I… Have… THE POWER!!!

Over the last week I’ve been getting a solar generation system installed on my roof. Today it finally became operational.

The system itself was designed and installed by Sun Path Electric, which were amazing to work with. I’d gone through the bid process with a few companies (including a fairly shady one that was advertising on YouTube) and Sun Path definitely gave me the best configuration and price, as well as the highest confidence in their ability to execute correctly.

So, my house now has 36 large panels on it (I had looked into solar shingles but the tech just isn’t there yet, despite a lot of breathless tech press about them) and an Enphase inverter, which includes a quite nice power monitoring system which gives me up-to-the-second and long-term stats about my power generation and consumption. It’s kind of cool to be able to turn on an appliance and see exactly how much power it’s taking, no kill-a-watt necessary.

Since it only came online at around 3 PM on an already-cloudy day I only ended up generating around 1.6kWh, but that was a surprising amount to get all the same. Of course, the really neat thing to see will be the long-term generation capacity. it isn’t expected to completely eliminate my power bill, but it should definitely put a rather large dent in it!

The current installation just has panels and an inverter that backfeeds into the grid, rather than having any sort of battery system to store the excess capacity. The reason for this is largely pragmatic; the idea is to use the grid as a battery instead. Most power generation in the Seattle area comes from sources which are demand-based (such as hydroelectric and nuclear), so it makes the most sense for excess home power to simply go back into the grid and reduce the demand-based generation, rather than trying to store it for later, and I get a credit on my bill for power shipped to others.

The downside to this is that if there’s a power outage, I still lose power (mostly as a safety thing, so that there isn’t power flowing into the lines that workers are trying to repair), and also the rate I get on excess power generation isn’t quite as high as the rate I get on “imported” power. But given the amount of power I use, throughout most of the year I probably won’t be generating that much excess anyway, and certainly not enough that it’ll make a sizable difference to my bill (or excess generation credit) in the end.

Also, there are systems that you can get where during an outage you at least get your own power directly even without a battery, but that didn’t seem worth the added expense either; power outages are pretty rare here, and when they do happen it’s usually during crappy weather where there wouldn’t be any power generated in the first place, so it’s not like it would actually help with anything anyway. A battery system would help with this but not enough to justify the added expense, I don’t think.

So anyway, I am not even remotely off the grid, nor do I really have any desire to be. I feel that my investment is best spent on things that benefit everyone, not just myself.

On that note, I also got a level 2 EV charger installed in my car port (Sun Path were just going to install the outlet but I already had the EVSE so they went ahead and installed that too), and it was really nice to be able to recharge my car at 6kW1 instead of the usual 1.2kW, and to not have to deal with the rigamarole of getting the portable EVSE out of my trunk and hooking it up and all that, worrying about theft, etc. (apparently portable EVSEs are a big theft target around here, because people like to scavenge the copper).

And I figured, hey, why not list my charger on Plugshare? So it’s open to the public, with a request that folks send me a bit of cash (recommended donation: $2/hour) for charging and let me know if they’re going to block my driveway for a while. The EVSE itself also has a smart monitoring app so I can see how much people are using it separately from the power usage spikes on my house.

I don’t expect it to get used all that much, but it’ll be nice to help out if someone’s having a bad day and really needs a quick charge while they’re nearby. And, y'know. I enjoy the idea of helping out any way I can.

Anyway. The system as a whole cost around $40,000 to install, and I’ll be getting about $12,000 back in the form of a tax credit, and possibly more due to various Washington State incentives (e.g. around the EVSE). Theoretically it should pay for itself in around 10 years (at least based on Sun Path’s initial models, but in a year it’ll be a lot easier to predict the long-term benefit), and will also vastly improve the resale value of my house. But the biggest benefit is I can now spuriously call everything I own “solar-powered.”

Of course this will make getting a new roof a bit more annoying (since I’ll have to coordinate removal and reinstallation of the panels), but theoretically I have a good 5-10 years before I have to worry about that, and also the solar panels have a nice side effect of prolonging the lifetime of the roof anyway.

  1. The EVSE itself supports 9.6kW — actually 11.5 if you hard-wire it rather than going through an outlet — but the Leaf limits AC charging to 6.6kW, supposedly because of the lack of active thermal management for the battery. DC fast charging can go up to 50kW though. Honestly even the 1.2kW trickle charge is enough for about 98% of my driving needs, anyway, and I only got the L2 charger for convenience and future-proofing in case I ever get a better EV down the road


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