Nowadays, the demand for energy in the agricultural sector is increasing to meet the demands of the growing population. The currently available energy sources are either insufficient or near to depletion. Due to this situation, there is an increasing interest among agro-researchers and experts in finding new sources of energy.
The sun is an eternal center of energy that converts solar fuel into solar energy through a fusion process since the beginning of the solar system. Solar energy is growing as a popular renewable energy source to meet current energy demands. Solar energy has several features that farmers can utilize directly and indirectly. The 21st century has witnessed a growing shift from traditional energy to renewable energy to ensure a sustainable and safe future while tackling climate change’s severe impacts.
Solar energy is one of the best renewable energy sources as it is free, abundant, and non-polluting. The agriculture sector has slowly begun to take advantage of the many benefits of solar energy. However, traditional sources of energy are still in use worldwide. Thus, there is a need for further research and awareness on the topic of ‘Solar Agriculture’- its uses and benefits.
Solar Agriculture: Concept of Agrovoltaics or Agrophotovoltaics (APV)
Agrovoltaics is the system in which both solar arrays and food crops coexist on the same land. Armin Zastrow and the Founder of the Fraunhofer Institute for Solar Energy Systems, Adolf Goetzberger, pioneered the concept of Agrovoltacis back in 1981. They came up with the concept to design and adapt solar power panels to enable additional crop production in the same area.
During the 1980s, photovoltaics was expensive, while computers were rare. The two experts worked out the equations for a dual-use system together on programmable pocket calculators. They published a paper titled ‘Kartoffeln unterm Kollektor‘ (Potatoes under Panels). Goetzberger and Zastrow’s idea was to raise the solar collectors to 2m above the surface and increase the distance between them to prevent any excessive shading of the crops. They assumed that the system would require just one-third of the incoming radiation and that further technical improvements could increase their suitability for use in food production.
The world was ready to accept the concept of agrophotovoltaics only thirty-five years later, being implemented in several projects and pilot plants globally. According to calculations, the application of agrovoltaic approach can help increase framer’s incomes by over 30 percent, if the selection of suitable crops cuts down the yield losses through shading effects.
The prices of solar panels have decreased by more than 50 percent since 2010. Thus, farmers find it much more profitable to put their land under solar arrays or grow crops for fuel instead of food. The shift for any farmer makes economic sense. However, overall, it sets up a zero-sum game that could weaken the goal of international food security.
The concept of agrovoltaics is one way out of the problem. However, it needs to work at an equal scale with the world’s growing demand for energy and food. Agrovoltaic systems also have potential in arid regions where synergistic effects may occur. The system provides a wide range of benefits such as water saving, economic viability, reduced soil evaporation, improved yield stability, etc.
Scope of Solar Energy in Agriculture
As solar energy is the cheapest and most prominent energy source on earth, it will be able to fulfill energy supply and provisions at farms quickly. Several solar energy systems and devices are developed and available for agriculture applications:
Solar PV operated pumping system or water-lifting: Solar-powered pumping systems can operate pressurized irrigation systems efficiently. In irrigation canals, solar pumps may be pretty helpful as water lifting systems. They also enable equal water distribution in areas where traditional water systems do not access, like elevated hilly lands.
Solar spraying machines: Solar pesticide sprayer machines are designed especially for small farmers, it enables them to improve their productivity. The machines are easy to hold and handle and come along with rechargeable batteries and direct solar illumination options. Pesticide spraying usually happens during the daytime; thus, the machines can capture solar power, avoiding the installation of new batteries.
Solar seed sowing machines: Solar-powered seed sowing and spreading machines provide an easy and appropriate way of sowing seeds. These machines come in handy in areas where traditional machinery can not be available. Solar-powered automatic machines such as these will enable farmers to avoid heavy-duty machines. Radio Frequency (RF) controlled solar sowing machines are currently developing to help farmers sow seeds at a controlled depth and distance between each seed.
Solar crop drying: Solar energy can be effectively used to dry agricultural products such as grains, carrots, potatoes, etc. Solar dryers are two types depending upon heating arrangements, active and passive dryers. Active dryers deal with solar energy heat transfer while passive dryers deal will heat circulation in a natural way by force or wind pressure.
Solar greenhouse heating: Greenhouses worldwide usually rely on traditional energy sources like gas or oil for heating purposes. However, now solar-powered greenhouses (SGHs) have arrived in the market and are built to use solar energy for both lighting and heating.
Solar-powered tractors: Tractors, one of the crucial types of machinery used in agriculture, generally consume a lot of oil. Solar-powered tractors function directly under the sun by consuming solar energy through PV systems during the day.
Solar energy, including the concept of APV, offers several opportunities for the agricultural sector, depending on regional and climatic conditions. Technologies at agricultural farms continue to improve rapidly to help facilitate farmers. However, the rapid increase of technology in agriculture requires many energy sources. The application of solar power will significantly help overcome energy and cost issues. Without its application, current energy sources would not be able to handle the energy demand and consumption of the growing population. Solar-powered energy is a reliable and trustful source to compensate for all requirements of energy for the future.