Optimising Operational Hours to Minimise Capacity and Consumption Charges
Imagine for a minute you wanted to maximise your electricity bill. Perhaps you’re a malicious employee looking to cost your company money. How could you get away with destroying profit margins while seeming to keep people happy? One way is to play silly buggers with your site’s operational hours. Pro tip: if you want to add a zero or two to the bill, turn on every piece of equipment in the building at the same time. To amp it up further, borrow a few kettles from your neighbours and boil 20L of water at the same time as you ramp up the heating from frostbite levels to Dante’s inferno level. While you’re into the swing of it, microwave a few bags of popcorn (in multiple microwaves of course), making sure to use the highest wattage level. Your colleagues will herald you as an office hero! They get into the office and find warm mugs of cocoa waiting for them and a bowl of freshly popped popcorn on their desk. Your conniving scheme will only be realised by the astute accountant who gets the electricity bill at the end of the month and sees a massive spike in the kVA capacity charge.
Following Sensible Operational Hours
Hopefully your facility manager isn’t hellbent on destroying your business and won’t follow the antipattern above. If they know their stuff, they’ll carefully plan operational hours to maximise comfort whilst minimising load spikes. A well tuned building will smoothly transition from a very low baseload (i.e. when everything is turned off overnight) to operational load (when people arrive to work). It should be fast but not too fast. If you have two ultra-dedicated people in the office at 6AM, it doesn’t make sense to have the lighting and heating going full bore. If they complain about the cold, give them a company emblazoned scarf and explain that it doesn’t make sense to turn the HVAC system on at 4AM so that they can arrive to a cozy temperature. Similarly, if you have one person working late in the accounts department, it doesn’t make sense to have all the site lighting and heating blaring. A flexible work policy could be a big win here – employees burning the candle at either end can do so from the comfort of their own home rather than burning up your energy quota.
How Fast Is Too Fast?
Depending on how efficient your HVAC system is, you’ll need to give it some time to kick into gear. As the kettle and microwave fiasco shows, ramping up too quickly can be quite costly. In fact, kettles and commercial breaks are one of the reasons why the grid has been gold-plated. You’ll do everyone a favour if you gently kick the system into gear rather than jumping from neutral to 5th gear. That said, you don’t want the transition period to be too slow either. If the majority of your building’s occupants arrive at 8AM and it takes one hour for the HVAC to achieve decent occupant comfort, you can probably get away with scheduling the heating to turn on at 7.15AM rather than 5AM. People don’t necessarily expect the office to be toasty when they first arrive. They can keep their coats on for fifteen minutes and you can reduce consumption charges.
Smoothing Out the Ramp Up
When planning site ramp up, it’s best to not turn everything on at the same time. The startup phase is the most power hungry part of the consumption curve. Start with the slowest starting piece of equipment (e.g. HVAC) and then schedule other equipment (e.g. instant boil hot water) to turn on a little bit later. Consumption spikes are what’s going to cost you at the end of the month and if you can smooth out the curve, your energy distributor will be much happier with you.
Turning things off quickly has fewer consequences than turning them on quickly. You’re not going to cop any extra fees from your retailer if you have a hard shutdown at 6.30PM and flick all the switches right at that time. The main variable here is occupant comfort and you’d do well to please the many at the expense of the few. Night owls and early worm hunters are already gluttons for punishment – they can deal with things being a bit chilly/warm. If they complain, either tell them to get a life and stop working so much or set them up with the ability to work from home so they’re the ones claiming heating in their tax return instead of you.
Time of Use Charges
The terms and conditions of your electricity contract are probably rather obtuse but it serves you well to read them through carefully. Chances are your retailer charges you much less/more for on-peak/off-peak periods. If you have load that can be time shifted, do it. Let’s say you’re running a cryptocurrency mining operation. Those Antminer S9s aren’t known for being power anorexic so you might benefit from only running them during off-peak periods.
Dealing With Multiple Operational Periods
If you’re running a restaurant + cafe, your energy needs probably fluctuate during the day. You’ll have an early startup to cater for the 6.30AM caffeineless zombies, a trough between 10AM and 11AM while you cut vegies in preparation for lunch and then the lunch hour rush between 11.30AM and 2.30PM. Between 2.30PM and 4PM you’ll have a lull and then a decent spike from 5PM to 9PM while you serve dinner to hungry patrons. Those lulls in between peak periods are an opportunity for savings. You can turn off your ovens, reduce the aircon in the seating area and play the music a little less loudly. It’s all about balancing occupant comfort and consumption.
Deciding What’s Worth Turning Off
Turning arbitrary pieces of equipment off is satisfying but it’s not necessarily going to make much of a difference. Efficiency pundits in mainstream media have been criticised for telling people that they needed to make sure to unplug phone chargers when not in use. A researcher found that even having 20 phone chargers plugged in had no measurable current draw. You need to identify what pieces of equipment contribute meaningfully to your operational load and decide whether they’re critical or whether they can be turned off with few consequences. To determine how much power equipment is drawing, a plug-in power monitoring device can be handy for small appliances. For bigger pieces of equipment (e.g. HVAC), you may want to invest in sub-metering to give you detailed data.
Visualise Your Operational Hours
Many of our clients are unaware of what their operational profile looks like (e.g. refer to these case studies). EnergyLink gives you detailed charts showing your consumption profile and can also give you tailored recommendations based on analysis from our skilled engineers and machine learning algorithms.
To learn more about EnergyLink, drop us a line.