Phantom Load (Vampire Energy): How to reduce standby power waste?

Phantom load, sometimes known as vampire energy, refers to the electricity consumed by appliances when they’re switched off or in standby mode. In this article, we’ll explore the different types of phantom load, why it matters to your business, how to measure it, and what you can do to reduce it.

Overview

Phantom load is the energy consumed by any electrical appliance in your premises that isn’t actively in use but is still drawing power from the grid. This is often a very small amount per device.

Examples include computer terminals left on standby overnight, chargers with built-in transformers (if it’s plugged in, not charging, and warm to the touch, that’s a vampire right there), printers, routers, and other devices that remain powered overnight or hold charge for quick start-up.

While each device may draw only a few watts, combined they can make a material difference to your business energy bill.

Why phantom load matters to your business:

Higher overheads: Standby energy waste increases electricity costs and reduces the return on energy-efficiency investments.

Increased carbon footprint: Unnecessary consumption makes it harder to meet sustainability and net-zero targets.

Regulatory and reputational risks: Larger businesses must report energy usage under SECR (Streamlined Energy and Carbon Reporting). Excess waste can reflect poorly on sustainability performance.

How to Measure Your Phantom Load

There are several ways to identify and quantify standby energy usage:

• Plug-in power meters: Affordable devices that sit between the plug and socket, providing quick and accurate readings. Some offer detailed reports showing peaks and troughs in demand.

• Submetering: Installing submeters in different areas of your building can reveal where energy is being wasted, though this can be more costly.

• Half-hourly or smart meters: Half-hourly meters, AMR meters, and all SMETS2 meters record energy use in 30-minute intervals. Your energy supplier can often provide this data, which is particularly useful for identifying overnight consumption.

• Building management systems: Many modern buildings have BMS dashboards that track energy use; learning how to interpret these reports can pay dividends.

• Energy audits: If your business undergoes regular audits, check whether phantom load is included. If you manage multiple sites, comparing data between similar properties can highlight opportunities for savings.

How to Reduce Your Phantom Load

Reducing phantom load doesn’t need to be complicated. Small actions can lead to meaningful savings.

• Take the first step: It’s easy to assume the savings are too small to matter, but they quickly add up.

• Buy right: When purchasing new equipment, consider standby power consumption as part of your buying criteria.

• Create a shutdown policy: Encourage staff to safely power down devices at the end of the day.

• Use smart plugs or timers: Configure equipment to power on only when needed.

• Raise awareness: Educate staff and visitors with reminders or signage to switch off devices when not in use.

Frequently Asked Questions

Can I calculate how much my phantom load costs?

A single device consuming 10 watts in standby uses around 58 kWh per year (10 W × 16 h × 365 ÷ 1,000). At a typical UK tariff of 24p per kWh, that’s roughly £14 per year. Multiply that by 100 similar devices, and it soon adds up.

Does switching off devices cause damage?

Most modern equipment can be safely turned off, but check with the manufacturer if you’re unsure. Some systems may need to stay powered overnight for updates or remote management, so plan accordingly.

Get Started

Now that you understand the value of tackling phantom load, start small. Focus on one department or a few key pieces of equipment to prove the impact.

Once you see the results, expand your efforts across the business.

Happy “ghost” hunting!