Energy is everywhere within reach, it just needs to be harvested: this is the principle of energy harvesting. Today, energy harvesting wireless solutions are already well established in the commercial building automation sector. But the technology is just getting started. Tomorrow, new application fields for batteryless wireless communication will be found to further enhance the world around us, including structural health monitoring (SHM), water quality control and forest fire prevention, smart city management and medical assessment.
This future is not so far off, when taking a look ahead at the further development of energy harvesting wireless solutions and potential future applications.
Based on energy harvesting wireless technology, a wide range of energy-autonomous applications are currently available for connected buildings that use motion, light, or temperature differences as their energy source such as batteryless switches, intelligent window handles, temperature, moisture, light sensors, presence detectors, heating valves, and smart home systems. However, building automation is by no means where energy harvesting wireless ends.
Everybody’s talking about the Internet of Things. But how should billions of communicating devices be powered? The answer is by energy harvesting and the reason is simple: Liberating sensors from external power, making them energy-autonomous, opens up unlimited processing and monitoring applications where cables or batteries represent an insurmountable hurdle.
Already today, the energy harvesting market is growing and multiplies on a year-by-year basis. Forecasts show that this trend will continue, especially as the next generation of energy harvesting wireless solutions are just around the corner. This includes the development of:
Longer Distance Communication
The next generation of self-powered radio technology will enable radio signal ranges of more than ten times the current range – capable of wirelessly transmitting data via a distance of more up to three miles and enabling new applications with high range requirements outside of the building.
New Energy Sources
This long distance radio range will be enabled by improved energy converters opening up new energy sources. In the near future, we will see new types of mechanical energy harvesters, which make use of the energy generated from flowing gases and liquids in particular. For example, metering applications.
New light harvester generations will combine smaller sized solar cells with improved performance. Together with improved energy storage, solar-powered devices will run in complete darkness for several months up to a year.
The potential of harvesting energy from differences in temperature is only at the early stages of development. One option is to harvest energy from temperature differences between day and night for outdoor applications.
As energy harvesting wireless technology advances, new application fields will become feasible:
- Structural health monitoring – Large structures such as bridges, tunnels, dams or drilling platforms have to resist extreme forces imposed by weather, earthquakes or traffic. Radio sensors, powered by light, temperature changes or vibrations, that permanently monitor critical parameters, can warn against non-conformance and prevent break downs. A similar functionality can provide an alarm notice in the event of an avalanche or rock fall.
- Environmental monitoring – Long range energy-autonomous wireless sensors could be placed over large areas to provide early warnings or monitoring of farm animals and plants to react rapidly to changing conditions. For example, to prevent the spread of forest fires or to ensure an optimal supply of water and care for plants.
- Resources monitoring – We only have one planet. So, all resources need to be protected and sustainably used. Batteryless sensor networks can support this by providing the data required to monitor water in terms of quantity and quality or the movement of shoals of fish. In addition, self-powered detectors can report water, oil or gas leaks.
- Smart Cities – By 2030, 60% of people will live in a city1 – representing almost six billion people. Intelligent control will be needed to coordinate people’s daily lives and prevent a city from collapsing into turmoil. This includes automated control of traffic, street lights, energy supply or transportation of goods as well as waste disposal. This can only be realised with millions of energy-autonomous sensor nodes collecting and delivering the necessary data.
- Health Care – Another wide field of application is making our life easier, more secure and comfortable. This includes new solutions for monitoring vital functions as well as an autonomous and healthy lifestyle. There are already bracelet prototypes that can monitor vital functions by using the heat from the body as a source of energy to transmit wireless signals.
These are just a few areas where batteryless wireless communication is currently developing. There are many more. Just think of your own daily life – you’ll find hundreds of further scenarios where energy harvesting wireless solutions would make things easier.
1 World Health Organization; Global Health Observatory (GHO) “Urban population growth” http://www.who.int/gho/urban_health/situation_trends/urban_population_growth_text/en/