Micro Inverter for single-panel DIY installation

[SunEagle]

If you live in the USA you will not be able to connect a single 250watt panel even using a legal UL listed grid tie inverter. Most grid tie systems are a bit larger and require approvals from the local Utility and code enforcers.

The Utility will also not approve any of those cheap inverters that "plug into" a house receptacle. Those are not UL listed, usually junk and will fail or worse cause fires.

The problem you have is the shade hitting the panel. It might be more beneficial to find a better place so it gets more sunlight.

[sheep]

Enphase micro inverters don't require the gateway to operate or set up. The ones that I'm familiar with are grid-tie only however.

That's not what I was told by Enphase Energy Technical Support.

Here's their reply to my query:

Hello (sheep)

The micro inverters we make do required to the Envoy communications gateway to commission the system but once they are up and running you can then remove the Envoy and use this to set up multiple systems.

If you have any other questions please just let me know.

Best Regards,

Richard Tullett
Enphase Energy
Customer Support Technician

This was also confimed by my local dealer, who told me that the micro inverters will not start until they have been configured by the gateway.

[kwilcox]

Enphase micro inverters don't require the gateway to operate or set up. The ones that I'm familiar with are grid-tie only however.

[sheep]

Hi everyone!

I have a single 250W solar panel, which is currently operating off-grid, charging up a bank of batteries. It is not ideally located, and only receives direct sunshine for part of the day - most of the day it is shaded, and generating only about 30-40 watts. I'm thinking about replacing the charger with a grid-tie inverter to make more use of the generated power. 30-40 watts would be sufficient to power my entire house (fridge excluded) most of the day.

It it possible to buy a micro inverter that can operate completely stand-alone, and does not require any kind of gateway or management unit to configure it?

I believe the old first-generation Enecsys units can operate stand-alone, but the Gen2 units require a management unit to enable them. Similarly the Enphase inverters require their (stupidly expensive) Communications Gateway unit to enable them.

I have spoken to a local solar installer, and he says that the Enphase gateway is only required for initial setup and can then be removed from site. However, I would worry about the inverter somehow losing its configuration at some time in the future, and I would be unable to re-enable it.

The price of the Enphase gateway is prohibitive, and would cost double the whole of the rest of the system including the solar panel, and wipe out any possible savings in electricity.

There are cheap Chinese ones available on eBay, but I was really looking for something good and reliable. Can anyone advise?

Annoyingly, a lot of inverters on eBay are described as "micro inverters" but are actually just normal grid-tie inverters and require quite high input power to initialise, and will not work with a single panel. I know because I bought one, found it to be useless, and sent it back.

Thanks in advance.