When it comes to energy alarms – what are you doing?

When it comes to energy alarms – what are you doing?

Do you have a month-on-month comparison? A year-on-year comparison? Do you involve degree days?

An energy alarm is a helpful tool for identifying unexpectedly high energy use before you’ve racked up too much extra cost.

Setting energy alarms can help you to take control of your energy use and save thousands in the process.

It’s a complex area, as you want to get to the truth of what’s happening in your estate, without ending up with thousands of useless alarms having you running around for no reason.

The issue is, the majority of buildings have a direct correlation between their building’s consumption and the weather.

An easy way to think of it is you’re at home on a cold day, you put the heating on, and then in the summer on a warm day, you might want to put a fan on (or your AC if you’re honoured to have some!).

Most energy alarms will look to compare the performance of a building, against the same period the year before, but what is this telling us?

Unless the weather (or any other driving factors) was the same, how can we compare apples to apples?

What we need to be doing is looking at what actual effect the weather has on the consumption of that building.

Looking at gas specifically, what gas consumption is there constantly (our fixed consumption) and then on top of this how does the consumption then increase due to the weather.

energy alarm graph

As you can see on the above chart, the place where the trend line touches the Y-axis is the ‘fixed load’ for the site – this is the gas that the building uses that is not related to heating the space. This could be for hot water, cooking etc. this is highlighted with the red line below:

Graph 2

The rest of the consumption for the site increases as the external temperature drops (and the heating degree days rise)

As you can see below, there is a pattern, as the HDD (heating degree days) increases, the consumption also increases.

Graph 3

You need to work out what the increase is per HDD then you can start to work out what is abnormal for your site going forward.

Where this gets us to, is that your energy alarm strategy should be based on the following conditions:

Actual consumption > Fixed consumption + (Variable consumption x Driving factor): you used more than expected
Actual consumption < Fixed consumption + (Variable consumption x Driving factor): you used less than expected

This isn’t the whole story. Because there will always be some random difference, we introduce a tolerance band so you’re not getting told about ordinary variances in the consumption. Our systems suggest a custom tolerance band for each meter which can then be tweaked over time to get it just right.

So, all of a sudden, we are able to say what would have been normal for that period, including typical variances, and compare this to the actual consumption – if the figure is higher than expected by more than the tolerance band, it triggers a high consumption alarm. If the figure is lower than expected by more than the tolerance band, we create a low consumption alarm (i.e., let’s find out what happened and see if we can replicate it again for MORE savings)

There are lots of other factors and things to consider here, like removing any abnormal consumption from your analysis data to make sure the ‘target’ your setting for the site is in line with good consumption. There will be other drivers which could have changed, such as opening hours, size of building etc.

Learn more about how our energy and optimisation team can help manage your compliance obligations, reduce carbon and create lasting behavioural change in staff with a suite of our services.

Get in touch with us on 0161 543 4131 or email us: info@thermaticenergy.co.uk