Enphase Microinverters

[Duff1234]

Hello, I am new to the forums here and have a general question I'm curious about. I know it's not the ideal situation but I am curious if any of you know or think it might work. I don't have any of the equipment in question but again, am just curious to know if it might be possible or might work.

On to the question. Lets say I can only afford a very small setup for solar right now. Maybe 2 grape solar 100w panels or 2 renogy 100w panels. If I want to use them in a grid tied setup there are several options but I'm most interested in microinverters. So lets say I then get an enphase micro inverter. Would it be possible to hook 2 100w panels such as the ones I've listed, in parallel (using Y branch connectors) to meet the 24v requirement on the microinverter and have it properly convert the energy for the grid tied application?

I know it would be recommended to get larger panels that are designed for that as opposed to getting the small 100w panels which really aren't designed for that, but when pricing out panels, the larger panels require freight shipping, and almost always equals a higher price per watt than the small renogy or Grape solar panels if you're only needing 1 or 2. Pricing it out from most of the web stores I can find it only starts to become a better deal if I'm looking to buy 3 or 4 or more large panels with freight shipping but then it's no longer a small project with a small price. Just curious though to see if anyone has ever tried the above setup or knows if it for sure will or will not work. Thanks for any input!

[ButchDeal]

On to the question. Lets say I can only afford a very small setup for solar right now. Maybe 2 grape solar 100w panels or 2 renogy 100w panels. If I want to use them in a grid tied setup there are several options but I'm most interested in microinverters. So lets say I then get an enphase micro inverter. Would it be possible to hook 2 100w panels such as the ones I've listed, in parallel (using Y branch connectors) to meet the 24v requirement on the microinverter and have it properly convert the energy for the grid tied application?

First you would be better not getting any PV module under 200w or rated for 12V. These are more expensive per watt than typical grid tie PV modules which are usually 250w and up.

If you absolutely had to get two 100W pv modules you would NOT want to use the Y branch connectors but instead connect them in series to increase the voltage so that it is in the operating range of the micro inverter. There are other things you would need to legally set this up as well, like racking, wire, disconnect, labeling, permit, inspections, interconnect agreement etc.

You would be best off getting a small loan and going a little bigger on the system.

I know it would be recommended to get larger panels that are designed for that as opposed to getting the small 100w panels which really aren't designed for that, but when pricing out panels, the larger panels require freight shipping, and almost always equals a higher price per watt than the small renogy or Grape solar panels if you're only needing 1 or 2. Pricing it out from most of the web stores I can find it only starts to become a better deal if I'm looking to buy 3 or 4 or more large panels with freight shipping but then it's no longer a small project with a small price. Just curious though to see if anyone has ever tried the above setup or knows if it for sure will or will not work. Thanks for any input!

There are local distributors in most areas that you can go to and pick up cheap last year models etc.
again though small projects are MUCH MUCH more expensive per watt, so you are far better off with a small loan to get it a bit larger. If you have a home to install on that loan should not be a problem as a HELOC or signature etc.

[jflorey2]

On to the question. Lets say I can only afford a very small setup for solar right now. Maybe 2 grape solar 100w panels or 2 renogy 100w panels.

You can do that if you want a system to "learn" on. Get those, a small battery, an inverter and a charge controller and do some experiments - if your goal is learning. Then sell them when you are done.

You cannot start small and expand later.

If I want to use them in a grid tied setup there are several options but I'm most interested in microinverters. So lets say I then get an enphase micro inverter. Would it be possible to hook 2 100w panels such as the ones I've listed, in parallel (using Y branch connectors) to meet the 24v requirement on the microinverter and have it properly convert the energy for the grid tied application?

Parallel increases current. You want to increase voltage so you'd need to put them in series.

Also, I suspect you won't want to pay the money to get the system approved for grid tie, if you are already fretting over the cost of a $300 panel.

I know it would be recommended to get larger panels that are designed for that as opposed to getting the small 100w panels which really aren't designed for that, but when pricing out panels, the larger panels require freight shipping, and almost always equals a higher price per watt than the small renogy or Grape solar panels if you're only needing 1 or 2. Pricing it out from most of the web stores I can find it only starts to become a better deal if I'm looking to buy 3 or 4 or more large panels with freight shipping but then it's no longer a small project with a small price.

Home Depot sells 300 watt panels in lots as small as 2.

[Duff1234]

You can do that if you want a system to "learn" on. Get those, a small battery, an inverter and a charge controller and do some experiments - if your goal is learning. Then sell them when you are done.

I plan on doing this with my off grid shed. I look forward to learning & experimenting with solar in this way and learning the best ways to make it work for my needs.

[/QUOTE]You cannot start small and expand later.[/QUOTE]

That's the whole point of the enphase microinverters, is to have each panel individually monitored and to be easily expandable as you don't have 1 string inverter rated for only so many watts. That way you don't have to upgrade the size of the inverter each time you add more panels as each micro inverter is self contained and rated for the wattage of each individual panel. Yes you may have to go through some resubmissions with your local inspector and the power company but you don't have to swap out the whole system just to add panels with micro inverters.

[/QUOTE]Parallel increases current. You want to increase voltage so you'd need to put them in series.[/QUOTE]

I always seem to get the two mixed up when I think about one increasing voltage (series) and one increasing amperage (parallel). So thank you for the correction, as the more I get corrected on it, hopefully the more it will get seared into my brain in the correct format and I can finally stop thinking of the wrong one!

[/QUOTE]Also, I suspect you won't want to pay the money to get the system approved for grid tie, if you are already fretting over the cost of a $300 panel.[/QUOTE]

That's a very big assumption to make about someone you don't know. Also I did make it a point to say that I'm just curious to know if it's possible. I didn't say that I'm doing this, or going to do this or that I have the items and want to make sure I don't blow anything up when I hook it up tomorrow, I was just curious if it COULD work if someone were to try it, however unconventional it may be.
I'm not fretting over the cost of any panels, I would much prefer to get the larger 275+ watt panels but when you're looking at experimenting and dipping your toe in the water before committing to a large scale project of any kind, a $95 100w panel with free shipping from home depot vs a $200 (or slightly higher price) 275w panel with $250 freight charge... tell me which one equals a better price per watt? If I plan to grid tie any solar setup I will wait until I have to redo the shingles on my house so that I don't have to have the whole setup taken down and re-installed in short order, and I will likely order as many panels as I can to try to fill a large portion of my roof. However I'm going to be smart about it and weigh my options between buying them and installing myself and working with the power company and county inspectors to get it all approved vs having a company install it for me. I'm not just going to throw money out the window in a careless manner if I can help it.

[/QUOTE]Home Depot sells 300 watt panels in lots as small as 2.[/QUOTE]

They do indeed but the lowest price that I could find on any panel larger than 100 watts with them was $424 for a 265 watt panel, in which case I would be much better off buying the 100 watt panels. As their packages get higher and higher it gets closer to the price of the 100 watt panels, but never drops below $1 per watt. Where as other online sites can get as low as $0.75/watt if you buy 3+ panels and they are reputable brand panels.

[Whalepod]

I plan on doing this with my off grid shed. I look forward to learning & experimenting with solar in this way and learning the best ways to make it work for my needs.

Micros are going to require a reference to utility voltage before they export power. Not a great fit for an off grid shed. Supposedly not impossible, but it's not going to be plug and play.

Want to learn and live in California? I suggest volunteering. There are Non profit organizations that specialize in solar volunteerism and workforce development if your in Cali/Colorado/DC.

[solardreamer]

I plan on doing this with my off grid shed. I look forward to learning & experimenting with solar in this way and learning the best ways to make it work for my needs.

If the goal is off grid shed then it would be much easier to setup a system if you use off grid inverters. Enphase only makes grid-tie microinverters that are more complex and require expensive extra equipment to use in off grid setup. Given your budget concerns I doubt you would want to buy the extra equipment. If you want to use microinverters then you should use off grid microinverters.

[Duff1234]

Sorry I should clarify that the Enphase micro inverters won't be part of my off grid shed at all. I will just be starting with 2 100w panels, an mppt charge controller, a deep cycle battery, 12v fuse block for 12v lighting and other 12v circuits, and a small inverter to power my drill battery chargers.

The enphase inverter was a separate question for my curiosity to know merely if it would be possible.

[Duff1234]

Micros are going to require a reference to utility voltage before they export power. Not a great fit for an off grid shed. Supposedly not impossible, but it's not going to be plug and play.

Want to learn and live in California? I suggest volunteering. There are Non profit organizations that specialize in solar volunteerism and workforce development if your in Cali/Colorado/DC.

I don't live in California, I live in Michigan. But that is really cool to know that there are programs out there for that!