let's talk about battery banks- I reckon the "they aren't worth it" thing is wrong

[GoldDigger]

YES!

I think you're finally getting it.

Net metering is the same as having a FREE battery. If POCO buy and sell prices are equal the cancel each other out - and therefore unless your battery is free using the net metering beats the hell out of using a battery.

"I don't like net metering at all in truth. All it does for the consumer is make the bill zero- if that's the only choice, sure , but why not make some money, if you're spending some? "
Well generally the consumer is much better off taking the net metering and getting his bill reduced to 0.
Selling the power reduced means you get paid market rates - and the market rates are likely to be around $0.04/kwh.
(Get paid $0.04/kwh or get credit toward usage at $0.30/kwh... I know which one I'm choosing)

But the absolute ideal is to be able to sell the power to the utility but cheat and put it into your battery instead when they are not looking.
That is very similar to some of the formulae that PVFarmer has tried to use.

 

[PVfarmer]

Sigh.

If the LCOE for the PV is less than what you sell it to the POCO for, then you are not losing money. You are making money. That's what net metering generally means.

Yes. But I didn't say "LCOE for PV is less than sell price to POCO". I said less than buy price from...
And it's true- if the cost to you of energy you produce is less than the price you'd pay to get it back...why would you sell?

I said:
Originally Posted by PVfarmer If you have no batteries and you get less for the kWhs you "sell" during the day and pay more for the ones you "buy" at night, because the LCOE for the PV is less than the price the POCO charges you to buy them back...

YES!

I think you're finally getting it.

Net metering is the same as having a FREE battery.

Net metering is having free electricity when you do it right.
But only when the price you are paying to get the power back out of this magical invisible battery (buying price) is equal to the selling price.
The "selling price" is = to the production price, or LCOE.
When you buy something for more than you sold it for, it isn't free.

 

[wwhitney]

If you have no batteries and you get less for the kWhs you "sell" during the day and pay more for the ones you "buy" at night, because the LCOE for the PV is less than the price the POCO charges you to buy them back...

The LCOE for PV is not the rate the POCO pays you when you sell during the day. They are unrelated.

You are right that if your daytime sell price is less than your nighttime buy price from the POCO, there may be a case for batteries economically.

However, with net metering is that this doesn't occur (assuming you are still a net consumer of electricity).

Cheers, Wayne

 

[wwhitney]

if the cost to you of energy you produce is less than the price you'd pay to get it back...why would you sell?

Because the price you get selling that energy is bigger than or equal to the price you'd pay to get it back?

If you're deciding whether to sell and buy back, your cost doesn't matter. Just the sales price and the buy price.

Cheers, Wayne

 

[TommyO]

Originally Posted by

PVfarmer If you have no batteries and you get less for the kWhs you "sell" during the day and pay more for the ones you "buy" at night, because the LCOE for the PV is less than the price the POCO charges you to buy them back...

Originally Posted by TommyO
YES!

I think you're finally getting it.

Actually my "Yes, I think you're finally getting it." was in response to your statement that when you have net metering and sell price is same as buy price you'd have to steal the batteries (ie. get them for free) in order for it to be as good a deal as net metering.

I don't know what you're trying to say above, and definitely did NOT quote that when I was agreeing with you.

Net metering is having free electricity when you do it right.

No.
It's not free electricity - it's free "storage" of the electricity.

But only when the price you are paying to get the power back out of this magical invisible battery (buying price) is equal to the selling price.

Since selling price = buying price for net metering, I don't understand why you are saying "only when".

The "selling price" is = to the production price, or LCOE.

No - selling price is equal to what the POCO pays you (or credits toward your bill)
With net metering the selling price is the same as what you pay.
Without net metering the selling price is typically some small amount around $.04/kwh (usually about the same as the production price for the utility)

The production price (for PV) is completely separate from that and is based on the individual PV install. The install on my house may have a LCOE of $.07/kwh while my neighbors may be $.12/kwh. Both of us sell to the POCO for the same price.

When you buy something for more than you sold it for, it isn't free.

True, but rather irrelevant to this discussion.

Bottom line - batteries add to the cost and are not an economical choice in the US for the vast majority of people. That's because we have net metering and/or cheap electricity in most places in the US.

 

[jaggedben]

The "selling price" is = to the production price, or LCOE..

No - selling price is equal to what the POCO pays you (or credits toward your bill)

Wash, rinse, repeat... :roll: And pass the popcorn.

 

[PVfarmer]

1 The LCOE for PV is not the rate the POCO pays you when you sell during the day. They are unrelated.

2 You are right that if your daytime sell price is less than your nighttime buy price from the POCO, there may be a case for batteries economically.

3 However, with net metering is that this doesn't occur (assuming you are still a net consumer of electricity).

4 me-if the cost to you of energy you produce is less than the price you'd pay to get it back...why would you sell?
Because the price you get selling that energy is bigger than or equal to the price you'd pay to get it back?
If you're deciding whether to sell and buy back, your cost doesn't matter. Just the sales price and the buy price.

5 If you're deciding whether to sell and buy back, your cost doesn't matter. Just the sales price and the buy price.

We are *almost* on the same page, but more like on the same sheet of paper but opposite sides of that one sheet.

1 If the LCOE was more than the price you were getting for selling the energy it produced, there would be no reason to do it, so they are related. "How" is the question.

2 Thank you. We have agreed!

3 Whoops! Your "daytime sell price" isn't just how much the POCO pays you- it costs you the LCOE/kWh to produce it. Again, if that daytime sell price was LESS than the LCOE to produce it, there would be no reason. So with net metering, sure you are "buying and selling" at X cents, but it really costs you the LCOE for what you have sold. You'd be losing money on what you sell if you weren't generating extra during the day to cover the night. X doesn't change on the "buying" side- that's why you have to put out extra during the day to cover the night.
You aren't really "buying" anything at night, like you say, you're just using your "free battery"...that's why the correct cost for filling that battery is important.

4. see #5

5. I think what might be happening is we aren't defining who net metering and/or batteries are "good for", while trying to discuss both.
Let's focus here- do you agree with this: net metering is only good for the person/company not trying to "make money" directly from net metering, ie- a homeowner who wants no bill and a longer payback period OR a PPA company/developer/installer who is making their money off of something other than a zero bill?

 

[GoldDigger]

Even with popcorn, I just can't take it anymore.....

 

[PVfarmer]

Actually my "Yes, I think you're finally getting it." was in response to your statement that when you have net metering and sell price is same as buy price you'd have to steal the batteries (ie. get them for free) in order for it to be as good a deal as net metering.
I don't know what you're trying to say above, and definitely did NOT quote that when I was agreeing with you.

No.
It's not free electricity - it's free "storage" of the electricity.

Since selling price = buying price for net metering, I don't understand why you are saying "only when".

Without net metering the selling price is typically some small amount around $.04/kwh (usually about the same as the production price for the utility)

The production price (for PV) is completely separate from that and is based on the individual PV install. The install on my house may have a LCOE of $.07/kwh while my neighbors may be $.12/kwh. Both of us sell to the POCO for the same price.

Bottom line - batteries add to the cost and are not an economical choice in the US for the vast majority of people. That's because we have net metering and/or cheap electricity in most places in the US.

I didn't say that "when you have net metering and sell price is same as buy price"- I said that is only true with looking at the costs, on both sides of that. It isn't free to produce, so you can't "get it back for free" when it cost money to produce!

So "free storage" is over simplified.


Since selling price = buying price for net metering, I don't understand why you are saying "only when".
They don't always- they only do when the actual LCOE (selling price) is = to buying price- then you have no bill. However, the buying price changes (the standard is it goes up 3% a year).
One is linear- the other isn't.

Without net metering the selling price is typically some small amount around $.04/kwh (usually about the same as the production price for the utility)
For a lot of people (millions perhaps?) the selling price can be 10 times that...so?

You and your neighbor wouldn't be selling for the same price! If the sell-to-POCO price was 10 cents there, your neighbor would be paying 2 cents for the power they were "selling". See!

So that wasn't really the bottom line then.

 

[PVfarmer]

so then.....?

so then.....?

Originally Posted by TommyO

The production price (for PV) is completely separate from that and is based on the individual PV install. The install on my house may have a LCOE of $.07/kwh while my neighbors may be $.12/kwh. Both of us sell to the POCO for the same price.

You and your neighbor wouldn't be selling for the same price! If the sell-to-POCO price was 10 cents there, your neighbor would be paying 2 cents for the power they were "selling".

We haven't hit the bottom of anything yet!

 

[GoldDigger]

If you have power that you cannot use at the time it is generated, then absolutely without regard to the LCOE and POCO selling price, you are better off sticking it into the POCO battery or a real battery than you are throwing it away. With the following exception:
If your cost to get the power back (having already produced it, and noting that not producing it does not save you anything on your PV system expense it just forces you to recalculate your LCOE) is more than your cost to buy replacement power outright, then it does not make sense to try to store it at all.

In the US, I would say that more than 90% of users have Net metering which either sets sell=buy OR has sell greater than buy because of TOU rates.
And if you have an overall yearly net surplus, you cannot keep it in your battery or use it, so you should sell it to POCO for whatever pittance they are willing to give you.

One very large advantage of the POCO battery is that it generally allows you to store energy all summer and pull it out again in the winter. Show me a battery that can do that.

PS: So much for my self-control and resolve. Pass the popcorn.

 

[TommyO]

They don't always- they only do when the actual LCOE (selling price) is = to buying price- then you have no bill. However, the buying price changes (the standard is it goes up 3% a year).
One is linear- the other isn't.

No - the selling price and buying price in this case is the price you buy/sell power to/from the POCO.
And those *are* equal in net billing.
Both may go up 3% or 6% in a year, but they'd still be equal.

The LCOE (for PV) is NOT the price you get when you sell to the POCO.

"Without net metering the selling price is typically some small amount around $.04/kwh (usually about the same as the production price for the utility)"
For a lot of people (millions perhaps?) the selling price can be 10 times that...so?

Actually about 5-8x that is effective selling price for many. I don't believe there are millions of people selling power to the POCO for $.40/kwh
The reason that millions can sell their power to the POCO and get a credit of $.15/kwh to $.35/kwh is because they are getting net metering.
And you see the beginning of my sentence? "without net metering ..." Which is to say NOT those people getting $.15 to $.35/kwh because of net metering.

You and your neighbor wouldn't be selling for the same price! If the sell-to-POCO price was 10 cents there, your neighbor would be paying 2 cents for the power they were "selling".

Yes we would be selling for the same price. ($.10)
My neighbor would have a net loss. ($.10-$.12 = -$.02)
I would have a net gain. ($.10 - $.07 = +$.03)

The sales price is the same - it's the purchase price (as amoritized over the lifetime) that is different.

And IMO it isn't appropriate to put selling in quotes because it is selling in the normal usage of that word.

 

[TommyO]

So that wasn't really the bottom line then.

"Bottom line - batteries add to the cost and are not an economical choice in the US for the vast majority of people. That's because we have net metering and/or cheap electricity in most places in the US."

That's still the bottom line.
1> We have net metering and/or cheap electricity in most places in the US.

2> Batteries will add to the cost

3> In most cases batteries don't provide enough of a benefit to people in the US to overcome their extra cost. (with net metering they provide $0 of benefit)

Those are the facts right now in the US.

Germany has different facts - they don't have net metering, therefore there it is more likely there can be a benefit.

 

[PVfarmer]

"Bottom line - batteries add to the cost and are not an economical choice in the US for the vast majority of people. That's because we have net metering and/or cheap electricity in most places in the US."

That's still the bottom line.
1> We have net metering and/or cheap electricity in most places in the US.

2> Batteries will add to the cost

3> In most cases batteries don't provide enough of a benefit to people in the US to overcome their extra cost. (with net metering they provide $0 of benefit)

Those are the facts right now in the US.

Germany has different facts - they don't have net metering, therefore there it is more likely there can be a benefit.

1. California has net metering, right? And the rate is 12.46 cents, slightly under the national average of 12.64. It also has 1/8th of the US population. So why is there currently 10MW+ of battery storage being installed in the state (residential backlog) and a goal of 10GW by 2020?
Those are facts!
So that's no on 2 and 3.

Also facts: 20MW for SHELL OIL!! And 50MW for SCE....big stuff!
I looked - Cali has had net metering for almost 20 years now, wow.

http://www.pv-magazine.com/news/det...rnia-storage-project_100020220/#axzz3gBFNtNs4

http://www.pv-magazine.com/news/det...w-of-battery-storage_100019924/#axzz3gBFNtNs4

 

[GoldDigger]

1. California has net metering, right? And the rate is 12.46 cents, slightly under the national average of 12.64. It also has 1/8th of the US population. So why is there currently 10MW+ of battery storage being installed in the state (residential backlog) and a goal of 10GW by 2020?
Those are facts!

Much, if not all of California is on a tiered usage rate system to encourage conservation. The buy/sell rate for second tier is closer to 20 cents and for third tier can approach 30 cents. (That is all in the process of changing though.)
So for cost avoidance, a less than 100% PV system can have a payback of well under 5 years.

 

[PVfarmer]

The reason that millions can sell their power to the POCO and get a credit of $.15/kwh to $.35/kwh is because they are getting net metering
And IMO it isn't appropriate to put selling in quotes because it is selling in the normal usage of that word.

No. The POCO makes it very clear (here anyway) that they aren't buying a single bit of power from you- it's applied to your bill as a credit. You cannot in fact get any payments in the form of a check for any excess.
So that's not really "selling" anything!

Selling is a PBI.
Lots of those for PV in lots of states...
http://en.openei.org/wiki/Performance-Based_Incentive

 

[ggunn]

I wanted to respond to this... I'm not sure the way you're putting it makes any more sense than the way I did. There's a certain sense in which it is not appropriate to talk about LCOE for batteries at all because they are not ultimately a source of electricity.

That's what I was thinking as well. You cannot buy energy from batteries. Batteries are not a source of energy, they are a net sink of energy because you can't get back all you push into them. "LCOE of batteries" makes no sense to me at all.

 

[GoldDigger]

That's what I was thinking as well. You cannot buy energy from batteries. Batteries are not a source of energy, they are a net sink of energy because you can't get back all you push into them. "LCOE of batteries" makes no sense to me at all.

OK, so you have an LCOE for directly used PV and an LCOE for PV generated and stored before use.
The difference between the two is what the batteries contribute to the LCOE of the latter option, even if you do not call it the LCOE of the batteries.
I think that is really a safer way to think of it since it removes the misguided temptation to compare the battery "LCOE" alone to the POCO rates.

And as long as there is no NET surplus at the end of the year, for most users it is perfectly reasonable to think of running the meter backwards as selling.
If there is a NET surplus at the end of the year, it would not have gone into the batteries and come back as useful energy either. :angel:

 

[jaggedben]

The POCO makes it very clear (here anyway) that they aren't buying a single bit of power from you- it's applied to your bill as a credit.

SELLING AND GETTING A CREDIT ARE THE SAME THING.

:slaphead::slaphead::slaphead:

Assuming that POCO credits and charges are equal on a yearly billing cycle, then...

If you produce exactly what you use , then your cost for all your energy is the LCOE for PV production.

If you install a PV system that produces more energy than you need, then you are foolishly spending money on energy you don't need. Your LCOE goes up. (Would you buy gas that didn't fit your in your car's fuel tank?)

If through foolishness, or just happenstance, you have a PV system that exceeds your needs, it still makes no sense to install batteries because you would never need to take out what you stored in them. (Edit: Golddigger said the exact same thing in the last sentence of his last post. Typing at the same time.)

 

[jaggedben]

I think that is really a safer way to think of it since it removes the misguided temptation to compare the battery "LCOE" alone to the POCO rates.

To each his own, but personally I have no problem conceiving of the battery's LCOE as being either positive or negative, depending on the effect on the overall LCOE. As I said earlier, that LCOE can only be negative if there's a significant difference between POCO charges and credits.