Grid tied inverters in off grid configuration.

[Sunking]

I find that if you ask a question, you often and get labelled as confused by "experts". Important to stay safe, comply with regs and judge quality and practicalities.
I am going to wade in with an "Update as of June 2018", mindful that many engineers make their living by adding value to expensive manufactured products.

eBay and Banggood search this morning reveals:
(1) Modified sine wave inverters, 5kW peak, costs just

Houston we have a SPAMMER.

[SunEagle]

I find that if you ask a question, you often and get labelled as confused by "experts". Important to stay safe, comply with regs and judge quality and practicalities.
I am going to wade in with an "Update as of June 2018", mindful that many engineers make their living by adding value to expensive manufactured products.

eBay and Banggood search this morning reveals:
(1) Modified sine wave inverters, 5kW peak, costs just

This thread is over 2 years old so are you posting to provide information or just to get your feet in the door?

[Simon Masters]

I find that if you ask a question, you often and get labelled as confused by "experts". Important to stay safe, comply with regs and judge quality and practicalities.
I am going to wade in with an "Update as of June 2018", mindful that many engineers make their living by adding value to expensive manufactured products.

eBay and Banggood search this morning reveals:
(1) Modified sine wave inverters, 5kW peak, costs just

[Sunking]

Someone is very confused. Does not know what type of Inverter is used and does. Wished I were in sales like Amy. That is a Pigeon waiting to be plucked.

[Mike90250]

Just to clear up a couple of terms being used

Grid Tie inverter. Special inverter fed by PV panels to back feed the grid. Must meet UL 1741 spec, disconnect if loss of Grid, impedance test of Grid. Pure sine
Hybrid Inverter. Even more special, often has dual AC inputs, 1=Grid, 2=Generator Meets UL 1741 also, to safely backfeed the Grid Runs of batteries. pure sine
Inverter / Charger simply uses grid to charge batteries with. Cannot backfeed or sync to grid. Often 12V for use in Camper vehicles. can be pure or mod sine wave
Plug-In GT inverter. OMG ! these never carry a valid UL 1741, seldom are efficient, and can easily start a fire. Fed by PV panels
MPPT Multi Point Power Tracking a way to electrically match PV panel to the load for most efficiency, MPPT generally should not be fed from batteries,

I am seeing a lot of I want to use ABC and then describe DFG and there is much confusion happening.

[organic farmer]

So hybrid inverter is solution - what ever that thing may be. My feeling is that you are referring to inverter/charger type of inverters. Search is on.

Thanks!

My E-panel takes power from photo-voltaic panels, or from the grid, to charge my battery-bank, and to run an inverter, which powers our house.

We are tied to the grid, but as 'grid-assist' instead of 'net-metering'.

[organic farmer]

... You will never save enough in electric bills to compensate for the cost of said equipment.

I will never save enough in electric bills to compensate for the cost of my equipment, either.

Very few people can make electricity for as cheap as you can buy it.

[jflorey2]

Reason why I am asking this is because there are so many more available to chose from in 36V DC world than in off grid 36V DC world.

There is very little available in 36 volt world when it comes to equipment designed to operate off a 36 volt battery bus. About the only common systems out there that use 36 volts are small vehicles (ebikes, golf carts etc.) 12-24-48 volt is far more common.

Second reason is that some of the grid tie type of inverters by default can run on a range of voltages(22 to 60V). This would also have positive impact to flexibility of my off grid system. 24-36-48 volts battery banks for example.

Solar panel voltage doesn't have much to do with what voltage you run your battery at any more. With the advent of cheap MPPT charge controllers, you choose your battery voltage by what loads the battery bank will see. 12 volts for small RV, backup or camping systems, 48 volts for serious home-sized systems.

"Grid tie type" inverters cannot be used to power AC loads from a DC battery, in any case.

[SIGP2101]

Well, for you, your best option is a standard off-grid inverter. They are reliable and cheap and are designed for what you want to do. I strongly suspect you do not want an AC-tied system (only reason you'd need a hybrid inverter) and are just confused as to what that entails.

not quite - I will quote myself:

Reason why I am asking this is because there are so many more available to chose from in 36V DC world than in off grid 36V DC world.
Before I pull the trigger on el cheapo unit I was looking if anyone has successful experience to share. Such a case would open up whole new world of possibilities for me.
Second reason is that some of the grid tie type of inverters by default can run on a range of voltages(22 to 60V). This would also have positive impact to flexibility of my off grid system. 24-36-48 volts battery banks for example.

[jflorey2]

So hybrid inverter is solution - what ever that thing may be.

Well, for you, your best option is a standard off-grid inverter. They are reliable and cheap and are designed for what you want to do. I strongly suspect you do not want an AC-tied system (only reason you'd need a hybrid inverter) and are just confused as to what that entails.

[SIGP2101]

Then use option 1. PV array -> charge controller -> battery -> standalone or hybrid inverter. You cannot use a grid tie inverter for that purpose.

So hybrid inverter is solution - what ever that thing may be. My feeling is that you are referring to inverter/charger type of inverters. Search is on.

Thanks!

[SIGP2101]

I guess I am just dense today, sorry.

Nothing to be sorry about at all.

[jflorey2]

I want option # 1 from your list - but I want to use grid tie inverter instead of off grid inverter since off grid type of inverter is hard to find in 36V DC in acceptable quality. Grid tie inverters are many in 36V on DC side. Do you implying in your option # 1 that is possible to use grid tied type of inverter?

Not unless you really understand what you are doing - and so far you do not.

There are small inverters like the Enphase M250 that will work from 27-39 volts. These CANNOT have batteries attached to them. To use them with an off-grid system you would need a bidirectional 240 volt inverter like the Radian (to generate the AC that the Enphase inverters need to sync to) and several relays to disconnect the Enphase inverters as the batteries get close to full charge. You would also need some custom controls to provide the level of resolution you need to control charge. For the Radian you are looking at $2500 or so.

I am inquiring about possibility of using grid tie type of inverter (instead of off grid type of inverter) hooked up to 36 volts battery bank on its DC side and 110 volts fridge on its AC, side for example.

Won't work.

Battery bank will be charged by PV array + CC.

Then use option 1. PV array -> charge controller -> battery -> standalone or hybrid inverter. You cannot use a grid tie inverter for that purpose.

[SIGP2101]

You will never save enough in electric bills to compensate for the cost of said equipment.

Thought this was off grid part of the forum. isn't it? If you didn't read my posts i suggest you do so. I do apologize in advance since my intention is not to be rude.
All inputs are highly appreciated.

SIGP2101

[organic farmer]

I guess I am just dense today, sorry.