Abusing free nights electricity plan with batteries

[45North]

For about $5,000, you can arbitrage 14kWh per day.
Net of 30% federal tax credit, that is $3,500.
At 15 cents per kWh, that is $2.10 per day. It would take 4.6 years to get your investment back, plus you have 15kWh of backup power.
After that, it is "free".
Once it is up and running, there is not much "maintenance". the only "management" is checking electric rates, which you are probably doing anyway.

Yes, but after 5 years your stuff is old & outdated & fading with many cycles on it needing replacement or at least updating. Dollar value minimal.
Better to invest your money and time in something else unless you are really just looking for a hobby project.

 

[wpns]

Yes, but after 5 years your stuff is old & outdated & fading with many cycles on it needing replacement or at least updating. Dollar value minimal.
Better to invest your money and time in something else unless you are really just looking for a hobby project.

See the ROI thread.

 

[DIYrich]

Yes, but after 5 years your stuff is old & outdated & fading with many cycles on it needing replacement or at least updating. Dollar value minimal.
Better to invest your money and time in something else unless you are really just looking for a hobby project.

Batteries last 10 to 15+ years. Even then, they should have atleast 70% of their original capacity. Inverter is cheap, probably even cheaper in 10 years. I'm guessing in 20 years, 1 year payback to fix up for another 10 years at 70+% capacity with little or no ongoing maintenance.

Btw: why are you here wasting your time?

 

[wattmatters]

Power arbitrage is not "free"
You still need to invest your own money in depreciating equipment and invest your time and attention to manage the process.
Think about all the other better uses of your money and time.

My system already existed before my free grid energy tariff period became available, so yeah, it's a free addition.

During that period I charge up my home battery and EV and sometimes run other appliances as well, maybe heat water if it needs a boost on poor solar days.

It's all managed by a home automation system which I also already had running. Just a few minutes to adjust the automation settings.

But you know what? It's also a hobby and I enjoy it.

 

[wpns]

I'm guessing in 29 years

I’m guessing in 2.9 years your power company will change the deal.

 

[Warpspeed]

That is the problem.
Initially offer a great deal, reel in the customers, then change the rules of the game.
Commonly known as the bait and switch technique.

 

[DIYrich]

I’m guessing in 2.9 years your power company will change the deal.

Fixed my post. Bad keyboard on phone.

 

[Austintatious]

I had to get in on this thread... I am currently using the Solar days free nights 8pm plan with TXU. I have a 17.5Kwh PV array. It is a Tesla system but I did not get the power walls. I am currently looking for a battery system to add that can be charged on a schedule.

The power walls might be the ideal solution, but they are expensive and it is unclear to me if Tesla will enable my ability to charge from grid power. This is critical to the powerwalls worth, if they cannot be charged from the grid they are mostly useless to me.

My idea is that I have the solar providing energy during the day to run the house, or at least reduce what I pull from the grid, which cost me about .35 per Kwh once you add in delivery fees. I want to add the batteries to carry me from 5am when free power ends up until about 11 am when I start to produce solar. Then use all available solar to run the home and charge the batteries again. In the afternoon as solar output wanes, the batteries can make up the shortfall to prevent grid pull, then at 8pm the power is free and I can let everything blast and recharge the batts.

The house has FIVE 5 ton heat pump Ac's (4 for house, 1 for pool) a lvl 2 EV charger (tesla wall) 2 Pool pumps and 4 water heaters. I control all the HVAC's with nest and have everything automated to reduce daytime usage, but I still eat a 3-400 dollar bill each month.

I am thinking that I could probably use about 20Kwh worth of storage. On an ideal day I would be about to use that capacity twice, so say 30 Kwh less grid use per day or about 10 bucks less per day / 300 less per month. The problem is that if I dont/cant do this with Tesla powerwalls, then I cannot figure out how to make sure the batteries being charged does not cause me to draw grid power during the day... For example if I schedule the batteries to charge from 11am until 4 pm... but it is a cloudy day and I am not making solar power. In that case I do not want them to charge since it would come from the grid. And if I ONLY charged them at night with free power, well that cuts their potential in half.

Cool to see a thread with like minds trying to get one over on these power companies... I hate them and find their practices detestable. They have tilted the deck so that they are the ones benefiting from residential solar, which our tax dollars are subsidizing... The advantage should 100 percent be to the homeowner who installs solar without us having to play these sorts of games... but if I'm going to play, I am going to win.

 

[Austintatious]

And that is the problem.
Its not going to be long term sustainable for the power utility as more and more customers hop onto the gravy train.
At some point it must all come to a screeching halt one way or another.
You don't need to be an MBA or clairvoyant to figure this out.

I still believe the best solution is to give the power utilities the middle finger and go completely off grid, or be capable of going completely off grid, even though short term, that might not be financially attractive.

Its rather like paying for insurance cover, or investing in a parachute or a lifeboat.......

TXU has had the free nights plan for over a decade and I have been abusing it for that long... Most people do not "win" on this plan... and this plan is not offered for any reason except to attempt to even out power demand. They hope to draw people in to these free night plans making people think they can come out ahead and thus change their power usage habits.... and they will do that, but they will certainly not save much if anything on their bill unless they go through drastic means... and the power companies know this and that most people will pay about the same as they did before going to the free nights plan and that very few will take the drastic measures necessary to come out ahead.

 

[blueforce]

TXU has had the free nights plan for over a decade and I have been abusing it for that long... Most people do not "win" on this plan... and this plan is not offered for any reason except to attempt to even out power demand. They hope to draw people in to these free night plans making people think they can come out ahead and thus change their power usage habits.... and they will do that, but they will certainly not save much if anything on their bill unless they go through drastic means... and the power companies know this and that most people will pay about the same as they did before going to the free nights plan and that very few will take the drastic measures necessary to come out ahead.

Check the Ercot grid and market conditions and especially the "real time location prices," "fuel mix," and "combined wind and solar."

The "free nights" is a money making scheme but I don't think it's just a malicious play by power companies to get one over on the consumer. Texas has a large amount of wind power and the winds blow stronger at night but usage is lower so the system has excess power during these times. This results in negative wholesale energy prices and free nights plans for us. The REPs (retail electricity providers) are hoping with these plans that we'll shift our usage to nights so the REPs can offset their daytime consumption. They'll never come out ahead this way which is why nights are free and not also negative for us and daytime charges are usually 2-3x higher than standard plans.

Here's a screenshot of the current prices (in MWh) where most are negative right now:

 

[45North]

Check the Ercot grid and market conditions and especially the "real time location prices," "fuel mix," and "combined wind and solar."

The "free nights" is a money making scheme but I don't think it's just a malicious play by power companies to get one over on the consumer. Texas has a large amount of wind power and the winds blow stronger at night but usage is lower so the system has excess power during these times. This results in negative wholesale energy prices and free nights plans for us. The REPs (retail electricity providers) are hoping with these plans that we'll shift our usage to nights so the REPs can offset their daytime consumption. They'll never come out ahead this way which is why nights are free and not also negative for us and daytime charges are usually 2-3x higher than standard plans.

Here's a screenshot of the current prices (in MWh) where most are negative right now: View attachment 267877

If Texas is in such great shape then why do they keep having blackouts whenever there's a hurricane or winter storm? Is it the distribution system that's failing?

 

[blueforce]

If Texas is in such great shape then why do they keep having blackouts whenever there's a hurricane or winter storm? Is it the distribution system that's failing?

Blackouts are for other reasons and not the point of the conversation here. And yes, there are charges built into the bill for recovery from snowmaggedon in 21 when they had to beef up the grid.

 

[summit]

why not connect to the other two national grids and help every one ?

 

[wpns]

why not connect to the other two national grids and help every one ?

Ah must haz muh Inderpendence!

 

[wattmatters]

why not connect to the other two national grids and help every one ?

It is panning to, at least partly:

ERCOT Power Grid Set To Connect To U.S. Grid: What The $360M Project Means For Texas And The Southeast

Key Takeaways ERCOT to Connect to U.S. Grid: A $360M federal grant will link ERCOT with the Southeastern U.S. grid, improving power reliability and

electricityrates.com

Key Takeaways​

• ERCOT to Connect to U.S. Grid: A $360M federal grant will link ERCOT with the Southeastern U.S. grid, improving power reliability and stability.
• Increased Resilience: The connection will reduce rolling blackouts and improve energy sharing during extreme weather events and high-demand periods.
• Cost and Energy Savings: Thanks to increased grid flexibility and resource sharing, Texans and Southeastern residents may see more stable electricity rates.
• Boost for Renewables: The project supports renewable energy integration, allowing Texas to share excess wind and solar power with neighboring states.

In a giant step for energy security, the infamously independent Texas grid (ERCOT) is preparing to connect to the U.S. grid. The Biden-Harris administration has committed a $360 million federal grant for this vast project as part of their Investing in America' program.

This new expansion will establish a critical link between Texas's energy grid and the Southeastern United States. The goal is to increase reliability, reduce power outages, and stabilize energy costs.

 

[DIYrich]

why not connect to the other two national grids and help every one ?

1) it costs money; and
2) it would subject them to regulation by FERC.

They were good until the freeze. Then they realized being connected to a multi state grid might be worth it.

 

[JWLV]

While your math and calculations might be correct, you are missing one critical factor. You are assuming that TXU will have this plan forever. I guarantee you that as soon as they find out too many people are doing this, they will change the plan or discontinue it completely.

Same as net metering. How many versions of that has there been already? Even the first people who got net metering with full retail buy back are no longer being paid the original price.

 

[DIYrich]

While your math and calculations might be correct, you are missing one critical factor. You are assuming that TXU will have this plan forever. I guarantee you that as soon as they find out too many people are doing this, they will change the plan or discontinue it completely.

If there is negative prices overnight, it could still be profitable for the utility.

 

[blueforce]

While your math and calculations might be correct, you are missing one critical factor. You are assuming that TXU will have this plan forever. I guarantee you that as soon as they find out too many people are doing this, they will change the plan or discontinue it completely.

Same as net metering. How many versions of that has there been already? Even the first people who got net metering with full retail buy back are no longer being paid the original price.

If there is negative prices overnight, it could still be profitable for the utility.

Exactly, negative prices overnight will start to even out the higher prices during peak demand when the REPs have to purchase power at a higher cost than they can sell it for, $200+/mwh. If anything the free nights plans won't go away but the window and peak kwh rate will be adjusted to make them the most money. We can already see some of that where free nights from 9pm-9am are the most expensive during the day and some, not all, of the shortest windows from 11pm-5am are much cheaper per kwh.

Either way, @Austintatious I would stay away from TXU. Their rates are garbage and they still charge TDU during the free hours.

 

[Austintatious]

Exactly, negative prices overnight will start to even out the higher prices during peak demand when the REPs have to purchase power at a higher cost than they can sell it for, $200+/mwh. If anything the free nights plans won't go away but the window and peak kwh rate will be adjusted to make them the most money. We can already see some of that where free nights from 9pm-9am are the most expensive during the day and some, not all, of the shortest windows from 11pm-5am are much cheaper per kwh.

Either way, @Austintatious I would stay away from TXU. Their rates are garbage and they still charge TDU during the free hours.

That is not true at all... where did you hear that... You can literally go see the Electricity facts label for the free nights plan and see that they refund the delivery charges....

I have been on the free nights plan for over 9 years... i have had 10,000 Kwh months that I paid an average of .03 per Kwh. Last month, I had 1000.00 worth of energy and TDU charges knocked off my bill.

If not for these free night plans, I would be paying a LOT more for electricity... I have 5500 square feet with 400 am service feeding four 5 ton HVAC units (they used to all be resistive heating, now they are heat pumps), pool pumps and a 5 ton Pool heater/chiller, lvl 2 EV charger, 4 water heaters and all the other stuff homes have. I manage to run all this typically for around 350 a month total. I dont do as well as I used to on the plan because my wife no longer works and I still want to run some ac/heat during prime time so she isnt so uncomfortable.

 

[blueforce]

That is not true at all... where did you hear that... You can literally go see the Electricity facts label for the free nights plan and see that they refund the delivery charges....

I have been on the free nights plan for over 9 years... i have had 10,000 Kwh months that I paid an average of .03 per Kwh. Last month, I had 1000.00 worth of energy and TDU charges knocked off my bill.

If not for these free night plans, I would be paying a LOT more for electricity... I have 5500 square feet with 400 am service feeding four 5 ton HVAC units (they used to all be resistive heating, now they are heat pumps), pool pumps and a 5 ton Pool heater/chiller, lvl 2 EV charger, 4 water heaters and all the other stuff homes have. I manage to run all this typically for around 350 a month total. I dont do as well as I used to on the plan because my wife no longer works and I still want to run some ac/heat during prime time so she isnt so uncomfortable.

You're right, I must've confused it with another company. EFLs are purposefully confusing and they're formula was the only place I could see the TDU was refunded:
Price per kWh = [Base Charge + TDU Delivery Charges per Month + (Monthly billed kWh Usage multiplied by the(Energy Charge + TDU Delivery Charges per kWh)) - ((Energy Charge + TDU Delivery Charges per kWh) multipliedby the applicable Nights kWh Usage)]/Monthly Billed kWh Usage

Your current plan ends free time at 5am. There are plans from other REPs that start at 8pm and end at 6am giving you an extra hour of free juice and, possibly, less batteries. Those are about $.01/kwh more than what TXU is offering me on their website. There are also plans that are free from 9pm-9am but they're about $.05/kwh more. You gotta look at your average usage over the past couple years, at least, and do a comparison for the different rates and hours of your usage. If Direct Energy 12 hour power 9pm-9am works out best for your use then you only need 2 hours of battery in the morning until you start producing and an extra hour at night instead of 6 hours of battery coverage in the morning.

Btw, just rechecked your original post. Are you really being charged $.35/kwh? Looks like I can save a nickel off the rate you're paying.

 

[Austintatious]

You're right, I must've confused it with another company. EFLs are purposefully confusing and they're formula was the only place I could see the TDU was refunded:
Price per kWh = [Base Charge + TDU Delivery Charges per Month + (Monthly billed kWh Usage multiplied by the(Energy Charge + TDU Delivery Charges per kWh)) - ((Energy Charge + TDU Delivery Charges per kWh) multipliedby the applicable Nights kWh Usage)]/Monthly Billed kWh Usage

Your current plan ends free time at 5am. There are plans from other REPs that start at 8pm and end at 6am giving you an extra hour of free juice and, possibly, less batteries. Those are about $.01/kwh more than what TXU is offering me on their website. There are also plans that are free from 9pm-9am but they're about $.05/kwh more. You gotta look at your average usage over the past couple years, at least, and do a comparison for the different rates and hours of your usage. If Direct Energy 12 hour power 9pm-9am works out best for your use then you only need 2 hours of battery in the morning until you start producing and an extra hour at night instead of 6 hours of battery coverage in the morning.

Btw, just rechecked your original post. Are you really being charged $.35/kwh? Looks like I can save a nickel off the rate you're paying. View attachment 268773

I just renewed the plan for the rate you are showing above... I am on the last month of my contract with TXU and my rate will be dropping from .295/Kwh to .247/Kwh .... the delivery fees add another ~.05

I spoke with Direct energy, they do have cheaper energy and longer free hours, but you get TDU charges... With the amount of power I use at night, paying a nickle for it isnt going to work... it would make my night time usage in the hundreds of dollars just in delivery fees, and that isnt accounting for the night time hours being longer.

Take a look at one of my bills attached.... Now imagine if I had payed .059 for delivery charges for night time.

 

[blueforce]

I just renewed the plan for the rate you are showing above... I am on the last month of my contract with TXU and my rate will be dropping from .295/Kwh to .247/Kwh .... the delivery fees add another ~.05

I spoke with Direct energy, they do have cheaper energy and longer free hours, but you get TDU charges... With the amount of power I use at night, paying a nickle for it isnt going to work... it would make my night time usage in the hundreds of dollars just in delivery fees, and that isnt accounting for the night time hours being longer.

Take a look at one of my bills attached.... Now imagine if I had payed .059 for delivery charges for night time.

They may have changed the terms since you last spoke with them but from what I'm reading they do refund TDU as well (Direct Energy EFL). If you switched over to that then you would only need enough batteries to carry you through the summer afternoon heat unti 9, and enough inverter capacity to meet your house's needs.

With your setup, however, it might be cheaper to stay on a plan where free time starts at 8pm since 8-9 is just as brutal as 7-8 in the summer time and especially with 4x 5 tons. I can't speak for your usage but my 4 ton draws ~4kw while cooling so 4kw x 4 = 16kw which becomes at least 2 tesla powerwalls for 1 hour (for total coverage). More batteries for multiple hours and soft starters if you don't already have them.

I'm using EG4 products so I don't know if the Tesla powerwal has a "grid assist" where excess demand can be supplemented by the grid but you could at least cut some of your usage that way. That's if you want to stay in the Tesla ecosystem and they can charge from the grid.

Big question is do you want to spend over $10k (give or take, before taxes) for just one powerwall with 13.5kwh of storage and 11kw of inverter power? If you choose to walk away from Tesla you can certainly meet your goals for cheaper. It just won't be as pretty.

 

[Austintatious]

They may have changed the terms since you last spoke with them but from what I'm reading they do refund TDU as well (Direct Energy EFL). If you switched over to that then you would only need enough batteries to carry you through the summer afternoon heat unti 9, and enough inverter capacity to meet your house's needs.

With your setup, however, it might be cheaper to stay on a plan where free time starts at 8pm since 8-9 is just as brutal as 7-8 in the summer time and especially with 4x 5 tons. I can't speak for your usage but my 4 ton draws ~4kw while cooling so 4kw x 4 = 16kw which becomes at least 2 tesla powerwalls for 1 hour (for total coverage). More batteries for multiple hours and soft starters if you don't already have them.

I'm using EG4 products so I don't know if the Tesla powerwal has a "grid assist" where excess demand can be supplemented by the grid but you could at least cut some of your usage that way. That's if you want to stay in the Tesla ecosystem and they can charge from the grid.

Big question is do you want to spend over $10k (give or take, before taxes) for just one powerwall with 13.5kwh of storage and 11kw of inverter power? If you choose to walk away from Tesla you can certainly meet your goals for cheaper. It just won't be as pretty.
View attachment 269139

It says right there on that facts label that you pay .28 per Kwh and also 5.29 cents per Kwh for delivery charges. I spoke to them on Monday or Tuesday this week and they confirmed that those delivery fees apply to the night time usage.... And their daytime is MORE than I am paying now after you add the delivery charges. An extra 3 hours of their "fee" window at 5.3 cents per Kwh is not going to help me vs 9 hours of COMPLETELY free power.

Big question is do you want to spend over $10k (give or take, before taxes) for just one power wall with 13.5kwh of storage and 11kw of inverter power? If you choose to walk away from Tesla you can certainly meet your goals for cheaper. It just won't be as pretty.

Well, I am willing to go another route, but the problem is that comparable systems are not all that much cheaper. I will be doing 2 power walls which will obviously double the storage but also 2 hybrid inverters since I have 400amp service. Having gone Tesla for solar I know how easy the process is with them... The other options would be DIY and would still cost close enough to what the Tesla system will cost that the extra seems justifiable for them doing the install and guaranteeing the work and it all being Tesla and compatible and controlled through 1 app. Plus, I can come out of pocket for as little or as much as I choose.

Lastly, dont need to run all 4 HVAC's... in fact, I probably will not run ANY of them if grid power goes out, unless the sun in shining or I decide to add a propane generator. I mostly want the batts for arbitrage. Tesla confirmed that the power walls will charge off the grid so I should be good to go.

 

[Zombiezach7]

Was looking to build out my existing back up battery bank and possibly add solar down the road. Looking at plans I came across this with Chariot Energy. This was for their free night plans which only run from 11pm to 6am.