I just joined the forum and have been reading so much great info and trying to absorb as much as possible. My hope is to squeeze in a diy solar system purchase before the death of the tax credit. I live in the Shenandoah Valley of Virginia and our rate is effectively $0.15 and I believe the coop has 1-1 net metering. Before I started reading on this forum the plan was a scalable grid tie system, hoping to stay as inexpensive as possible right now but expand when we can. Now I'm thinking maybe not a grid tie system but a stand alone with batteries? My goal is to save money, period. I don't really have a budget in mind and we have plenty of open space to place an array. I've attached the electric usage history, hopefully that's a good starting point. My service is 400amp with 2 Siemens 200amp panels, located in my unfinished basement. I am not a master electrician but I have many years of electrical experience and am planning to DIY this project even though I am a complete novice when it comes to solar. We don't loose grid power very often and almost never for very long so the batteries would be for cost savings overnight but not at all opposed to eventually being completely off grid, assuming we can keep all our modern conveniences.
I'm looking for recommendations for a scalable system. Should I grid tie or stand alone? What's a good jumping in price point with expansion in mind. Hopefully I've provided enough information to get the conversation started.
Matthew
Welcome!
I'm in the "Expandable Grid-Tie" crowd:
Set up grid-tie now, ensuring that you know for sure what the gotchas are in your current 1:1 net metering coop agreement. "The Grid Is My Battery" is the best of all worlds. This will also allow you to start datalogging with an Emporia Vue or equivalent to get an idea of the peak power (KW) and energy storage (KWHR) requirements for future steps.
Install as much solar PV as you can reasonably afford at this time, adding on later is more difficult than you think. Even if you have room to (for instance) add another ground-mount array identical to the first one, you won't be able to get the same parts (panels in the exact size, etc) in a few years.
Since you planned ahead, and got inverters that will support common batteries (16S LFP with common RS485/CAN interfaces and protocols, for instance), when (not if) the co-op changes the rules, add batteries to self-consume more of your production, time-shift your grid consumption, and maybe push power back into the grid if there are TOU tarrifs you can use. [Note, as above, if they are too lucrative for you, they _will_ change, and throw all your ROI calculations into disarray.]
Going fully off-grid is a big step and fraught with peril, but once you have a few years of experience with the above, you'll be able to make a new determination of the costs and benefits of the above. At $280/month, $3300/year, you don't have a lot of financial incentive to spend a lot on batteries and a backup solution for going completely offgrid.
Going fully off-grid requires redundancy, backup power (ChargeVerters from the grid(*), or generator, or fuell cell, of whatever the future holds), more batteries, and a lot more expense and risk. It doesn't sound like you really need to do that at this time, and the solar power market is changing monthly, so a perfect solution today is going to look very different from the one you design 5 years from now.
(*) Yeah, I know, CV from the Grid isn't really 'off-grid', and if your grid is stable and reliable, there's probably no point.
signaturesolar.com
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