eChapters

Introduction

Humans primarily get their nourishment from agriculture. According to the most recent UN estimates, the population of the globe could increase to over 9.7 billion in 2050, and to fulfill the demands of an expanding population and a rising need for food, the energy demand in the agricultural sector has dramatically expanded. However, a farm that produces food needs a steady supply of energy to run the machinery, irrigation pumps, and other devices that are often powered by fossil fuels. Because of the ongoing demand for energy, there is growing concern that these fossil fuels will also run out soon (Aroonsrimorakotet al., 2020). Additionally, other global issues like climate change, water shortage, and energy security are just a few variables affecting agricultural production that require more environmentally friendly and sustainable farming methods As a result, it is crucial to maximize land usage and increase agricultural production through the deployment of cutting-edge farming techniques and new technology for both economic effectiveness and the best possible use of the limited resources available in the form of land. There are many distinct uses for renewable energy in agricultural systems. Renewable energy sources can also be used to generate electricity for a range of agricultural tasks (Torshizi and Mighani, 2017). Renewable energy can come from a variety of sources, but solar energy is the ideal option because it can be installed practically anywhere on the field, is pollution-free, and is also the most economical. Unlike the usage of fossil fuels, using solar energy doesn’t release greenhouse gases. For remote locations with erratic access to electricity, it is the best renewable energy choice. Applications for space and water heating, greenhouse heating, solar photovoltaic systems, and water pumps for irrigation using various forms of solar energy technology (Mekhilefet al., 2013). There are numerous benefits of using solar energy technologies, such as solar panel water pumping systems, aside from being free of fuel costs, solar panels also have lower maintenance costs and require fewer replacement components than generators powered by diesel engines. In order to meet the growing demand for agricultural products from the expanding population, agriculture is a sector that aspires to accept the usage of solar energy and reaps enormous benefits from it. Therefore, solar energy technology has emerged as a solution in order to boost economic benefits to farmers and improve the environment by reducing CO2 emissions into the atmosphere, thereby addressing the issues caused by a growing population and a shrinking amount of available resources (Aroonsrimorakot and Laiphrakpam, 2019). The potential for farmers to move from using fossil fuels to using renewable alternative energy, which might lead to produce superior in both quantity and quality of food produced in various kinds of agricultural farms (Bardi et al., 2013). The issue will get worse unless the farmers change their perception about the adoption of solar energy technologies. Therefore, it is advised for farmers to employ energy-saving tools for producing crops and to maximize land by installing solar energy systems because they are practical, affordable, and useful for a variety of tasks (Duprazet al., 2011). Since many people still solely rely on fossil fuels for energy and lack access to modern energy sources, in light of this, the current study was done to assess the level of awareness and adoption of solar energy in agricultural operations.

3.1 Introduction

The sun emits electromagnetic radiation, which is referred to as solar radiation. Every location on the Earth’s surface receives some sunlight during the course of the year, but the amount of solar radiation varies. On a daily basis, we see much less energy from the sun than it emits and incident upon the earth. In an hour and a half, the amount of sunlight that reaches the surface of the earth is enough to provide enough energy for an entire year. 

7.1 Introduction

A greenhouse is quasi-permanent structure, covered with a transparent or translucent material, ranging from simple homemade designs to sophisticated pre-g\fabricated structures, wherein the environment could be modified suitable for propagation or growing of plants. Materials used to construct a greenhouse frame may be wood, bamboo and steel or even aluminum. Covering can be glass or various rigid or flexible plastic materials. Depending on the covering material, different terminology have been used in the context of greenhouse structures as mentioned below:

Glasshouse: A greenhouse with glass as the covering material is called glasshouse

Polyhouse: It is a greenhouse with polyethylene as the covering material.

Solar heat plays a pivotal role in the functioning of greenhouses, serving as a primary energy source that influences the internal climate crucial for plant growth. The absorption of solar radiation by the greenhouse covering material initiates a complex process of heat transfer, involving conduction, convection, and radiation. This solar energy, once absorbed, contributes to elevating the temperature within the greenhouse, creating a favorable environment for plants. A fundamental understanding of solar heat dynamics is essential for optimizing greenhouse design and operational efficiency.

9.1 Introduction

Basically, for heating or cooling the space using solar energy, the solar energy is to be collected, stored and distributed properly in the space to be heated or removed from the space to be cooled. There are two basic approaches for solar houses, there are:

(a)Active solar house technology

(b)Passive solar house technology

In active approach, the solar energy is collected and stored in some separate solar energy collector and then energy is distributed in the space where heating is to be done using electrically operated pumps and fans coupled with radiator etc. The storage of solar energy in active solar house may be in the form of storage as sensible heat or storage as latent heat or chemical heat storage. As per requirement of heating the size of solar collector and storage system be decided. Generally, the active concepts of solar houses are used for heating purpose. Active concept can also be used for space cooling applications. Solar vapor compression and absorption system can be used for this purpose, essentially, this includes incorporation of solar heat collectors, thermal storage system, auxiliary heat supply system (to compensate intermittent nature of sun energy) and control systems. Further, there are three ways of solar space heating i.e. solar air systems, solar liquid systems and solar heat pump systems.

Introduction

In Indian Thar desert regions, excessive heat is the major problem that causes human and animal thermal discomfort. Space cooling is, therefore, the most desirable factor for the inhabitants. Various examples of dwellings responsive to climatic constraints are found in vernacular architecture throughout the world. Compact cellular layout with minimum external surface exposure to the sun, whitewashed surfaces to reduce absorptivity, blind external facades, courtyards, vegetation to provide humidity and shade, and heavy buildings constructed from high thermal capacity materials are common passive features in most of the arid regions. Wind towers for cooling ventilation are well known in Iranian and Middle East architecture, which along with cooling of the air by earth and water evaporation keep the building comfortable in hot periods. Building underground to take advantage of the large thermal storage capacity of the earth is also used in Tunisia and central Turkey.

9.1 Introduction

Solar energy can be directly converted into electrical energy through photovoltaic route. Energy conversion devices which are used to convert sun light into electricity by use of the photovoltaic effect are called solar cells. The advantages of solar cells are:

1. They are reliable, convenient and durable.
2. It is green, sustainable and pollution free technology.
3. Directly solar radiation can be converted into electricity (conversion of global solar light by flat plate photovoltaic).
4. Maintenance cost is quite low therefore suitable even in isolated and remote area, since no moving parts are involved.
5. Solar cells are quite compatible with almost all environments, respond instantaneously with solar radiation.
6. Considerable expected lifetime i.e. 20 years or even more.
7. No distribution system is required, because they are decentralized source of energy and located at the place of use.

8.1 Introduction

Solar energy can be directly converted into electrical energy. Energy conversion devices which are used to convert sun light into electricity by use of the photovoltaic effect are called solar cells. The advantages of solar cells are:

1.They are reliable, convenient and durable.

2.It is green, sustainable and pollution free technology.

3.Directly solar radiation can be converted into electricity (conversion of global solar light by flat plate photovoltaic).

4.Maintenance cost is quite low therefore suitable even in isolated and remote area, since no moving parts are involved.

5.Solar cells are quite compatible with almost all environments, respond instantaneously with solar radiation.

6.Considerable expected lifetime i.e. 20 years or even more.

Introduction

Agriculture has been the back bone of Indian economy and culture and it will be continued to remain as such for a long time in future. Parallel to this, energy security of a country is also very important and efforts have been given on renewable energy utilization since the fossil fuel based energy is depleting at a very fast rate. In agricultural fields, considerable amount of energy is used to do different field activities e.g. ploughing, irrigation through pumps, intercultural operations, spraying of agricultural chemicals for plant protection, harvesting, post-harvest processing etc. Therefore, there is also need to replace the conventional energy source with renewable sources to operate above mentioned agricultural activities.

Approximately, 35% of the crop production is damaged if pest and diseases are not controlled at right time. Uniform spraying of liquid formulations throughout the crop field is very important for effective control of pest and diseases. Using sprayer, liquid pesticide formulations are generally broken down to minute droplets of effective size for uniform distribution over a large surface area. Different types of sprayers are used in agricultural field based on different requirements.

Introduction

Water is the primary source of life for mankind and one of the most basic necessities for crop production. The demand for water to irrigate the crops is increasing. For sustainable production from agricultural farms, irrigating the crops at right stages is highly important. Even in rainfed situation, lifesaving irrigation during long dry spell has also been found beneficial for crop survival and to obtain the targeted yield. Considering the depletion of groundwater below the critical zone in most part of the country, energy intensive pumping for irrigation is not a viable option. Therefore utilization of available runoff water through surface storage systems followed by pumping may be a potential solution to achieve the set goal of ‘crop per drop’ mission. In this connection, micro-irrigation system including drippers and sprinklers is of great importance. However, ensured power supply is essential to operate the micro-irrigation system even in remote areas. Reliable solar photovoltaic (PV) pumps are now emerging in the market and are rapidly becoming more attractive than the traditional power sources. These technologies, powered by renewable energy sources, are especially useful in remote locations where a steady fuel supply or electricity supply is problematic. About 16 million electric pumps and 7 million diesel pumps are in operations in the country for irrigation purpose; however they are highly energy intensive. Moreover, diesel operated and electrified pumps directly or indirectly emit large amount of CO₂ gas in atmosphere and hence are not environment friendly. To meet the energy demand for irrigation, solar PV pumps have been introduced under the off-grid power generation category of National Solar Mission (NSM) with a target of 1000 MW by the end of phase II (2013-2017). The target has been revised in 2015 to a total grid connected solar power generation of 1,00,000 MW comprising 40,000 MW roof top generation and 60,000 MW grid connected solar power plants (Resolution of MNRE, Govt of India, No. 30/80/2014-15/ NSM dated 1^st July 2015).

The Sun is the primary source of heat to the Earth and its atmosphere. The heat received from other celestial bodies as well as the interior of the Earth is rather too significant. The distance that separates the Earth from the Sun is about 149.0 million km. The diameter of the Sun measures roughly about 1.3824 million km. The surface temperature of the Sun is estimated between 5500^o C and 6100^o C. (or 5762^o K).

The weight of the sun is about 1.9 X 10 30kg. The radius is 6.97 X 10 8 m or the diameter of the sun is 14 X 10 5 km. The mass of the earth is 6 X 10 24 kg, the radius is 6.4 X 10 6 m. The gravitational force of the earth is 9.81m/s². Whereas the sun‘s attractive force is 274m/s². This is 25 times higher than earth’s gravitational force.

The process through which heat energy is transferred from a body at higher temperature to a body at lower temperature without any material medium between the two bodies is x called radiation. The outer surface of the the Sun is at higher temperature compared to the surface of the earth. Solar radiation is the electromagnetic energy emitted by the Sun. It is the primary source of energy for the Earth’s climate system, driving atmospheric and oceanic circulation, influencing weather patterns, and sustaining life through photosynthesis.2 This energy  travelsthrough space as electromagnetic waves, encompassing a broad spectrum of wavelengths, from high-energy gamma rays and X-rays to ultraviolet, visible, infrared, and radio waves. The portion of this spectrum that reaches the Earth’s surface is crucial for a multitude of processes, making the study of solar radiation fundamental to understanding our planet’s environment. This introduction will lay the groundwork for exploring the characteristics, distribution, and interaction of solar radiation with the Earth’s atmosphere and surface.
4.1. Wave Length of Radiation
The wavelength of radiation refers to the distance between two consecutive peaks or troughs of a wave. It’s a measure of the length of one complete cycle of the wave (Fig. 4.1).

Sun is the prime source of energy injected into the earth’s atmosphere. The sun is the nearest star to the earth. It is a hot ball of glowing gases at the heart of the solar system. Its radiant energy is practically the only energy source to the earth. Very small and insignificant quantities of energy are available from other sources such as the interior of the earth, the moon, and other stars. Without the sun’s intense energy and heat, there would be no life on earth.

NATURE AND PROPERTIES OF SOLAR RADIATION

The mean distance of the sun from the earth, also known as one astronomical unit (1 AU), is approximately 1.496 × 10⁸ km, though the distance varies as the earth revolves round the sun in an elliptical orbit. At this average distance, light travels from the sun to earth in about 8 minutes and 19 seconds. The energy of the sunlight supports almost all life on earth by photosynthesis, and drives earth’s climate and weather. The minimum sun-earth distance is about 0.983 AU and the maximum is approximately 1.017 AU. The earth is at its closest point to the sun (perihelion) on around January 3 and at its farthest point (aphelion) on around July 4.

Sun is the prime source of energy injected into the earth’s atmosphere. The sun is the nearest star to the earth. It is a hot ball of glowing gases at the heart of the solar system. Its radiant energy is practically the only energy source to the earth. Very small and insignificant quantities of energy are available from other sources such as the interior of the earth, the moon, and other stars. Without the sun’s intense energy and heat, there would be no life on earth.

The mean distance of the sun from the earth, also known as one astronomical unit (1 AU), is approximately 1.496 × 10⁸ km, though the distance varies as the earth revolves round the sun in an elliptical orbit. At this average distance, light travels from the sun to earth in about 8 minutes and 19 seconds. The energy of the sunlight supports almost all life on earth by photosynthesis, and drives earth’s climate and weather. The minimum sun-earth distance is about 0.983 AU and the maximum is approximately 1.017 AU. The earth is at its closest point to the sun (perihelion) on around January 3 and at its farthest point (aphelion) on around July 4.

The sun makes up about 99.86% of the mass of the entire solar system. The visible disk or photosphere has a radius of 6.599 × 10⁵ km, and the solar mass is 1.989 × 10³⁰ kg. The sun is a completely gaseous body. The chemical composition (by mass) of the outer layers of sun is 71 per cent hydrogen, 26.5 per cent helium, and 2.5 per cent heavier elements like oxygen, carbon, neon, and iron among others. Since the sun is not a solid body, different parts of the sun rotate at different rates. At the equator, the sun spins once about every 25 earth days, but at its poles the sun rotates once on its axis every 36 days.

The process through which heat energy is transferred from a body at higher temperature to a body at lower temperature without any material medium between the two bodies is x called radiation. The outer surface of the the Sun is at higher temperature compared to the surface of the earth. Solar radiation is the electromagnetic energy emitted by the Sun. It is the primary source of energy for the Earth’s climate system, driving atmospheric and oceanic circulation, influencing weather patterns, and sustaining life through photosynthesis.2 This energy travels through space as electromagnetic waves, encompassing a broad spectrum of wavelengths, from high-energy gamma rays and X-rays to ultraviolet, visible, infrared, and radio waves. The portion of this spectrum that reaches the Earth’s surface is crucial for a multitude of processes, making thestudy of solar radiation fundamental to understanding our planet’s environment.  This introduction will lay the groundwork for exploring the characteristics, distribution, and interaction of solar radiation with the Earth’s atmosphere and surface.
5.1. Wave length of Radiation
The wavelength of radiation refers to the distance between two consecutive peaks or troughs of a wave. It’s a measure of the length of one complete cycle of the wave

3.1 The Sun

The Sun is a star. It is a huge, spinning, glowing sphere of hot gas. It appears so much larger and brighter than the other stars because we are so close to it. The Sun is the center of our Solar System and contains most of the mass in the Solar System. All of the planets in our Solar System, including Earth, orbit around the Sun. In sun the energy generation is a multi-step process of thermo-nuclear fusion reactions. In the thermo nuclear fusion hydrogen (four protons) combines to form helium (one helium nucleus). The mass of the helium nucleus is less than that of four hydrogen protons and mass having been lost in the reaction is converted to energy. The reaction is represented as

5.1 Introduction

Energy in the form of heat is one of the main energy requirements in domestic, agricultural, industrial and commercial sector of our economy. From an enduse point of view, solar thermal energy finds its application in these areas. Solar thermal energy devices convert radiant energy of the sun into thermal energy for different productive works. In fact, solar energy consists of infrared radiation, it is characteristics of infrared radiation that whenever it falls on any object, it converts into thermal heat energy.

The conversion of sun light into thermal energy is easily or conveniently achieved by means of a metallic or plastic cover, painted black with ordinary black board paint or having selected coating over it and covered with one- or double-glazing cover for transmitting solar radiation inside it. This metallic cover is known as absorber, below it either channels or pipes or passages for allowing entry of water or air are provided, through which heat energy is transferred to working medium either air or water. The absorber plate is covered with suitable thickness of insulating material on its back or sides for preventing loss of heat from the absorber plate. This complete system is enclosed in an airtight box. When exposed to solar radiations, the blackened metallic surface absorbs solar energy and converts into heat. This heat could be used for cooking of food, heating of water and air, evaporation of moisture form the grains etc. In fact, absorber works on the principle of black body, which absorbs maximum and a good absorber, is a good emitter. Hence generated heat could be utilized for different applications.

Greenhouse essentially functions based on solar energy to control environment for protecting cultivation from adverse condition. Computer simulation and mathematical modeling are important tools for determining the energy efficient design as well as predicting the overall system performance. The greenhouse climate may be used for crop drying, distillation, biogas plant heating, space conditioning, and aquaculture. Thus, any required configuration of greenhouse can be thermally modeled for predicting and optimizing the performance. The solar energy based greenhouse modeling are useful in evaluation of various applications like greenhouse heating, greenhouse cooling, greenhouse drying and aquaculture greenhouse. Greenhouse clubbed with ground air collector increase in plant and ambient temperature of 5–7°C during night in winter. Whereas, using evaporative cooling pad with greenhouse reduces the ambient temperature of 4–5°C during midday summer. A greenhouse can be very well used for large-scale crop drying, while not in use for cultivation. Some other applications such as covered crop drying and aquaculture are also discussed.

Abstract

The primary commercial energy sources such as coal, oil and natural gas poses an enormous challenge to our development goals including environmental degradation, as India is not well endowed with these exhaustible natural resources. Further, these conventional sources are also not available in right quantity and producing environmental pollution manifold in land, air and water. There are number of unit operations in food processing and value addition consuming bulk of conventional energy sources where renewable energy sources can easily be integrated for energy conservation and environment protection. There is significant potential for application of Renewable Energy Sources in different unit operation of food processing including drying of food products for energy conservation and for reducing hydrocarbon emissions.

Introduction 
In a time when the world is in dire need of sustainable energy solutions, investigating biofuels becomes an essential path to supplying the always expanding supply[1]. This book chapter explores the dynamic world of solid and liquid biofuels, providing a thorough analysis of their properties, methods of production, uses, and wider ramifications in relation to renewable energy sources. Setting the scene, the introduction clarifies the role of biofuels in the larger context of renewable energy. Exploring solid and liquid biofuels becomes critical as the globe struggles with issues like climate change, depleting fossil fuel reserves, and the need to switch to cleaner energy sources[2]. These biofuels, which are defined as energy carriers made from biomass, offer a viable substitute and have the capacity to both reduce environmental impact and promote energy security. As the chapter progresses, biofuels are divided into two main categories: liquid and solid. Biofuels that are solid, such as wood, agricultural leftovers, pellets, and briquettes, serve as a starting point for investigating alternative energy sources. This section walks readers through the complexities involved in producing solid biofuel, including harvesting, pre-treatment, and creative pelletization methods. By doing this, it highlights the renewable nature of solid biofuels and their ability to lower greenhouse gas emissions, highlighting their benefits for the environment. Simultaneously, difficulties associated with its application, ranging from administrative worries to land use issues, are examined closely. Turning its attention to liquid biofuels, the chapter tells the story of ethanol, biodiesel, and advanced biofuels. By examining the choice of feedstock, manufacturing procedures, and real-world uses, it highlights the adaptability of liquid biofuels in the energy system. Although they are not without difficulties related to land use, food production, and water use, their ability to function with current infrastructure and their critical role in improving energy security stand out as distinguishing characteristics[3].