Watt-lite Twist

The Watt-lite Twist is an oversized torchlight projecting energy statistics in a pie- chart interface. It proposes an alternative way of understanding the relationship between electricity use and the, often considered, abstract energy unit; kilo-watt- hours (kWh). Bellow is an explanation of the external properties of Watt-lite Twist, its function and design rationale. A short background to the concept is also given.


The Watt-lite Twist builds on the idea of trying to materialize the understanding of electricity use in a more tangible way. When the user are twisting the torch, setting the amounts of kilo-watt-hours to be measured, he or she can literarily feel the physical resistance from the mechanism – something that has a possibility to be transferred into an understanding of the otherwise rather abstract notion of electrical energy in general and the kWh unit in particular.

The intension with Watt-lite Twist has been to encourage an explorative use educating about electricity use in an engaging way. It can act as an ambient display reminding and informing about the state of things as one passes by but as a tool for taking measures, it requires active participation.

The Watt-lite Twist helps you to become aware of, to discover and to understand the world of electricity.

User Scenario

This comic strip shows a user scenario of a family using the ambient interface Watt-lite Twist to control their energy usage.

Exterior & Function

Watt-lite Twist consists of one small, built-in, laser projector, a small light-weight computation unit and a wireless receiver. This technology is placed inside a case shaped like a traditional, but oversized, flash-light. The dimensions of the Watt- lite Twist is 31 centimeter high and about 12 centimetre in diameter.

The front part of the torch can be rotated and winded up just like an egg-timer. Instead of twisting and increasing the amount of preferred minutes, Watt-lite Twist is winding up kilo-watt-hours. From as little as 0,1 kWh to 10 kWh – how long will it take to consume? The information projected by the torch will tell you.

The two full circles to the left show the process of winding up the Watt-lite Twist. The radius (and the area) of the projected circle increases. The circle to the right is when all kWh are used up, displaying the amount of kWh used and the time it took to consume them.

Two circles on the left depicts the beginning of the count down. The small circle from 1 kWh and the big one from 10 kWh. Two circles on the right are illustrating a later stage when more kWh is used up.

On the side of the cover of Watt-lite Twist is an info-button. When pressed and held down, the projected image changes from showing the amount of kWh left(right) to the amount used (left). Furthermore, more information about individual measuring points are displayed and assigned different colours on the pie chart. The colour on the pie chart corresponds to the colour of the plug sending the information wirelessly to the Watt-lite Twist. When letting go of the button, the pie chart reverts back to the right stage.