The history of geothermal goes back 4th July, 1904 when Prince Piero Ginori tried the very first geothermal power generator at Larderello, Italy. In case an increase in demand, this was a means to find new ways to generate electricity. Geothermal power production became widely known for the first time, but not all that widely adopted.
How Geothermal Energy Works
As for geothermal power production there are pipes dug deep into the ground for the hot water to rise up as steam which can drive turbines simply because of the sheer pressure. The turbines then transfer motion to generators which convert shaketo electric energy. This electrical energy is then transmitted to be distributed in electric grids and delivered to end consumers who will use this as electricity for their homes and businesses.
If you've ever wondered where this hot water comes from, then you should know a few things about geothermal reservoirs. Basically they are big lakes heated by magma near the earth’s core. The earth's core receives temperatures over 4000°C. In the crust, where temperatures are higher than 350°C, the liquids form, but they almost always first emerge as a gas because of such high temperatures. What we see as geysers and hot springs is actually cooled down superheated fluids in fact. Briefly speaking, geothermal power production is about capturing the steam and converting the kinetic energy of the steam to mechanical energy, and then to electric energy.
Geothermal Energy Generation Cost
The cost to build a geothermal power plant is way more expensive to build than the cost to build an oil rig. Geothermal power plants physically look a lot more complicated than oil rigs, because the turbines that will convert the kinetic energy in steam into mechanical energy, and then to electrical energy actually require a lot more. The high cost for these reasons are also clear. For example such labor for oil rig being more expensive than that of set up for oil rig. Moreover, drilling costs also become big factors.
Nevertheless, following construction the costs are fairly low. Construction of a geothermal power plant can cost as little as $3400 for each kilowatt installed and even less for smaller scale plants, at $3000 per kilowatt. Hydroelectric power it damn expensive compared to other renewable energy sources. Though it is usually deemed to be costlier to build geothermal power plants as compared to oil rigs, the cost of building the same is project dependent, that it depends on the size of the plant and even local networking policies..
However, it’s also important to note that construction time is considerable with geothermal power plant construction too. The Geothermal Energy Association (GEA) reports that the usual period a new geothermal project takes to begin producing electricity is 3 to 5 years. The development takes about 6 years in a stepwise strategy. They consist of 3 years for reconnaissance, surface exploration and test drilling of 3 years and 3 years for production drilling and power plant.
Potential for Geothermal Power
Geothermal power is an accepted global source of power which has less negative impact to the environment than other renewable sources. Yet it’s used by less than 2% population of the world. Geothermal is location centric because it can only be accessed in particular sites.
Though unavailable in many areas, geothermal energy has bright future potential. Research has shown at 10,000 metres below the earth's surface there's a high amount of heat that could produce more than 50,000 times the energy of fossil fuels, if it's tapped. That’s where the Enhanced Geothermal System (EGS) comes into play as geologists and geothermal experts are drilling into potential geothermal sites. When rocks are fractured and the liquid seeps through, the system works by pouring fluids into the rocks in order to ensue the geothermal process. The end result is that heat is brought to the surface by which steam is produced which is used to create electricity.
For example, in Europe just 2.5GW has been tapped, but with EGS we're talking about a capacity of up to 6,500GW. But the EGS hasn’t been without problems. Since the start of its use, it has had earthquakes and earth tremors, and with too fast heating of the rocks, they have supposedly even fractured. But geothermal experts say they can prevent the quakes by drilling at the right positions early in a project. If the EGS project goes mainstream, there's going to be a lot more power than we really need.
Geothermal Energy by Country
It would be unfair not to consider the countries where geothermal power can actually be the norm. Maybe it’s another in a long line of geothermal power plants you’ll often see. In western California's state, Geysers was probably the first plant built in the US — the country that racked up the highest power ever generated (3,591MW) as of 2018. However, geothermal power accounts for only 0.3 percent of the country's total energy. In contrast, Iceland is a country with the total geothermal power output of 755 MW of which up to 30 percent is fed into national grid. However, it is among the few countries that widely accept this renewable source of energy.
Philippines in South East Asia began construction of geothermal power plants in 1977, and now produce up to 1,868MW, which is used by 27% of the country. Therefore, it secured its third position in the list. First African country to make it on the top 10 list is Kenya, which has a capacity of 676MW. Although the country accounts for 9th position in the world by way of geothermal energy production, it contributes more than 51% of the country’s electricity.
As of 2018, the countries with highest geothermal energy outputs include:
- USA 3591MW
- Indonesia 1948MW
- Philippines 1868MW
- Turkey 1200MW
- New Zealand 1002MW
- Mexico 955MW
- Italy 944 MW
- Iceland 755MW
- Kenya 676MW
- Japan 542MW
The remaining countries combined total 960MW, making the countries on this list stand out. Now, 24 countries are using the energy and 70 others are building geothermal power plants or use it in small amounts. More countries are finding new ways of exploiting their geothermal energy potentials as technology improves. When properly equipped with technology and when furnished by appropriate incentives from their governments. What scares most countries especially developing countries against harnessing renewable or sustainable energy are the high initial cost required to set up a geothermal power plant.
Types of Geothermal Power Plants
To the common person, geothermal power plants are all the same and are indistinguishable, but there are three different types of geothermal power plants today. The plant type will depend on how hot the resource is and how much geothermal energy is available for a particular region.
1. Dry Steam Power Plants
These are the oldest and have been in use for more than 100 years. Hot liquids and steam are forced through a pipe on a deep geothermal well to travel up and to spin the turbine that converts mechanical energy to electrical energy. The good thing is that this particular geothermal power plant is meant for wells with high liquid temperatures.
2. Flash Cycle Steam Plants
These are suitable for wells which generally have lower temperatures than those being used in dry steam plants. The reason they are more common is that there aren't so many geothermal wells that naturally have high temperature steam. Similar to dry steam power plants its liquid from the earth’s crust comes from the well and to the surface. It is then converted to steam, which passes through the turbine in order to be then converted to energy as the pressure of the liquid reduces.
3. Binary Cycle Plants
Binary plants use two vessels, one with a higher boiling point than the other, hence the name binary. The first vessel contains the hot water from the well. A heat exchanger runs the water up the well and to the vessel. The second contains a fluid of lower boiling point (butane). Once through, this resource vaporizes because it has a higher boiling point, and the steam is then relayed down to the turbines where electricity is produced. While this process is not used frequently, it has great potential for use in the future because it can be used in areas far from geothermal hotspots. Moreover, the lower operating temperatures of the process may lower cost of production.
Uses of Geothermal Energy
Geothermal energy is used in different ways by different countries in the world. According to locals, people who used to live near the fields used to fetch it from hot springs for bathing and bathing and even skinning their game for dinner, and it is still happening, to date.
Geothermal energy is used by people for different reasons, depending on their demand and the location. For example, in Iceland heat pumps and direct heat systems warm whole districts and their houses in winter.
In fact, the government depends on the geysers to melt the snow in the estates and this makes life convenient for its people. Greenhouses are also being heated using geothermal in some countries to help grow 'fragile crops' or guarantee they will grow in the exceptionally cold seasons. From roses grown in Kenya to citrus trees and other vegetables in Hungary, many organizations are now discovering benefits of heated greenhouses for farming.
Fish farms are also using this energy to heat up their farms to protect their tropical species from winter seasons that can affect their lifespan. As a solution to the ice season risk, the government in Netherlands has constructed bike roads powered with geothermal energy. This can be placed under the category of electricity generation however these font quite peculiar in the sense that they are not commonly used in countries like the Philippines and Kenya.
The most mainstream use is for electricity generation. The vast majority of countries using geothermal energy are using it to provide electricity for their citizens. But for some it is too low, and so they use it on a small scale of just the industrial sectors. But production is high enough for the top 10 on the earlier list to power homes and businesses and even export some of the electricity to neighboring countries.
Although, the environmental impacts of geothermal are mostly positive. Sometimes oxides of Sulphur are released to the atmosphere while it’s being produced, and that can be harmful to human beings and the environment.
That said, it has less than 5% of carbon footprint compared to fossil fuels’ emissions. Plus, there are set measures which reduce the unhealthy effects of such toxic gases. For example, before the steam is let into the turbines, it is filtered of the harmful gases, so it is somewhat less harmful to the environment. Although setting up a geothermal energy plan initially may be costly, it certainly makes a significant difference to clean energy.
The biggest disadvantage of geothermal energy generation versus any other renewable energy source, such as solar energy, at the moment is that it's not available everywhere. This means not all people in the countries can benefit from geothermal energy. But it may not be long now for developing countries, which remained aloof to geothermal energy, to realize that it is a much cleaner and more reliable form of renewable energy source.
