Beware, long post....
After the pointers on Friday (thread title "How accurate are domestic electricity meters typically") I did a load of testing over the weekend. This became an excuse to buy a clamp ammeter! (Do we all need excuses to buy new tools??!)
Clamp meter confirmed 0 amp draw when everything is off, and electricity meter also didn't move so good start. Plug-in kwh meter revealed that the 500w heater in the garage got through about 7kwh in a 24 hour period. Obviously this would be more in colder weather. Clamp meter showed that 3 computers and associated equipment drew about 2 amps, therefore about 12kwh in 24 hour period. Clamp meter showed that fish tank also draws about 2 amps and gets through about 12kwh in 24 hour period.
Suddenly it's not hard to see where the 30+ kwh per day is going, before I even switch on the kettle! So, focus is now off the meter and on to reducing running load.
Garage: The 500w heater has a built-in 5 degree thermostat (minimum setting) to keep the garage above freezing. In the past there were 2 of these (and lower bills), maybe both helped maintain the temperature better (and used less power overall?) than the one that's there now. Dunno. Changes: I've re-instated 2nd heater and used timers to fire up both heaters during the E7 period, and one at a time intermittently during the "peak" period. So far E7 usage has gone up by about 3kwh/day but too early to tell if peak rate has come down by much.
Computers:
3 running 24/7 will soon reduce to 2. Jobs are: workstation, surveillance (security camera motion detection) and backup PC (Solaris box with DLT tape drive hung from it, backing up other 2). Tape drive will move to one of the other machines so backup PC can go. Workstation is used regulally all day every day and waiting to boot is not really an option so this will continue to run 24/7, as will security camera PC.Fish tank: This draws more power than I expected it to, and has been pretty much unchanged in 5 years running. However, I will break down each component's load over the next few days and see what can be left off or run in E7 period instead. Some life-critical tank equipment is fed from a big UPS, and my testing so far has shown this is pretty inefficient. Will get figures soon but this may be due for replacement next.
So, any ideas how to further reduce power usage? I need to work out if E7 is actually saving me anything. If not then I'll switch. Power supplier switch on the cards also as Virgin Energy are not the best deal any more acording to
Also, any suggestions on how to reduce the garage running costs? I just need to prevent things in there from freezing without introducing moisture - so free standing gas heating is out. No mains gas there either. Maybe use a more powerful [blower] heater but on a more accurate thermostat set to 1 degree so it only runs when really needed? I have a plug-in digital thermostat unit and 2x 3kw wall mounted air-curtain type heaters in there also for heating when I use the garage as a workshop - maybe I could utilise this lot?
Any ideas gratefully received!
Alan.