Comment by Riaz Haq yesterday

From Ahmad Faruqui: The Man from Sunrun

I had just entered the Lowe's hardware store when I saw him, standing next to a stand, and holding brochures in his hand. He smiled, offered me a brochure and asked, Have you considered installing solar?

Yes, and I am very happy with it.

What's your True Up bill?

Around $112 a month. That may seem high but without solar, it would be $450 a month. I drive a Tesla and while $112 a month may sound high, I save two or three times on driving costs with my EV compared to my gasoline car. I drive 10,000 miles a year which consumes 2,500 kWh. That’s 25% of my pre-EV consumption.

When did you install solar? December 2019.

Oh, then you probably don't have a battery. I have a battery. I installed in to deal with frequent power outages and to save money on my three period TOU rate.

How many power outages have you had? Oh, I stopped counting. At least a dozen. My friends with solar panels made fun of me when I installed a battery, saying I had been played by the solar contractor. Now, they are lining up to install batteries.

I live on a court with ten homes, of whom six have solar and at least two have batteries. We also have five EVs and one plug-in PHEV on the court.

Investing in solar and storage is one of the best investments I have made. Of course, the Guardians of the Status Quo are accusing me, and all customers with solar, of stealing money from other customers. But I have yet to meet a non-customer who feels that way. In fact, all of them would like to install solar (but it's still quite expensive -- even with all the incentives, it is twice as expensive as in Australia and three times as expensive as in Pakistan). Solar is the fastest way to cap skyrocketing bills.

He said that Pacific Gas and Electric Company earned $2.1 billion in profits last year and they have several applications pending to keep on raising rates. The good news, they say, is that while rates will go up, they won't go up as much as they did last year.

I said, yes, the biggest cost shift is from their customers to their shareholders. IOU has come to mean I Own You.

As I was stepping away, he said it was great talking to you. What's your name? "Faruqui."

He repeated it, with a smile, and even pronounced it correctly.

That made my day! There was no reason now to tell him that I was an economist with a Ph. D. who has worked on energy issues on six continents or that I was a prolific author and public speaker. But I did tell him I have several friends at Sunrun. At that point, my wife's patience ran out. She simply pulled me away and whispered, "We have come here to shop."

PS The one thing he did not mention was VPPs (Virtual Power Plants). Had he done so, my answer would have surprised him.

Comment by Riaz Haq 22 hours ago

From Ahmad Faruqui:

Can homes with solar+storage act as virtual power plants?

https://pv-magazine-usa.com/2022/07/14/can-homes-with-solarstorage-...

Given California’s looming power shortages, a hypothesis has been put forward which would allow homes with solar+storage to be used as a virtual power plants (VPPs) when the grid encounters an emergency. A system-wide emergency would most likely arise during the peak period. Customers who would otherwise be avoiding the peak rate of 56 cents/kWh on the EV2-A rate by powering their home with the battery during such times would instead be paid $2 a kWh for exporting power from the battery to the grid.

This proposition sounds very attractive in theory. But will it pan out in practice? Using data from my house, I put it to a conceptual test on three dates. The first date is June 29 of this year. It was a mild weather day. My system of 25 panels (rated at 8 kW) produced 49.41 kWh’s that day. The house consumed 23.32 kWh’s. The balance was exported to the grid. I have paired my solar panels with an LG Chem battery rated at 9.8 kWh.

Let’s now look at August 14-15, 2020 when the grid in California did encounter a serious emergency. Hundreds of thousands of customers lost their power on those dates because the grid came up short. The weather was very hot in much of the state and central air conditioners in most if not all homes were running flat out. The skies were smoky, reducing the amount of solar generation, both central scale and at home. The wind was not blowing, reducing the amount of wind generation at central scale.

The grid came up short of power in the late afternoon and early evening hours. Homes such as mine did not have much of a surplus to send to the grid. I was actually concerned whether I had enough to keep my lights on in case the grid lost power. Why would I have exported power to the grid on either day?

On August 14, my system generated 32.79 kWh and the house consumed 63.12 kWh (even though I had adjusted the thermostat upwards by a couple of degrees). As seen in the graph, around 5 pm, the battery was unable to keep up with the consumption in my house. I started importing power from the grid. This would not have been the time to release whatever battery power I had remaining to the grid, regardless of the price being offered to me.

A similar situation was encountered on the next day, August 15, when my system generated 34.76 kWh and the house consumed 60.55 kWh. On neither day would I have wanted to export any power from the battery to the grid. Instead, I wished I could have tapped into the battery in my Tesla Model 3 that was parked in the garage. When fully charged, the car’s battery holds upwards of 70 kWh’s of energy. My wish could not be fulfilled because Tesla does not allow power to be pulled from the battery to power either the house (or to export it to the grid). Additionally, I would need to install a two-way charger rather than the one-way charger I currently have in the garage.


Of course, that’s just the data from my system. Other systems might behave differently. Diversity might exist across customers on mild-weather days. But are those the days when the grid will have an emergency? Probably not.

An emergency is likely to arise on days when everyone’s consumption is really high as it was on August 14-15, 2020. On such days, customers would be hard pressed to meet their own needs, let alone export power to the grid. Diversity would disappear.

What if the customer has multiple batteries paired to their panels? Won’t they may have an exportable surplus on emergency days? Yes, but that essentially means they had overinvested in batteries. How many customers would do that?

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