Geothermal Energy

Geothermal Energy is the thermal energy generated and stored in the Earth. The production of Geothermal Energy involves drilling wells into the Earth’s crust at approximately a depth of 3 ~ 10 km. Geothermal Energy comes from the sub-surface of the earth, contained in the rocks and fluids beneath the earth’s crust and can be found as far down to the earth’s hot molten rock, magma. Hot water and steam from deep underground can be used to generate electricity in a geothermal power plant. Electricity is generated when geothermal heat produces steam that spins turbines on a generator. It's clean and sustainable, but the possibility is limited to a few locations on Earth and many technical problems exist that limit its utility. 

Geothermal Energy is a carbon-free, renewable, sustainable form of energy that provides a continuous, uninterrupted supply of heat that can be used to heat homes and office buildings and to generate electricity. Geothermal Energy only produces one-sixth of the CO2 produced by a natural gas plant and is not an intermittent source of energy like wind or solar. However, there are some drawbacks to the energy source. Despite low CO2 production geothermal has been associated with other emissions like sulphur dioxide and hydrogen sulphide. Geothermal Energy could reach at least 35GW and as high as 2TW, but a high initial cost to build.

Geothermal Power Plant is a power generation plant by geothermal energy, and types are: 1) Dry Steam Power Station: Dry Steam takes out of the ground and uses it to directly drive a turbine. Hot steam is piped directly from geothermal reservoirs into generators in the power plant; 2) Flash Steam Power Station: Flash Steam uses high-pressure hot water into cool, low-pressure. Hot water is brought up through a well and flashed into steam. The condensed water is returned to the ground; 3) Binary Cycle Power Station: Hot geothermal water is passed through a heat exchanger, where its heat is transferred to a liquid that boils at a lower temperature than water, which spins the turbines.

Thermal Energy is 1) the energy possessed by an object or system due to the movement of particles within the object or the system; 2) the energy developed through the use of heat energy that is transferred spontaneously from a hotter to a colder system or body. The Thermal Energy is the kinetic energy measured in joules, watt-hours, or in electron-volts that exchanges between two bodies.

Global geothermal capacity additions are projected to amount to 0.3 GW in 2020, one-third of last year’s level, which was the highest ever recorded. This year, Indonesia is again expected to lead new development, with 145 MW of capacity added (90 MW from the Rantau Dedap plant and 45 MW at the Sorik Marapi plant), followed by Turkey (+70 MW). These two countries are expected to account for more than two-thirds of new capacity additions in 2020, while the Philippines, the United States and Bolivia are responsible for most of the rest. A number of projects have been delayed by disruptions to the global supply chain for machinery and materials and by deferrals of strategic decisions (including for financing) caused by the Covid‑19 crisis. Therefore, several small and medium-sized projects originally scheduled to come online in 2020 are expected to be commissioned in 2021 instead. In Turkey, the 10-year FiT scheme for new plants, originally scheduled to end at the end of 2020, has been extended until mid-2021 to cover projects affected by such delays. (Source: IEA Renewable 2020)

Geothermal Electricity Generation is currently used in 24 countries, while geothermal heating is in use in 70 countries. As of 2015, worldwide geothermal power capacity amounts to 12.8 gigawatts (GW), of which 28 percent or 3,548 megawatts are installed in the United States. International markets grew at an average annual rate of 5 percent over the last three years and global geothermal power capacity is expected to reach 14.5–17.6 GW by 2020. Based on current geologic knowledge and technology, the Geothermal Energy Association (GEA) estimates that only 6.5 percent of total global potential has been tapped so far, while the IPCC reported geothermal power potential to be in the range of 35 GW to 2 TW.[2] Countries generating more than 15 percent of their electricity from geothermal sources include El Salvador, Kenya, the Philippines, Iceland and Costa Rica. (Source: Wikipedia)

Binary Cycle (Geothermal Power Plant) is a type of geothermal power plant that is combination of two power plant turbine cycles utilising two different working fluids (the hot geothermal fluid vaporises a secondary working fluid) for power production.

Binary Cycle Power Station is a type of the Geothermal Power Plant in which hot geothermal water is passed through a heat exchanger, where its heat is transferred to a liquid that boils at a lower temperature than water, which spins the turbines.

Closed Loop Geothermal Heat Pump System uses a continuous loop of pipes as the heat exchanger that connects to the heat pump. Together these form a sealed, underground loop through which the fluid being used to transfer the heat is circulated. The loops can be installed in the ground horizontally or vertically.

Dry Steam Geothermal Plant is the conventional turbine generators that uses steam directly from a geothermal reservoir to turn generator turbines.

Dry Steam Power Station is a type of the Geothermal Power Plant in which the hot steam is piped directly from geothermal reservoirs into generators in the power plant.

Geothermal Heat Pump is a type of heat pump that is a central heating and/or cooling system transfers heat to/from the ground uses the ground or ground water as a heat source and heat sink, rather than outside air.

Ground Loop 1) in a geothermal heat pump, system is a long series of pipes buried in the ground at the depth where temperatures remain consistent year-round: Vertical Ground Loop is installed in holes drilled deep into the ground with a closed-loop geothermal heat pump (Refer to the Closed Loop Geothermal Heat Pump System); Horizontal Ground Loop is installed over a wide area of ground and buried at the optimum level (Refer to the Open Loop Geothermal Heat Pump System); 2) in an electrical system, a ground loop or earth loop is two points of a circuit that is in a signal circuit referenced to ground, if enough current is flowing in the ground to cause two points to be at different potentials.

Surface Water Loop