When discussing potential energy savings with prospective customers, it’s important to set expectations as to how much money will be saved – and to be as accurate as possible. While we know that the Verdant energy management system saves money and energy, there is one variable that we can’t control that can sometimes confuse results if taken at face value – weather.
From one year to the next, seasonal temperatures can vary widely, and as a result, so can your energy bill. But that doesn’t mean you aren’t saving money or energy. You may be surprised to know that it’s conceivable that your energy bill rises by 15%, even though your energy management system is reducing overall kilowatt hour usage by 20%!
So how can we account for these temperature changes from year to year and attempt to quantify the real savings from an energy management thermostat? Fortunately, we have a useful metric called a “degree day” that helps us measure the true impact an energy management system is having on a building.
For those who may not be familiar with the concept, a degree day is a measurement that quantifies the demand for energy needed to heat or cool a building relative to a baseline exterior temperature, usually 65 degrees. To learn more about this topic, visit this website.
So how does Verdant measure true energy savings? It starts with a history of utility bills for the 12 months prior to our system’s installation (2-3 years history is even better and can produce more accurate results), and the 12 months following installation. Once we input billing information into a spreadsheet, we’ll export degree-day data for that same period, and overlay it with the billing history. If we’re lucky, the degree day measurements (and temperature) will be very similar year-over-year, and produce a clear and obvious result. Here’s an example of that over 3 different months. The rows in green represent months post-Verdant system installation.
A simple degree day analysis that that compares kWh usage and electricity costs year-over-year.
As you can see, the degree days are virtually identical from one year to the next, but the kWh consumption has been reduced by between 10-20% in the months identified post-Verdant EMS installation. We can confidently say that this kilowatt-hour reduction is the result of Verdant’s energy management system.
But many instances of post-installation billing analysis are not so straightforward. Most calculations end up looking something like this. In the instance below, you can see that we’ve matched two similar months in terms of billing days and degree days, and most importantly degree days. This ensures that we’re comparing apples-to-apples as much as possible.
A more complex billing analysis.
This type of billing analysis is not perfect. There are a variety of other factors that cannot be accounted for in these calculations such as overall occupancy rates, efficiency of the HVAC units, etc. However, when we present annualized savings projections as part of our free trial program, we more-often-than- not find this method to be an accurate predictor of future results.
To learn more about how Verdant’s energy management thermostats can save energy at your commercial property, book your web demo today.