I am thinking about doing something similar, however I want to use the micro grid tie inverters to feed back into the grid while the grid is on (but have a battery bank charged also). Then if the power goes out, I could shut off the grid, and plug in my master inverter to turn on the micro grid tie inverters.
What I would like to know, is if there is a way to divert power to charge the batteries, or into some other useful place if the grid inverters are producing more than is being used.
@davidtwillis Depends a little on your power production, there are some additional components shown in my later videos which might go more to explain this. Most of what you want to do can get accomplished by manually plugging and unplugging stuff as the situation dictates, which is fine for the small scale, on larger scale installations people put in extra breaker and switch boxes, one of which is used to isolate the house system from the grid when flipped a certain way.
Thanks, I will take a look at your later videos. But I don't think I explained myself very well. I want to have about 10 200 watt solar panels, each plugged into a 250w micro grid-tie inverter. I am not sure how I will keep my batteries charged yet, but it might just be a charger plugged into the 110 power. I will just keep this setup until I have a power outage in the grid. At that point I will disconnect the grid, and plug in my master inverter (to activate my micro)
So then the question arises, what happens when I am producing 2kw of power, but my house is only using 1kw? I would like for that to spill over and start charging my batteries, however it doesn't make sense to have my battery charger charging when I am using 3kw, and my solar panels are only producing 2kw.
@davidtwillis Some new style panels are set up that way, each having its own GTI, they are nicknamed "AC solar panels" which are specifically for grid tie only applications. What you are trying to accomplish though would actually mainly be done through a conventional current technology charge controller, not the newer stuff. There are larger commercial charge controllers which handle all of that internally.
Yes, they can, but the conventional inverter is expensive, and is not modular like these new ones are. I love the Idea of being able to just keep adding on as I go, and don't have to fork out $3k for an inverter just to get started with a 100W panel. I may just try hooking up my little 600 watt inverter to a battery, then plug my 250w grid tie (with a 100w panel) into it, and run a 100 watt light bulb off of it and see how it goes.... worst case I am out $200.
@davidtwillis It definitely pays to shop around with the solar equipment. The big firms operate on very generous profit margins then downtalk the cheaper stuff, which seems to work quite well in my experience. The cheaper stuff has vastly improved in just the last two to five years. I will probably be getting into the business since just on my own I secured some pretty good wholesale arrangements with suppliers.
I have been searching for something to do this. However it seems like it would actually be cheaper to just buy a grid-tie inverter, and run it while the grid is up. then if the grid goes down, shut the grid off, and have a separate charge controller with, and inverter to run the house with a off grid setup.
If you could point me to an inexpensive inverter that will run as grid-tie (around 2kw), then switch over to off grid when the grid goes down, that would be great.
@davidtwillis The grid tie inverters will automatically stop feeding into the grid if the grid power is off or unplugged, so you can leave one wired into your system and when it is not plugged into a regular grid outlet, all that gets used up is a little power running the LED light which says it is not feeding the grid. Higher end units will have a built in switch. I just leave mine disconnected when not in use.
@davidtwillis If your panels produce more power than the grid tie inverter would use, for example, 350 watts in full sunlight, but your GTI is a 300 watt, then you can put the GTI inline between your panel connection and your charge controller. It should bleed off its 300 watts then leave the remaining 50 to keep the batteries topped off. That does not work though if the GTI uses more power than the panels make. You would still have to manually unplug the GTI to charge 12v+
@davidtwillis yeah, although I have removed the GTI from my system for now. One very reliable way of accomplishing this is a simple bypass switch. You wire the GTI in line between the panels and the charge controller, with switches to selectively bypass the GTI or charge controller depending on what you want to do. I can make a diagram of this to explain it.
Found this video looking for any information on the same product from same seller. When you quickly picked up the manual I thought I might have seen one of the 'fake pure sine wave' graphs. Is the graph shown in the video supposed to represent the wave output by this inverter? If so, it's not true/pure, and it would be good to know before ordering. This is my worry with a lot of the 'pure' sine wave inverters from China. They should be an unbroken arch.First post on youtube.
I am not planning on obtaining a $2,000 test unit to validate the inverter but I can say that nothing I have plugged into it that would normally be sensitive to a "dirty power" inverter seems to be ringing any alarms.
I see the same seller is now calling some of his other inverters "SEMI-PURE SINE WAVE"... An old $20-$50 oscilloscope let you verify a wave. Some electronics guys told me that one positive thing about some Chinese inverters were they are built very old school, almost everything would be repairable from parts at the old 'radio shack'.. Mod-wave should still run everything fine, it's the added 20% power loss I'd like to avoid(10-15% for inverter + 20% on fridge/motors).
The ebay seller on this goes by the name "dmssgs" I have yet to find lower prices on this stuff from anyone else on the planet, and believe me, I have checked. I regularly buy electronics direct from Chinese factories and these guys have some hookup over there I cannot even touch.
I should say that I like the idea. If each person on the micro-grid could have their own panels and feed it into a GTI it would be like a small community grid. Then all you have to worry about is people who would pull too much power, or take more than their share. You would also have to deal with a lot of start up spikes from things like refrigerators. It might be easier to just have everyone on 24V and run #10 wires to each "camp" and each has a 300W $15 MSW inverter for their few needs.
@nrodge1 Yeah, the issue on that is the 24v system. I think you can run 12v as long as no single run is over 50ft which I figure is the established upper limit between the tail lights of a long trailer and the engine/alternator system on a tow vehicle in established practice on 12v systems. I am reconfiguring this to a little different format on the first trailer and will probably just be hopping 12v lines between trailers just starting out. Maybe a bundle of cables, 12v and 120v, all 10G.
I thought about this and here's what will happen. The GTI does NOT regulate itself via the AC side, it watches the DC amps and volts and will try to put out as much power as it can. So when your fridge turns off, the GTI will just keep on pushing and will over voltage the AC side which may shut off your inverter depending on what sensing they have on the AC side but you will risk blowing other loads such as a lamp or anything AC voltage sensitive. Feel free to drop by the forums at techluck.com
@nrodge1 OK so does anyone make any sort of AC regulator that can deal with this say on the 10KW scale?
If the regular power grid pushes essentially infinite amps, but things usually run 10 to 20 amp fuses, does that mean we are realistically already looking at most household electrical items being able to handle an easy 10KW "hot" in the wiring? I am thinking that safety is maintained if the system stays below a certain threshold, or is it that adding more power has to only be on the DC side?
Picture a 50W bulb connected to your inverter, and the GTI. When the GTI starts running it sees good AC and ramps up to 50W, then still sees good AC and keeps going up to 250W raising the Ac voltage at the same time, your light bulb blows and maybe your inverter shuts down which makes the GTI turn off too. If I ran the test I would connect the GTI to a variable power supply and ramp it up slow and watch the AC side voltage and see what happens but be able to shut it down quickly.
It should be an interesting experiment. You want to ramp it up slow of course and I'm not sure what the GTI will think when you turn something on and the AC voltage drops a lot. I assume you are ready to blow both inverters, or don't care much. Like you said, the grid is a pretty much unlimited load so a GTI can push power out as hard as it wants.
@nrodge1 Oh well, of course I care about the inverters, i care for and love them very much, but this is an important project and while there is risk involved, I think the chances of success outweigh the chances of roasting the stuff. The sine wave inverter is the most at risk, and I don't think it would be damaged by only one 300 watt grid tie. The GTI are pretty bulletproof in their programming. If they sense a problem, they shut down.
Respond to this video... As long as the circuitry in the sine wave inverter is in fact one way circuitry, then there should be no risk of roasting anything. The deal on this is that the GTIs are placed in proximity to their own loads anyway, so that minimizes feedback. For example, I have one carry out solar system that produces 270watts of real world power, so that on a GTI and then the GTI plugged into a two space outlet wired to the micro grid gets the 250 watt freezer.
So with loads placed in proximity (plugged into one side of the two space house style outlet) and then the outlets tied into the micro-grid, the system send surplus into the grid and automatically shifts it around in the daytime, but only the primary system charges batteries. Thus there is less need for heavier and more costly 12v wiring to go all over, and then the system automatically rations itself to daytime power production, but with a nighttime current availability of 2KW off batteries.
What makes this a micro-grid as opposed to just a solar based single user system is that anyone can show up with their own power production capability and boost the grid as a whole, Each cluster of trailer encampments is its own little power company.
I am thinking about doing something similar, however I want to use the micro grid tie inverters to feed back into the grid while the grid is on (but have a battery bank charged also). Then if the power goes out, I could shut off the grid, and plug in my master inverter to turn on the micro grid tie inverters.
What I would like to know, is if there is a way to divert power to charge the batteries, or into some other useful place if the grid inverters are producing more than is being used.
davidtwillis 2 months ago
@davidtwillis Depends a little on your power production, there are some additional components shown in my later videos which might go more to explain this. Most of what you want to do can get accomplished by manually plugging and unplugging stuff as the situation dictates, which is fine for the small scale, on larger scale installations people put in extra breaker and switch boxes, one of which is used to isolate the house system from the grid when flipped a certain way.
8digitPDX 2 months ago
@8digitPDX
Thanks, I will take a look at your later videos. But I don't think I explained myself very well. I want to have about 10 200 watt solar panels, each plugged into a 250w micro grid-tie inverter. I am not sure how I will keep my batteries charged yet, but it might just be a charger plugged into the 110 power. I will just keep this setup until I have a power outage in the grid. At that point I will disconnect the grid, and plug in my master inverter (to activate my micro)
davidtwillis 2 months ago
So then the question arises, what happens when I am producing 2kw of power, but my house is only using 1kw? I would like for that to spill over and start charging my batteries, however it doesn't make sense to have my battery charger charging when I am using 3kw, and my solar panels are only producing 2kw.
davidtwillis 2 months ago
@davidtwillis Some new style panels are set up that way, each having its own GTI, they are nicknamed "AC solar panels" which are specifically for grid tie only applications. What you are trying to accomplish though would actually mainly be done through a conventional current technology charge controller, not the newer stuff. There are larger commercial charge controllers which handle all of that internally.
8digitPDX 2 months ago
@8digitPDX
Yes, they can, but the conventional inverter is expensive, and is not modular like these new ones are. I love the Idea of being able to just keep adding on as I go, and don't have to fork out $3k for an inverter just to get started with a 100W panel. I may just try hooking up my little 600 watt inverter to a battery, then plug my 250w grid tie (with a 100w panel) into it, and run a 100 watt light bulb off of it and see how it goes.... worst case I am out $200.
davidtwillis 2 months ago
@davidtwillis It definitely pays to shop around with the solar equipment. The big firms operate on very generous profit margins then downtalk the cheaper stuff, which seems to work quite well in my experience. The cheaper stuff has vastly improved in just the last two to five years. I will probably be getting into the business since just on my own I secured some pretty good wholesale arrangements with suppliers.
8digitPDX 2 months ago
@8digitPDX
I have been searching for something to do this. However it seems like it would actually be cheaper to just buy a grid-tie inverter, and run it while the grid is up. then if the grid goes down, shut the grid off, and have a separate charge controller with, and inverter to run the house with a off grid setup.
If you could point me to an inexpensive inverter that will run as grid-tie (around 2kw), then switch over to off grid when the grid goes down, that would be great.
davidtwillis 1 month ago
@davidtwillis
The only ones I can find are outback, and xantrex.
davidtwillis 1 month ago
@davidtwillis The grid tie inverters will automatically stop feeding into the grid if the grid power is off or unplugged, so you can leave one wired into your system and when it is not plugged into a regular grid outlet, all that gets used up is a little power running the LED light which says it is not feeding the grid. Higher end units will have a built in switch. I just leave mine disconnected when not in use.
8digitPDX 2 months ago
@davidtwillis If your panels produce more power than the grid tie inverter would use, for example, 350 watts in full sunlight, but your GTI is a 300 watt, then you can put the GTI inline between your panel connection and your charge controller. It should bleed off its 300 watts then leave the remaining 50 to keep the batteries topped off. That does not work though if the GTI uses more power than the panels make. You would still have to manually unplug the GTI to charge 12v+
8digitPDX 2 months ago
@davidtwillis yeah, although I have removed the GTI from my system for now. One very reliable way of accomplishing this is a simple bypass switch. You wire the GTI in line between the panels and the charge controller, with switches to selectively bypass the GTI or charge controller depending on what you want to do. I can make a diagram of this to explain it.
8digitPDX 1 month ago
Found this video looking for any information on the same product from same seller. When you quickly picked up the manual I thought I might have seen one of the 'fake pure sine wave' graphs. Is the graph shown in the video supposed to represent the wave output by this inverter? If so, it's not true/pure, and it would be good to know before ordering. This is my worry with a lot of the 'pure' sine wave inverters from China. They should be an unbroken arch.First post on youtube.
Ostmpeace 2 months ago
@Ostmpeace
I am not planning on obtaining a $2,000 test unit to validate the inverter but I can say that nothing I have plugged into it that would normally be sensitive to a "dirty power" inverter seems to be ringing any alarms.
8digitPDX 2 months ago
@8digitPDX
I see the same seller is now calling some of his other inverters "SEMI-PURE SINE WAVE"... An old $20-$50 oscilloscope let you verify a wave. Some electronics guys told me that one positive thing about some Chinese inverters were they are built very old school, almost everything would be repairable from parts at the old 'radio shack'.. Mod-wave should still run everything fine, it's the added 20% power loss I'd like to avoid(10-15% for inverter + 20% on fridge/motors).
Ostmpeace 2 months ago
The ebay seller on this goes by the name "dmssgs" I have yet to find lower prices on this stuff from anyone else on the planet, and believe me, I have checked. I regularly buy electronics direct from Chinese factories and these guys have some hookup over there I cannot even touch.
8digitPDX 4 months ago
I should say that I like the idea. If each person on the micro-grid could have their own panels and feed it into a GTI it would be like a small community grid. Then all you have to worry about is people who would pull too much power, or take more than their share. You would also have to deal with a lot of start up spikes from things like refrigerators. It might be easier to just have everyone on 24V and run #10 wires to each "camp" and each has a 300W $15 MSW inverter for their few needs.
nrodge1 4 months ago
@nrodge1 Yeah, the issue on that is the 24v system. I think you can run 12v as long as no single run is over 50ft which I figure is the established upper limit between the tail lights of a long trailer and the engine/alternator system on a tow vehicle in established practice on 12v systems. I am reconfiguring this to a little different format on the first trailer and will probably just be hopping 12v lines between trailers just starting out. Maybe a bundle of cables, 12v and 120v, all 10G.
8digitPDX 4 months ago
I thought about this and here's what will happen. The GTI does NOT regulate itself via the AC side, it watches the DC amps and volts and will try to put out as much power as it can. So when your fridge turns off, the GTI will just keep on pushing and will over voltage the AC side which may shut off your inverter depending on what sensing they have on the AC side but you will risk blowing other loads such as a lamp or anything AC voltage sensitive. Feel free to drop by the forums at techluck.com
nrodge1 4 months ago
@nrodge1 OK so does anyone make any sort of AC regulator that can deal with this say on the 10KW scale?
If the regular power grid pushes essentially infinite amps, but things usually run 10 to 20 amp fuses, does that mean we are realistically already looking at most household electrical items being able to handle an easy 10KW "hot" in the wiring? I am thinking that safety is maintained if the system stays below a certain threshold, or is it that adding more power has to only be on the DC side?
8digitPDX 4 months ago
Picture a 50W bulb connected to your inverter, and the GTI. When the GTI starts running it sees good AC and ramps up to 50W, then still sees good AC and keeps going up to 250W raising the Ac voltage at the same time, your light bulb blows and maybe your inverter shuts down which makes the GTI turn off too. If I ran the test I would connect the GTI to a variable power supply and ramp it up slow and watch the AC side voltage and see what happens but be able to shut it down quickly.
nrodge1 4 months ago
It should be an interesting experiment. You want to ramp it up slow of course and I'm not sure what the GTI will think when you turn something on and the AC voltage drops a lot. I assume you are ready to blow both inverters, or don't care much. Like you said, the grid is a pretty much unlimited load so a GTI can push power out as hard as it wants.
nrodge1 5 months ago
@nrodge1 Oh well, of course I care about the inverters, i care for and love them very much, but this is an important project and while there is risk involved, I think the chances of success outweigh the chances of roasting the stuff. The sine wave inverter is the most at risk, and I don't think it would be damaged by only one 300 watt grid tie. The GTI are pretty bulletproof in their programming. If they sense a problem, they shut down.
8digitPDX 5 months ago
Respond to this video... As long as the circuitry in the sine wave inverter is in fact one way circuitry, then there should be no risk of roasting anything. The deal on this is that the GTIs are placed in proximity to their own loads anyway, so that minimizes feedback. For example, I have one carry out solar system that produces 270watts of real world power, so that on a GTI and then the GTI plugged into a two space outlet wired to the micro grid gets the 250 watt freezer.
8digitPDX 5 months ago
So with loads placed in proximity (plugged into one side of the two space house style outlet) and then the outlets tied into the micro-grid, the system send surplus into the grid and automatically shifts it around in the daytime, but only the primary system charges batteries. Thus there is less need for heavier and more costly 12v wiring to go all over, and then the system automatically rations itself to daytime power production, but with a nighttime current availability of 2KW off batteries.
8digitPDX 5 months ago
What makes this a micro-grid as opposed to just a solar based single user system is that anyone can show up with their own power production capability and boost the grid as a whole, Each cluster of trailer encampments is its own little power company.
8digitPDX 5 months ago
Thanks for the video! I just ordered one of these for my camper.
GyreFunk 5 months ago