Time of Day for Pool Pump/Sweeper

[PVTim]

Getting a 12.7kw installed this week, and am hoping to eliminate the electric bill as much as possible.
We normally run the pool pump at night (as rates are lower), but now with PV, I'm guessing best to run mid day?
My understanding the most power while on PV as possible, and minimize the grid power... even if the rates are lower at night.

It is confusing now with the Net Metering 2.0, and I'm still not sure what is best.. what do most of you pool owners on PV do?
As a side note we usually on run about 3kw during the day, and 5kw at night.
Pool pump is a variable speed mag drive unit, and normally is about 800-1250w depending on speed.
Usually run for about 8 hours a night.

[malba2366]

If you are on TOU plan you should be paid for the price of the energy at the time you are generating it. It would still benefit you to run your pool equipment during off peak times.

[J.P.M.]

1.) Minimize the use of electrical power, first through use reduction and then through efficiency improvements in equipment.

2.) After use is as low as possible for your lifestyle, and if you are on T.O.U. rates, shift as much of your remaining use as possible/practical to times when electricity rates are lowest.


In terms of how NEM and T.O.U. works, generally, if your rate schedule does not have a tiered rate feature incorporated into it, you can, for the most part, consider a PV system as a revenue generator with the revenue produced pretty much independant of when you use electricity, and used to offset the cost of the electricity you do use, pretty much regardless of when you use it.

Think of what you use and pay for and the energy your PV system generates as separate commodities that both feed into your bill.

Without a PV system your bill would be a certain and variable amount per billing period depending on how much you use and when you use it. Your bill will amount to how many kWh you use in any hour times the price of electricity for that hour, with that product summed over all hours for that billing period of, say a month.

Somewhat conversely, A PV system with no use against it in a billing period will still be generating electricity that has a certain value as a credit against future use. That value is the system
generation rate in kWh for any hour times the electricity rate for that hour, with that product summed for all hours in that billing period, again, provided your system does not generate more than use, and to repeat, provided you have a straight T.O.U. billing schedule.

So, with generation value of a PV system independent of how much electricity you use or when you use it, more use during off peak hours will mean that, for the same use per billing period you will pay less per kWh and have a lower bill. Or, because generation and its value as a bill offset is independent of use and charges for that use, time shifting of use and loads to off peak times will mean that it will be possible to use more electricity than if used at peak times and still have the PV revenue offset the higher usage.

All the conservation and time shifting efforts and their effects should be considered and done and before any PV is considered to avoid oversizing a system which results in a less cost effective PV system.

As a first priority for the filter schedule and use, run the filter with an eye toward keeping the water and the pool as clean/bacteria free as necessary. Saving on pumping costs, while always good, and can be a cost effective measure to seriously consider, but is a secondary consideration to health/safety.

[PVTim]

J.P.M. Thanks for the detailed reply. I've heard it so many times but it is starting to settle in.

Correct me if I am wrong, but with NEM 1.0 it was straight kw for kw regardless of TOU
But with NEM 2.0 is really is Only $ based, so the credits are Earned at the Current TOU rates, and spend at the current TOU rates
Or is it a hybrid of the two in 2.0?

[J.P.M.]

J.P.M. Thanks for the detailed reply. I've heard it so many times but it is starting to settle in.

Correct me if I am wrong, but with NEM 1.0 it was straight kw for kw regardless of TOU
But with NEM 2.0 is really is Only $ based, so the credits are Earned at the Current TOU rates, and spend at the current TOU rates
Or is it a hybrid of the two in 2.0?

You're most welcome.

I'm assuming you are in CA.

NEM and the rate schedule you get billed on are loosely related.

NEM is net energy metering. It applies to folks and businesses with PV and/or other methods of onsite generation. It's an agreement between the cust. and the POCO about what to do with the generated electricity and its vaule.

Somewhat separate from that, there is the matter and the form of the rate of payment/value of the power that's transmitted to a customer, or in the case of a PV owning customer, the rates charged or credited going either way. Non PV users also have a choice of rate plans. Some are tiered, most are T.O.U.

Tiered rates are being phased out, but they will be around for awhile for some folks depending on a user's status.

NEM 1.0 customers have a choice of rate plans. Some are tiered. Most are something called T.O.U.

As an NEM 2.0 customer, you too will have choices as to which rate plan you can use. Depending on your POCO's rules, as a new NEM 2.0 customer, you may not have a tiered rate schedule available to you. My guess is you'll get steered or mandated to a T.O.U. schedule.

There are probably several T.O.U. rate schedules to choose from. Depending on your quantity of usage and use patterns, different rate plans will produce different bill $$ amounts. Choose wisely.

Depending on your POCO, as a new NEM customer, you will also have a less favorable deal for your PV. New NEM 2.0 users are not "grandfathered" into the old T.O.U. time schedules. The new time schedules make PV billed using a T.O.U. schedule about 20-25 % less cost effective than a PV system on a T.O.U. schedule billed using the old, or "grandfathered" T.O.U. time schedules.

Example: For my POCO, for T.O.U users either NEM 1.0 or NEM 2.0 that are grandfathered, and using PVWatts modeled generation and data, and current SDG & E rates and times for sched. DR-SES, the average value of a kWh of PV electricity for a 180 deg. az., 20 deg. tilt array orientation is ~ $0.346/kWh. Without grandfathering, or for new PV users, that value is ~ $0.263/kWh. Your numbers will probably be a bit different but probably somewhat similar in terms of the spread.

Some - and more than a few - T.O.U. rate schedules also have a tiered level laid over them. The way it works: The rates and times are T.O.U., but the schedule "credits" use up to the tier two level in any billing period for a certain amount per kWh. In effect, the user pays less for electricity on a T.O.U. schedule for what amounts to tier one usage and a higher amount for all usage above that usage per billing period. So to repeat, examine your options and choose wisely.

Aren't you glad you asked ?

Welcome to the forum of few(er) illusions.

[Ampster]

[
Correct me if I am wrong, but with NEM 1.0 it was straight kw for kw regardless of TOU
But with NEM 2.0 is really is Only $ based, so the credits are Earned at the Current TOU rates, and spend at the current TOU rates
Or is it a hybrid of the two in 2.0?

The biggest difference between NEM 1.0 and NEM 2.0 is the Non Bypassable Charges. Otherwise the accumulation of dollars and kWhrs is the same. I have two buildings on NEM 1.0 and I accumulate dollar credits and kWhr credits. The kWhr credits for each TOU rate period times the rate is how the accumulated dollar credit is calculated. My home on NEM 2.0 is the same but I am charged an extra 2 to 2.5 (NBC charges)cents per kWhr for consumption.

[foo1bar]

Getting a 12.7kw installed this week, and am hoping to eliminate the electric bill as much as possible.
We normally run the pool pump at night (as rates are lower), but now with PV, I'm guessing best to run mid day?

Most likely from an electric billing perspective you want to do during off-peak times.

My understanding the most power while on PV as possible, and minimize the grid power... even if the rates are lower at night.

Depends on your billing situation.
Some billing systems you're better off selling 10kwh@ $.25/kwh at 2PM and then buying back 10kwh@$.10/kwh at 2AM.
Others you're better off not moving those kwh to the POCO and then getting them back later.

It is confusing now with the Net Metering 2.0, and I'm still not sure what is best.. what do most of you pool owners on PV do?

it really depends on your billing situation.
I'm not on a TOU plan, so it doesn't matter from a billing perspective when I run my pump.
I believe that I keep the pool warmer by stirring the water (pumping) while the sun is shining, and not doing that when the sun is down.
So I run mostly during the day.
Were I on a TOU billing I'd probably run mostly at night.

I have friends on PG&E (northern CA POCO) that shift as much as they can to off-peak (at night). They generate fewer kwh than they use but still have a $0 bill because the credits at the higher peak rates offset the larger kwh consumption at lower per-kwh rates.

As a side note we usually on run about 3kw during the day, and 5kw at night.
Pool pump is a variable speed mag drive unit, and normally is about 800-1250w depending on speed.
Usually run for about 8 hours a night.

So which pump do you have?
I just changed to a pentair Intelliflo VS (011018) and installed an automation system (easytouch)