Introduction and Context
We have grown so reliant upon our home electronics that we hardly notice them anymore. In the US, we take it for granted that most homes have several televisions and computers. Each of these main devices is often paired with its own set of support equipment: speakers, printers, displays, cable box, DVRs. The list goes on. Oh, and then there are all the independent small, battery-powered devices: coffee makers, vacuums, tools. And of course, our phones – which often have multiple chargers plugged in all around the house “just in case” we need them.
However, we might be surprised to learn that these devices consume far more power than we imagine. Worse, they drain electricity from our homes even when not in use. This drain has a great name: Vampire Load. Upon close examination, you can sense this load. Maybe a device will hum or chirp. Or perhaps it will be warm to the touch. Regardless, we are paying a cost for these devices to remain in perpetual standby mode. How big are Vampire Loads — and how can we avoid them?
But First: A Little Math
To understand the magnitude of these vampire loads, we need to appreciate that power (the instant flow of electricity – or electrical energy) is measured in Watts. Most of us are familiar with a 60-Watt bulb (hopefully more often replaced with a 9-Watt LED!). If that bulb operates 24/7 for a full year, it consumes 60 Watts x 24 x 365 = 525,600 Watt-hours of energy. Because this number is large, we prefer to quantify in kilowatt-hours, in this case 525.6 kWh. On average, we pay about $0.12 per kWh in the US. At this flat rate, that 60-Watt bulb would cost us $63.07 for our year’s non-stop use.
Of course, most of us would NEVER leave the light on all the time! But, effectively, that is EXACTLY what we do with respect to vampire loads.
What the Math Means for Vampire Loads
Think about all the Watts required to heat up those chargers and other devices in our homes. On average, each of these loads accounts for less than 5 Watts each, but they add up. Especially if you look at big loads like a DVR (23-49 Watts), digital cable boxes (13-30 Watts), and televisions (0-22 Watts). These loads and others are captured in the graphic below from the Lawrence Berkeley National Laboratory. Since on average, each Watt of vampire load costs us a little over $1 per year, it is easy to see how the cost adds up. In fact, a 2015 report from the National Resources Defense Council found that idle load accounts for 23% of annual household electricity consumption.
Savings Calculations for the Vampire Loads We Avoid
In calculating savings, Emporia considers that with diligence a large number of vampire loads in a home can be avoided. Two strategies exist for removing these loads. First, devices such as chargers can be unplugged while not in immediate use. Second, smart power strips or outlets – sometimes equipped with motion sensors – can be used in areas where multiple problematic devices are concentrated, such as the office, the kitchen, the family room, or the garage.
Although the NRDC report points to vampire loads’ consuming 23% or household electricity, Emporia recognizes that not all loads may be eliminated. Therefore, savings will fall within a range of 5% to 10%. As with other savings calculations, Emporia then scales these savings based upon the frequency of app use. Ultimately, these savings and others may achieve savings as high as 50% on energy!