Thinking of self installing a 5kW solution onto a South facing garage. DIY solution appears to be 60% cheaper than hiring a local installer (Ohio)
Thinking of self installing a 5kW solution onto a South facing garage. DIY solution appears to be 60% cheaper than hiring a local installer (Ohio)
I’m an electrician, I found my own solar panels incredibly easy to install. The job is 90% racking and I would recommend buying a racking package if possible which includes all mounts, rail and fasteners.
Take care as solar panels are ALWAYS LIVE. This is why they use the shielded connectors that they do. Do all the rest of your wiring first, then plug the panels in last.
Make sure you have appropriate disconnecting means. If this is going to be grid tied in any way, make sure you’re familiar with the code as it will be inspected. If not grid tied you may be exempt, but this is no reason to just slap it up, still follow the code as it’s there for your safety.
I recommend grid-interactive systems over grid-tied if you actually want to be power independent. Microinverters seem great until the power goes out and your panels are good for nothing. I would recommend a power blending transverter type system that allows 3-way power flow between panels, battery and grid. They have come way down in price and allow seamless integration of your loads compared to a charger/inverter system like I have.
Run a string voltage as close as possible to your battery voltage to avoid conversion losses. It’s tempting to go for high string voltages but roof mount distances are usually really short and conversion will likely be most of your loss. I started with 140VDC strings and my charger ran hot, dropping to 70VDC made it run cool and boosted my output by over 10%.
Depending on your utility it may not be worth selling power and the hassle or extra fees and regulations that come with it. That’s the case here - I just have automation set up to burn excess power for heat in winter and cooling in summer.
Best of luck with your install, for sure it is way cheaper to DIY and not hard at all.
Thanks for this extensive reply. Not the OP, but I’ve been slowly doing my research on this, and this gave me a good base of things to look into. Cheers!
An example of of “grid-interactive” system is the ecoflow smart home panel. It’s the front runner I’m looking at right now for my own system. It will dynamically balance where power is coming from based on your batteries/solar/grid state. Easy to expand battery packs, and ties directly into up to 10 circuits.
What kind of charger are you using that needs to voltage match the batteries? I’m running 500V strings on a Luxpower 18K and it’s not an issue with the chargers in that.
Schneider MPPT 150. We sell a lot of Schneider at work and I got a good price on it. However it’s totally a piece of crap. It’s the only “150v” device I’ve ever seen where 150v is the do not exceed voltage rather than the operating voltage, and it will trip offline at 140v which causes a huge issue here in Canada where OCV can rise greatly below -20C.
Wouldn’t recommend Schneider in general as they require their own proprietary CANBus mod to get telemetry out of any of their equipment.
That’s been my impression of Schneider, great on AC but their solar stuff is a placeholder for “nobody every got fired for buying Schneider”. I thought they ran Modbus on their comms, pretty sure I’ve seen the modbus maps for them around the Homeassistant forums. Maybe it’s just some equipment, but the Conext is modbus afaik.
I wouldn’t say the “150V” should be operating voltage by default, most SCCs I’ve used put that as the “do not exceed” number, just like the current. I’ve smoked relatively expensive charge controllers by being slightly over either of those numbers. Though Victron seem to be able to take it for a while without cratering.
Conext series support modbus BUT only through an overpriced gateway unit, the actual devices speak Xanbus unless they have updated them. There have been reverse engineering efforts that I think found it to be a polarity flipped or bit flipped CANbus but at the time nobody had a reliable translation layer. I believe Schneider bought Xantrex and rebranded their inverters and chargers as their Conext solar line.
The “do not exceed” nameplate ratings may be more typical in solar, but in the regular electrical world when I buy a solid state device like a 480 volt VFD, I expect it to run at 480VAC, and in fact to have a fairly broad operating range from probably 450-500VAC. Likewise I would expect the current rating to be full load operating current, hopefully with at least a 10% service factor and 20% safety margin on top of that.
I was honestly pretty disappointed when a 150VDC unit tripped offline at 140VDC, not even making the “nameplate rating” but if this is standard for the industry I guess I can’t pick at Schneider for that at least.
140 is a little light but yah, it’s definitely a solar thing only. It’s possible it bounced over the 150 for a very short time to trip the cutout, and the 140 number you’re seeing is a time-smoothed average in your reporting system. If you’re using something trustworthy like a Smartshunt to get that data, then yah, tripping 10V short isn’t great.
I checked the manual and it’s actually documented to trip at 137V and open its fault relay, and won’t reclose until the input voltage drops to 134V. This is hidden in the fault section and not really advertised in the specs.
Obviously in a cold weather overvoltage situation this loss of load causes immediate runaway, which resulted in many full days of lost generation until I rewired the array down to 2s strings.
This issue was actually what resulted in me building the first dump load for the system, because as long as I kept the array loaded enough it wouldn’t trip out. No way I was breaking the connectors or my fingers off during several weeks at -30C!
Yah, I’m in N Alberta and a farmer, fixing things at -30 is never fun. Those MC4 connectors are a pain in the ass when they’re cold.
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