CleanTech Terms Explained: Energy Harvesting
Clean technology (CleanTech) refers to products, services, and processes that reduce environmental impact while conserving natural resources. Renewable energy sources like solar, wind, and hydroelectric power have become ubiquitous in CleanTech discussions over the years. Emerging technologies like energy harvesting are slowly gaining momentum and recognition as a powerful approach for harnessing energy that would otherwise go to waste. In this article, we explore the concept of energy harvesting, the science behind it, and its various applications in CleanTech.
Understanding Energy Harvesting
What is Energy Harvesting?
Energy harvesting, also known as energy scavenging, is an electronic process of extracting usable electrical energy from the surrounding environment and converting it into electrical energy to power devices and systems. With energy harvesting technology, you can extract energy from everyday sources such as light, heat, vibrations, and electromagnetic fields. The amount of energy that can be extracted depends on the strength of the source and the type of energy harvesting technology used.
Energy harvesting technology is becoming increasingly popular because it offers a way to power devices without the need for batteries or external power sources. This can be particularly useful in remote locations where access to power sources is limited.
The Importance of Energy Harvesting in CleanTech
Energy harvesting has enormous potential in CleanTech applications because it is a clean and efficient way of generating power. CleanTech refers to technologies that help to reduce the impact of human activities on the environment. Energy harvesting systems can operate on their own, without being dependent on external power sources. They also have the potential of reducing the dependence on batteries in various applications which can create e-waste. Energy harvesting technology itself is low maintenance, environmentally friendly and improves device longevity by eliminating the need for battery replacements.
One example of CleanTech applications that can benefit from energy harvesting technology is smart buildings. Smart buildings use sensors to monitor and control various systems such as lighting, heating, and cooling. Energy harvesting technology can be used to power these sensors, eliminating the need for batteries and reducing the amount of energy required to operate the building.
The Science Behind Energy Harvesting
The science behind energy harvesting involves capturing energy in its various forms and transforming it from one form to another to power devices. Energy harvesting applications are based on principles of physics and engineering of energy-converting devices, which are designed to convert one type of energy into another. A device called a transducer is used to convert the energy from the source into electrical energy that can be used to power devices.
There are many different types of transducers, each designed to convert a specific type of energy into electrical energy. For example, a photovoltaic cell can be used to convert light energy into electrical energy, while a thermoelectric generator can be used to convert heat energy into electrical energy.
Energy harvesting technology is still in its early stages, and researchers are constantly developing new and innovative ways to capture and convert energy from the environment. As this technology continues to evolve, it has the potential to revolutionize the way we power devices and systems, making them more efficient, sustainable, and environmentally friendly.
Types of Energy Harvesting Technologies
Solar Energy Harvesting
Solar energy harvesting is the process of converting solar energy into electrical energy. Solar energy harvesting systems use photovoltaic (PV) panels to convert the energy from the sun into DC electrical energy. The DC voltage is then converted to AC voltage, which can then be used to power devices. Various types of solar panels like monocrystalline, polycrystalline and thin-film technology can be used in solar panels for energy harvesting. Solar energy harvesting is commonly used in outdoor environments where sufficient sunlight is available.
Wind Energy Harvesting
Wind energy harvesting is the process of converting wind energy into electrical energy. Wind energy harvesting systems use a wind turbine generator to convert the mechanical energy of the wind into electrical energy. The blades of the wind turbine generator are designed to capture and convert the kinetic energy of the wind into electrical energy. Wind energy harvesting is commonly used in rural or remote areas where sufficient wind is available to generate energy.
Kinetic Energy Harvesting
Kinetic energy harvesting is the process of converting the energy generated by the movement of people or machinery into electrical energy. Kinetic energy harvesting systems use devices such as piezoelectric transducers or electromagnetic generators to convert the kinetic energy into electrical energy. Kinetic energy harvesting is commonly used in applications such as walking tiles and dancing floors or amusement parks and other high-traffic areas where significant movement is available for generating energy.
Thermal Energy Harvesting
Thermal energy harvesting is the process of converting the heat energy generated by machines or the human body into electrical energy. Thermoelectric generators (TEGs) or thermoelectric modules (TEMs) are used in thermal energy harvesting systems to convert the temperature difference into electrical energy. Thermal energy harvesting is commonly used in small-scale applications, such as digital watches or body-worn devices.
Radio Frequency (RF) Energy Harvesting
RF energy harvesting is the process of converting the energy generated from radio waves into electrical energy. RF energy harvesting systems use antennas to capture energy from radio signals and convert it into usable electrical energy. RF energy harvesting is commonly used in wireless sensor networks and other Internet of things (IoT) applications where battery replacement can be an issue.
Applications of Energy Harvesting
Energy Harvesting in Smart Buildings
Energy harvesting can be used in smart buildings to power various IoT devices like sensors, beacons, and actuators. By eliminating the dependence on lithium-ion batteries, the risks of e-waste and maintenance costs can be reduced. Implementation of energy harvesting in smart buildings can increase overall efficiency and reduce energy loss.
Energy Harvesting in Transportation
Energy harvesting can be used to power various sensors in transportation systems. For instance, in the aerospace industry, energy harvesting technology can be used to capture energy from the vibrations of airplane wings, which can be used to power wireless sensors embedded in the wings. In the automotive sector, energy harvesting can be used to power tire pressure sensors, parking sensors, or in-vehicle displays.
Energy Harvesting in Agriculture
Energy harvesting can be used in agriculture to power wireless sensors for monitoring soil moisture, temperature and other environmental factors. Energy harvesting systems can be installed in fields to generate power from solar, wind or kinetic energy generated by farming activities to power farm equipment or wireless sensors. The use of energy harvesting technology in agriculture helps in improving yield and reduces costs incurred on energy bills.
Energy Harvesting in Consumer Electronics
In consumer electronics, energy harvesting technology can be used to power many devices and wearables. It eliminates the need for battery replacements, which results in less e-waste. Devices like fitness trackers, smartwatches and wireless headphones are ideal applications for energy harvesting technology, which can power them through the kinetic energy generated by the body movement or solar energy.
Conclusion
Energy harvesting technology has enormous potential to contribute to CleanTech. By capturing ambient energy sources, energy harvesting can help in reducing dependency on limited fossil fuels, providing renewable energy sources, and reducing e-waste. The technology can be used in various applications to power sensors, actuators, or other IoT devices, which can improve the overall efficiency of systems and reduce maintenance costs. In the future, the adoption of energy harvesting is expected to grow exponentially as it becomes more cost-effective and efficient technology.