Cost per PIP Charge

Charging LiIon batteries is a complex process where the charger has to adapt the instantaneous charging rate to feedback from the battery, like battery voltage or temperature. Doing it wrong can lead to not just battery failures, but spectacular failures (read: explosions). That is why the LiIon batteries in consumer devices like cell phones have fail-safe logic chips in the batteries themselves to prevent overcharging, even if the charger malfunctions.

 

I remember we were discussing the 15% charging loss in an old thread (maybe 3-3.5 months ago?) and all the big brains were working on it and spewing numbers and tossing around data. As I recall, "everyone" seemed to settle on the 15% number as being just about right.

If you look at the PiP MPG spreadsheet, there are a few people who logged their KAW consumption numbers. When comparing those to the PiP reported kWh, its about 15%.

PiP MPG Spreadsheet

Example:

ukr2 logged 187.9 on his KAW and the car reported 161 kWh
crewdog logged 71.29 and the car reported 61 kWh


The results vary still, especially smaller numbers where, most likely, the car is less accurate in reporting kWh consumption.

 

Not sure why your 'good friend' is going to believe a document you create, when they don't believe what you say.

Instead, I would start carrying a kill-o-watt (or similar) with you. When you are done charging, show them the total kWh, and pay them that at their going rate. Don't even try to tell them how much it is going to be beforehand.

 

that's interesting. i had only been looking at the single charge numbers. are the car and the kaw using the single charge number for the total or some internal number that is higher? possible carried out t o a larger fraction? otherwise, i'm not sure why the totals would be different % than single charge.

 

We've never been able to establish if the KWh number reported on the EV/HV ratio screen takes into account regen from braking, etc. In theory, it's supposed to be all the electricity that the car consumed from the battery pack, which can include power from the wall and from regen. Another frustrating part of that screen is the fact that both the KWh consumed, and the gallons of gas used have their first and second decimal places truncated. Not rounding off, but simply truncated. I'd also like it if the EV and HV miles would have the first decimal place shown...

 

agreed, i hate that it only gives round numbers for gallons consumed. big diff from 6.0g to 6.9!

 

wow, that's almost half of what i pay!

 

why pay to charge at all - when you can get it for free. With one big up front solar cost - not only are you helping out our antiquated grid, you can get your electric bill down to zero, even with charging - even with high tiered utility cost rates. Throw enough panels up, and not only do you get free charging - your utility may pay you for your surplus ! !



Oh yea - nothing better than stickin' it to the utility AND the oilies - all in one fell swoop



.

 

love to, but unfortunately, it's not the panacea in the northeast as it is in the southwest.

 

What size system do you have? And how much electricity were you using before you put the system up? And will SCE cut you a check for the surplus at the end of your 12-month cycle? Or do they just carry any credit forward indefinitely? We've got a 4.94 Kw system waiting to be turned on. Paperwork was submitted to PG&E 3 weeks ago, but apparently they have up to 6 weeks to bless the system and swap the meter...

 

over 24 months our average usage per month would be $224. Our system is rated at 7.1 kilowatts (AC). BTW, when our system came online in 2009, they never changed out our old fashioned mechanical kWh meter. The gear simply runs backwards. We decided against TOU because we get a bigger surplus payback by not using it - plus we don't have to worry about using power before 6 pm or after 10 am. We do a lot of Work out of the house. So yes, the utility cuts you a check for your surplus or you can just let the credit ride. fwiw I take the cash when I can get it just in case the law changes. The utility is not doing this voluntarily.

SGH-I717R ? 2

 

Unfortunately, in our area PG&E has been very aggressive about rolling out Smart Meters. Our mechanical meter was swapped out for a Smart Meter about 3 years ago. Even if we still had a mechanical meter, it would automatically get swapped out for a Smart Meter. They require you to go on a TOU Net Metering plan these days if you do solar. Our average bill for the last 24 months is around $267, or about 970 KWh. The Solar system won't replace all our monthly usage obviously, but by getting us out of Tiers 4 & 5, and possibly eliminating even Tier 3, it should cut our bill by a huge amount.

 

What are you paying for electricity? In Maine, we pay more per kWh than the payment on a loan for a corresponding solar system would be. If you have a clear Southern exposure, it always pays from day 1 (well, 30). Massachusetts has a very favorable rebate (that we don't). My brother works for SunBug Solar - Solar Energy Systems for Home & Business - SunBug Solar, you might give them (or some other solar dealer) a call.

 

Isn't that good? You are making power near the peak times, I would think that would be most beneficial. (I concede that PG&E rate structures confuse me...)

 

we're paying .16/kwh. i was contacted by solar city? but after an assessment, they wanted me to cut down 2 large maple trees in front of my house. i can't bring myself to do it and that for only a 10% rate reduction.i asked about putting them on the ground in the field behind my house but they said it wasn't cost efficient at this time.

 

Whoa - you sure about that? This kind of stuff is mostly determined by state law, and CA does not require Time-of-Use (TOU) for Net Metering customers. Hard to believe PG&E is *requiring* TOU for solar.

 

You are correct, it's not required. I was under the impression it was required. However, the TOU rate does make the most sense for solar. I produce a lot during the day when consumption is low, getting credit at peak rates, and shifting consumption to partial and off peak hours.

 

Yes, TOU is the most beneficial for me.

 

Wow Cali guys and gals, you sure do pay a lot for electric power!!!

I have the greatest deal here in Ithaca NY. My rate is $.049/kwh. But I dont even pay that. I charge for free in my own garage at my apartment complex.

In addition to that. Most of my daily commutes are on ev only.