Parasitic energy harvesters are urbanites who tap into wasted, overflow energy and repurpose it. One German designer has come up with an invention to aid them. From Pop-Up City:

“Recently we found a stunning new invention in the field of parasite energy harvesting that we want you to know about. German designer Dennis Siegel created a small device that is able to harvest energy from electromagnetic fields and instantly recharge batteries (!).

Since electromagnetic fields are omnipresent, this small invention has a huge potential. Siegel explains that we are surrounded by electromagnetic fields which are the results of information transfer, or byproducts of electric equipment. Those fields can be found near power supplies of electronic devices like a coffee machine, a cellphone or an overhead wire. Many of those fields are very capacitive and can be harvested with coils and high frequency diodes. Siegel’s small harvesting device is able to tap into several electromagnetic fields to exploit them. The energy is stored in an ordinary battery. This way spoiled energy that flows around in the air can be ‘re-used’ easily.”