**2. Batteries, problems, and solutions**

Batteries have played an important role for decades both in small-scale energy storage and in high-scale energy storage. For small-scale (e.g., video/audio players, medical equipment,

<sup>1</sup> Connected Things: an IoT-device connected to the Internet.

power tools, meters and data loggers and remote sensors), batteries enable portable use [3] and free the device from power cords and also from being near to an energy power socket. However, the batteries in these devices are discharged and then recharged periodically, meaning that the portability feature takes the fixed costs of replacement or of recharging as a disadvantage.

using connected computers [1, 2]. For its turn, the IoT revolution has its premise that any object or thing (like a light lamp, a door, a refrigerator, a garment, etc.) can directly originate and send data to the Internet without any human interaction. For example, a sensor in a connected light lamp may automatically order a new one when it is near the end of life. In short,

As the world population is estimated to reach 8 billion by 2020 and supposing that each indi-

connected Things by this time. However, the IoT revolution does not relate only to people, but all kinds of enterprises and industries (e.g., all products of a given industry may be con-

From the energy point of view, deploying IoT devices in urban or industrial environments is not a dramatic problem since chemical batteries are easily available and electrical outlets are

Nevertheless, it is important to highlight that this huge number of connected Things would need batteries to work and, more importantly, chemical batteries wear out, even the recharge-

From the point of view of urban life, IoT is an extraordinary technology despite the chemical batteries issue where massive recycling campaigns worldwide or even recycling laws can

From the point of view of non-urban life, as rural, forest and other natural environments, the IoT will certainly be a very interesting technology. We have to be carefully prepared to take advantage of such technology because it could be hard or impossible to take back batteries for

From this perspective, the future may bring an Internet of Natural Things (IoNaT). For example, a Thing could be a tree, a fruit, a submerged stone in a river, etc. However, IoNaT presents some challenges as radio frequency (RF) communications in the presence of vegetation and powering the electronics of the Things using batteries. Considering the battery issue, deploying them directly into the nature is certainly not an environment-friendly option. The

In this chapter, we suggest different and innovative natural, easily available, energy sources and the main processes to harvest them. The use of these natural and revolutionary technolo-

Batteries have played an important role for decades both in small-scale energy storage and in high-scale energy storage. For small-scale (e.g., video/audio players, medical equipment,

recycling from battery-powered IoT devices deployed directly into the environment.

question is how to power the IoNaT using a non-battery approach.

**2. Batteries, problems, and solutions**

Connected Things: an IoT-device connected to the Internet.

1

gies may ensure that monitored data could be obtained in a sustainable way.

able ones, and, if not properly disposed, they can be harmful to the environment.

, we can compute 40 billion of

the Internet is based on human-entered data and the IoT on Thing-entered data.

vidual may be related to about five different connected Things<sup>1</sup>

nected). In this sense, that number could reach trillions.

almost everywhere to recharge them.

26 Energy Systems and Environment

minimize its damage to nature.

*Nevertheless, batteries do not free the device users from power cords since they still need them to connect the battery charger to energy power socket. In this sense, charged batteries works as an invisible cable or, better, as an energy transportation system since the energy source is distant from the device. Ever the most modern wireless charging station based on Inductive Power Transfer* [42] *need its base to be plugged to an energy power socket.*

Batteries are devices that convert the chemical energy contained in their active materials, immersed in an electrolyte solution, directly into electric energy by means of electrochemical oxidation–reduction (redox) reactions [4]. They come in two different forms, namely, disposable or primary batteries and secondary or rechargeable batteries [5]. The reactions are reversible in secondary batteries so that discharging the batteries returns the electrodes to their pre-charged states [5].

Many different battery chemicals are used as active materials, namely, lead, nickel, cadmium, lithium, zinc, manganese, mercury, and others and as electrolyte, namely, acid, potassium hydroxide, organic carbonates, and others [4, 5]. In addition, it is important to observe that electrolyte can be in liquid, gel (which means that it can leak) and solid form [4], and those batteries are packed in metal and plastic cases or containers.

All parts of a battery, as shown in **Figure 1**, are made of pure or compound chemical material where some can be toxic, environmentally unfriendly, or not sustainable. As a result, if batteries are not properly disposed, then their toxic material can leak and contaminate the soil and water, and some of the materials can accumulate into the surrounding environment. Some of these materials can also contaminate humans and the wildlife.

Researchers are continually inventing lower cost and longer life battery chemistries and as batteries become integral part of high-volume products, economies of scale will reduce costs [3]. However, splitting the battery market into small-battery and of large-battery relating it to the IoT industry and the electric vehicle (EV) industry, respectively, it is expected between 22 billion and 30 billion of connected devices ("Things") by the year 2020 [7] and, for electric cars, it may achieve globally between 9 million and 20 million by the year 2020 [8]. That means that billions or trillions of small-batteries and millions of large-batteries will be manufactured, deployed and the wasted ones may be dumped on the nature if not properly recycled. The worst scenario may be one of the IoT worn-out batteries, since the electric vehicle's wear-out battery regulations tend to be extremely rigorous with the carmakers holding responsibilities for them, which differs from the IoT scenario, where responsibility holds on individuals.

In order to show a fair comparison between the IoT and EV battery scenarios, we can normalize the expected number of batteries by the year 2020, using the standard 18,650 cells as normalization base. That is a standard type of Li-ion (LiMn<sup>2</sup> O4 ) battery where 18 indicates that the cell has a diameter of 18 mm, 65 indicates the height of the cell is 65 mm, and 0 indicates

impact on the environment. As a result, we can consider that the IoT battery scenario has to

Energy Resources in Agriculture and Forestry: How to be Prepared for the Internet of Things…

http://dx.doi.org/10.5772/intechopen.74940

29

An actual solution for this issue is to eliminate the need of batteries of IoT devices generating their energy on the spot where the devices are. Such a solution is theoretically simple, but in practice it needs lots of scientific and technological researches. For instance, how to power an IoT in the middle of an office or on a street? That is where the development of energy harvest-

In general, to harness energy from the environment is not a novelty, for instance, solar and wind energies are harnessed for centuries. Despite harnessing energy to high-power applications like industries and cities, which wind and solar power plants are good examples, harnessing energy to low or ultra-low-power applications gave rise to the expression "Energy

Energy harvesting is defined as the process of capturing very small amounts of energy from naturally occurring energy sources surrounding the low-power electronic device to be powered, accumulating, storing and converting them to electrical energy for powering the device

*The possibility to harvest energy from the environment to power electronic circuits became a reality due to the advanced in microelectronic technologies that occurred during the last decades. With this advance, the size of electronic devices has becoming so small, make possible the development of tiny portable devices integrated in objects like watches, glasses, clothes, etc., as well as the energy needed to* 

Some possible energy sources can be solar light, thermal, mechanical vibration, electromagnetic waves, and so on. For example, a wireless seismic sensor powered by solar cells was the first to be installed in a bridge in Corinth, Greece [17]. Another example, bridges vibrate when vehicles travel over them, and such vibrations have a kinetic energy that can be used to

be considered as harmful to the nature as well as the EV batteries.

ing system takes place.

**3. Energy harvesting**

*power these devices has decreased drastically* [16]*.*

**Figure 2.** Basic structure of an energy harvesting system.

Harvesting."

[11–17].

generate electricity [4].

**Figure 1.** Internal structural design of a cylindrical Ni-cd battery [6]. Copyright Wiley-VCH Verlag GmbH & co. KGaA. Reproduced with permission.

the cell is a cylindrical battery [9]) and considering, as an EV default battery size, a battery formed by 6831 18,650 cells. That is also exactly the battery used in the luxury Roadster introduced by Tesla Motors [10].

In this way, it is expected between 3.2 million and 4.3 million of EV-battery-equivalent connected devices by 2020 at which means that IoT battery impact is about 25% of the EV battery impact on the environment. As a result, we can consider that the IoT battery scenario has to be considered as harmful to the nature as well as the EV batteries.

An actual solution for this issue is to eliminate the need of batteries of IoT devices generating their energy on the spot where the devices are. Such a solution is theoretically simple, but in practice it needs lots of scientific and technological researches. For instance, how to power an IoT in the middle of an office or on a street? That is where the development of energy harvesting system takes place.
