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For the past couple of days, I've disconnected my Outback GS8048 hybrid system from the grid and just run the critical loads panel off of pure solar and battery. It's sunny and the days are long, so there's been no problem powering everything. My AGM battery bank (410 Ah) has only gone down to 75% SOC each night with no adjustments to how we live whatsoever.
What really stands out for me, after watching my system produce 35-40 kWh each day when connected (and mostly exporting) to the grid, is how underutilized the PV panels are when off-grid on sunny days. The battery bank finishes bulk charging well before noon, and then the charge controllers throttle down their production over the course of a couple of hours in absorb mode before finally sitting at float where they only produce what's being consumed at the moment, plus a few watts.
Yesterday I hooked up a wall-mounted air conditioner (1.2 kW) and ran it for a few hours in the afternoon just to feel like I was using the otherwise wasted PV power, even though it wasn't that hot outside. Yet I wound up producing a measly 8 kWh for the whole day. That represents lots of wasted capacity.
I'll be resetting the breaker and hooking back up to the grid after the batteries complete their absorb cycle today. Then, of course, the charge controllers will stay in MPPT mode all day long and the PV panels will produce whatever they can, exporting to the grid and earning me credits from the power company. The reductions in my electric bills this spring have been dramatic, I will say.
I designed the system for significant excess capacity during the long sunny days of summer because I want to have some chance of being able to rely on it (with a generator) during the cloudy short days of winter. Spending months "in the trenches" with this hybrid grid-tie/off-grid system is reinforcing an important point I knew before starting this project, which I want to emphasize to others reading this: PV solar is not a way to "stick it to the POCO man" (as Sunking puts it) and gleefully disconnect yourself from the grid with any economic or environmental benefit. The amount of fossil fuel expenditure involved with manufacturing and shipping all the stuff out in my clearing and that solar equipment shed won't get paid for--financially or otherwise--for a long time to come if ever.
Don't get me wrong, I'm having a lot of fun with my expensive toy. Having done the whole installation myself--from the 24-panel ground-mount to building an equipment shed to running conduit--was immensely satisfying. I knew all along that this would never pay for itself and it is a bit of a paranoid prepper hobby. If you want to do this, too, instead of golf or model trains or RC planes or going to Las Vegas twice a year or whatever, then more power to you--no pun intended. Just don't expect that it will have any payback besides personal enjoyment and satisfaction, and maybe, just maybe, a sense that you might be a tiny bit better off drinking your well water, keeping your freezer running, and heating up your cans of beans out in the sticks if the grid goes out for any length of time.
What really stands out for me, after watching my system produce 35-40 kWh each day when connected (and mostly exporting) to the grid, is how underutilized the PV panels are when off-grid on sunny days. The battery bank finishes bulk charging well before noon, and then the charge controllers throttle down their production over the course of a couple of hours in absorb mode before finally sitting at float where they only produce what's being consumed at the moment, plus a few watts.
Yesterday I hooked up a wall-mounted air conditioner (1.2 kW) and ran it for a few hours in the afternoon just to feel like I was using the otherwise wasted PV power, even though it wasn't that hot outside. Yet I wound up producing a measly 8 kWh for the whole day. That represents lots of wasted capacity.
I'll be resetting the breaker and hooking back up to the grid after the batteries complete their absorb cycle today. Then, of course, the charge controllers will stay in MPPT mode all day long and the PV panels will produce whatever they can, exporting to the grid and earning me credits from the power company. The reductions in my electric bills this spring have been dramatic, I will say.
I designed the system for significant excess capacity during the long sunny days of summer because I want to have some chance of being able to rely on it (with a generator) during the cloudy short days of winter. Spending months "in the trenches" with this hybrid grid-tie/off-grid system is reinforcing an important point I knew before starting this project, which I want to emphasize to others reading this: PV solar is not a way to "stick it to the POCO man" (as Sunking puts it) and gleefully disconnect yourself from the grid with any economic or environmental benefit. The amount of fossil fuel expenditure involved with manufacturing and shipping all the stuff out in my clearing and that solar equipment shed won't get paid for--financially or otherwise--for a long time to come if ever.
Don't get me wrong, I'm having a lot of fun with my expensive toy. Having done the whole installation myself--from the 24-panel ground-mount to building an equipment shed to running conduit--was immensely satisfying. I knew all along that this would never pay for itself and it is a bit of a paranoid prepper hobby. If you want to do this, too, instead of golf or model trains or RC planes or going to Las Vegas twice a year or whatever, then more power to you--no pun intended. Just don't expect that it will have any payback besides personal enjoyment and satisfaction, and maybe, just maybe, a sense that you might be a tiny bit better off drinking your well water, keeping your freezer running, and heating up your cans of beans out in the sticks if the grid goes out for any length of time.
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