ESSAY BUTTRESSING SUSTAINABILITY (BS)
Geothermal: Our Resolution
Our Earth is like a giant ball of power plant. Its Creator has generously provided the Earth’s inhabitants that includes us humans an abundance of energy in eclectic forms, originating from a wide variety of naturally occurring processes. One of which came from the very soul of the Earth: its core. Around 6,000 kilometers beneath the lithosphere, a never-ending nuclear fission reaction have been taking place since the dawn of the Earth’s formation. The intense heat from the nuclear reaction radiates from the core, flowing through the mantle, penetrating the asthenosphere (the ductile magmatic layer beneath the rigid rocky lithosphere of the Earth’s crust), and when the thickness of the lithosphere allows it, the heat could break through the crust and manifest on the earth’s surface as lava, hot springs, fumaroles, solfataras and of the sort. This overflowing heat from inside the Earth is the main component of geothermal energy.
Throughout history, humans have befriended this infinite source of renewable energy since Paleolithic times, whether it is for a nice hot bath in the warm waters of hot springs, hypocaust or also known as underfloor heating during the Roman times, even for greenhouse heating which is a method to keep plants and crops inside a greenhouse warm. But, it is not until the 20th century that engineers found a way to convert the thermal energy into electricity.
Apart from its mainstream usage as electrical power plants, Indonesia’s geothermal profusion serves a wide variety of purposes in other aspects of daily life. As an example, the Kamojang geothermal field had found a way to utilize its waste geothermal fluids for agricultural purposes. Waste fluids from aged geothermal wells could be used in mushroom growth media sterilization process. The temperature of waste fluids from the electric power plant is still relatively high. Usually, these fluids are reinjected to the geothermal wells. Thus recycling the hydrothermal fluids. But like every other thing on this planet, the wells age over time. When it reaches a certain age, the fluids from a geothermal well could not be used to supply the power plant, due to its decreasing production of steams. Normally, the hydrothermal fluids of an aged well are let to bleed out to the atmosphere in forms of hot steam. Therefore, wasting the valuable fluids and causing negative side effects such as ground water depletion, subsidence, erosion, even deforestation. Researchers and engineers have found a better use for the waste fluids to heat mushroom growth media sterilization. Mushrooms need a clean and sterile growth media. Traditionally, mushroom farmers sterilize the growing media by steaming them to 60-80oC using oil fueled boiler. A more eco-friendly method has been developed in Kamojang. Geothermal heat is used as a substitute for the kerosene generated boiler. When the heat was mixed with fresh water, it produces steam required in the sterilization process, exterminating any bacteria and pests while creating the ideal humidity also minimizing carbon dioxide emission to zero percent due to the absence of fossil fuel usage. By using the heat from geothermal, farmers could sterilize wider areas of mushroom growth medias efficiently and most of all with cheaper cost. Agaricus bisporus sp, Pleurotus spp., and Auricularia spp. are the examples of mushroom species that grows well with geothermal
In addition, geothermal heat can also be applied for growth-stimulating greenhouses. The heat is used to modify and control the greenhouse’s temperature, optimizing and accelerating plant growth. Experiments involving potatoes in Pengalengan, West Java has proven that geothermal could also help with potato seeding process.