Enphase Battery information

[solar_newbie]

Have anyone had more info about enphase battery ? I see it is more usefully vs Tesla power wall.

For Tesla, you must have solar and feed DC power from solar during the day to charge the battery and use it during the night. It is stupid it is 1-1 convert. If I sell my power during the day to power company and buy back during the night, I got 2X - 3X benefit.

What the best is to buy power during the night and use during the day. Sell everything solar generate during the night. So my value from solar increase 2-3 times

I am not sure if I could control Enphase AC battery to charge during the night and supply during the day or not?

For example with 5KW system, it can generate around 22KWH per day. If I use 12kwh during day time and 20kwh during night time. I virtually can sell 10Kwh to get 20kwh credit for night time to use (Assume 2x credit different in TOU)
Now, if I have 12kwh smart AC battery, I will move all my usage to night time of 32kwh. Charge the 12kwh battery at night and use during day time. Solar power will put back to the grid during day time to get 44kwh credit. So I get 12 extra kWh for any extra things to use.

If I use 10 kWh tesla powerwall, I will end up to pay 10kwh more for my night usage as I get zero credit from Power company
If I use 20 kWh tesla Powerwall, I end up to pay 10kwh day cost which is equal to 20kwh night cost.

I do not see any benefit to have solar edge and tesla power wall for Us where net meter is provided.
What do you guys think?

[inetdog]

Not going into the details of your analysis, I agree with your conclusion. Net Metering is cheaper than any battery could ever be.

[paul65k]

Have anyone had more info about enphase battery ? I see it is more usefully vs Tesla power wall.

For Tesla, you must have solar and feed DC power from solar during the day to charge the battery and use it during the night. It is stupid it is 1-1 convert. If I sell my power during the day to power company and buy back during the night, I got 2X - 3X benefit.

What the best is to buy power during the night and use during the day. Sell everything solar generate during the night. So my value from solar increase 2-3 times

I am not sure if I could control Enphase AC battery to charge during the night and supply during the day or not?

For example with 5KW system, it can generate around 22KWH per day. If I use 12kwh during day time and 20kwh during night time. I virtually can sell 10Kwh to get 20kwh credit for night time to use (Assume 2x credit different in TOU)
Now, if I have 12kwh smart AC battery, I will move all my usage to night time of 32kwh. Charge the 12kwh battery at night and use during day time. Solar power will put back to the grid during day time to get 44kwh credit. So I get 12 extra kWh for any extra things to use.

If I use 10 kWh tesla powerwall, I will end up to pay 10kwh more for my night usage as I get zero credit from Power company
If I use 20 kWh tesla Powerwall, I end up to pay 10kwh day cost which is equal to 20kwh night cost.

I do not see any benefit to have solar edge and tesla power wall for Us where net meter is provided.
What do you guys think?

I think your conclusion is correct as long as the current CA net metering scheme is in place.....namely selling power back to the Power company at retail (day or night rates) vs. what certainly looks to be the future (and current in some places already) where the PoCo buys from the homeowner at their overall wholesale rate and selling it back to you at retail.......at SCE that current number is around $.035 vs buying at anywhere from .16-.32 per KWh.........makes solar a little less attractive on a net metering basis and at some point COULD make batteries look attractive.....but not until there is some serious technology improvements that drive down the cost per KWh on Batteries.

[lkruper]

I think your conclusion is correct as long as the current CA net metering scheme is in place.....namely selling power back to the Power company at retail (day or night rates) vs. what certainly looks to be the future (and current in some places already) where the PoCo buys from the homeowner at their overall wholesale rate and selling it back to you at retail.......at SCE that current number is around $.035 vs buying at anywhere from .16-.32 per KWh.........makes solar a little less attractive on a net metering basis and at some point COULD make batteries look attractive.....but not until there is some serious technology improvements that drive down the cost per KWh on Batteries.

Costco golf car batteries cost 11.09 cents / kWh delivered during their lifetime and $67.62 per kWh stored. How low do batteries need to go to make batteries look attractive?

[solar_newbie]

I think your conclusion is correct as long as the current CA net metering scheme is in place.....namely selling power back to the Power company at retail (day or night rates) vs. what certainly looks to be the future (and current in some places already) where the PoCo buys from the homeowner at their overall wholesale rate and selling it back to you at retail.......at SCE that current number is around $.035 vs buying at anywhere from .16-.32 per KWh.........makes solar a little less attractive on a net metering basis and at some point COULD make batteries look attractive.....but not until there is some serious technology improvements that drive down the cost per KWh on Batteries.

As long as you are in NEM 1.0 in Calif, I think everywhere is the same right ? Sell and buy as retail rate. Why SCE is different ?
Plus NEM 1.0 is locked for 20 years right.


I see many states have better plan than California. I do not hear anyone complains that they sell with lower rate than buying as of now.

Future I do not know...

[paul65k]

As long as you are in NEM 1.0 in Calif, I think everywhere is the same right ? Sell and buy as retail rate. Why SCE is different ?
Plus NEM 1.0 is locked for 20 years right.


I see many states have better plan than California. I do not hear anyone complains that they sell with lower rate than buying as of now.

Future I do not know...

NEM 1 IS buy and sell at same rate....as I stated in my post, however this expires sometime next year and the follow-on program in as yet undefined. In AZ they have petitioned the state to allow buy at wholesale and sell at retail.....IMO it's only a matter of opinion until we get there. In my case I have a 20 year commitment for NEM1 but..........this if course can always change

[solar_newbie]

NEM 1 IS buy and sell at same rate....as I stated in my post, however this expires sometime next year and the follow-on program in as yet undefined. In AZ they have petitioned the state to allow buy at wholesale and sell at retail.....IMO it's only a matter of opinion until we get there. In my case I have a 20 year commitment for NEM1 but..........this if course can always change

Yeah. That is why I wonder how come a lot of people reserved for PowerWall batteries? Did they really do any economic calculation or just want to have for fun or do not know how to do the math?

[solar_newbie]

I just go through enphase dream video. They dream to have smart energy system where home owner sells all energy to power company when the price is high and buy back to store them when the price is low.
It seems very attractive.
Rule 21 does not allow users to send back storage energy to the grid. However, it does not prevent solar energy to send to the grid.

I can't wait to see enphase AC battery, envoy-S and new enlighten software release next year and how flexible enlighten software allow user to control AC battery Via envoy-S.

If they allow AC battery generate a bit higher voltage than enphase (currently enphase will generate a bit higher voltage than the grid), I could see enphase users can maximize their solar and TOU.

Like example I states, first during the day, all power will come from the Enphase battery. All solar power will go to the grid (I am not sure how to prevent battery power drain to the grid ?) Maybe control the max mount of Watt release from battery. Envoy can do it if it get grid usage from smart meter (if plan to do it via envoy-s) and solar production info.

During the night, charge the battery.

So TOU user will get double or even triple credit on All solar generated power ...

If this work as their dream, I would see the benefit of enphase vs Solaredge.

[inetdog]

Costco golf car batteries cost 11.09 cents / kWh delivered during their lifetime and $67.62 per kWh stored. How low do batteries need to go to make batteries look attractive?

Well, if Net Metering is available, a battery cost of zero will still not allow an off-grid inverter and CC based storage system to do any better than a GTI under NM. And the GTI will cost less. Panels are a constant to both.
Oh, and any current battery storage system will have an overall efficiency (CC loss, battery loss, inverter loss) well below 90% while a GTI could be 95% or better. The POCO virtual battery is 100% efficient and there are no losses pulling the power back out of that "battery."

There is, however, a battery cost (which has not, IMHO, been reached yet) which will make a storage system profitable when POCO is using a Time Of Use rate system, without the need for any PV at all.
Then you can compare the overall economic return between spending your money on a GTI system or a non-PV storage system.

[Willy T]

For Tesla, you must have solar and feed DC power from solar during the day to charge the battery and use it during the night. It is stupid

No clue where you got this from. The concept is the battery recharges from the grid during the night during the lowest Tier pricing or before noon on solar in the low tier depending on your net meter pay rate. The Battery discharges during the evening hours of peak Tier pricing, say 5:00 to 9:00 PM or whatever you have the capacity to support.

Of course you have to have programmable control of the Discharge time and the Recharge time of the battery, without that ability it would be worthless, as per your example. The concept example is to buy ( charge ) at $.10 and store to sell at $.40 with a net difference of $.30 per KWH credit, this makes it win/win.

The ROI is a big question mark. Number of KWH's offset, cost of system, lifespan of system ( Batteries ) and about 10 other things.

By the way anyone with a Grid Zero, Schneider XW or Outback G series hybrid Inverters can already do this by using generator / grid support and the AGS settings.

[lkruper]

Well, if Net Metering is available, a battery cost of zero will still not allow an off-grid inverter and CC based storage system to do any better than a GTI under NM. And the GTI will cost less. Panels are a constant to both.
Oh, and any current battery storage system will have an overall efficiency (CC loss, battery loss, inverter loss) well below 90% while a GTI could be 95% or better. The POCO virtual battery is 100% efficient and there are no losses pulling the power back out of that "battery."

There is, however, a battery cost (which has not, IMHO, been reached yet) which will make a storage system profitable when POCO is using a Time Of Use rate system, without the need for any PV at all.
Then you can compare the overall economic return between spending your money on a GTI system or a non-PV storage system.

My analysis, granted, not for everyone, was to use a conventional battery charger during the 10 hours at night which up to my baseline (13 kWh summer, 25 kWh winter / day = CA TOU SCE) charges the battery at one cent per kWh (11 cents / kwH - 10 cents / kWh). No cost for panels or charge controller. Was going to simply put a timer on the charger to give it power during those 10 hours to control the cost.

My batteries would be in battery heaven, regularly charged consistently to 100%, and not tormented by cloudless days. However, for a delta of only couple pennies at best per kWh, my time is more valuable.

[solar_newbie]

No clue where you got this from. The concept is the battery recharges from the grid during the night during the lowest Tier pricing or before noon on solar in the low tier depending on your net meter pay rate. The Battery discharges during the evening hours of peak Tier pricing, say 5:00 to 9:00 PM or whatever you have the capacity to support.

Of course you have to have programmable control of the Discharge time and the Recharge time of the battery, without that ability it would be worthless, as per your example. The concept example is to buy ( charge ) at $.10 and store to sell at $.40 with a net difference of $.30 per KWH credit, this makes it win/win.

The ROI is a big question mark. Number of KWH's offset, cost of system, lifespan of system ( Batteries ) and about 10 other things.

By the way anyone with a Grid Zero, Schneider XW or Outback G series hybrid Inverters can already do this by using generator / grid support and the AGS settings.

I got from Tesla. The usage case is to charge battery during the day (peak time) and use during the night. It does not make any sense until POCO not allow you to sell power back to their grid (unlimited battery with 100% efficiency)

http://www.teslamotors.com/powerwall

Since you are not control inverter, there is no way to charge during night time Plus rule 21 requires you are not put the power you charge on your battery to the grid. Who will control it. Battery itself can not. You need a hardware to connect to your smart meter to control it.

[solar_newbie]

My analysis, granted, not for everyone, was to use a conventional battery charger during the 10 hours at night which up to my baseline (13 kWh summer, 25 kWh winter / day = CA TOU SCE) charges the battery at one cent per kWh (11 cents / kwH - 10 cents / kWh). No cost for panels or charge controller. Was going to simply put a timer on the charger to give it power during those 10 hours to control the cost.

My batteries would be in battery heaven, regularly charged consistently to 100%, and not tormented by cloudless days. However, for a delta of only couple pennies at best per kWh, my time is more valuable.

This is illegal if you connect your battery to the grid It will endanger people who work on the grid when it is down...

[jflorey2]

No clue where you got this from. The concept is the battery recharges from the grid during the night during the lowest Tier pricing or before noon on solar in the low tier depending on your net meter pay rate. The Battery discharges during the evening hours of peak Tier pricing, say 5:00 to 9:00 PM or whatever you have the capacity to support. . . .
By the way anyone with a Grid Zero, Schneider XW or Outback G series hybrid Inverters can already do this by using generator / grid support and the AGS settings.

You can't do it with the Outback and a standard battery pack; the "sell to grid" settings effectively require you to have an external DC source to get the battery voltage high enough to sell. Per the tech support person I talked to at Outback this was partially because they did NOT want to be able to do power arbitrage, due to pressure from utilities.

(BTW it's still doable; you just have to run at a higher battery voltage. I am currently running at 54 volts and it works pretty well at that voltage, although there are problems with charging the battery from the grid due to lower available cell voltages.)

[lkruper]

This is illegal if you connect your battery to the grid It will endanger people who work on the grid when it is down...

I have a load side, 10 circuit manual transfer switch that I use with my generator for power outages. If I were to try to use batteries it would be with the output of the inverter into the transfer switch ... completely safe and legal.