Hey all.
I've been shopping around for inverters, and they've got me a bit confused. I'm totally new to the big ones, and I'll probably get some terminology wrong. I also don't really know where to look besides whatever randomly pops up in Google searches. But maybe you guys can help me figure this out.
I should probably let you know that I'm neither rich nor acrobatic. So this will all have to be done in stages while I recover financially from each one. And I'll have to hire out the solar panel installation. The primary goal is to have some power available to critical circuits during power outages. I figure 8 circuits based on how various things are split up in the main panel currently, and 6kW of power. I've actually counted up more like 4.5kW, but a buffer between typical and maximum would be nice.
Stage 1: Add a sub panel with the critical circuits. Fed by either the main panel (US grid) or by a 6kW generator. I'll also have a transfer switch so the grid and generator never get to "see" each other. This I could do pretty easily. The main panel is surface-mounted to a cinder block wall, and has room for more panels and boxes to be installed nearby. The wiring is also easily accessible.
Generator.png
Stage 2: Add the inverter and battery. Because my primary concern is having power during outages, the next step is adding a battery, rather than solar. And to use it I'll need an inverter. The idea is that for short outages, the battery can be used to power the sub panel until grid power is restored. For longer outages, the generator would still be used to run the sub panel when the battery is depleted, and can also recharge the battery. This may be less efficient, but it would allow the generator to not be run for several hours at a time. Depending on how conservative we are with our energy usage, and the size of the battery. At this stage, the inverter wouldn't need any particularly special features other than being able to deliver up to 6kW of power from the battery to the sub panel. An internal AC to DC battery charge controller would be nice, but an external one could also be used.
InverterBattery.png
Stage 3: Add solar panels. I determined a while ago that no amount of solar will power my whole house in the winter. I got 136 inches of rain last year, and my property isn't large. But what panels I can get would certainly be enough to make an impact on my electrical bill during nice weather. First priority for the inverter would still be to power the sub panel during outages. But now I'd need to either have a solar charge controller, or an inverter with one built in. I don't plan to produce enough power to back-feed to the grid for credit or whatever. But a smaller electrical bill in the summer would be nice to offset the large bills I'll get in the winter. Plus in a longer power outage, there might be some nice days where the solar could reduce my dependence on the generator.
Solar.png
So to sum up; here are some things I'm looking for in an inverter:
-Needs to provide up to 6kW of power.
-I think because of the amount of power, it will need to be 240V split phase. (The generator and sub panel will be split phase.)
-Would be nice to be compatible with the grid/generator transfer switch. (I've heard some aren't.)
-Would be nice if it can be set to use solar and battery as primary, but include grid to cover the difference if solar and battery aren't enough. (I've heard some can do this, and some can't.)
-Internal AC to DC programmable charger for the battery would be nice.
-Internal MPPT solar controller would be nice.
-It does not need to be able to back-feed the grid.
-It does not need to function as a UPS. (I have those in place already.)
There's lots of You Tube videos out there describing and reviewing various inverters, but none of them answer all of my questions. Maybe I'm not asking the right questions. Beyond the specs, I have concerns about tech support and return policies. Every inverter I've looked at has at least one horror story to go with it. I don't want my inverter to come with free drama. Also, where does one actually buy them? What stores can be trusted? A lot of the brands out there don't sell directly. So suggestions are welcome.
I've been shopping around for inverters, and they've got me a bit confused. I'm totally new to the big ones, and I'll probably get some terminology wrong. I also don't really know where to look besides whatever randomly pops up in Google searches. But maybe you guys can help me figure this out.
I should probably let you know that I'm neither rich nor acrobatic. So this will all have to be done in stages while I recover financially from each one. And I'll have to hire out the solar panel installation. The primary goal is to have some power available to critical circuits during power outages. I figure 8 circuits based on how various things are split up in the main panel currently, and 6kW of power. I've actually counted up more like 4.5kW, but a buffer between typical and maximum would be nice.
Stage 1: Add a sub panel with the critical circuits. Fed by either the main panel (US grid) or by a 6kW generator. I'll also have a transfer switch so the grid and generator never get to "see" each other. This I could do pretty easily. The main panel is surface-mounted to a cinder block wall, and has room for more panels and boxes to be installed nearby. The wiring is also easily accessible.
Generator.png
Stage 2: Add the inverter and battery. Because my primary concern is having power during outages, the next step is adding a battery, rather than solar. And to use it I'll need an inverter. The idea is that for short outages, the battery can be used to power the sub panel until grid power is restored. For longer outages, the generator would still be used to run the sub panel when the battery is depleted, and can also recharge the battery. This may be less efficient, but it would allow the generator to not be run for several hours at a time. Depending on how conservative we are with our energy usage, and the size of the battery. At this stage, the inverter wouldn't need any particularly special features other than being able to deliver up to 6kW of power from the battery to the sub panel. An internal AC to DC battery charge controller would be nice, but an external one could also be used.
InverterBattery.png
Stage 3: Add solar panels. I determined a while ago that no amount of solar will power my whole house in the winter. I got 136 inches of rain last year, and my property isn't large. But what panels I can get would certainly be enough to make an impact on my electrical bill during nice weather. First priority for the inverter would still be to power the sub panel during outages. But now I'd need to either have a solar charge controller, or an inverter with one built in. I don't plan to produce enough power to back-feed to the grid for credit or whatever. But a smaller electrical bill in the summer would be nice to offset the large bills I'll get in the winter. Plus in a longer power outage, there might be some nice days where the solar could reduce my dependence on the generator.
Solar.png
So to sum up; here are some things I'm looking for in an inverter:
-Needs to provide up to 6kW of power.
-I think because of the amount of power, it will need to be 240V split phase. (The generator and sub panel will be split phase.)
-Would be nice to be compatible with the grid/generator transfer switch. (I've heard some aren't.)
-Would be nice if it can be set to use solar and battery as primary, but include grid to cover the difference if solar and battery aren't enough. (I've heard some can do this, and some can't.)
-Internal AC to DC programmable charger for the battery would be nice.
-Internal MPPT solar controller would be nice.
-It does not need to be able to back-feed the grid.
-It does not need to function as a UPS. (I have those in place already.)
There's lots of You Tube videos out there describing and reviewing various inverters, but none of them answer all of my questions. Maybe I'm not asking the right questions. Beyond the specs, I have concerns about tech support and return policies. Every inverter I've looked at has at least one horror story to go with it. I don't want my inverter to come with free drama. Also, where does one actually buy them? What stores can be trusted? A lot of the brands out there don't sell directly. So suggestions are welcome.
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