There are 3 sources of renewable energy on the planet earth they are solar radiation, the gravitational force from the planetary movements in the form of tidal energy, and heat from the earth’s core that is geothermal energy. Energy from solar radiation constitutes 99.99% of the total renewable energy on the planet earth.
Solar energy is the energy got by converting solar radiation into other forms of energy. The main solar energy is got by photovoltaic (PV), solar thermal electricity, and solar cooling and heating. In agriculture, solar energy is used for irrigation, cooling, and drying.
Table of Contents
- 0.1 1.Solar-powered irrigation –
- 0.2 2.Solar drying –
- 0.3 3.Solar cooling –
- 0.4 4.Solar Photovoltaic in agriculture –
- 1 The solar business is helping farmers in India
1.Solar-powered irrigation –
This irrigation is found to be successful in many countries including India. The photovoltaic pumping is used for the irrigation of large fertile and arable land.
2.Solar drying –
It is noted that many of the food and crops get destroyed in open-air drying due to inadequate infrastructure and insufficient processing capabilities etc. Due to this the fruits and vegetables get spoiled. Drying is carried out after harvest time when the local markets are saturated with fruits and vegetables produce. Drying with thermal energy enables longer times and easier transportation.
There are various types of solar dryers available, they are direct drying which is also called solar box dryer, indirect drying which is also called solar cabinet dryer, mixed-mode dryers such as solar tunnel dryer, and hybrid dryer which uses the combination of solar and biomass cabinet dryer. The solar dryers and cabinet dryers are based on natural air convection and the solar tunnel dryers are based on forced convection which requires a fan.
3.Solar cooling –
This is a very niche market in the agriculture business. The market has grown exponentially in recent years. This is employed for cooling and refrigerating the fruits and vegetables and other agricultural products for preserving the food products. Solar-powered cooling is employed highly in rural areas where there is less energy from the electric grid.
4.Solar Photovoltaic in agriculture –
This is increasingly used in less power-intensive units. such as irrigation, refrigeration of the agricultural products, electric fencing, poultry lighting, pest control and aeration for the aquacultures, etc
The solar business is helping farmers in India
Agricultural application of solar energy
1.Crop and Grain drying –
The solar dryers are used in large quantities to dry the fruits and vegetables. The need for these dryers arises as the natural air drying is subjected to damage from rodents, birds, wind, and rain. Also, there is the contamination of the food due to windblown dust and dirt. The solar dryers protect the produce by reducing the losses, dry uniformly, and faster and produce better quality heating.
The main parts of the solar dryers are collectors, racks, and enclosures. The solar collector is the gazed box with black colored painted surfaces that absorbs heat from the solar energy and dries the air. The air n the collector is done by natural convection or by forced dry air from the fan. The size of the collector and rate of airflow depends on various factors such as the amount of material being dried, the moisture content of the materials, the humidity in the air, and the average amount of solar radiation available in the particular season of the year.
2.Space and water heating –
This technique is used in agriculture in heating the air and water for cleaning the agricultural produce.
3.Greenhouse heating –
The conventional greenhouse uses solar energy for lighting and gas or oil for heating the greenhouse. However, the solar greenhouse uses solar energy for heating and lighting the greenhouse. The solar greenhouse has thermal mass to collect and store the solar heat energy and uses insulation to protect the greenhouse heating during the night and cloudy days. Often the oil and gas-based greenhouse heating is used as a backup. The passive solar greenhouse is used by small growers. Here the oil and gas are supplemented for heating. In an active solar greenhouse, heating uses the solar energy heated air and water from storage or collection areas to the other regions of the greenhouse.
4.Photovoltaic solar energy –
This is used to convert the direct solar light energy into electricity. PV is used where there is direct solar energy on the PV modules. They can power the electric appliances or store in batteries. This can be used instead of diesel generators, wind turbines, or batteries alone. This can be used for various purposes where there are no electrical lines such as power lighting, small motors, electric fencing, aeration fans, irrigation valve switches, sprinkler irrigation systems, and automatic supplement feeders.
5.PV for pumping water –
PV can be used successfully to power the water pumps where there are no power lines. It may be used directly without the batteries however the large systems need batteries, inverters, and tracking mounts to follow the sun during the day. They are very cost-effective when compared to other sources of power. The factors that affect the solar water pumping are the amount of solar energy available, the depth of water, the water demand, system purchase, installation costs, etc. For example, the system that consists of a 128 watt PV array and a submersible pump can produce 750-1000 gallons of water per day from 200 foot drilled well.
In this article, we have seen how solar energy systems can be successfully used in various forms in the agricultural industry. There are lots of researches going on to use more solar energy powered systems in agriculture. This is nothing but the tip of the iceberg as the technological advancements take place and the cost comes down there will be many more uses of solar energy in agriculture.