Post B6vGKYEecxebof5we0 by azonenberg@ioc.exchange
(DIR) More posts by azonenberg@ioc.exchange
(DIR) Post #B6ut4Cqw3suXv7Ens8 by azonenberg@ioc.exchange
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Yesterday was another interesting solar record: the 88.6 kWh of solar production didn't quite beat Saturday's record of 93... but our grid power consumption was the lowest I can recall seeing.We consumed only 111 kWh, compared to the 150ish we more typically burn. Not entirely sure why... we didn't do any laundry or much in the way of cooking and it was a nice day so we had the windows open and no heat or A/C usage, which probably was part of it. Lab power demand was about the same as usual.But combining the low consumption with the high production meant a net consumption of only 22.4 kWh, with a whopping 80% of our total power demand self-generated.
(DIR) Post #B6utIdhf1sHlFWmXAm by azonenberg@ioc.exchange
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Looking at our demand graphs and instantaneous usage, the hot water heater is actually one of our biggest non-lab power users (the power draw is pretty flat with big spikes every time we run the water heater).Our normal base house power usage is on the order of 5.5-6 kW but when the water heater is busy, it seems to spike to 10ish.Replacing the water heater has been on the TODO for a while due to it being old and probably rusting (plus not having any insulation between the tank and the exterior wall due to poor design of the utility room, which I plan to fix during the replacement process). Might go for a heat pump unit as a replacement.
(DIR) Post #B6utVs0TA2YnNJt8Km by LapTop006@aus.social
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@azonenberg we had an electric hot water heater in our Melbourne place that had a broken thermostat and would boil for hours every day and even then we were only using a tiny fraction of that power.
(DIR) Post #B6utk9XMmNj5nd5Oym by azonenberg@ioc.exchange
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@LapTop006 I'm talking about peak power not average.There are obvious spikes in the consumption graph that seem to show up during/right after laundry and shower periods. So I'm concluding this is the tank reheating.
(DIR) Post #B6uuGrNZJMtJ2W6DGS by ponygol@chaos.social
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@azonenberg Not meant negatively, just wondering. What are you running to get 6kW base power use? That comes up over 50.000kWh per year.Everything over 10.000kWh per year here is considered extremely high, even for old buildings without any efficiency treatment.
(DIR) Post #B6uulQd0owDj3Atnvc by jpm@aus.social
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@azonenberg @LapTop006 yeah 3-4kW is pretty normal for a storage tank resistive electric hot water system.
(DIR) Post #B6uv41W8PGoMfjY5mi by forthy42@mastodon.net2o.de
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@azonenberg A hot water heat pump is an investment that pays off quickly.
(DIR) Post #B6uwxazEKm56YkDkbQ by azonenberg@ioc.exchange
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@ponygol this isn't all of it but...The 16 GHz scope alone is 600+ watts 24/7. Overall lab power draw is around 4 kW plus cooling and lighting.There's a reason I have 41 solar panels on the roof.
(DIR) Post #B6ux6DnhuLkfFvwbQ0 by azonenberg@ioc.exchange
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@jpm @LapTop006 Yep. What I do not currently have is data on *integrated* power (i.e. how long it pulls that much juice) to figure out typical kWh/day etc.
(DIR) Post #B6uxJydx3jmmIgwM8e by azonenberg@ioc.exchange
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@ponygol I've been gradually consolidating and upgrading, shut down a few of my oldest pieces of inefficient hardware and folded one of the 2U servers into a VM on the main VM server.But fundamentally my compute and instrumentation needs are high enoguh that there's only so much I can do.One of the biggest long term planned upgrades is an energy harvesting VRF heat pump to use waste heat from the lab to heat the house in the winter, rather than air conditioning it outside (throwing that heat away for nothing) then burning more power to bring heat in from outside to the house.
(DIR) Post #B6v6x20BPBQFb92IXQ by ponygol@chaos.social
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@azonenberg Wow, that is a pretty impressive lab and explains the power requirements. Wasn't aware that this kind of equipment becomes that hungry for energy.
(DIR) Post #B6v9WncyWepXLmMdf6 by LapTop006@aus.social
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@azonenberg sorry, and I was actually referring to total daily energy usage. For once I actually god a good nights sleep so don't even have that excuse for being obtuse.
(DIR) Post #B6vGDPRQvNeYW0fOYi by 0h00000000@ioc.exchange
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@azonenberg I think a heat pump HW heater would be a great idea. Maybe set it to a bit lower temp and add in point of use hot water heaters where needed (shower). If you were in Arizona you could add rooftop hot water heating, but probably wouldn't work so well in PNW.Do you have any options for installing a wind turbine? It's hard to get them high enough with all the trees up there.
(DIR) Post #B6vGKYEecxebof5we0 by azonenberg@ioc.exchange
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@0h00000000 I'm at the bottom of a hill wind is not really useful here
(DIR) Post #B6vIXjirQgL37Fdf16 by RoganDawes@infosec.exchange
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@azonenberg Heat pump is definitely recommended. See if you can guess when I changed from a 2kW resistive element to a heat pump? Note that this is only energy spent heating water.
(DIR) Post #B6vbgz4Fe1d2RWlcLg by CliffsEsport@mastodon.social
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@azonenberg Do on demand hot water heaters help? I've thought passive warmed/heated water plus on demand was ideal if I am ever in situation to set it up
(DIR) Post #B6vbop3KlNfRhQ4kOO by azonenberg@ioc.exchange
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@CliffsEsport It's not viable for me because we have no gas service, and the available power capacity to that room is a single 240V... 30A, I think? or is it 40? breaker.Tankless heaters may use less average power but the peak demand during flow is much higher and I can't support that.My options are resistive tanked or heat pump and heat pump looks the better choice.
(DIR) Post #B6vd3Z0gn8fkF3QoqW by azonenberg@ioc.exchange
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@CliffsEsport But the install will be a royal pain because I need to:* Demolish the drywall enclosure around the water heater the previous owners put there for some monumentally stupid reason* Turn off the water, drain and disconnect the old heater, temporarily cap the pipes, physically remove it* Construct ~1m of new insulated wood frame wall over what is currently bare concrete foundation behind/adjacent to the water heater. This will take several days of waiting for multiple coats of foamboard glue, drywall mud, and paint to dry with just a few minutes of work at the end of each step to sand/paint the ~2.5 m^2 of wall* Once the wall is finished, install and set up the new water heater ~15cm offset from where the existing one is currently located, possibly extending pipes slightly to make up for the shift