noy897
New Member
double posted sorry - close this thread
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Seeking for some DIY advice battery/solar combo to charge my EV
- Thread starter noy897
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noy897
New Member
DIYrich
Solar Wizard
What inverter do you currently have? Add panels to your current inverter?
When are off-peak times? Why not let the utility do the time shifting, and charge the car, from say 9pm-5am? 60 miles is about 15-20kWh, and with a Level 2 charger, you can do that in about 3 hours.
Eg4 powerpro is about $4,000 for 15kWh. 7kw of panels is about $5,000. Don't know what racking and other costs are.
Off grid growatt inverter is about $1,500. On grid Schneider is $3,500.
I'm guessing 5kW of panels is enough. Use the savings to buy another 5kWh of battery.
Off grid you want to minimize over production, as you can recharge battery from grid during off peak times. On grid, your net additional solar (what isn't used by batteries) may be small enough you can export to grid without the utility noticing.
When are off-peak times? Why not let the utility do the time shifting, and charge the car, from say 9pm-5am? 60 miles is about 15-20kWh, and with a Level 2 charger, you can do that in about 3 hours.
Eg4 powerpro is about $4,000 for 15kWh. 7kw of panels is about $5,000. Don't know what racking and other costs are.
Off grid growatt inverter is about $1,500. On grid Schneider is $3,500.
I'm guessing 5kW of panels is enough. Use the savings to buy another 5kWh of battery.
Off grid you want to minimize over production, as you can recharge battery from grid during off peak times. On grid, your net additional solar (what isn't used by batteries) may be small enough you can export to grid without the utility noticing.
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noy897
New Member
I have solar through emphase that is connected to the grid. I don’t think I’m allowed to touch that without getting permits right? Off peak time is 12 am to 3pm at 29c, I have been charging off peak but it’s still too much money. I want to purely charge from the sun.
Can I buy the eg4 battery,inverter and solar panels without permits in CA
Can I buy the eg4 battery,inverter and solar panels without permits in CA
DIYrich
Solar Wizard
Permits are from the Municipality for safety purposes. Permission to Operate (PTO) is from the Utility to protect the grid. If you do not feedback the grid, then you don't need PTO. Almost anything of significance requires Permits.
You can build an off-grid system that does not require PTO, but will probably require a permit.
If you have decent net metering, you might want to go the PTO/Permit route and avoid having the cost of batteries.
You can build an off-grid system that does not require PTO, but will probably require a permit.
If you have decent net metering, you might want to go the PTO/Permit route and avoid having the cost of batteries.
noy897
New Member
DIYrich
Solar Wizard
You don't need a Permit to purchase it. If you want to install it to power you house, you may need a Permit. If you just plug stuff into it, you don't need a Permit. I see it has 2kw of panels. Not enough for what you want to do.
noy897
New Member
Can you explain why would it not be enough? Im assuming it has 21kwh of capacity and with 6-10 hours of sunlight that should be sufficient amount of charge to give my tesla. What am I missing here?
400bird
Solar Wizard
When the sun is low in the sky you don't get full production. Output is more like a sine wave as the sun rises and sets.
You can go here and punch in your address and PV to get expected output.
PVWatts
Estimates the energy production and cost of energy of grid-connected photovoltaic (PV) energy systems throughout the world. It allows homeowners, small building owners, installers and manufacturers to easily develop estimates of the performance of potential PV installations
zanydroid
Solar Wizard
10 hours is excessively optimistic. 4-5 hours the rule of thumb people use for a lot of latitudes in the US. This will handwave away the fraction of full power at the beginning and end of the day. And that's average over the whole year.
PVwatts is the gold standard, and takes 10 min to use.
zanydroid
Solar Wizard
Another approach you can take, while retaining NEM2, is to upgrade to a UL9540 battery, add it to your NEM2, and then schedule your exports during peak. Then switch to EV2 or E-ELEC. Your exports during peak, if I understand the compensation scheme correctly, will be $0.55/kWh while your consumption, now all off-peak, will be $0.25
You might be able to get a SGIP credit from PG&E for the battery. There will be a waitlist though (complicated).
There are a handful of AHJs in Northern California that don't let you owner/builder batteries/solar.
You might be able to get a SGIP credit from PG&E for the battery. There will be a waitlist though (complicated).
There are a handful of AHJs in Northern California that don't let you owner/builder batteries/solar.
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