Have you ever looked at automating a 'suspend' for the PCs based on the battery charge? I'd looked at doing something like this; there are python toolkits for querying the inverter (& batteries SOC) and I know how to do network suspend. What i have in mind is putting the PCs to sleep if the battery drops below a certain level during the evening (and poss wake when the sun comes up).

Just wondering if you (or anyone) has ever tried something like this?

It's totally doable, and I've thought about it. However, I'm not sure it's going to be needed. In the winter, I don't have the battery I want to spend on 24/7 compute - we get too many dark days, so I want a decent battery bank in the morning. Come spring/summer, I'm not sure I even have to suspend them - I have sun until nearly 10PM at the peak of summer, and it's up again at 6 or so.

This year, I'm also moving my compute rigs out into the battery box outside my office come spring - I'll get the old lead acid pack out of the way, and build some filtered air inlets so I can run rigs out there, which will rather dramatically reduce my air conditioning requirements (that tends to chew a lot of power in the summer). So I'm hoping once things warm up and I move the boxes out there, I can just let them purr 24/7 without worrying about it.

Grid tied here but with 5.2KW of solar. Once I get batteries, I might well look at that. Summer, I reckon I would need somewhere between 5 &8KWH or storage to not draw anything from the mains but winter, I could probably extend what I do a bit without drawing from the grid.

Have you ever looked at automating a 'suspend' for the PCs based on the battery charge? I'd looked at doing something like this; there are python toolkits for querying the inverter (& batteries SOC) and I know how to do network suspend. What i have in mind is putting the PCs to sleep if the battery drops below a certain level during the evening (and poss wake when the sun comes up).

It's totally doable, and I've thought about it.

How do you do it? I don't have the inverters yet. Most of my computers run Windows. At the moment, I have one which can sleep/hibernate/whatever according to "battery level" which it gets through USB from the UPS. Do decent invertors have a USB connection? How would I get 10 machines to receive the same instruction in Windows? And how would I get them to wake back up when the battery is charged up again?

Do decent invertors have a USB connection?
I can connect to my inverter either via a network cable or wireless. When I control where the electricity goes though, e.g. a diverter putting it into the thermal store tank rather than back onto the grid, it is a clamp around the tail to the mains that is used to control it.

How do you do it? I don't have the inverters yet. Most of my computers run Windows. At the moment, I have one which can sleep/hibernate/whatever according to "battery level" which it gets through USB from the UPS. Do decent invertors have a USB connection? How would I get 10 machines to receive the same instruction in Windows? And how would I get them to wake back up when the battery is charged up again?

I have no idea how I'd do it with Windows... and, no, I don't USB connect to the inverters.

My state of charge estimation comes off my charge controller - a MidNite Classic 200 with a WhizzBang Junior shunt hooked up to the battery bank for net current monitoring. I set it up with my battery bank parameters (it's quite flexible), and it estimates SoC of the bank. I have monitoring software that charts/graphs/etc the various parameters. If I wanted to do something fancier than "a cronjob that sleeps my machines at a certain time of day, that I modify throughout the year as sunset changes," I'd have the machines query this for the current state of charge, and shut themselves down (or suspend themselves) when the SoC hit a certain point. Most of my boxes will do wake on LAN, so I could do the reverse to wake them, and have a job (on the monitoring system) that starts poking them with WOL packets when things are charging again.

I've just not bothered, because the manual process isn't a problem for me. Though with the new bank and the 15kWh I can beat up pretty hard, I may set something like that up. The big issue is sorting out "tomorrow's forecast" - if it's cloudy, I want more SoC reserve in the bank than if it will be sunny all day and I can recover a seriously drained bank.

I guess I just do it manually then, and adjust every day or so the number of computers running according to recent battery levels. I will have enough battery it doesn't jump up and down in a shorter period.

I guess I just do it manually then, and adjust every day or so the number of computers running according to recent battery levels. I will have enough battery it doesn't jump up and down in a shorter period.

No battery yet here but that is what I do adjust what I do according to light levels.

No battery yet here but that is what I do adjust what I do according to light levels.

Sounds like too often to adjust manually, I'd have to be awake and around all the time. I'd want to do it every few days, so I'd need bigger batteries. I'd want that anyway to cover dark days for other uses. There's a lot of cheap batteries on AliExpress. They may well be fakes (lower capacity than advertised), but you can get money back if they are.

As long as you can mechanically read state of charge, it's easy enough to just configure computers based on SoC (and optionally net current in). If SoC drops below some threshold, start reducing compute cores on the rigs, and if it drops further, suspend them. When it comes up, wake on LAN, and if you're "low but charging strongly," turn all the compute cores on. It doesn't have to follow the load exactly unless you're running batteryless, which I don't see working well for something like this unless you're massively overpaneled (that said, I can probably do exactly that in the summer with how many panels I have on my office).

I've freed up space this year to move my compute rigs outside, once I get the old batteries out of that box, though. :) So more compute, less air conditioning.

I've freed up space this year to move my compute rigs outside, once I get the old batteries out of that box, though. :) So more compute, less air conditioning.

Living in Scotland means I don't need air conditioning. I can use the cheaper technology called windows. Those greenhouse window opening mechanisms connected to thermostats look cool.

Grabbed a few for my VMs, and they're running with no trouble. Of course, as soon as there's new work, I've got half a week of clouds, rain, and snow coming...

Grabbed a few for my VMs, and they're running with no trouble. Of course, as soon as there's new work, I've got half a week of clouds, rain, and snow coming...

Solar and Boinc is no good for long tasks. Solar requires variation of the computer power.

Solar and Boinc is no good for long tasks. Solar requires variation of the computer power.

My track record of tasks completed says, "It works just fine the way I do it." https://www.cpdn.org/results.php?userid=744912 - I don't think I've set that or my computers to be private.

I don't try to match instant power demand to solar production, my machines are either running at rated load (typically either 8 or 12 tasks on a 12C/24T AMD chip, loading up the hyperthreads reduces total instructions retired per second which is what I try to optimize), or they're in S3 suspend, which is the "everything in RAM" suspend state. It works fine with native Linux tasks, it works fine with Windows tasks in a VM, and it works fine with the old 32-bit MacOS Intel tasks that showed up a while back. I vary power demand by modulating how many machines are powered on at any given point in time, and I still meet the deadlines even doing this - though I'm not inclined to pull too many CPDN tasks during the dead of winter. The tasks are never suspended or resumed - only the full system, which doesn't trigger the suspend/resume problems a number of the binaries have. From their perspective, they run continuously from start to end.

I've been doing it this way for 8 years now. And at this point, given a string of sunny weather, I have enough battery bank to actually just run tasks throughout the night and make up for it the next day.

But there's also another thread, specifically related to off-grid solar, better suited to informing me how what I'm doing can't possibly be working.

I'll assume this is the thread you pointed to from the new tasks thread.

Like you I plan to use batteries to even the load and not switch computers off day to night. But you can have a sunny week or a rainy week, where presumably you adjust something. Do you get computers to run for half the day? Or reduce the cores used? Reducing the number of computers running causes tasks to not get done for a week, which is no good.

I'm on windows and I'm not sure this can be automated at all.

What I'd really like is a way to tell windows "you're on battery", which will suspend Boinc, or even the computer (although the computer would require manual turning back on if I went that far).

The only way I can see to do this is to make the computer think it has a UPS and it's switched to battery, when what's really happened is the solar batteries have dipped below a certain voltage. I can do basic electronics but not much. Not sure how to interface that to perhaps a salvaged bit of electronics from an old UPS to give it the USB signal.

Solar and Boinc is no good for long tasks. Solar requires variation of the computer power.

I don't try to match instant power demand to solar production...........But there's also another thread, specifically related to off-grid solar, better suited to informing me how what I'm doing can't possibly be working.

I've posted on the end of here: https://www.cpdn.org/forum_thread.php?id=9208&postid=70706#70706

But you can have a sunny week or a rainy week, where presumably you adjust something. Do you get computers to run for half the day? Or reduce the cores used?

If it's a sunny week, there's nothing to adjust. The computers just run. If it's particularly hot, I may let them sleep overnight to avoid cooling loads, though I'm planning to move some hardware into a box outside with filtered vent fans this year to help reduce the summer cooling demand.

If it's rainy, I'll only run one computer at a time, or let them sleep, though I try to avoid grabbing too many short-lived tasks if I know the weather is going to be cloudy in the next week or so - I just set my machines to not grab new tasks, drain them out, and wait until I have more power.

Reducing the number of computers running causes tasks to not get done for a week, which is no good.

That depends entirely on what the deadlines are. If it's a week deadline, it's probably a fairly short (4-6h task). If it's got a 90 day deadline, not working for a week doesn't matter much. Though outside the dead of winter, it's rare to get a week of "no compute at all." It's more a day or two at a time where I'll let the machines idle.

But I can also swap around which machines run - a few of them share a power supply, so I try to run those machines together, and just toggle between what machines run one day to another to help spread the load out. Lots of ways to solve it.

I'm on windows and I'm not sure this can be automated at all.

I don't automate any of this beyond "Sometimes I have a cron job that will S3 suspend machines at a certain time of the evening." I used to have wake on LAN capability to power machines on remotely (from either powered off or to wake them from sleep), but I just walk out and turn the machines on physically now.

What I'd really like is a way to tell windows "you're on battery", which will suspend Boinc, or even the computer (although the computer would require manual turning back on if I went that far).

If you really want to do it, you can do wake on LAN with most hardware - you'll have to tweak some settings in your BIOS or NIC or something, but I had a Windows box that would wake-on-LAN just fine years back.

But if I wanted to automate more, I'd just have scripts on the systems that poll the state of my battery (I have a VM that reads charge controller state and reports useful things) and act locally. I've just not found it to be worth the hassle, over doing it manually and keeping an eye on things. If I miss a couple hours of compute because I'm out, oh well. So be it.

But you can have a sunny week or a rainy week, where presumably you adjust something. Do you get computers to run for half the day? Or reduce the cores used?

If it's a sunny week, there's nothing to adjust. The computers just run. If it's particularly hot, I may let them sleep overnight to avoid cooling loads, though I'm planning to move some hardware into a box outside with filtered vent fans this year to help reduce the summer cooling demand.

Ah, so pretty much manual then, I'll stick to that too.

If it's rainy, I'll only run one computer at a time, or let them sleep, though I try to avoid grabbing too many short-lived tasks if I know the weather is going to be cloudy in the next week or so - I just set my machines to not grab new tasks, drain them out, and wait until I have more power.

You must live in an alternate reality where weather forecasting is remotely correct.

I'll just keep an eye on battery level and tweak something. At the moment I'm predicting 250W continuous in winter and 1250W continuous in summer, which isn't much, but that was 3 grand (UK money) of panels and batteries, I don't want to hurry to spend that again!

I'll probably start buying some newer more efficient CPU/GPUs instead of more solar.

Ah, so pretty much manual then, I'll stick to that too.

Yup. I poke the "suspend time" a couple times throughout the year, will manually change things as needed, but I've avoided too much automation on it. I just don't find automation helpful for a lot of this stuff, and I've seen it go badly wrong more than a few times. It's not a production system, it's a hobby system, but "the rest of my office" is a production system (I work from here), so I err on the side of battery state of charge when needed.

You must live in an alternate reality where weather forecasting is remotely correct.

It's not, but it generally will give me day or two ahead guidance on total solar flux. I don't really care if it's raining or not, I care if there's a heavy cloud layer or not, and the forecast for that is at least better. Sometimes. Or sometimes I'm wrong and hook the backup power up. But I'm seriously overpaneled out here, so can make up a lot of it on "Well, I screwed that up, but 5kW of panels solves a lot."

... but that was 3 grand (UK money) of panels and batteries

I haven't totaled up my system... it's certainly far more, but I also have a system suited to a small house on and around my shed out here. It's also partly R&D for me on other projects - knowing my way around off grid power systems is useful for some other side projects I have.

I'll probably start buying some newer more efficient CPU/GPUs instead of more solar.

Take a look at the power settings on your CPUs. If I'm not mistaken, you have some 3900X chips too - I've disabled turbo on mine, because it adds a lot of power consumption for rather marginal additional compute throughput when the system is loaded up (and on hotter days, it starts throttling more) - I've seen a net loss in throughput, at higher power consumption (on a Wraith Pro cooler, that genuinely can't keep up with a loaded 3900X unless it's very cold in here).

The same goes for GPUs - you can lower the power use on them, and substantially increase compute-per-joule.

Yup. I poke the "suspend time" a couple times throughout the year, will manually change things as needed, but I've avoided too much automation on it. I just don't find automation helpful for a lot of this stuff, and I've seen it go badly wrong more than a few times. It's not a production system, it's a hobby system, but "the rest of my office" is a production system (I work from here), so I err on the side of battery state of charge when needed.

If only I could simply have the computers suspend (or just pause Boinc) when battery voltage is under x. Sounds like a very simple thing, but unless you're a programmer, impossible.

But I'm seriously overpaneled out here, so can make up a lot of it on "Well, I screwed that up, but 5kW of panels solves a lot."

Do you mean 5kW peak? That's not very much. The standard for a UK house is 16 250W panels. I've got 12 410W panels, so same as you if you meant peak. But then I think you're in a sunnier place.

... but that was 3 grand (UK money) of panels and batteries

I haven't totaled up my system... it's certainly far more,

If it's only 5kW peak it shouldn't be far more. But then you bought it a while ago and prices are plummeting.

but I also have a system suited to a small house

Most small houses don't run many computers, which use a lot if they're on 24/7.

The same goes for GPUs - you can lower the power use on them, and substantially increase compute-per-joule.

The only setting I have on my ones is "power limit". I guess that would do the job, I've never tried putting it under the standard "0%". I only raise it to max (usually +20% or +50%). The +50% one then immediately melted the power connector, so I had to solder the wires on.