Still researching my home solution to offset some grid cost with PV and have a battery backup. I am looking at Outback and Schneider exclusivly simply because of surge power, true UL listings and was planning an off gird build with grid passthrough (mini-grid setup) which would also allow inverter to charge batteries if needed. Then I went down the hole of grid tied, micro inverters, optimizers, etc and truly see the advantage and ease of wire runs with AC vs DC for the PV. Basically I'm stuck in my mind. I could get a ok Grid-Tie system for the price of some good charge controllers and have an easier install with off-grid inverter/battery. Again goal is to use Grid when required, no interest in sell back as power company will only buy back for max of 2 years. Any thoughts no my ramblings? Max array size will be 10Kw and I already have my critical loads panel circuits wired and critical load panel wired to main panel to code for the time being.
To Grid-Tie or Not
- Thread starter ChrisG
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Not sure where you are but you discribed my system almost to the T.
9600kw not giving power back to grid and still using grid if needed. Charging and using 22.5kw lithium batteries for peak power and night use times.Extra power feeds a water heater now but that can change toi a hoit tub or whatever.
I have a sol-arc 12kw inverter and a ground mount array.I really like the sol arc as its flexible and will accept future changes .
diysolarforum.com
9600kw not giving power back to grid and still using grid if needed. Charging and using 22.5kw lithium batteries for peak power and night use times.Extra power feeds a water heater now but that can change toi a hoit tub or whatever.
I have a sol-arc 12kw inverter and a ground mount array.I really like the sol arc as its flexible and will accept future changes .
Ground Mounted 9,600 watt Sol Arc do it yourself solar system-Solar Pirate
Here are the details of my 24 x400 9600 watt jinko panel system. I started with a solar assessment tool for the site Its a handy device loaned out from a local energy supplier. Our side hill was a perfect south facing site. Due to the slope I also slanted it a bit to the west a few degrees. We...
diysolarforum.com
sunshine_eggo
Happy Breffast!
You've answered your own question.
I was looking at the Schneider for a friend. The lack of built in solar charger was a negative to me, so I kept looking. (the Schneider still might win because of surge) The Phocos Any-Grid (video) caught my attention. Alt-E offering. It appears that it does all of its work at the high voltage DC side and not at the 48v battery side, which allows PV energy to be put to the inverter directly rather than into a battery charger, to the battery, to the inverter. Anyway, it might be worth a look.
@sunshine_eggo I didn't yet. Grid-Tie can still be used with off grid solution without sell back and get benefits of micro inverters and how it overcomes any shading issues/etc. I would have PV->GridTie->Critical Panel<-OffGrid Inverter<-Grid/Battery. Just wondering if the complexity outweighs the benefit of micro AC Coupling vs string inverters .
timselectric
If I can do it, you can do it.
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String is usually cheaper. And two wires is two wires. Whether it's AC or DC. If not selling to the grid, I don't see any point in grid tied. It's even more expensive to work batteries in.
Just my opinion.
Just my opinion.
WYtreasure
It's not happy hour, I'm just like this.
Without knowing your "general location", it is difficult to offer good advice.
jasonhc73
Cat herder, and dog toy tosser.
For me, I think if you have access to the grid, then grid-tie.
If you are out in the boonies and don't have a pole nearby, then stay 100% off-grid.
If you are out in the boonies and don't have a pole nearby, then stay 100% off-grid.
sunshine_eggo
Happy Breffast!
Marginally true, but is it really worth the cost of a whole second system? If you have shading issues, it's going to be a problem either way, and you should address that before making any decision. Shading will kill your PV system.
Microinverters don't magically overcome shading, they are just more efficient at the utilization of partially shaded panels. The benefit is usually over-stated.
Microinverters are often rated for LESS than the solar panels to which they are attached, so you may string up a bunch of luscious 360W panels, but you'll NEVER see more than 290W out of them due to the microinverter limitations.
GT PV AC coupled to an off grid inverter is notably less efficient than direct PV to the off-grid battery, and your off grid inverter needs to be about the same size of 1.2X larger than your GT PV output.
Ampster
Renewable Energy Hobbyist
I think there is some confusion about what @ChrisG means by Grid Tie. I think he means a grid connection for charging his batteries but zero export. That is possible and practical and location does not matter as long as he has a low enough rate to economically charge when needed. I think the concept he is getting at is what I call self consumption and that is what my Outback Skybox can do. The Skybox is an All In One but does not have as much surge as the Outback Radian. The Radian would require separate charge controller and other peripherals but comes in 4k and 8k versions. The new Outback Mohawk is an All In One with a large capacity but I do not know about surge. It is designed to integrate with Outback's Mohawk batteries which I assume are NEC 2020 compliant if that is a consideration.
sunshine_eggo
Happy Breffast!
Read his reply to me. He's considering using GT AC coupled to an off grid inverter that receives AC in from grid.
I agree with the rest of what you said.
timselectric
If I can do it, you can do it.
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I don't think that I am confused. But if I was, I probably wouldn't know it.
Warpspeed
Solar Wizard
I built a system without a battery as a starting point.
During the day, my inverter is powered from solar direct from the panels.
If that is insufficient (and at night) the inverter receives power from a grid powered dc rectifier.
At dawn and dusk changeover is smooth and progressive as the inverter draws power from the highest voltage source via a pair of diodes.
It always draws solar first, then the grid makes up any defecit.
Its the lowest cost and best bang for your buck possible. In mid summer about 85% comes from solar, around mid winter about 55% still comes from solar.
Nothing is fed back onto the grid ever. But my utility bills are vastly reduced.
I have since purchased a very expensive lithium battery, and am now off grid.
But the cost of the battery has totally changed the economics of the whole system such that its now not any cheaper than just running off grid power.
The only advantage is if/when the grid goes down I am independent.
If my battery craps out in less than fifteen years I would be financially worse off than if I had just kept the original "no battery" system going.
During the day, my inverter is powered from solar direct from the panels.
If that is insufficient (and at night) the inverter receives power from a grid powered dc rectifier.
At dawn and dusk changeover is smooth and progressive as the inverter draws power from the highest voltage source via a pair of diodes.
It always draws solar first, then the grid makes up any defecit.
Its the lowest cost and best bang for your buck possible. In mid summer about 85% comes from solar, around mid winter about 55% still comes from solar.
Nothing is fed back onto the grid ever. But my utility bills are vastly reduced.
I have since purchased a very expensive lithium battery, and am now off grid.
But the cost of the battery has totally changed the economics of the whole system such that its now not any cheaper than just running off grid power.
The only advantage is if/when the grid goes down I am independent.
If my battery craps out in less than fifteen years I would be financially worse off than if I had just kept the original "no battery" system going.
Warpspeed
Solar Wizard
One point worth mentioning.
The dc rectifier voltage is selected to equal the maximum power voltage of my solar panels.
As the inverter load increases, it pulls the panel voltage down to the max power point.
Any further load comes from the grid, but the panels can never be pulled down lower in voltage than their most efficient operating point.
Its really like poor mans mppt, without an mppt controller.
Massive surge loads, such as starting up a refrigerator are drawn from the grid and only lasts about a second or so.
Its probably the simplest and most efficient system possible for those on a budget.
The dc rectifier voltage is selected to equal the maximum power voltage of my solar panels.
As the inverter load increases, it pulls the panel voltage down to the max power point.
Any further load comes from the grid, but the panels can never be pulled down lower in voltage than their most efficient operating point.
Its really like poor mans mppt, without an mppt controller.
Massive surge loads, such as starting up a refrigerator are drawn from the grid and only lasts about a second or so.
Its probably the simplest and most efficient system possible for those on a budget.
timselectric
If I can do it, you can do it.
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Ouch
That's a shame.
This is why I waited so long to get solar.
The ROI wasn't worth it until now.
timselectric
If I can do it, you can do it.
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Pretty neat design.
Ampster
Renewable Energy Hobbyist
AC coupling works with the Radian and presumably with some of the other combinations. Zero export can also work with the right GT inverter. Surge should not be a problem with even a Skybox because the grid can cover the surge so he really doesn't need the expense of a Radian depending on the loads and his maximum consumption in kWs. He could find an economic solution combining a less expensive GT inverter with a medium priced hybrid.
Ampster
Renewable Energy Hobbyist
My comment was not directed at you. Someone suggested that he should only consider Off Grid if the expense of bringing power to the site was too much. His concept of Off Grid is more like mine, which is self sufficiency with the grid as backup.
timselectric
If I can do it, you can do it.
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My setup is also off grid with grid available for backup. Done with an off grid AIO.
Ampster
Renewable Energy Hobbyist
I have two EVs so if I need a big charge I use the grid late at night. Most of the time after the equinox I am self sufficient. Winter clouds and heat pump mean I need the grid for backup as well in winter. My plan is to net zero.
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