Ecobutton - computer-based energy saving device August 2009


The Ecobutton is designed to save power when you leave your PC or laptop unattended, simply through pressing its big button. We gave the Ecobutton a quick test to see how its energy saving credentials measured up.


The Ecobutton is an energy saving device that conveniently puts your desktop or laptop computer into a lower power mode when you're not using it - simply press the Ecobutton before leaving your equipment unattended. The device is a visible reminder for eco-conscious computer users to switch their PCs or laptops to a more energy efficient setting when taking a break.

When you return to your PC, it switches back to ‘on’ mode when any key on the keyboard is pressed. The calculated energy savings you've made by using the Ecobutton are then displayed on the computer screen.

The Ecobutton is compatible with Windows 2000, XP and Vista 32 bit operating systems, but it’s not Mac compatible. It comes with 1.1m black USB lead, which is long enough even if your PC sits beneath your desk. The device's base is made out of hard plastic and easily slides around - it could benefit from a nonslip base, or a sticky pad for attaching it to a monitor or fixed position. The packaging is also a little tricky to open.

Ecobutton website

The Ecobutton website is easy to navigate

Free Ecobutton software

To connect the Ecobutton with your computer you'll first need to install a piece of free software, which is downloadable from The software is well laid out and simple to follow, with little more required than the continual clicking of the ‘next’ button. You’ll need 1.6Mb of spare space on your computer.

Once the software is downloaded, the Ecobutton will be recognised by the PC or laptop when plugged into a USB port. The translucent button then glows green before slowly fading on and off alternately.

The device claims to put the PC into the most economical sleep mode available - however during our test we found it put the PC into ‘sleep’ mode, even though the more economical ‘hibernate’ mode was available.

Power modes on a computer

Power modes on computers can get a little confusing. 'On' is clearly 'on', but what Microsoft Windows calls 'Standby', those in energy circles refer to as 'Sleep' - this is the mode that the Ecobutton will switch your computer to.

By clicking on the 'Start' button in Windows and opting to 'Shut down' your computer, you are actually only switching it to what we call 'Stand by'. To truly turn the computer off you will need with switch it off at the mains. There is a glossary of modes at the bottom of this report to help explain.

You can either use the device's default energy settings or enter the energy usage of your PC or laptop yourself, through the ‘systems parameters’ window. We found the default numbers were higher than expected at 16p/kWh of electricity. By comparison, the Energy Saving Trust uses an average figure of 12.96p/kWh, while Ofgem uses 12.5p/kWh. This means the stated amount of money and energy saved by the device may be slightly inflated when using the default settings.

The default power consumption figures used by typical PCs and monitors also seem slightly exaggerated at 175 watts. In our labs, we found a PC and 17-inch monitor typically uses in the region of 150 watts. The carbon per kWh figure (0.43kg) appears to be more accurate, and is in accordance with Defra’s estimations.

Ecobutton online demo

The Ecobutton website has some useful and well-presented demos of how the Ecobutton can be used


We tried this device out on a PC running the Windows Vista Home Premium operating system, with an Intel Core2 processor and 2GB of RAM. It was connected to a 17-inch Samsung monitor.

The PC and the monitor drew 120.3 watts of power when on. We hit the Ecobutton once and the energy consumption dropped to 3.79 watts. Hitting the Ecobutton a second time switches off the illuminating light and brought the power usage down to 3.7 watts, in line with the 0.08 watts required to illuminate the button’s green light.

The second press of the button is not documented in the instructions. It occasionally caused the Ecobutton to stop working and required us to disconnect then reconnect.

We also tested energy consumption after manually adjusting the PC settings without the aid of the Ecobutton. Switching the PC to ‘standby’ reduced energy consumption to 3.7 watts - equal to the amount of energy used when the Ecobutton is pressed twice. When we put the PC into hibernation, the energy consumption went down to 3.17 watts.


Despite it being possible to save more energy without using the Ecobutton, we think it’s a good product which will visibly remind people to conserve more energy.

Users should attempt to add specific information for their computer into the ‘systems parameters’ page in order for the device to calculate money, energy and CO2 saved more accurately. But even with the default settings, if used conscientiously, the device will result in significant energy savings on most computers.

Pros: Makes the switching of a PC or laptop to standby more ‘visible’, easy to install and use, likely to save money and energy

Cons: Default settings are a little inaccurate, sets computers to standby rather than hibernate, lacks non-slip base

The Ecobutton is available from for £12.99.

You can also read independent reviews of desktop computers and laptop computers to find out which models were crowned Which? Best Buys.

Glossary of power modes

We've listed these in order of power consumption level - from highest to lowest:

Idle mode This is the when the PC has been on for a while, but is not being used.

Sleep mode This occurs when the user sets the computer to switch to a low power mode referred to as 'standby' by Microsoft Windows. The PC appears to be switched off, but can 'wake up' within a few seconds. It does this by storing the system status of the operating system and any open applications (for example the user's open documents) in memory (RAM), which is fast to read and write to. A little power is required to maintain this information in RAM, but other parts of the computer can be switched off.

Hibernate mode A computer can be programmed to hibernate automatically after a pre-determined amount of time without use, or will switch to this mode when instructed by a user. It uses even less power than 'sleep' mode, as it stores the system status of the operating system and open applications on to the hard disk instead of RAM - but it takes longer to recover the computer and its applications.

Standby mode This occurs when the user shuts down Microsoft Windows. Most people consider this to be switched off but it still draws some power. It requires the most time to return to the usable 'on' state.

Off This can only really be achieved by switching the computer off at the mains and unplugging it.

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