I live in Texas, and one of the energy companies I can choose from is TXU energy. They have a plan where you get 100% free energy from 8pm to 4:59am. During the day the cost is 29.6 c/kwh, so I'd never want to use power during the day.
EFL: https://residential.txu.com/Handler...ype=EnergyFactsLabel&custClass=3&tdsp=CENTERP
I've been brainstorming about designing a battery backup system that can fill up during the night for free, then discharge during the day, so I'd have 100% free power (minus a $10/month base charge).
Assuming a power usage of 2000kwh/month, that works out to 67kwh per day. So I'd need to charge a 67kwh battery pack every night. 67kwh/day is way overkill, but I'm just brainstorming, so I'm trying to see what a theoretical reasonable maximum of the system would look like.
Also, that 67kwh is for a full 24 hours, but I only need batteries to last from 5am - 8pm. However, I'll leave it at 67kwh for brainstorming.
The battery I'm currently brainstorming with is the EVE MB30. https://www.alibaba.com/product-det...fferlist.topad_classic.d_title.87aa458eANU1mh
67kwh over 12 hours means the inverter needs to be able to sustain 5.583kwh, not too bad.
The inverter I'm currently brainstorming with is the Schneider Conext XW PRO 6.8KW. https://signaturesolar.com/schneider-conext-xw-pro-6-8kw-inverter-charger-48v-120-240v/
It can charge the batteries at 48v 120A on 120vac, so it can charge 67kwh in about 11.6 hours, which is barely within the 12 hour free nights window.
The inverter is a bit expensive, I don't know if there's a cheaper one that will work for this.
The payback period I've currently calculated is 3.2 years, and that's with an overkill amount of batteries.
I'd appreciate any feedback on this idea.
All of this would also be contingent on the power company not refusing to renew my contract after a year, or kicking me off even sooner than that. I didn't read anything in the fine print about banning this kind of usage.
I may be able to get the federal tax credit for this, so that's 30% off the price. Battery shipping will increase the price, and so will miscellaneous things like cables, battery BMS, and battery case.
EDIT:
Here is the spreadsheet I used for my calculations. https://docs.google.com/spreadsheet...mZqEpd6nbbDKSrW7RShEYtWl6QY8A/pub?output=xlsx
EFL: https://residential.txu.com/Handler...ype=EnergyFactsLabel&custClass=3&tdsp=CENTERP
I've been brainstorming about designing a battery backup system that can fill up during the night for free, then discharge during the day, so I'd have 100% free power (minus a $10/month base charge).
Assuming a power usage of 2000kwh/month, that works out to 67kwh per day. So I'd need to charge a 67kwh battery pack every night. 67kwh/day is way overkill, but I'm just brainstorming, so I'm trying to see what a theoretical reasonable maximum of the system would look like.
Also, that 67kwh is for a full 24 hours, but I only need batteries to last from 5am - 8pm. However, I'll leave it at 67kwh for brainstorming.
The battery I'm currently brainstorming with is the EVE MB30. https://www.alibaba.com/product-det...fferlist.topad_classic.d_title.87aa458eANU1mh
67kwh over 12 hours means the inverter needs to be able to sustain 5.583kwh, not too bad.
The inverter I'm currently brainstorming with is the Schneider Conext XW PRO 6.8KW. https://signaturesolar.com/schneider-conext-xw-pro-6-8kw-inverter-charger-48v-120-240v/
It can charge the batteries at 48v 120A on 120vac, so it can charge 67kwh in about 11.6 hours, which is barely within the 12 hour free nights window.
The inverter is a bit expensive, I don't know if there's a cheaper one that will work for this.
The payback period I've currently calculated is 3.2 years, and that's with an overkill amount of batteries.
I'd appreciate any feedback on this idea.
All of this would also be contingent on the power company not refusing to renew my contract after a year, or kicking me off even sooner than that. I didn't read anything in the fine print about banning this kind of usage.
I may be able to get the federal tax credit for this, so that's 30% off the price. Battery shipping will increase the price, and so will miscellaneous things like cables, battery BMS, and battery case.
EDIT:
Here is the spreadsheet I used for my calculations. https://docs.google.com/spreadsheet...mZqEpd6nbbDKSrW7RShEYtWl6QY8A/pub?output=xlsx
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