ponytug
Super Member
A well constructed concrete home sounds wonderful, and your energy use definitely demonstrates the energy advantages. Your corner of the world is gorgeous, we looked for house around there for a few years, but I suspect that solar is going to be a challenge without some logging.
I choose the Tesla batteries at the time (2019) as they were the only batteries that had any track record and anything approaching a believable MTBF. Given our location in a wild lands fire area, I was particularly concerned about both failure to fire and failure to not being there when we needed them. We are sandwiched between two of the major sister faults to the San Andreas fault, and I planned for post earthquake power.
At this point, I would consider the Enphase batteries as well. Unlike say buying a new phone, I think that adding batteries is not a trivial investment, and it is attached to your home with the possibility of electrical and fire issues. One downside to Tesla batteries is that they don't play well with generators. I would bet that makes the Enphase batteries a much better choice for your location
Yes, Tesla only sells their batteries with panels these days. We bought from a third party installer, primarily to get the SGIP rebate, as Tesla was ineligible for SGIP rebates by the time we were looking to add batteries. I have heard that Tesla is very cookie cutter about the jobs they do, and that is why they are such low cost bidders. I have not heard about price shifts once the contract is in place, the opposite in fact, to the penny. Their initial quote does change as they get your site details, but usually because of the details of panel layouts changing due to zoning, vents, etc. With Tesla, it is my perception based on other buyers' experiences that you get very low cost, low hand holding, next to no customization (small, medium, large) and next to no customer service. I do not think it is for everyone. Whether the savings are worth the hassles, I can't comment. If you are interested, Tesla Motor Club has an extensive energy forum;
We had to upgrade our main panel as part of the solar/battery installation due to a subtlety of the national electrical code (NEC), that included two new electrical panels and plus some extra trenching to meet the county's fire code requirements (they apparently aren't following NEC for energy storage systems for reasons that are unclear to me). Basically, 225A bus bars are required in the main panel to be able to feed 200A to a subpanel. (It is a long story and as a non-expert in the subtleties of NEC requirements and calculations, not one that I feel qualified to pass on.)
We are in a bit of a ravine, so we get about six hours of sun these days and more like two to three hours in the wintertime, barring, of course, overcast. We use around 620kWh/mo, including a plug in hybrid, and have panels generating a peak power of about 6.5kW, and, these days, about 1MWh/mo, but only 0.2MWh in January, so May/June banks us through the winter. We are net energy consumers for November through February and net positive the rest of the year. Our single biggest draw is an electric dryer, as we use propane for heat, hot water and stove. (Due to the frequency of electrical outages here, not something I am likely to change any time soon.) Our ROI would be much longer if we weren't able to "bank" summer generation for winter usage.
Does that help?
All the best,
Peter
