Battery Math
Today I went to a battery fair here in Escondido. I was invited by Baker Electric, the premier electricians here in Southern California, who installed my solar system last year. They were joined in this extravaganza, replete with free donuts and mimosas and great swag (umbrellas, string backpacks and notebooks with pens) by the strong and mighty Tesla, the dominant maker of home batteries. Naturally, I had to drive to the fair in my Tesla and meet my brother-in-law Jeff there, who drove his Tesla. I had decided that now that I’m fully resident here and using electricity more than when the house sat empty for long stretches, its time to consider all my home energy issues. Truth be told, I should have installed the battery last year when I was putting in the solar, but the costs had gone up to accommodate my needing a new service panel upgrade. That added $10k to my tab and I pulled the plug on the battery, figuring I would address it once I moved out here. So, here I am.
Judging by the crowd at the battery fair, I would say that this is sort of a retired-guy fascination. Average age looked to be 68.4 years. I am guessing that for people who don’t so much make money anymore, finding big buckets of potential opportunities to save money might make them feel productive. I wish I could say that everyone who is examining the home battery issue is ecologically focused, but I’m a lot less certain than not about that. If my wife were there, you would bet that she would be doing it for the right reasons rather than the pocketbook reasons. I think I’m somewhere in the middle of that spectrum. I think it’s all interesting. I want to be ecologically correct, I want to save money and make a good home investment, but mostly I want to stop feeling like a total dope at the hands of SDGE’s scare tactics (maybe done for the right reasons and maybe done to make me feel like my big bill is all my fault for some inexplicable reason.)
Up until last year, San Diego Gas & Electric (SDGE) would send me a monthly bill that made me feel horrible. It was extra horrible because I wasn’t even living in the house so it all felt expensive, ecologically inefficient and extra wasteful in a fashion that my supposed neighbors weren’t suffering. That monthly report/bill would tell me I owed SDGE $600-800 and that I was spending more than last year, a multiple of what the average SDGE user used, and a smaller, but no less troubling multiple of what my neighbors used. And that happened every stinking month.
I used to call my brother-in-law Jeff and ask about what was going on. I’m reminded of that old Twilight Zone episode where a kid suddenly disappears under his bed in his bedroom. The father comes in to help the upset mother and after looking at and under the bed, he rubs his chin and says, “Let’s call Bill, he’s a physicist.” That always struck me as hilarious since I’m not sure Bill’s physics courses covered kids disappearing under their beds. Or there is the the movie Rounders where Matt Damon is delivering snacks to a bodega and the clerk, knowing Damon is a law student, asks him if George Steinbrenner can really move the Yankees if he wants to. When Damon says he doesn’t know, the clerk says, “What, you don’t learn that in Law School?” Damon says, “We don’t cover Steinbrenner until third year.” So, calling Jeff to asking what in heck was going on with my electric made lots of sense. In fact, I had bought a device called Sense that hooked into the electrical system to give me on an iPhone app, all the information I could ever need about what was going on electrically at my house. Which appliance was using how much and when. Jeff had installed that for me, but truth be told, I don’t know how to use it very well. Just wanting and hoping does not seem to be enough.
One of the things I heard at the presentation by Baker and Tesla (they were double-teaming us) was that Baker sells more Tesla home batteries than anyone else in this area and that based on the online app that Tesla offers that lets you program your battery to do exactly what you want it to do (emergency back-up or daily cost-minimization or whatever), the only real home battery choice was Tesla I I wonder what LG thinks of that argument?). But the surprising number was when Baker said that they, as leader had installed over 580 units. What? That doesn’t sound like so many to me ($14,300 x 580 = $8.3MM). If you had said 58,000 units or $830MM in sales I would have been more impressed. My sales rep told me that any of the people who install solar end up doing exactly what I did. They get spooked by the added $10-14k when they are spending $30-50k for solar and they pause. If my brother-in-law Jeff doesn’t have a battery yet, that is VERY telling…and he doesn’t. He had enough spare change to buy a Tesla, but not enough to drop a dime on a home battery.
Anyway, I ordered two batteries for a net cost (after subsidies and rebates of about $12k. The gross price is $24k, but the government (Federal gets you a tax credit, but California actually sends you a check). These government subsidies are going away slowly, but surely and there seems to be about another year or two to get them. I’ve gotten them for installing the solar and buying the Tesla, so I guess I’ll be filing for the batteries next year.
When I got home I went on the SDGE website and not my profile to check my bill. Here’s the thing, my solar installation has worked great. Those $700+/month bills were non-existent in 2109 even though my nephew’s family lived here for a few months and we’ve been resident here for most of two months now. I am sitting with a net credit of $550 with SDGE now. But don’t be fooled, that was because I overpaid a bill a year ago and my monthly use has been so small or zero that it hasn’t eaten away the credit very quickly. The last month, my bill was $31. Not bad, but here’s the disgruntled guy part of it all. I pay $0.19/KWh for peak usage. During off-peak times my solar is cranking and providing all my needs and feeding excess onto the grid. For that I get paid $0.00/KWh. So I used 185 KWh of peak and gave them 200 KWh of off-peak so my net cost was $31 after taxes and surcharges. That is the mini nut I will be cracking with my two Tesla batteries since I will use my off-peak power to load up my battery and use the battery during the peak hours. At that rate, I will pay back the batteries (even net of subsidies) in a mere 32 years or when I reach the ripe age of 98.
Needless to say, the main reason for the batteries is to provide back-up power in a land where wildfire risk alone can almost assure you that your power will be cut more times than you want, by a lot. I need two batteries to power all my electrical stuff and that means I will need to watch my Sense, more to keep my cents in line with my ecological sensibilities.