Key steps to power production and transfer

Article By : Stefano Lovati

Electronic applications involving the production and transfer of energy are of fundamental importance today.

Electronic applications involving the production and transfer of energy are of fundamental importance today. The search for increasingly sustainable solutions, combined with the need to contain carbon dioxide emissions by reducing the greenhouse effect, are favoring the use of renewable energy sources. The ability to produce energy from alternative sources such as sun, wind, wave motion, and biomass allows for a significant reduction in environmental impact and polluting emissions compared with traditional energy sources based on fossil fuels. Solar energy, for example, can help developing countries or small mountain and rural communities to equip themselves with efficient, economical, and virtually zero environmental impact plants to produce electricity. Photovoltaic (PV) panels have undergone a rapid and significant evolution in recent years, offering users increasingly efficient and reliable solutions that require reduced maintenance and are able to produce energy even in conditions of low solar radiation. At the same time, the simplicity of installation has grown, favored by the introduction of flexible panels capable of adapting to surfaces of various types. PV systems are normally combined with special units for storing the electricity produced, made with storage batteries more or less evolved according to the available budget. These batteries accumulate energy during the day and then make it available for lighting and powering different loads during the night. Not only that, they can detect blackouts, automatically becoming the primary energy source in the event of a power failure. Unlike generators, storage batteries can deliver energy without the use of fuel and in a silent way.

Of equal importance to energy production is the transfer of energy, especially if this can take place wirelessly, without requiring the use of bulky and often annoying electrical cables. The wireless electricity transfer technique, based on the principle of electromagnetic induction, has returned to the fore in recent times thanks to two applications that have become priority. The first, relating to the consumer electronics sector, concerns the charging of battery-powered mobile devices (typically smartphones), which can be recharged simply by placing them on a suitable source capable of transferring electricity by conduction. The second main application concerns the recharging of batteries in electric and plug-in hybrid vehicles, carried out by means of devices that can be placed on the floor below the car or even integrated into the road surface. In addition to not requiring the connection of electrical cables, this solution proves to be very effective from a safety point of view, as it does not expose the user to the potential risk of contact with the high powers involved.

In this article, two highly innovative applications will be presented, relating to the exploitation of solar energy as a source of electricity and the transfer of wireless energy in various types of contexts.

Flexible solar PV

Power Roll, based in Sunderland (U.K.), has developed an innovative model of solar film capable of generating and storing energy. Lightweight and flexible, the solar film can adapt to any type of surface, producing electricity at a cost up to 20× lower than traditional PV panels. The new technology is based on a flexible film patterned with thousands of microgrooves. Each microgroove is a few microns thick, smaller than a human hair.

The advantages offered by this solution are:

  • Low cost: $0.03/W for the finished product
  • Low weight: 0.3 kg/m2
  • Easy installation and reduction of maintenance times
  • Sustainability, due to the use of fully recyclable materials and absence of rare earths
  • Adaptability: The same technique can be used either on the roofs of buildings or for powering small IoT sensors
  • High power density: 500 W/kg

As shown in Figure 1, the flexible film enables roll-to-roll manufacturing of capacitors using a range of dielectrics and storage materials. This capacitor technology, employed for storing energy, offers:

  • Ultra-low–cost manufacturing
  • Exceptional energy density
  • Multiple shapes and sizes with voltage and capacitance flexibility
  • Enhanced operating lifetime compared with wet electrolytic capacitors

The phases of the flexible solar film manufacturing process are outlined in Figure 1.

Manufacturing steps of a flexible solar PV
Figure 1: Manufacturing steps of a flexible solar PV

“Our technology has several advantages over flexible solar technology,” said Neil Spann, managing director at Power Roll. “It is extremely easy to produce. There are fewer steps in a manufacturing process. If you look at flexible photovoltaics, we can say that it is much more expensive. So in reality, the main advantage of our technology is cost-effectiveness. In terms of efficiency, our efficiency is good. But we don’t aim to make the highest-performing solar panel in the world. There are some technologies that push the devices upward. We are looking for a compromise, a good level of performance. So our current cell performance is 11%, which is somehow comparable to other flexible solar panels like organic photovoltaics. But we plan to increase it up to 20%. And thanks to the possibility of customization, there is a wide range of applications.”

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This article was originally published on EEWeb.


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