Geothermal power plant principle

Unlike other power plants that rely on coal or other fossil fuels to generate electricity for homes and businesses, geothermal power plants use superheated fluids from the earth’s geothermal resources to generate electricity. The natural heat of the earth creates geothermal resources. This heat comes from molten rock, called magma, located at the earth’s core deep below the geothermal resource. Over thousands of years, rainwater seeps through cracks in the earth’s surface and collects in underground reservoirs. The magma heats the water until it becomes a superheated fluid.

Geothermal power plant.

To reach the superheated fluid, wells are drilled 5,000 to 10,000 feet (1.5 km to 3.0 km) below the surface of the earth (1.5 km to 3.0 km). These wells, called production wells, bring the superheated fluid to the earth’s surface where it can be used to generate electricity for homes and businesses. Geothermal power plant from the video bellow uses crystallizer-reactor clarifier technology, a process that turns the geothermal superheated fluid into steam while removing solids from it. The steam is used to drive a turbine and generate electricity. All remaining geothermal fluids are injected back into the reservoir for reuse. Under its own pressure, superheated fluid from geothermal resource flows naturally to the surface through production wells. As the liquid flows toward the surface, the pressure decreases, causing a small portion of the fluid still within the well to separate into steam.

Geothermal energy production well.

At the surface, the superheated fluid and steam mixture flows through surface pipelines and into a wellhead separator. Inside the separator, the pressure of the superheated fluid is reduced. This causes a large amount of the superheated fluid to rapidly vaporize and flash into high-pressure steam. The geothermal fluid that is not flashed into steam in the wellhead separator flows to a second vessel, called a standard-pressure crystallizer, where an additional amount of standard pressure steam is produced. The flash process continues in the low-pressure crystallizer. The remaining fluid is again flashed, this time at a lower pressure, to produce low-pressure steam. All of the low-pressure, standard-pressure and high pressure steam is delivered into a turbine. The fluid that is not flashed into steam flows into the reactor clarifier system and is then returned to the geothermal reservoir through injection wells.

Turbines are the primary piece of equipment used to transform geothermal energy into mechanical energy. Pressurized steam created from the geothermal superheated fluid flows through pipelines to large steam turbines. The force and energy in the steam is used to spin the turbine blades. Turbines turn a shaft directly connected to an electrical generator. An electrical charge is created when magnets rotate within the generator. Large copper bars carry the electrical charge to a step-up transformer outside the plant. Within the transformer, the voltage is increased before the power is sent to the power lines that carry it to homes and businesses.

Geothermal energy is a sustainable resource because, with proper management, a geothermal resource can remain a renewable source of energy. Water trapped deep within the earth will naturally replace the superheated fluid that is drawn from the geothermal resource through surface wells. However, it is possible to deplete the geothermal resource by removing fluids faster than it can be naturally replaced. To help prevent this, the steam used in the geothermal power plant passes through a condenser that turns it back into fluid. At this stage, it is possible to recover minerals from the geothermal fluid before it is injected back into the earth. This condensed fluid, along with the fluid that did not flashed into steam, is injected back into the underground reservoir. Magma naturally reheats the fluid so it can be used again.

Source: video from youtube.

India launches National Solar Mission plan

Indian Prime Minister Manmohan Singh recently stated a rather ambitious plan to make India a global leader in solar power as he launched a government initiative to boost use of the solar technology, and make solar energy the most important renewable energy source in country.
According to Singh solar energy can not only help secure India's energy independence and decrease the need for expensive foreign oil import, and it would also help fight against climate change, as well as offering brand new opportunities for further growth of Indian industry that is constantly in shortage of the energy.

In order to do so he formally launched the so called “The National Solar Mission” that should establish India as a global leader in solar energy, in the areas of both power generation as well as technology production.

The Solar Mission has the goal of increasing solar energy capacity exponentially to reach 20,000 megawatts for the year 2022, reducing reliance on coal and other fossil fuels that are mostly imported. This amount should provide enough power for 20 million homes in India.

India plans to increase solar energy capacity exponentially to reach 20,000 megawatts for the year 2022.

This certainly looks like the very bold plan especially when you consider that approximately 80,000 poor Indian villages still lack basic access to grid electricity but as the Singh said: "The rapid spread of solar lighting systems, solar water pumps and other solar power-based rural applications can change the face of our rural energy sector."

India's current numbers show production of only nine megawatts of solar power but still the prime minister thinks that “solar energy can be the next scientific and industrial frontier in India”, and could soon replace wind energy as the India's No.1 renewable energy source.

It will be very interesting to see whether India could actually achieve such huge solar power expansion.