#1 By: Graeme Stuart, April 30th, 2014 09:52
I am interested in getting your opinion on this. There is a strong assumption that a lot of energy is wasted by equipment using energy when it is not needed (e.g. lights, PC's, lasers, ..., whatever). The simple solution to this problem is to turn stuff off when its not being used. However, this is actually a very difficult thing in complex buildings with lots of different equipment being controlled by lots of different people. For example there may not be anyone specifically responsible for a piece of communal equipment such as a photocopier so everyone assumes it is someone else's responsibility.
It seems to me that consumption during unoccupied periods can reveal something about this. If we assume that the legitimate demand for energy during unoccupied periods (for things like security systems, lighting, servers and so on) should be effectively constant over time[*]. Therefore, if demand during unoccupied periods is variable, we might conclude that this is related to the amount of waste due to equipment being left on overnight and during weekends. The level of overnight consumption (ostensibly legitimate energy services) seems to vary wildly between buildings.
To provide an example of good practice, the Leicester Central Library seems to be very well controlled or at least to have low and consistent overnight and weekend consumption. This implies that most unnecessary equipment is turned off at the end of each day and the remaining load is for the kind of legitimate purposes I describe (certainly anything else that is left on is consistently small). Since these loads are constant we see a constant, small load every night and every Sunday when the Library is closed. As described in this post, I understand @MMcBride has procedures in place in the Library to turn equipment and lighting off at the end of the day and the evidence shows they work well.
So, how hard is it to turn stuff off?
- How much effort is it to put these kind of procedures in place (mainly for @MMcBride)
- Is the Central Library an easy building to control in this way?
- Can other buildings achieve this low baseload and if so, how?
- What kind of equipment should be running overnight and during unoccupied periods?
[*]Other than a bit of seasonal variation in lighting (long summer days might reduce lighting consumption) and heating (during very cold periods, frost protection will kick in)
#2 By: Michael McBride, April 30th, 2014 11:08
It is probably easier for us to control what happens in Leicester Central Library. We are a single team in a single building, with set closing times. When the library closes, staff have set responsibilities as part of our closing routines - those working on each of the 3 floors are responsible for switching off lights, computers, printers, copiers etc. on that floor. When the library closes, we all leave - nobody stays behind doing extra work, unless we have a special evening event.
Controlling unnecessary overnight energy consumption will be much more of a challenge for larger buildings, which may house several teams and have staff working more flexible hours.
#3 By: Tim Stagg, May 13th, 2014 03:07
Would you believe it!! I discovered two electric convector heaters left on all weekend! It appears to be extremely hard to turn stuff off.
#4 By: Graeme Stuart, May 13th, 2014 05:59
If it relates to this extra consumption (electricity increase way above normal for the weekend) then it seems they were turned on on Saturday morning. Would this make sense?
#5 By: Tim Stagg, May 13th, 2014 08:52
yes a trusted contractor with a key did some work for me on Saturday morning. He had a key to save money being spent paying a regular keyholder attending (irony!)
Hopefully a "one off" event
#6 By: Richard Snape, May 14th, 2014 07:24
I think that's true. The basic answer to your question is
We're all used to it not really mattering - it's something easily forgotten / overridden by other concerns (e.g. safely locking up the school for your contractor, maybe). I count myself in that - even though I try to be careful, I often forget.
A secondary issue is that there is not necessarily consensus in a shared building as to what is legitimate overnight usage. For one person, the PC left on and ready to use immediately they sit down in the morning is legitimate, for another, ridiculous. A vending machine being left on to keep drinks cool even though the likelihood of anyone wanting to use it at 2am might be legitimate if you're the catering provider, less so if you're the energy manager.
Maybe a debate and consensus in each building could help. Of course first you need to know what's in the base load...