Last updated: August 2019
How to Calculate Maximum Demand From kWh
Your organisation is typically billed for its half-hourly consumption patterns and peak demand for energy, so monitoring both your consumption (kWh) and demand (kW) is vital in reducing energy costs.
Most businesses don’t have submeters onsite, meaning that the only way to analyze energy use in search of energy-saving opportunities is to take manual readings at the meter and run some spreadsheets, or review aggregated kWh consumption figures from electricity bills and try to make sense out of it.
[Related: Analysing electrical demand and supply (kW, kVAR, kVA, PF, V)]
You may be able to spot some patterns if you dedicate much time and effort, but if you haven’t yet subscribed to a data collection service providing you with interval data from your fiscal meters, or invested in a few meters at strategic locations within your electrical installation, you may be wise to invest a few hundred euros to get your hands on more granular data readings.
Measurements you will get from your data collection service or submeters are typically analysed in spreadsheets or preferably within an online energy analytics platform, so you can centralise all your data and projects in one place, with access shared with your colleagues. In the figure below (Figure 1), we use kW load demand readings to illustrate the methodology for understanding what’s driving your energy use, but the same analysis can be done with interval kWh readings.
Maximum Demand Formula
What you are looking for in such a graph is very specific:
- Overnight demand levels, to compare to daily levels and find out if more equipment could be switched off;
- High consumption hours (when demand starts to increase and decrease), to find out if it matches your business/operating hours;
- Down-time periods (e.g. lunch time breaks, weekends), to find out if your staff operates equipment efficiently;
- Unusual demand peaks (e.g. peak at night or drop during the day), to find out if electric equipment/appliances/devices have been left on or have failed;
- Peak demand information (max kW value over a period and the time it occurred), to find out if you are being charged correctly for your peak demand charges (you need to select the meter that monitors your entire site for comparison with your electricity bill).
Very often, a daily or monthly kWh figure does not reflect what’s happening during the day. Now that you know how to identify what’s really happening (and what shouldn’t), you can:
- Go back to your staff and call for action (awareness campaign to switch off equipment when not in use during breaks, overnight and at weekends);
- Go back to your supplier or energy consultant and ask them to revisit the MIC (Maximum Import Capacity) you are registered for to reduce your electricity bills;
- Set up alerts in your energy management dashboard to be notified when abnormal demand is detected at any of your submeters;
- Revisit your BMS and timer settings throughout your site to align them with business hours and space occupancy (major potential savings on HVAC and lighting)
With centralized SaaS-based systems, like Wattics energy analytics, energy companies can eliminate most (if not all) of the challenges (manual entry, data delays, compatibility issues … and the list goes on) associated with using spreadsheets.
Forget Excel –> contact one of our experts by filling in the short form below ↓↓↓ to know more about how Wattics can help you simplify and streamline your energy analyses and reporting so that you can focus on other business-critical activities.
