Maurizio Di Paolo Emilio on Energy Harvesting

18 May 2020

Previously a researcher of gravitational waves, Maurizio is the Editor in Chief of Power Electronics News. We discuss energy harvesting techniques and their applicability to IoT. This episode was recorded in Apr 2020.

Yuval Boger (Chief Marketing Officer, Wi-Charge, @TheChargeGuy): Hello Maurizio, and thanks for joining me today.

Maurizio Di Paolo Emilio: Hello Yuval thanks for inviting me to this podcast.

Yuval: So who are you and what do you do?

Maurizio: So I am Maurizio, and I am the Editor in Chief of Power Electronics News for Aspencore channel. And I am an editor and I like to write about power, technology in general and automotive IoT and this is my passion.

Yuval: And you’re calling from Italy today?

Maurizio: Yes, I’m from Italy, I’m based in Italy, in Pescara, exactly. Pescara is a small city on the East Coast, just on the same line of Rome, in front of Croatia.

Yuval: And how are you doing, with the corona? Are you still at home?

Maurizio: Yes, we are still at home, lockdown until to May 3rd, and then we will see.

Yuval: Excellent. Well, I hope you stay safe.

Maurizio: Thank you.

Yuval: Maurizio, I’ve done this podcast for quite some time, and this is the first time I have someone who did research in gravitational waves in space research. So how did you get from gravitational waves to being an editor?

Maurizio: So it’s a long story. So I started with Physics because I am a physicist too. And, during that period, during my Ph.D., I worked with the LIGO and VIRGO for the detection of gravitational waves. And, then I have decided to change my work, my job because I like to share with each one, my idea about the technology, about electronics. And after my Ph.D., after my research on gravitational waves, but also others I decided to start with a new job with the technical writing for Italia magazines just last years, but also as now for English magazines, E-times, Power Electronics News, and so on.

Yuval: Great, so obviously I understand the physics and I think you write a lot about IoT and about energy. Is that correct?

Maurizio: Yes, correct.

Yuval: Excellent. So, it seems like there are many approaches to energy harvesting I think, I saw you write about WiFi harvesting, about the ambient light, about harvesting energy from the movement of doors and so on.

Maurizio: Yeah. Could you tell me a little bit what you think about sort of the advantages, disadvantages and how much power can you get using these methods? [Maurizio]: Yeah, so, energy harvesting is a way to obtain electrical energy already available in the world in this environment. So, this concept can represent a good solution for IoT devices.

In particular for ultra-low power IoT devices. In recent years, much attention has been placed on the Internet of Things. So, the whole range of commercial and industrial devices interconnected by wireless protocols such as Bluetooth to WiFi, Zigbee just for smart home etc. So, energy harvesting could be very useful to power these devices by using green energy. So, it can help, because devices can use power generation elements such as solar cells for example, or others for converting a type of source in electric current electric sources. So, we have a lot of energy harvesting, for example, solar radiation is a green, is a free and has the advantage to be a green energy of course, as I told but to guarantee the possibility to have, don’t have the production of polluting waste. So, the limits can maybe define it in several waves. So, I know that solar energy is discontinuous caused by the alteration of the day and the night and also with the conduction conditions.

So, the hardware can be a low intensity, which implies the need to have large areas of energy storage for example, battery. But in this way, it’s very important to consider the efficiency of the solar cells. If we have a good efficiency, about solar cells, we can convert a lot of photons in electrical current and to power in this way, the IoT devices, for example, ultra-low power IoT devices. So, a part of solar energy, we have also RF energy harvesting, but we could only get to microwatts about RF energy harvesting. Not good to use, for example, for wireless charging, so, because it’s very, very low, but also for a couple of reasons for safety for example, because RF signal have diffraction. In this way for example, a good helmet could be infrared light that can offer a good combination about power, distance efficiency and safety.

The power in this way is delivered with millimeter precision using invisible rays of light, infrared light. And the transmitter can use the standard power supply and can power the devices by using small photovoltaic cells to convert the light received into a good usable electricity good usable electric current.

Yuval: So, you’re saying that there’s a wide range of applications. If you need microwatts of energy, 1 million of a watt for a very, very small sensor, then maybe RF charging makes sense. You can consider solar energy especially if you’re outdoor, and if don’t need continuous charging. And then you mentioned, of course, something like what Wi-Charge does, which is infrared, which can get you to watts of energy. So there’s actually a very big range. Now, when you look at IoT devices, would it be correct to say that they are getting more intelligent, they want to do more processing at the edge, they want to send maybe more and more information? Is that correct?

Maurizio:  Yes. It is correct? So the Internet of Things, or IoT, so refers to the billions of, physical devices around the world that are now connected to the internet. And all of these devices are collecting and sharing data. Thanks also to the super chip computer, we have now a lot of wireless sensor network. Because just by using a small, single-board computer that we know because we have a lot of these, we can connect it easily to sensors and a CPU and it’s possible to turn anything. Connecting all these different objects and having a sensor, we can add to device a new level of digital intelligence that can enable us to communicate real-time data without the involve a human without involving people.

So, of course, as you told your IoT devices are used to acquire process, transmit data and to control processes in industrial, in automotive, in several automation for example. They are designed for of course everyday use by consumers and it’s important to take care of security officials about security aspects about these IoT. So, the important element when you describe when you speak about IoT device is security but also power. Because, a lot of data and a lot of digital processing, inside the IoT devices needs to have strong security feature of course, but need more power and need more power means to have battery means to have to understand how to charge, in easy way, the battery and so on. [Yuval]: Now, in terms of IoT architecture, I think that some IoT devices are self-contained that they do both the processing and then also the communication to the sort of IoT center, where the information is collected.

And in other architectures, there is sometimes the hub, a very nearby hub and then maybe the IoT devices communicate via BLE, or ZigBee or something like that. Do you see one architecture becoming more popular than the others meaning standalone versus hub-and-spoke? [Maurizio]: So I think that it’s important to consider good hardware just a good balance about hardware and software about standalone or not standalone depends on the application. I think that it’s important for IoT devices to guarantee the acquisition data, the processing, by using a specific protocol if you are sending data in the cloud, so by using WiFi, for example.

So depends on application, but it’s important in this case, to guarantee, to have a good microcontroller that can be helped the acquisition of data acquisition of Internet of Things. In fact, one of the main challenges for the designer is to assess the energy factor, in this case, estimating the energy requirement and designing its power configurator for each device. So, these can be defined also the stand or not alone about the IoT device. But in general, I think and because we should consider also if it’s important to have battery accumulator, a method of accumulation or not.

So, in general, energy harvesting can help to remove battery until at a certain point of course, because we should understand the level of energy, the level of power than we have converted. And, also the sensor because we should use a lot of sensors of which sensor and the position if indoor or outdoor.

Yuval: Understood. So, as we get close to the end of our discussion, so, if you are controlling the R&D of light charge, what would you have us focus on in the next 18 to 24 months? What would you want us to do more than anything else if you could wish and we would just execute?

Maurizio: So, I would like to see more application about that, in particular in outdoor, I think that is difficult, but also to have more application for high power, because for low power, I think that the technology is very good. And we see you describe to me time ago a lot of the application about that and I think that we can see a lot of these for high power and to have good control of the power for several applications not only for indoor but also for outdoor.

But for outdoor we should check the implementation by considering the solar the photon solar in outdoor. So the longer range wireless power supply using infrared light allows to freely deliver power without the need for cable and this is important, to guarantee a good application of energy harvesting without the cables. I see a lot of applications for high power.

Yuval: Very good. So Maurizio how can people get in touch with you or learn more about the work that you’re doing?

Maurizio:  So, I cover several technical aspects of power in several Aspencore channels, powerelectronicsnews.com for example, and also eweb.com. Where you can see a lot of articles, but also on eetimes.eu and eetimes.com. Where I write about power and technology.

Yuval: Very good. Well, thank you very much for joining me today.

Maurizio: Thank you so much and have a nice weekend. And stay safe, take care.

Yuval: Stay safe, take care, bye.

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