We thought our solar journey had begun and ended about twelve years ago, when REC Solar – who has since left the consumer market to focus solely on commercial customers – casually mentioned that as part of the installation process we would have to remove two mature oaks and a twenty foot tall redwood. Our response was short and sharp – along the lines of “Hell no,” – and we invited them to leave our property and never come back. Every so often in subsequent years we’d talk wistfully of possible advances in panel technology, but other projects beckoned – bathroom and kitchen remodels, a new roof, new windows – so we never looked seriously again.
Then my husband bought a Model S. And by the end of last year Tesla was sniffing around, asking if we’d ever considered solar. We warned them that we were skeptical, but they sent a representative out anyway, and after looking the site over he said he was confident they could make it work. And they guaranteed the capacity they estimated, so if they were wrong for the next ten years we’d get a check for the differential between target and actual production after the annual PG&E True-Up. Between my husband’s work bonus, a little money I’d come into, and a small dip into our savings we could afford to take the plunge, so we told them to go ahead.
The estimator was a little more cautious than the sales rep when he arrived on the property. He said we’d have to trim a few branches back on the redwood, though far from the whole tree, to which we agreed. And he was deeply unhappy with the pitch and construction of the roof. “You don’t have an attic?” he asked, enough times that by the third “No, really we don’t,” I was started to get a little annoyed.
“We have a crawl space under the house,” I smiled brightly at him, “but I don’t suppose that’s helpful.”
“Well then how is your roof constructed?” he demanded.
I frowned. “I don’t know. I didn’t build it.”
“I need to go up and drill some holes.” I must have looked alarmed, because he suddenly grew more polite and reassuring. “I’ll be careful about filling them.”
He clambered up onto the roof, from the sound of it drilled three holes in various locations, climbed back down and spent several minutes on the phone. “The engineers can work with what you have,” he said. “But those shingles have to go. You need rolled composition.”
“But that roof is only two years old!” I protested, giving him an aggrieved look.
“I’m sorry,” he said, almost sounding like he really was, “but that’s a shallow pitch. It’s too likely to leak at the junction points.” He said we had a choice between our roofers or theirs. We decided to go with the latter, offering us one-stop recriminations if something went wrong.
Building the Tiny Power Plant
The roofers were…fine. Noisy but neat, and at least unlike the previous installers they didn’t destroy any of our landscaping or drive too close for comfort to our propane tank. (The high point of the prior roofing job was when I shouted at one of the drivers in Spanish as he drove over a juniper and was treated to a chorus of ¡La señora habla español! ¡La señora habla español! Yes, I thought with a delighted grimness, yes she does. Less perhaps than they thought, but enough to make them nervous, and that was enough for me.) We were a little puzzled, though, when the workers were done and hanging out in our driveway, drinking soda and smoking. After about twenty minutes we strolled out casually, ostensibly to ask about the job.
We weren’t fooling the crew chief, however, and even as we walked up to him he was pointing at the roof. “We use a blowtorch for the seal,” he said. “And we like to stay about twenty minutes or so,” he inserted a dramatic pause, “to make sure your roof doesn’t catch fire.”
“That’s good!” we laughed nervously. “Roof not catching on fire is good.”
A few days later the solar installers arrived. We had more panels than a typical installation of our size because the site is 28% shaded, and ended up with higher capacity panels than the initial quote specified because the standard size was out of stock and they didn’t want to screw up their schedule by making us wait (we certainly didn’t complain). The crew was quiet and neat, and aside from a glitch involving also out of stock glue the mounting system and the panels went up quickly and easily.
The same could not be said for the wiring. The electrician gave me an overview of the system before he went to work, and to my layperson’s ear it sounded hopelessly complicated (I researched it all later). The inverter, which converts direct current coming from the panels to alternating current for home use. The disconnect switch, used to shut off the system for repairs or maintenance. The backup load center, which contains the logic to determine whether to draw energy from the grid or the local system. The relatively self-explanatory batteries, and a blank grey box which, when opened, merely contains warnings about not mucking with it unless you’re a certified Tesla technician.
In the wall of words, one thing that stuck out was the fact that configuring the load center involved porting all of our old breakers over to a new box. My warning that our breaker panel was something of a mystery cabinet was accompanied by an obvious note of pity, but the electrician was experienced, enthusiastic, new to Tesla, and certain he could handle it.
Well, at least the first day. By day two when I went to check on him his jaw was clenched, but he smiled gamely and said that he liked a challenge. By the third day the lead installer was beginning to hassle him – just a little – about why he wasn’t done yet. Perspiring profusely, head buried in the panel, he mumbled something about having to match different wire gauges.
I don’t know much about home wiring, but I do know that our breakers don’t neatly line up with much of anything, so if similar care was put into the rest of the system I could imagine the electrician’s frustration. Flipping one labeled “overhead lights” is just as likely to turn off all of the outlets in the living room. “Water heater solar” refers to a long defunct and demolished system, and instead powers a shed that we had built a couple of years ago.
And while our contractor was working on that particular project, I had walked past the study early one morning and was convinced there was a crackling sound in the wall. My husband couldn’t hear it, but I dragged Dave in, and he immediately charged outside and started flipping breakers until power to the room was shut off. “That,” he informed me when he returned, “is the sound of grease burning in a wire cap.”
We had suspected that our study was a bit overburdened in the power load department – two desktop computers, a laser printer, router, cable modem, NAS box and assorted switches and backup drives will do that – but Dave gave our suspicion additional urgency when he grumbled that if we didn’t change something we were asking for a house fire. So although I offered to hire a dedicated electrician he spent four tricky, profanity-filled hours rerouting half of our study power to the circuit that supported the more lightly burdened kitchen – and another mislabeled breaker was born.
At the end of the third day, the solar electrician could rest. The wiring was finished, and he was ready to test the system. He asked me to turn on a couple of lights in the house and keep an eye on them as he took us off grid and onto the backup batteries.
It was, in a word, magical. The transition happened so quickly that the uninterruptible power supplies didn’t have time to shriek, the lights held steady, and the clock on the microwave remained unblinking. A giddy euphoria – perhaps better suited to first love than self-sustaining electricity, but there it was – bubbled up within me. The electrician must have seen that look before, because he met my laughter with a knowing smile.
Then he turned it all off, awaiting the county inspector and permission from PG&E to add our system to the grid. I was sad, but consoled myself with the sure and certain knowledge that in just a few weeks’ time at the outside (a neighbor with solar said their approval took a mere three days) it would all be up and running again.
Into the Silent Utility Wasteland
The inspector reviewed the system two days after completion. The installer was on hand to answer his questions, which were so myriad that I began to wonder if something was wrong. The inspector reminded me, to the Tesla employee’s obvious discomfort, that battery systems never pay for themselves and he hoped no one had told us otherwise. I replied that I was aware of that, but that we were tired of PG&E’s summer brownouts, and concerned about their threats to shut off power to transmission lines during high wind and high fire risk events. He nodded. “As long as you know.” Then he beamed and clapped the Tesla rep on the back. “This is actually one of the nicest installations I’ve ever seen. Good work.”
I couldn’t wait to see the “nice installation” up and running. But a week went by with no word from PG&E. Then two. January turned to February, then March. On week thirteen I contacted PG&E, asking what the holdup was. They replied – promptly, at least – that on February 22nd they had requested additional paperwork from Tesla. My husband contacted Tesla, who insisted that PG&E had everything they needed. I called PG&E directly instead of using their online form, and a pleasant representative looked up the paperwork and said that they needed a building permit showing the backup batteries, which were missing from the permit that Tesla sent.
Tesla replied that they had submitted the correct paperwork. Then they went radio silent, failing to respond to any further inquiries. I spoke with PG&E again, who replied that actually they were missing two things: the updated building permit and a signed interconnection agreement. They suggested I have Tesla send us copies of precisely what was sent to PG&E which, after some haranguing, we managed to obtain. The interconnection agreement seemed to be there, but instead of a permit Tesla had sent the inspection report – which clearly showed the batteries but wasn’t precisely the document PG&E had requested. Could that be the source of the problem? Could we work around it?
Now PG&E grew as uncommunicative as Tesla. March went by, then April. I tried to go through PG&E to gain some visibility into the project status but was told that I’d have to refile all of the paperwork myself – at a not inconsiderable cost in processing fees. My husband threatened Tesla with legal action. I researched how to file a complaint with the California Public Utilities Commission. I became, perhaps, a little more obsessed with the delay than I should have. A niggling, unhelpful voice in my head kept hissing, You spent what was left of your parents’ money on this. Of course it was going to be a cursed project – they wouldn’t have had it any other way.
A few days after the intimation of lawyers and despite my burgeoning pessimism we received an automated email from Tesla stating that they had resubmitted the entire project to PG&E from scratch. Given our previous experience I was winding up to ping the utility after two weeks had gone by when PG&E informed us that we were cleared to power up our system: four months after the county certified it ready to go and just in time for the first late May heat wave.
Devils in the Details
The Tesla Model 3 has been justifiably referred to as a car for the “smartphone generation,” and their solar products are no different. There is of course an app, that displays your solar production, what you’re feeding back to or drawing from the grid, when you’re discharging or charging your Powerwalls. There are settings for specifying your utility’s peak usage hours so the system can minimize draw from the grid, and a Storm Watch setting that processes severe weather or fire watch alerts and keeps your backup batteries charged to full to buffer any power outages.
We couldn’t wait to see it in action. So as soon as we got the go-ahead from PG&E we flipped the two system breakers, watched the inverter flicker to life and the Powerwalls announce that they were online, then retreated to the study to configure the gateway. A Tesla technician had offered to help us with that, but since my husband and I are both technologically adept we figured he’d just be in the way. Half an hour later, unable to establish a connection between the gateway and the inverter no matter how close we were to the damned thing, we wondered if we’d made a mistake.
We took a dinner break, and when we came back to it lo and behold there was a signal! For a while. Then it cut out again. Then came back, then vanished. We perhaps shouldn’t have been surprised. We use Google Fi for cell service because it will operate over Wi-Fi in addition to standard cellular networks, the latter of which are notoriously terrible in our semi-rural corner of the world; so a spotty connection between Tesla’s gateway and the inverter was a nuisance, but not entirely a shock.
After a day of this up and down and some research we found a way to tell the inverter how to communicate with our far more robust wireless network rather than whatever protocol it and the gateway were using. Happy with the connection, we unplugged the gateway, only to have Tesla send an email a few days later asking why they couldn’t monitor our system remotely anymore, which they needed to do to see if actual power generation was matching their projections. Oops. Back online the gateway went.
There was one final hitch before we were fully functional. The Powerwalls came online at 8% charge. Then dropped to 5%, then 3%, and never seemed to be charging, neither from the grid nor the solar. My husband finally contacted Tesla, who replied – promptly, tech support seems more responsive than sales – that sometimes cycling the system would fix that problem.
“Easy enough,” I murmured to myself as I went outside. “Shut down the Powerwalls and the inverter: check. Flip the breakers off: check. Flip the breakers back on…hang on a second – ”
I stared at the panel, then texted my husband. So…it looks like there are four breakers to the system instead of two. And we never actually flipped the Powerwalls to On. Ummm, my bad?
In my defense, the green status light strip on the side of the Powerwalls made it look like they were powered. But I suppose, in retrospect, that’s why the batteries were draining. In any case, once that little mystery was solved the system was finally fully up and running.
I admit I was a little dismayed when the installation was first completed. Unlike some of our neighbors I actually don’t mind the look of solar panels on the roof – seeing them up there soaking up the sun’s energy makes me happy. But although it was equally functional, I had decidedly more mixed feelings about an entire wall of our cabin-style home looking like a tiny power plant, awash in panels and conduits and big battery packs (Black, I murmured to myself as the Powerwalls went up, Why couldn’t they be black? Or brown?)
But then I pulled up the app, and my phone was showing me lovely images like these:
A solar installation running at peak capacity in the middle of the day reminds me of drawings of well-balanced chakras. The first image shows the panels meeting the electricity needs of the house, charging the Powerwalls and feeding back to the grid, and it’s a thing of beauty.
I was puzzled the first time the app displayed the situation in the second image – the Powerwalls fully maintaining the house, the solar feeding all of its energy into the grid – until I took a bit of a dive into the concepts of TOU (time of use) plans and net metering. Because I’m home most of the time, prior to going solar we were on PG&E’s tiered rate plan, in which electricity costs the same any time of the day or night. You’re given a baseline allowance, with costs going up based on the total amount of energy you draw, and high usage fees imposed if you exceed that allowance by a certain amount. (One of the reasons we wanted solar was because as the summers are getting hotter we use the air conditioning more, but PG&E hasn’t changed the baseline allowance or the tiers.)
When you activate a solar installation PG&E requires you to switch to a time of use plan, in which energy costs more at certain times of day – typically when demand is highest. We are on a TOU plan which has so-called “peak pricing” from 3-8 p.m. Monday through Friday. (There is also an EV plan, which offers cheap energy late at night, peak pricing from 3-8 and so-called “part peak” the rest of the time, but since we typically utilize Supercharger stations to charge the Model S it isn’t cost effective for us.) Even on longer summer days the solar stops producing any interesting amount of energy sometime between five and six, so it makes a certain sense that the algorithms driving our overall system would use the Powerwalls to provide power to the house from six to eight p.m. while electricity from the grid is more expensive, then charge them up again in the morning when it’s cheaper.
Net metering makes this even more appealing. In California at least, utilities must provide credits to consumers for discharging energy back to the grid. These credits can be used to offset higher energy usage at other times – say in winter, when the solar panels may not produce as much – or, if over the course of a year you have returned more to the grid than you’ve drawn, you may receive a check from your energy provider. If you’re careless, you can end up owing them money, but PG&E provides tools that allow you to track your monthly usage to keep that from happening, and the Tesla app itself gives you a pretty good idea of how you’re doing. (In the rightmost image you can probably guess when we were charging the Powerwalls up from their low point of 3%.)
In an additional wrinkle, you receive slightly more credits if you feed back to the grid during peak hours. So the Powerwalls, which we originally bought only for independence during unexpected events, have had a benefit that we didn’t anticipate.
This kind of visibility into our energy usage has changed our habits and made us more conscious of unnecessary expenditures. We powered down the entertainment system – TV, game consoles, sound system – in the game room over the garage rather than leaving it on standby, and unplugged appliances in the detached studio that are only used when we have guests. I used to be fairly casual about leaving my desktop computer on during the day, but not anymore. We discovered that the Model S takes a shocking amount of energy to charge, with our usage leaping from a base of 0.3 kWh to 7.7 kWh as soon as we plug it in, validating our feeling that the Supercharger was a better deal, even if we do usually grab some breakfast while we’re charging.
I’ve also shifted when I use certain appliances. In the past I followed the default wisdom of running the dishwasher or doing loads of laundry early in the morning or late at night. Now I wait until the solar is producing enough to power the appliances, generally late in the morning or at noon but before peak hours set in. I know now that turning on an overhead ceiling fan adds 0.1 kWh to our usage, and it’s up to me to decide whether having three fans generating a breeze throughout the house during a heatwave is worth it or not (my answer was yes).
Am I a little obsessive about it all now, like a child with a new toy? Probably. Will the impulse to check our solar production every hour fade? No doubt. But I find that I like being conscious of the energy that I’m using, and having data to validate my intuitions. I certainly like knowing that I don’t have to worry about my food spoiling during a power outage. And even a measure of reduced reliance on the grid makes me happier than I would have expected. Getting to this point was a little more painful than I anticipated. But it definitely felt worth it in the end.