I'm sure 5 rpis will devastate the power grid

Still less than renting the same amount of compute. Somewhere between several months and a couple years you pull ahead on costs. Unless you only run your lab a few hours a day.

I need to heat my house too so maybe it helps a little there.

You still pay for power for the cloud.

I got past that back when I was paying for ISDN and had 5 Surplus Desktop PCs...write it off as 'Professional development'

What does a few rpis cost on a monthly basis?

Depends. At full load? At Irish power prices? Just the Pi, no peripherals, no NVMe? 5 units? €13/mo.

Handy: https://700c.dk/?powercalc

My Pi CM4 NAS with a PCIe switch, SATA and USB3 controllers, 6 SATA SSDs, 2 VMs, 2 LXC containers, and a Nextcloud snap pretty much sits at 17 watts most of the time, hitting 20 when a lot is being asked of it, and 26-27W at absolute max with all I/O and CPU cores pegged. €3.85/mo if I pay ESB, but I like to think that it runs fully off the solar and batteries :)

> Depends. At full load? At Irish power prices? Just the Pi, no peripherals, no NVMe? 5 units? €13/mo.

Pretty sure most of us aren't running anywhere close to full load 24/7, but whoa, Irish power is expensive. In the central US I pay $0.14/KWh.

Yeah, it's brutal. Was €0.39 right after Mad Vlad kicked off his vanity conflict.

That’s rough. What’s your progress on renewables? Wind has made electricity really cheap in my state and I would think Ireland would be pretty windy (esp offshore)?

Ireland has had hydro for a century[1], and wind and tidal are productive here. There are wind farms EVERYWHERE around where I live (mountains, Cork/Limerick border). There are solar farms, as well, but sun is not our strong suit. Trouble for individuals is that small, affordable wind turbines are basically useless, and most people don't have hundreds of thousands of Euros plus planning permission to erect megawatt-scale units, so solar is pretty much it.

[1] https://en.wikipedia.org/wiki/Shannon_hydroelectric_scheme