Thanks for the Dislike! Seriously. It lets me know folk read my more long-winded posts.
That was not a hypothetical example. It was based on an actual bill. It is how much it can cost to charge an EV in Los Angeles, California in the low-cost winter rate period if you have lots of solar power generation. It is
not the highest rate possible allowed under our laws. The situation I describe exists today as we speak, and stops some employers from providing EV charging.
It's about how Demand-Based Metering approved by our California state utility commission allows the power company to charge >50% more per kWh AFTER installing solar, and also makes charging EVs very expensive for businesses.
Here's Southern California Edison's TOU-GS-2-B rate plan for small to medium businesses:
The Demand Meter costs $231 / month rent which they call a customer fee, but only affects you once they install their demand meter.
The lowest Demand fees are in the winter, and they are $15.89 / kW. This is measured at the highest 15 minute segment in a month, but is not time-of-use based.
Power is cheap at roughly .07 / kWh in the winter, day or night. Most of your bill is not kWh's or TOU, it's demand fees and rent.
But let's put some real numbers to it. Prior to installing solar, our cost per kWh was .18 / kWh at the highest summer rate, which is twice as high as winter as long as you do not have Solar.
After supplying 75% of our own kWh's, the bill was .26 / kWh in the winter. The more kWh we generate, the higher the cost per kWh from the utility rises. Solar production is worth .07 / kWh since you cannot reverse demand fees.
On a $1100 bill, $800 of it is demand fees, and $300 is for kWhs used.
This affects EVs is because they are high-demand devices. The more EV charging kW you hook up, the faster the Demand segment of the bill rises as compared to kWh billing. So both Solar and EVs increase your cost per kWh.
Like posted above, some of this can be mitigated by load shifting battery arrays. Oddly enough, if you have solar, you are shifting your power to the AM when folk plug in their EVs. But due to the variability of weather and clouds, there is never a 'correct' balance, since you cannot predict solar output in advance.
I finally got so fed up with fighting this I contacted the California Attorney General about the California Public Utility Commissions misbehavior when it comes to solar and EVs, and Southern California Edison's misleading marketing of their support for Solar and EVs.
The AG said they don't handle matters concerning California government bureaus. Yes, that's a fib. But oddly enough, SCE finally switched me to a plan that was based on my energy consumption. The result? I can now plug in my EVs again, and my solar will payback in 2.5 years by saving ~$10,500 in 2018 over 2017.
Cliff Notes: Disagrees can be helpful. Yes, you can pay insane amounts of money for charging EVs even if you have a lot of solar. Government entities are trying to migrate residential customers to such plans, and no amount of panels will fix that except 100% off grid.
Trivia: We produced over 100 kWh of juice yesterday on a cloudy cool day. Today I am working on adding 4.2 kW more panels for a total of 24.2 kW.
We make >10 more electricity than our 3 EVs use. We are are on target to make 40-50 MWh in 2018.
