Alex Kretzschmar

This winter storm is making me actually think about installing a whole home backup power source (I know, me and half the US right now).

I already have solar but no battery as my utility company does 1:1 net metering.

Does anyone reading this have any experience in building a grid-tie battery system? Powerwall is an option I guess but I’d like to DIY this thing if I can so I choose when it get charged not an algorithm.

Jan 25 at 1:11pmWeb
Show threadPhil Rosenberg-WattJan 25
@ironicbadger I went with EG4. Aside from the incredible weight of a 13 KWh battery, it's DIY friendly. It's hard to stomach the "professional" install costs of other systems when they do the same thing.
Show threadZSJan 25
@ironicbadger I run my house off a Victron Multiplus II and 3x Pylontech 5kW batteries.
Solar charges them during the day, if there’s no solar then they charge off night rate grid.
Victron might be a bit too European for decent availability in the US though. Everything except the really high current stuff runs off its “UPS” supply, so we never notice power failures in the grid, except for the notifications on our phones.
I have a Victron EV charger too, which ties in with everything else, so it’s able to charge the car before exporting the excess solar.
Show threadAlex KretzschmarJan 25
@ZS I’ve heard about Victron a lot from the RV market. Maybe I just need to research all that and apply it to residential
Show threadZSJan 25
@ironicbadger Well here’s it in residential. Photo taken during install.
Show threadAlexander SJan 25

@ironicbadger First of all, what type of the inverter do you have?
If it's grid-tie, most likely there are micro inverters under panels generating pure AC and shutting down when they don't sense the grid.
You may need to add a transfer switch that isolates home from the grid and AC battery (like powerwall) that generates base 240v.

Most diy batteries are DC (like recommended EG4) that you connect to a string inverter (takes solar panels in series). This one is much easier.
My friend has installed Sol-ark 15k inverter and thrown in 48v batteries.

Show threadAlex KretzschmarJan 25
@alexgreen the issue my research has highlighted is that my SolarEdge inverter is grid tied as is and thus I cannot use the solar if the grid is down (I knew this but it is still stupid).
Powerwall gateway solves this but I don’t really want to give that fascist money.
Show threadAlexander SJan 25
@ironicbadger understand you. if you can modify the existing setup, you may replace the inverter and use standard cheap 48v batteries.
Or buy another 'offgrid' inverter with DC batteries and use as fat UPS for dedicated circuits or the whole house. Even if the old inverter goes down with the grid, a second one (that stays between house circuits and the grid) will power your house.
Show threadAlex KretzschmarJan 25
@alexgreen with the minor downside i can't use my existing 8kw array to power them in an outage!
I already have the interlock for a generator so some kind of hybrid where I can slam the batteries from the gennie for 1-2 hours and then run the house for 12 hours at a time seems like a great middle ground without breaking the bank. not as swanky as a grid tie battery but not as $ either!
Show threadAlexander SJan 25

@ironicbadger yeah, interlock is a good temporary workaround.
I installed it as well. Tiny 1800w generator-inveter may power all critical outlets in my house, but I need to dance around what circuit to turn up :)

There is a big room for efficiency and reliability in the solar world.

Show threadPete KeenJan 25

@ironicbadger not an answer to the question you asked, but we installed a 26kW Generac after a big ice storm and subsequent 5 day outage in 2023. Hugely beneficial for our peace of mind, especially with electric ground source heat pump heat. We've had several multi-day outages and several more multi-hour outages since then and it's worked every time.

Essay series I wrote at the time: https://www.petekeen.net/backyard-fiber/

Backyard Fiber

I'm installing a generator and a backyard fiberoptic network.

Pete Keen
Show threadAlex KretzschmarJan 25
@zrail this is the info I was hoping for!!! It’s hard to tell yourself when everything is fine and your outages are “just a day or 3” to drop that $ but after running around this week prepping… I will not do that again!
Show threadPete KeenJan 25
@ironicbadger just don't ever try to convince yourself it's a financially sound decision. When I look at it as an investment in mental well being it paid off after the first big outage.
Show threadAlex KretzschmarJan 25
@zrail I feel that way after paying pre-storm gouge prices for a 6500w generator this week. Yes it hurt, but I felt like I had a plan after.
A tangental goal that would be fun would be to charge the car as close to 100% off-grid as possible using a second, smaller solar array or perhaps disconnecting what I have and having that all feed 100% into an "off-grid" side all the time. Then if for any reason that's not enough I can flip it over using a normal breaker to charge from the grid.
What a fun project.
Show threadSystem AccidentJan 25

@ironicbadger I am using BasePower. Its awesome. They took care of battery/ATS etc.

Does your solar have ATS (automatic transfer switch)?

First thing to check is if your solar will "let you" hook up to "their" inverter. Base will not, so I have to get a second inverter for my (ground mounted, 4kw) solar panels.

Show threadSystem AccidentJan 25
@ironicbadger Many folks report success with ordering battery systems from China. I've built some large battery systems. Integration (HVAC / BMS for the cells) is a pain. Not sure if anyone sells a whole system for DIY. Its a big learning curve! Lots of variables.
Show threadSystem AccidentJan 25

@ironicbadger The middle ground is a generator and inlet/interconnect kit on your main panel.

Base (once I upgrade to the next gen of their hardware) (once its out of beta) has a generator inlet on the battery stack.

Show threadSystem AccidentJan 25
@ironicbadger Also check out https://sol-ark.com/ for an all in one inverter/ats etc. Its about 10k or so all in (depending on how much Kw you need to manage).
Home

Sol-Ark® provides best-in-class solar energy storage systems and solutions for homes, commercial businesses, and industrial applications. Learn more.

Sol-Ark®
Show threadTed CarstensenJan 25
@ironicbadger I learned a lot from this gentleman https://youtube.com/@willprowse and designed a system (design only, we rent atm 😣) based on a lot of his recs - this was the heart of that design - https://eg4electronics.com/categories/inverters/eg4-18kpv-12lv-all-in-one-hybrid-inverter/
DIY Solar Power with Will Prowse

Want to build an awesome off-grid solar power system? My videos will teach you everything you need, no experience necessary :)

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Show threadAlex KretzschmarJan 25
@ted saved! It’s such a rabbit hole my gosh. It might not even be totally out of the question to use some AC with one of these systems in place after a hurricane
Show threadNeilJan 25
@ironicbadger YouTube channel Undecided with Matt Ferrell he did a video about the comparison between PowerWall vs alternatives not so long ago https://youtube.com/@UndecidedMF
Undecided with Matt Ferrell

As a UI/UX designer by trade, I explore how sustainable and smart technologies impact our lives. And I try to dive deeper into those topics to provide context. Topics like electric vehicles, solar panels, and renewable energy that is meant to transition the world off of fossil fuels. Smart home technology that can make our homes not only more convenient, but safer and more accessible. Wearable technology that can track our health and save lives. Or how technology might be invading and breaking down the walls of our privacy. So in short... Exploring how technology impacts our lives. If you’d like to support the channel, you can do so at https://www.patreon.com/mattferrell. Get in touch: https://undecidedmf.com/contact-me Sponsorship inquiry form: https://undecidedmf.com/sponsorships Non-sponsorship inquiries will not be responded to at this address.

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Show threadAlex KretzschmarJan 25
@Neilisin Matt’s channel is super!
Show threadDinosJan 26
@ironicbadger hey wait, I thought you were in England now. I was going to say it’s a bit excessive for handling just constant drizzle 😂
Show threadSamuelJohnsonJan 26
@ironicbadger YouTube @garydoessolar is worth a look, and possibly his site https://www.solarazma.com/landing/.
Gary Does Solar

Gary Does Solar: In-depth UK solar PV, batteries, Octopus Energy, modelling tools and installer recommendations for a sustainable future.

Show threadChristoph LeideFeb 19
@ironicbadger The batteries, inverter, charge controller etc. are not the big issue. Like you mentioned, the brains is the issue. And it can get very interesting, very quickly with the power company, inspection and UL listing requirements, etc. The building industry is, like most others, securely in the fangs of big tech, but there are initiatives. Don't give up on this and please keep sharing!