Global market for energy harvesting to exceed $4bn by 2019

Energy harvesting, also known as power harvesting and energy scavenging, is the process by which ambient energy is captured then converted into electricity for small autonomous devices, such as laptops and nodes in sensor networks, making them self-sufficient. Applications like wind-up laptops for Africa and wireless light switches working from the power of a finger are available now or are imminently available.

One of the earliest forms of energy harvesting — photovoltaics,  long used in aerospace — has now come down-market to many commercial applications, but still has a long way to go to be manifest as ‘solar film’ or ‘solar paint’. Some new, low-cost photovoltaic technologies are printed on a reel and generate electricity from heat as well as light. Sony, for example, is commercialising this technology as flexible solar cells for indoor use.

Energy harvesting is a substantial business already and will become a multibillion-dollar business within 10 years because it addresses so many key issues — environment, safety and security. So far, commercial successes include photovoltaics on road furniture and consumer goods and piezoelectrics in light switches and other building controls.

Energy harvesting is now becoming more affordable and feasible for large applications including:

• 90% of envisaged uses of wireless sensor networks (WSN) are impractical without energy harvesting. These mesh networks are rarely feasible because, in the biggest projects envisaged (such as those where nodes are embedded in buildings and machines for life or on billions of trees), the batteries would be inaccessible or prohibitively expensive to access.
• Almost-free power for electronics and lighting in nations where batteries are not affordable or obtainable.
• Bionics and sensors that stay in the human body for the life of a patient.

Technology analyst firm IDTechEx forecasts global sales of energy-harvesting devices to reach US$4 billion within the next decade. In the projections, the firm sees only very slow adoption of energy harvesting in wireless sensor networks despite the particularly acute need for it. Consumer applications such as bicycle dynamos, watches, calculators, toys, wind-up lighting, laptops, mobile phones and radios are projected to dominate the growth potential.