Out of interest if they are meant to run 24/7 what is their power consumption. Ie watts p,/h?
I donth think these are A or A+ rated products for energy efficiency when used conventionally and it depends on the use they get (volume of beer poured through), the waterbath containing an ice wall is insulated so it retains the cold mostly, the ice wall works as a cold sink due to the extra energy required to shift from solid to liquid state.
the chiller i use for serving gets a quick 30-45min run of an early evening which is sufficient to reduce the waterbath temp to 0C and is sufficient to chill more than i can sup of an evening, if entertaining i may run it more conventionally, in which case it can run for 3 hours+ to form an ice wall before cutting off, only cutting back in when sufficient ice has melted to trigger more chill.
So if comparring to running a keg fridge, as your unlikely to be in n out of a keg fridge daily i think the manufacturers running guide costs should be a pretty fair representation unless built by a car manufacturer
and compare that to the cost of running for 3/4 of an hour at full pelt each evening you fancy a few beers, and factor in running for the duration of any parties you host.. but if supping 3-4 evenings a week during the spring/summer imho modest running of a shelf chiller can work out quite cost effective compared to the 24/7 running of a fridge
My kegs sit in an outhouse so benefit from a natural chill in the shade most of the year, so 3-4 months per year i need to switch the chiller on a lil in advance of running,
if planning on running like me its advisable to wire the agitator or recirc pump up to run independently of the main power so you can run it durrin a pour to maximise the chill effect and avoid hot pocketting the effect of heating the water sat around the tubes
a segment timer to turn the thing on in advance of your arrival of an eveing works well, or for less than a fiver you can buy a sonoff wifi switch to turn on/off a a/c power switch via the web/mobile phone as you head off home..
( and if adventerouse you can reprogram the esp8266 at the heart of the sonoff device , but tbh it works pretty well out of the box ..
https://www.fasttech.com/product/4586500-sonoff-wifi-wireless-smart-switch-for-mqtt-coap