 23 CanadianSolar CS3N-395 panels with Enphase IQ8+ microinverters.

I have a Tesla Model Y P as my primary vehicle and would love to shed the solar load for charging at night. I would say my average charge every night is 20-25kwh.

But here's the problem. I have 15kwh of 48v (14s) scooter batteries I snagged from Jag35 a couple months ago for ~$1400. I would love to put these batteries to use.
My power utility provider (Rocky Mountain Power) buys my net metering solar at 5.160¢/kWh and my usage is tiered at 9.0279¢ per kWh first 400 kWh, 11.7210¢ per kWh all additional kWh. Winter is credited at 4.462¢ per kWh and my usage is 7.9893¢ per kWh first 400 kWh, 10.3725¢ per kWh all additional kWh. Sadly they don't offer any good time of use plans.

Anyways, I'd like to put those batteries to use when charging my car every night. With 15kwh, at 6¢/kwh difference, that's a monthly savings of ~$30 for any powerI can store locally and not buy back at night. I'm averaging about 1200kwh/month of total power usage.

What do you guys think the best most economical solution for me would be?

Here's an overview of my power in my house and how it's laid out.

 

[BentleyJ]

Based on the size of your grid-tie system 23 x 395W = 9kW approx. for the sake of simplicity lets assume you have 5 Peak Solar Hours per day on average, your monthly production will be 1,363 kWh per month. What portion of the 1,200 kWh per month you reported using is going to the house vs. the Tesla? How much excess production is available to charge the batteries and then transfer that power to the car. I believe this question needs to be answered before proceeding.

If it turns out you do wish to use the 15kWh battery you already purchased then my advice would be set up a stand alone system using an Inverter/Charger (AIMS??) that is connected between the Garage Subpanel and the Tesla charger. During the day the batteries charge. At night the Inverter/Charger uses the batteries as first priority to charge the Tesla and when the batteries reach the Low Voltage Cut-Out, the Inverter switches over to Utility and completes the Tesla charge cycle.

 

[rcoleblack]

It's about half. 600kwh to house and 600kwh to the Tesla. Yeah and I kinda figured doing a dedicated hybrid system is probably gonna be the best. Maybe I pull off some of the microinverters on 3kws of panels to go to the tesla system.

 

[James464277]

Hey y'all long time viewer of Will's YT channel, finally joining in on the forums.

I bought a new house and I'm getting a grid-tie system. It's being engineered right now and then it will move to permitting with the city. This system is by projectsolar.io and I'll be installing it myself. The system will be 23 CanadianSolar CS3N-395 panels with Enphase IQ8+ microinverters.

I have a Tesla Model Y P as my primary vehicle and would love to shed the solar load for charging at night. I would say my average charge every night is 20-25kwh.

But here's the problem. I have 15kwh of 48v (14s) scooter batteries I snagged from Jag35 a couple months ago for ~$1400. I would love to put these batteries to use.
My power utility provider (Rocky Mountain Power) buys my net metering solar at 5.160¢/kWh and my usage is tiered at 9.0279¢ per kWh first 400 kWh, 11.7210¢ per kWh all additional kWh. Winter is credited at 4.462¢ per kWh and my usage is 7.9893¢ per kWh first 400 kWh, 10.3725¢ per kWh all additional kWh. Sadly they don't offer any good time of use plans.

Anyways, I'd like to put those batteries to use when charging my car every night. With 15kwh, at 6¢/kwh difference, that's a monthly savings of ~$30 for any powerI can store locally and not buy back at night. I'm averaging about 1200kwh/month of total power usage.

What do you guys think the best most economical solution for me would be?

Here's an overview of my power in my house and how it's laid out.
View attachment 97840