Your game plan?

[Bossrox]

Getting the most out of what you have.

Except for experimenting & getting your feet wet, unless you have enough bucks, like 20 grand or more to invest in a serious high power system, this is a rather expensive endevour to dable with & unless you got really high kilowatt rates, this will shave some bux off your bill but overall it will likely take decades to break even.

This is a hobby for me & a challenge like a car nut wanting to have the hottest ride around. I'm building up my system a bit at a time working towards needing very little utility power & currently at a point where I can make about a third of the power I need for the summer & about 2/3 in fall, winter & spring but shouldn't be long I'll be able to make all I need..

So how can I make the most with what I got? I've tried various ways to figure out which would be the most efficient from using battery power overnight which would drain the batteries down around 50%, not good for battery lifespan & the charger would be busy all day restoring the batteries & not leave much power to spare for running heavy loads very long. But soon realized using panel power for heavy charging was way less efficient than using it live on demand.

So I switched it around to running heavy loads all day then after sunset, switch to utility power til about 4am, then when the charging starts back up, I've only drained about 20% off the batteries. This way the charger can easily restore 20% thru the day & run pretty heavy loads all day. What determines how you can best utilize your system will be panel output, charger output, battery bank & inverter size.

Having an inverter that can meet your demand is the best starting point, then enough panels to feed that demand is next along with a charge controller that can output as much as your panels can, but bigger if you intend to add more panels, then how much power you wanna make after the sun is done determines the battery bank size you'll need will be next if you want to go beyond just making power during the day.

For me, my battery bank is 1100 amp hours which is about 12kw from full charge to nearly discharged but on lead acid power you best not use more than 25% of it's capacity if you want them to last & being the most expensive part of a system makes that a priority, so 3 or 4kw is the most I should try & take from them from a full charge.

To get the best use of them is to run them when your power demand is it's lowest & only for as long as you stay within the safe drain %, for most it would be after midnite, everything is at a minimum & the a/c isn't on as much where most of your power gets used from, so with my bank size, I can start my system at 4am & by the time the sun comes up to start charging, I've used about 2kw which doesn't take much for the charger to restore & a light enough draw to insure a good lifespan.

After the sun is up, now you need to think about having enough power to supply your typical demand & enough extra to restore the batteries before the end of the day & this can be tricky depending on the solar conditions for the day but if you spend time to astutely monitor your system often, you'll eventually develop an intuition on running your system efficiently.

I keep an eye on the differential between the inverter amp draw & the charger amp output. If I see a 20 amp inverter draw & a 100 amp charger output, that tells me it's in heavy charging mode. On the other hand if there's only a 10 amp difference between inverter draw & charger output, I know the batteries are near fully charged & can then tax the inverter pretty heavy if I need to.

Near the end of the solar day, I look at the differential & if I see a significant charge still in effect, I'll shut down as much as needed of solar powered stuff to get the batteries topped off to start the next day strong.

If you can be on hand the whole day to ration out power for the best efficiency, that's great but most can't, nor can I so I had to come up with a scheme to automate how it rations out power to ensure the batteries are at full capacity to start out another day.

I did just that & articles about how that was done is scattered thru out other sections of this forum & should find useful as well as fascinating in helping you build a automated system so it'll be less of a chore. I'd compare running a solar system a lot like handling a yaught, you need to keep an eye on the conditions & make adjustments often for smooth sailing.

That's pretty much the basics to think about if you want to dive into this solar adventure & looking forward to hearing from others about their systems.