Energy consumption is a slippery concept. We know it’s happening, because every month we’re greeted with a utility bill that tells us how much energy we’ve used. But on a day to day basis, it’s more of a subconscious activity. We plug things in to an electrical outlet, they turn on, we use them, and then (hopefully) turn them off. There’s no alarm that sounds when our energy consumption gets too high, or buzzer that goes off when we leave the bathroom light on all night. So the meter keeps on chugging away, and we don’t realize our wasteful habits until the bill comes.

German designer Philipp Käfer was tired of being kept in the dark about energy consumption. So he invented the okay?! reading lamp. With a variety of electrical sockets embedded into the lamp’s base, it at first seems to be encouraging users to use more power. But something surprising happens when they do.

Image via Philipp Käfer

Each time a new appliance is plugged into the lamp’s electrical sockets, the light diminishes ever so slightly. “The more electricity the appliances need the weaker the light will become – a reminder that even though it looks that way, electricity is not unlimited available,” writes the designer on his website.

Image via Philipp Käfer

Unlike energy usage monitors that inform you of energy consumption after the fact, Käfer’s okay?! lamp is a powerful real-time reminder of the impact of our energy consumption. Every time we plug in another appliance, we’re adding additional strain on the power grid. Seeing the impact one appliance has on the lamp might inspire people to imagine the effect a million appliances is having on the coal-fired or nuclear power plant that generates their electricity. Hopefully being able to visualize this drain will encourage more people to unplug altogether.