Solar with microinverters

[theoldwizard1]

Believe it or not the solar technology has advanced to the point of just install a solar panel, wiring in a special box called a microinverter (solar panel in, cord out) and plugging into an outlet !

This type of setup is meant to augment your existing PoCo supplied power. Because it is very limited wattage (300W-400W ?) and because it literally plugs into and existing outlet, they "get around" a lot of expensive "issues" (no second meter, no disconnect, etc.)

Each panel and inverter feeds a 120V circuit. One microinverter per circuit, but you can have multi- microinverters as long as they are all on separate circuits.


Has anyone installed a system like this ?

 

[u3b3rg33k]

i've seen many systems with power optimizers (individual buck/boost converters) and a central inverter. the idea is to prevent the shading of a single panel from limiting the output of the entire array.

as for "getting around" requiring a disconnect, that depends on your local utility. a separate circuit for each inverter with a 15kW array with 300W panels would require a 50 space panel. that's nuts.

 

[HOTFR8]

I do believe this is the same or similar to what 1/2 Cup installed going back some time ago. Each panel has an invertor.

 

[rsanter]

Believe it or not the solar technology has advanced to the point of just install a solar panel, wiring in a special box called a microinverter (solar panel in, cord out) and plugging into an outlet !

This type of setup is meant to augment your existing PoCo supplied power. Because it is very limited wattage (300W-400W ?) and because it literally plugs into and existing outlet, they "get around" a lot of expensive "issues" (no second meter, no disconnect, etc.)

Each panel and inverter feeds a 120V circuit. One microinverter per circuit, but you can have multi- microinverters as long as they are all on separate circuits.


Has anyone installed a system like this ?

Junk, don’t bother.

Now, micro inverters can be good and they have been around more than 10 years. They have their advantages especially when you are only installing a few panels.
However the just plug it into an outlet thing is ****. You can cause some real issues in your electrical system .
If you want to use micro inverters on just a few panels that’s fine but run them direct into your main electrical panel and have a disconnect

 

[Git]

Micro Inverters have been on the market for several years. As with anything, there are pros and cons

Basically you have three types of inverters

String - the cheapest and easiest to work on since it usually mounted at ground level next to your meter. One of the problems with a string inverter is if only one panel gets some shade, it can bring down the output of the whole system because the current flows through each panel to the next and then to the inverter

Micro Inverters like you mentioned, get mounted to the backs of each panel and you eliminate the inverter by the meter. Micro Inverters are expensive and there is a train of thought that you don't want to have expensive electronic items baking in the heat under the panels, and if you have one that goes down, it is a little harder to replace. On the other hand, they are not affected by shade

Lastly, you have power optimizers, which is kind of a hybrid system. You still have a string inverter on the side of your house, but you also have optimizers (very similar to micro inverters) attached to the underside of each panel. Like microinverters, each panel operates independently so one shaded panel won't affect the entire system.

I actually went with power optimizers because at the time ( summer of 2016) the panels were producing more power than most microinverters could handle and 'clipping' would occur once they reached their limit. (My panels were rated at around 320 watts and the microinverters were at 300 watts). I also liked the idea of having the string inverter out of the sun and heat mounted by the power meter in case it ever needed to be serviced or replaced (my SolarEdge optimizers and string inverter is warrantied for 25 years so it should not be a problem)

In my area, everyone has smart meters that can run backward if your producing more power than your using, it will detect it and credit your account. The only time I see a second meter is a leased system where they are charging you for the electricity but it is still cheaper than buying from the power company

I don't buy the 'plug it in' thing - remember in case of a power outage, grid tied solar goes offline

 

[mcbane]

One last consideration is that "island mode" operation, where you can operate from batteries and solar during times when the grid is down, is more difficult with microinverters. In many states probably not a consideration but in states like CA where the grid is frequently down, you need some way to keep going without the poco.

 

[BajaScout]

Micro Inverters have been on the market for several years. As with anything, there are pros and cons

Basically you have three types of inverters

String - the cheapest and easiest to work on since it usually mounted at ground level next to your meter. One of the problems with a string inverter is if only one panel gets some shade, it can bring down the output of the whole system because the current flows through each panel to the next and then to the inverter

Micro Inverters like you mentioned, get mounted to the backs of each panel and you eliminate the inverter by the meter. Micro Inverters are expensive and there is a train of thought that you don't want to have expensive electronic items baking in the heat under the panels, and if you have one that goes down, it is a little harder to replace. On the other hand, they are not affected by shade

Lastly, you have power optimizers, which is kind of a hybrid system. You still have a string inverter on the side of your house, but you also have optimizers (very similar to micro inverters) attached to the underside of each panel. Like microinverters, each panel operates independently so one shaded panel won't affect the entire system.

I actually went with power optimizers because at the time ( summer of 2016) the panels were producing more power than most microinverters could handle and 'clipping' would occur once they reached their limit. (My panels were rated at around 320 watts and the microinverters were at 300 watts). I also liked the idea of having the string inverter out of the sun and heat mounted by the power meter in case it ever needed to be serviced or replaced (my SolarEdge optimizers and string inverter is warrantied for 25 years so it should not be a problem)

In my area, everyone has smart meters that can run backward if your producing more power than your using, it will detect it and credit your account. The only time I see a second meter is a leased system where they are charging you for the electricity but it is still cheaper than buying from the power company

I don't buy the 'plug it in' thing - remember in case of a power outage, grid tied solar goes offline

I have the same set up. With 10 panels I overproduce almost every day.