Recent content by Symbioquine

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Is that all extrapolated from their marketing numbers or have you measured for yourself? 6.667 (kWh generated) / 33.41 (kWh total energy) = 19.95% efficiency 6 (kWh generated) / 33.41 (kWh total energy) = 17.96% efficiency If we assume ~$6/gal for fancy ethanol free gas in the US, that's...

Probably worth mentioning (at least for other folks that find this topic), power supplies like the ones for computers usually aren't designed for supplying constant current (CC). In other words they will try and hold their output voltage stable at all costs until you try and draw too much power...

Haha, don't beat yourself up. Lots of folks talk about "days of autonomy" (i.e. total kWh ÷ kWh/day) which is what you're referring to there. "Coasting" (as I'm trying to define it here) is a bit different. It's about the behavior that the system exhibits under real-world conditions. While you...

Not sure why (almost) everybody thinks I need "advice" here. I'm at ~48.6 degrees N so I know about seasonal variations in production (though maybe not as intensely as @upnorthandpersonal) - and yes my system is arguably oversized for the rest of the year too. That's not the point of this...

Not relevant. The question I'm posing (updated title to make it clear that it is a question) refers to the abstract reservoir of power a system has relative to production capacity and usage. Whether that reservoir is in one big battery or segmented somehow with a software control scheme...

I'd argue that you should replace "full" with "full enough", but otherwise that's correct. I should have specified that the idea of "coasting" as a system size metric really only makes sense in the least productive time of year. Most of the late fall and early winter I get that. A good day at...

We'll call the time where a system is neither all the way full nor too close to empty: "coasting" IMHO, time spent coasting is one measure of how well an off-grid system is balanced in terms of production capacity, storage capacity, and usage. Lots of ways to look at this, but; If your...

I think you may have missed the specific case I was talking about. I'm referring to dry never activated flooded lead-acid batteries. For example the Rolls documentation includes this; I can't remember where I saw the 5 to 10 years claim, but I'm pretty sure that's true. Presumably, storing...

There are a lot of trade-offs, but several of the flooded chemistries can be purchased as dry/empty cells and activated by adding electrolyte when needed. Some lead-acid battery manufacturers advertise 5 - 10 years of storage with minimal loss of capacity. Nickel iron batteries should store more...

I do have an ugly script that I use to produce summary metrics - interpolating and adding up data from my batteries/inverters/SCCs/etc. Maybe it will serve as inspiration since you could do something similar for down-sampling purposes...

I'm curious to hear what you learn/find. I also have this "problem", but I've just been assuming my metrics db would grow more or less indefinitely since storage is cheap. (My .tar.gz backups are up to ~11 GB now for 3.5 years of data)

You need to plan for the replacement cost of your critical hardware anyway and you'll learn a lot by living with a system for a while. So if your budget is $60K because that's what it would cost to get grid power, I'd argue for spending less than half that up-front on your electricity/energy...

This is a good point to bring up. That long tail (low) charging current for lead-acid batteries would be stupid to try and serve with a large generator under normal conditions. I think a fair number of folks here have large LFP battery banks which can take pretty high charge rates for long...

This. Curious if folks in this thread are measuring their own kWh produced & fuel usage and doing the efficiency math... See https://diysolarforum.com/threads/how-efficient-is-your-generator.50418/