Convert Grid Tie to Off Grid?

[wildbill-hiccup]

About 7 years ago I had a 4.5 Mw PV installation made, 16 Solarworld 280W panels, and 16 Enphase M250 micro inverters with Envoy.
Later I had domestic solar hot water added.
It now seems to be at least slightly overproducing when averaged throughout the year.

When first installed, we had Net Metering with a payback for overproduction.
Not sure just how consistently it's overproducing, but we do seem to have some shortfall during the cloudy, heavy rainfall winter months.

If it hasn't been done yet, there does seem to be at least a movement towards deleting the overproduction return.

That has me thinking about converting to off grid.
What would I need to do to do so?

[solarix]

Don't go off-grid. The great boom in solar happened because of grid-tie solar. Co-operating with your utility to swap excess power back and forth and eliminate the need for batteries is the most reliable and cost effective way to harness solar power. The amount of equipment, let alone the batteries, to stand alone and be off-grid will never pay for itself. Your average home runs on a 200A electric service which is 50kW. The typical off grid inverter provides 6 to 8kW of power, and a typical battery pack may have 10kWh of capacity. You will need multiples of these costing many tens of thousands of dollars to be equivalent to the grid.

[SunEagle]

First off you will need to get your terminology correct. A 4500 watt system is 4.5 kW not Mw.

Next even if your POCO stops all Net metering you will still be ahead of the game compared to going off grid. The battery cost and baby sitting of the system will rarely pay for itself unless you are purchasing power above $0.30/kWh. So IMO just stay where you are and if you get even a few pennies for what you send to the grid be happy because it will be cheaper then an off grid system.

[bcroe]

Going off grid means spending time every day of your life just keeping everything
going. Sort of like a few centuries ago, I call it STAYING ALIVE another day.
Bruce Roe

[J.P.M.]

Your solar ignorance is showing. Of course production varies by day and by season. Production is less in winter for the same reason it's cold in the winter.

As others have written, don't go off grid unless you're looking for another part time to full time job maintaining the off grid system, and can also accept the idea that your cost to meet the electrical needs of your residence will be going up.

[wildbill-hiccup]

We are in Hawaii.
Supposedly, we have the highest electrical rates in the country.
Our delivered/billed price is about $0.38/KwH.
Before installing the PV system, we paid about $185/mo. for light to moderate usage.
Our PV system has more than paid for itself since installation.

The utility's minimum hookup charge was about $20/mo.
That has been raised to $25+ recently.
We're paying at least $300/yr just to be connected to the power company whether we use it or not.

We do lose grid power for short periods, hours to a few days, as long as 3 to 6 days on a couple of occasions after hurricanes or wind storms.
When that is lost, we are without electrical power until it gets fixed, using a sun heated bag for shower water and a Coleman stove to cook on.
I bought a generator just for minimal requirements during the longer periods, refrigerator, freezer, etc while still having to buy ice for cooling them.

I have avoided off grid mostly because I have not wanted to deal with the batteries, still don't.

With all that said, I cringe at the thought of the babysitting an off grid install would probably need.
Are there options to make our electrical supply more reliable?

[J.P.M.]

Are there options to make our electrical supply more reliable?

Put less stress on the system by using less electricity. Doing so means you'll be less inconvenienced and so less impacted by reliability issues.

[azdave]

We're paying at least $300/yr just to be connected to the power company whether we use it or not.

In Arizona, I pay $275 annually as a meter connection fee and I export power every single month so on paper, I could say I don't use their power but that's not true at all. $300 annually is a very small price to pay when they are effectively your endless capacity battery bank that requires no upkeep by you. Yes, outages are unfortunate but don't cut off your nose to spite your face. From what you have told us, I would stick with what you have but maybe get a bigger generator for essential needs during long outages.