If you live near an inexpensive datacenter, you can park it there. Throw in a storage machine or two (TrueNAS MINI R looks like a credible low-effort option).

If you live near an inexpensive datacenter, you can park it there. Throw in a storage machine or two (TrueNAS MINI R looks like a credible low-effort option). If your workload is to run a year long computation on it and otherwise mostly ignore it, then your operational costs will be quite low. Most people who rent cloud servers are not doing this type of workload.