Is better to schedule or just charge?

Technically you’re not to keep Li-ion batteries fully charged. I think keep as in stored for a length of time. I personally don’t think 8 hrs is considered storage. Scheduled charging is more important when you use the precondition option where your cars climate control system will run before the charge cycle completes so your car is warm/cool when you are ready to depart. My opinion on that. As far as 40% I’ve heard 80% is a good level for storage. My iPhone has an option to charge it’s battery to 80% prior to topping it off just prior to when it thinks you’ll start using the phone. Fwiw. Welcome to Priuschat. Enjoy your new car.

 

I have solar panels, so most days 8 AM to 3 PM is free*. Scheduled charging can help, if the car was charged by 1 PM, I could still fill the solar batteries by 3 PM.

This may not fit your schedule, or only fit it on weekends, but free is nice!

*My inverter is set to prioritize local loads first, then solar battery charging. You can set have other priorities. Because the solar battery is charged by the cells, I am not using Utility power between 7:30 AM and 10:30 PM, but 8 AM to 3 PM is when I have excess solar for charging a car.

 

Don't quote me, but many Li-ion batteries self discharge a little in the first hours after charging. Just a few percent, but if you are looking for the maximum range you want every watt that you can get out of that battery.

I schedule my charge time to be from midnight to 3 pm in order to match the cheap electricity rates. There's been no ill effects.

 

Does MA not have net metering? In CA you receive a bill credit for the retail price of each kWh generated. People were getting large credits generating a lot of power during peak price periods and then using grid power during off-peak periods. The utilities in CA got "smart" and moved peak price times from the afternoon to evening so that solar customers wouldn't be racking up large bill credits during peak generation times. This has started to influence panel placement, as people are starting to favor western exposures to maximize production during peak price periods rather than south to maximize net kWh production. Either way, if I generate $5 worth of electricity at noon, I can pull $5 worth of electricity from the grid at 3 am and don't get charged a cent.

 

I am going to answer for MS, which I am pretending you meant.
If you are a TVA or a private electric company customer, then yes, you have Net Metering.
If your electric utility is a Co-Op or a municipal department, then the MS Public Service Commission does not have the jurisdiction to mandate Net Metering. In my case, the Greenwood Utilities will cancel my account if their electric meter ever attempts to go backwards. As such, no matter how much solar it is generating, my inverter very carefully uses 40 watts of city power at all times.


So much of MS has Net Metering, but cities and very rural area may not.

I have no idea about MA.

 

Yes. I actually meant MA, but because I had misread your profile as Massachusetts for some reason. The error was my reading comprehension rather than my typing.

 

I'm about to find out in person how net metering works here since they should be installing my panels late next week. As the representative from the people selling me the system explained it, Duke Energy lets the electric meter run back and forth and then settles up at the end of the year. If I come up short, I pay them retail for the kWhs I have to buy from them. If I'm over, and that's what we're planning for, they will buy my excess for about three cents per kWh.

 

If you have a time of use plan the important thing is whether the accounting is done in dollars and cents, or whether it's done in kWh. Hopefully it's done in dollars and cents so you rack up dollar credits during the day and can "spend" them at night when each dollar buys more kWh.

 

No such thing here. Thank the Lord!! But with the new meters they are going around installing, they might be thinking about TOU.

 

TOU saved me about 30% on my power bills. The off-peak rate is 75% less than the peak rate. By running the pool pump, charging the car, and pre-cooling the house in the summer during off-peak, I was able to shave hundreds from my summer bills.

 

You could also say that the peak rates are 4 times higher than the off-peak. They hike that peak rate to a "not for sale" price to discourage use during the times people most need power so those people will find a way to reschedule energy use to a time that makes it easier for the electric company to meet the demands. It's a really smart move for them, but not intended to save us money even though we might be able to reduce the impact with timers and stuff.

We pay about 11 cents per kWh 24/7. What are your rates? If I had to guess, based on what I've read about rates nationwide in general, I suspect that the off peak might be a little less than our all day rate while the peak is way higher. But I'm just guessing since I can't find the actual numbers online. I'd love to see actual prices according to time of day.

 

3 cents per kWh! That's a robbery. BUT that's still much better than our Net Metering system. In our state, the utility pays nothing back for the excess production. Only credit up to the actual usage. And the credit expires in 12 months on a rolling basis. This is one of the reasons the large capital investment on oversized PV on one's roof here is a waste of money.

 

Here, you have to sign up for off-peak discounts. But there's a massive gotcha: Your on-peak rate almost doubles so unless you stop using power on-peak you can wind up paying much more over-all. This plan was designed for large commercial users. As it is they charge one rate for the first 600kwh and bump that for the next block of usage. So in the normal billing tier there's no incentive to charge off-peak.

There's a move to change to a different on/off peak billing scheme that's more geared towards car charging, but the average user won't see much if any difference.

 

That was my initial reaction, too. Then I got to thinking about it yesterday. I'm basically using the utility as a battery. How much would batteries cost? A LOT! So with that in mind, I really don't mind letting them buy my excess at a discount as long as I can use their very expensive system as a battery at night. The only drawback is that that "battery" obviously doesn't help me in a power outage. LOL!

 

We have three tiers. Super off-peak is 13 cents (10 pm - 8 am), off-peak is 18 cents (8 am - 2 pm weekdays and 8 am - 10 pm weekends), and peak is 51 cents in the summer (2 pm - 9 pm). The non-TOU plan works out to about 18 cents.

I was going to link to the rate plans on my utility's web site, but it's down as it often is since they fired their entire IT department and outsourced it. They even made the existing staff train the new outsourced staff before their last day.

 

But batteries aren't taking the power you used to charge them up and selling it to your neighbors at retail rates. The utility acts like "poor me, this is all so expensive!" They're forgetting to mention how they're getting plenty of money for that power, and then making another markup when they sell you that power back. They're literally double-dipping and complaining that it's putting them in the poor house.

What's really going to put them in the poor house is people like me getting fed up with them and turning to battery solutions to cut them out of the equation entirely. Then they'll run to their lawmaking friends to get a law that you have to buy from them.

EDIT - Plus, keep in mind that the 3 cents is for power you never draw back. It's power you gave to them and never used. They sold it to your neighbors at retail and never had to supply it back to you, and they didn't need any expensive high-voltage transmission lines, substations, or generating plants to do it. Almost pure profit.

 

They do that at the end of each year. If I haven't needed it by then, I probably never will. I should be able to store up enough now when my energy needs are at the lowest so that I'll have plenty available for the high usage months. If for some reason I don't produce enough in a given month and have used up the excess from previous months, then I might have to buy a few kWh from them, but I don't expect that to happen. At the end of the year, if I have produced more than I needed, they buy it. I'll find out next January how well we sized the system.

Last month, I only used a little over 700 kWh. My system is sized to produce a hair under 10,000 kWh per year. Since we're in a sunny time of year and close to 12 hour of daylight per day, I think it would have produced about 833 kWh this past month. It should do more than that next month since there's more daylight. And the A/C load still won't be at summertime levels. That electricity will be "in the bank" for me to draw from later in the year as need arrises.

My biggest indication that I made the right decision is that a guy who lives next door from our offices works for the power company and he says they really don't like that stuff. Them not liking it makes me pretty sure that I will like it.

Oh my. That genuinely sucks. I think I'd say you aren't "saving" with off peak prices; you just aren't getting raped as brutally as the other times. How can they not manage to maintain their grid so it doesn't set the forests on fire while charging those kinds of prices??? Reminds me of where we used to live in Honduras ... 50 cents/kWh for off-and-on electricity and voltages all over the place.

 

That's the grandfathered plan you're not allowed to choose anymore. They'll kick me off soon enough. The new rate plans are as shown here: Time-Of-Use Residential Rate Plans | Rates | Your Home | Home - SCE

The best you can get is 27 cents/kWh off-peak and 43 cent on-peak if you don't have an electric car. They give us a "break" at 17 cents per kWh off-peak and 44 cents on-peak.