Parallel inverter generator tied with Solar DC output. Possible?

[tjbcatch22]

Hello,

Hoping someone can comment and share thoughts on the feasibility of taking the DC output from a solar charge controller (powered from the battery bank and solar panels) and run it into an inverter generator's inverter to product AC power, with or without the generator running.

Some details on this... Why? What's the application? I'm finding that a really good DC to AC inverter is about the same cost of a decent inverter generator of similar wattage. If my solar battery bank is low or the load increases, and I need to run critical appliances, I would like to run the generator to maintain power without a bunch of switching power cables from Solar to Generator. Since the inverter generator is already able to convert DC to AC, it would be ideal to have 1 less piece of equipment and just use the generator's inverter with the DC output of the Solar charge controller being converted to AC power.

 

[slow]

I would just charge the battery bank with the DC power to supplement. What voltage is your battery bank? No generator I am aware of has input or output to the high current DC bus behind the inverter.

 

[tjbcatch22]

Thank you. The battery bank is 12v 250 ah. Its small for just a few items with low power consumption. However, I like having options and backups - hence the question being posed.

For the inverter generator, I was considering modification so I can access the DC bus on the inverter and plug in the DC output from the solar charger. (if this is even possible)

For some insight on my solar system and my motivations... The solar setup is also small, ~ 500w to a 60 a solar charger. The inverter generator (which I do not yet have) would be around 2000w, portable. I like to tinker.

 

[slow]

https://forum.solar-electric.com/di...s by generating 200,converts to 120v ac power. This was a link I found before, The honda inverters use high voltage and thin windings to generate the DC bus at around 200 volts. I would just use a DC power supply to charge your battery bank. Personally, I have a similar setup, Xantrex 1000 watt pure sine inverter, solar charge controller for 12v battery and an APS-55 120 vac to 55 amp 12V dc output to charge the battery/power the inverter from any source. This allows me to power it with my honda inverter generator or other generator if available without changing any cords to my refirgerator.

 

[tjbcatch22]

Guess I won't be charging directly from the inverter's DC !

My other associated tinker was to not get a separate inverter and opt to modify the generator to take in the DC from the solar charger and output to the generators AC panel for AC power, without running the generator. I wouldn't be charging the batteries from the DC Bus on the generator, especially after reading the link you shared. Essentially, I would hijack the generator's inverter for use with the solar setup when the generator is not running.

I've look at a few tear downs and repair manuals of portable inverter generators but its not clear if I can connect into the generator's inverter in a way that's needed to produce AC current and not cause unintended damage

Thoughts anyone? Slow?

 

[briann898]

Well, maybe you should try some alternatives like 2000W 12V pure sine wave inverter charger?.. I've got it like a backup for my main inverter generator, and it helps a lot in many situations. It goes with awesome LCD display, and works perfectly just like it should. You can find it at this solar inverter resource, where I found it. They have pretty awesome options and models to compare with, and different specifications of each model is written in details, so you understand what you're gonna purchase. I love that resource because of it's wide assortment.

 

[u3b3rg33k]

I've seen NOT UL listed grid tie inverters from china that have a CT so they will not backfeed your non-grid tie service. usually with a 5-15P on the end. while I don't like that, the application of the CT to keep from over-feeding your generator makes sense here. most grid tie inverters are set up intending to dump as much power out as possible.

 

[nadogail]

You might consider an engine driven alternator to charge your battery bank.

https://theepicenter.com/blog/ac-dc-generator/ has what I consider to be useful information.

 

[rlitman]

I've seen NOT UL listed grid tie inverters from china that have a CT so they will not backfeed your non-grid tie service. usually with a 5-15P on the end. while I don't like that, the application of the CT to keep from over-feeding your generator makes sense here. most grid tie inverters are set up intending to dump as much power out as possible.

I don't know what "over-feeding" an inverter generator means? Honda (and many other) inverter generators are parallel capable.

 

[u3b3rg33k]

I don't know what "over-feeding" an inverter generator means? Honda (and many other) inverter generators are parallel capable.

i'm talking about a GT inverter with a CT you put on your mains so it will not output power "to the grid", aka it won't push out more amps than you're pulling in.

I'm not endorsing non-code/POCO blessed installs just saying they exist.

 

[Solarphil]

There are “non-export” PV inverter systems available today, UL-listed, from American companies (or reputable European companies). Yes, there are some hinky imported **** being promoted as well, but let’s ignore that for a moment. At their core, these systems are designed to throttle back output to match and simply offset your loads without sending any excess power out to the grid. The better systems also use batteries to make more effective use of your solar power, but batteries aren’t strictly required. However, that’s not what the OP wanted to do - he wanted to know if it’s possible to connect a PV array directly to the power conversion portion of a gen-verter, bypassing the primer mover. Short answer, no. Longer answer, well, um, maybe... given large enough budget of time and money and willingness to blow up some expensive gear in the meantime, but jeezus there’s easier ways to get what you’re asking done, done. Ask an engineer and you’ll find all things are possible given a large enough playing field. Ask two engineers and you can get three or four opinions on how to do it, too!

In either case, non-export / zero backfeed PV systems won’t help.