Geothermal Energy Association: 2014 annual report. The international geothermal power market is booming, growing at a sustained rate of 4% to 5%. Almost 700 geothermal projects are under development in 76 countries. Many countries anticipating the threats caused by climate change realize the values of geothermal power as a baseload and sometimes flexible source of renewable energy. Global installed capacity is just over 12,000MW with about 12,000MW in the pipeline and about 30,000 MW of geothermal resources under development. Of those 12,000 MW about 1,900MW of planned capacity additions are under construction in 14 countries. If all geothermal power plants under construction are completed on schedule the global geothermal industry could reach about 13,450 MW of nameplate capacity by 2017. link   (Photo: The Pohutu Geyser in New Zealand erupts with a natural blast of the Earth’s interior heat.)



  •     What is geothermal energy?
  •     Limitations geographically
  •     Geothermal around the world
  •     The future potential for geothermal
  •     Are there downsides?            

Geothermal Resources Council – link

 What is geothermal energy? 

Geothermal energy is thermal energy generated and stored in the Earth and originates from the original formation of the planet, from radioactive decay of minerals, from volcanic activity, and from solar energy absorbed at the surface. The geothermal gradient, which is the difference in temperature between the core of the planet and its surface, drives a continuous conduction of thermal energy in the form of heat from the core to the surface. Geothermal Energy is relatively emission-free, and unlike other renewables, isn’t tied to the sun’s energy as a source. [On a global scale, geothermal has failed to flourish in the same way as solar or wind, and currently (May 2017) produces less than 1% of the world’s electricity according to the World Energy Council – link] The International Energy Agency estimates that with sufficient technological improvements and financial incentives, geothermal could provide 3.5% of global demand by 2050. Although initial investment is high for geothermal, natural gas and geothermal are still economically comparable over a long term. But as with any energy source, there are problems, in the case of geothermal with drilling.

The Earth has molten core. About 3-6km below the surface of the Earth in some places are layers of super hot granite that can be as hot as 250 degrees centigrade. One cubic kilometre of hot granite at 250 degrees centigrade has as much energy in it as 40 million barrels of oil. Although areas with telltale signs like hot springs are more obvious and are often the first places geothermal resources are used, the heat of the earth is available everywhere, and we are learning to use it in a broader diversity of circumstances. It is considered a renewable resource because the heat emanating from the interior of the Earth is essentially limitless. The heat continuously flowing from the Earth’s interior, which travels primarily by conduction, is estimated to be equivalent to 42 million megawatts of power, and is expected to remain so for billions of years to come, ensuring an inexhaustible supply of energy. Because no burning takes place, only steam is emitted from geothermal facilities. (Pictured is a geothermal plant in Iceland where thousands of megawatts of electricity are generated.)

September 2017: The Florence Declaration. Despite being one of the lowest-cost and most reliable renewable energy sources, harnessing heat from the Earth almost doesn’t happen outside Iceland. At the Global Geothermal Alliance meeting in Florence, ministers from more than 25 governments hope to change that. Along with 29 partner institutions from the private sector they signed the Florence Declaration, committing to a 500% increase in global installed capacity for geothermal power generation by 2030. Although that may sound like a lot, it’s starting from a low baseline. Geothermal energy today accounts for just 0.3% of globally installed renewable energy capacity. link

September 2013: The global geothermal market is expected to reach 12,000MW of capacity by the end of 2013, showing signs of steady expansion. Growth is led by progress in developing areas such as Africa and Latin America and is highlighted in the recently released report entitled: 2013 Geothermal Power: International Market Overview by the Geothermal Energy Association (summary). For comparison, 415MW went online in 2012, while more than 700MW have been commissioned so far in 2013. These numbers have equated to a steady 4% growth rate each year. However unlike other renewables, geothermal projects tend to be larger endeavors and can take up to a year to construct. link

Geothermal power has historically been limited to areas near tectonic plate boundaries. Geothermal wells release greenhouse gases trapped deep within the earth, but these emissions are much lower per energy unit than those of fossil fuels. As a result, geothermal power has the potential to help mitigate global warming if widely deployed in place of fossil fuels. Although there are emissions of nitrous oxide, hydrogen sulfide, sulfur dioxide, particulate matter, and carbon dioxide they are extremely low, especially when compared to fossil fuels.

How a Geothermal Power Plant Works

How geography determines geothermal supply

The most active geothermal resources are usually found along major plate boundaries where earthquakes and volcanoes are concentrated. Most of the geothermal activity in the world occurs in an area called the Ring of Fire. This area encircles the Pacific Ocean. When magma comes close to the surface, it heats ground water found trapped in porous rock or water running along fractured rock surfaces and faults. These features are called hydrothermal. They have two common ingredients: water (hydro) and heat (thermal). Geologists use various methods to look for geothermal reservoirs. Drilling a well and testing the temperature deep underground is the most reliable method for finding a geothermal reservoir.

Naturally occurring large areas of hydrothermal resources are called geothermal reservoirs. Most are deep underground with no visible clues showing above ground. But geothermal energy sometimes finds its way to the surface in the form of volcanoes and fumaroles (holes where volcanic gases are released), hot springs and geysers.

 September 2010: Geothermal could provide all the energy the world will ever need.
The Norwegian company Rock Energy wants to be an international leader in geothermal heat and energy. A pilot plant has been planned for Oslo that will collect heat from 5500 metres deep. Temperatures from this depth can heat water to 90-95°C and can be used in district heating plants. One of the unique aspects of geothermal heat is that it is found everywhere throughout the world. Call it a “democratic” energy source that anyone can take advantage of, regardless of the conditions at the Earth’s surface, such as the weather. The United States, the Philippines, Mexico, Indonesia and Italy are the international leaders in terms of producing electricity from geothermal energy. Iceland comes in at a surprising 8th place. link

April 2014: Global market saw huge 2013 growthThe global geothermal industry had a boom year in 2013, bringing the most capacity online since 1997. The market saw 530MW commissioned, which brought total global capacity to just over 12,000MW, holding a steady 4 to 5% growth rate, according to the Geothermal Energy Association’s (GEA) 2014 Annual U.S. & Global Geothermal Power Production Report. These projects are located in the U.S., Philippines, Mexico, New Zealand, Germany Kenya, Australia and Turkey. Looking ahead, there are 12,000MW in the global pipeline, which refers to projects in phases of exploration or under construction, and 30,000MW under development. About 10-16%, around 1,900MW, of projects are currently under construction in 15 countries, and if all are completed on schedule, global capacity could reach 13,450MW by 2017, according to the report. link

Geothermal energy around the world

Top 10 countries as of 2016 producing geothermal energy. The USA led 3,567MW installed, followed by the Philippines, Indonesia and New Zealand. Full list link

May 2018: 330MW geothermal plant in Indonesia reaches full capacity. All units of the Sarulla geothermal power plant in Indonesia have reached commercial operation, bringing the project to its full 330MW capacity. The project has three 110-MW units, the first coming online in March 2017. link

February 2017: Geothermal posed to grow by leaps and bounds internationally in the coming years, with rapid growth in countries like Indonesia, the Philippines, and Kenya, all rich in geothermal resources. Major players involve investment banks who are teaming up with countries with untapped geothermal energy like Chile to diversify their national energy portfolios and meet Paris Climate Agreement goals. Between March and September 2016, a total of 44 new geothermal power projects began development throughout 23 countries, adding 1,562.5 MW of developing capacity and representing a significant spike in projects worldwide. link

June 2016: More African countries embrace geothermal – receive $37m funding. The tiny East African countries of Rwanda, Djibouti, and the Union of Comoros have joined the African league of geothermal power producers, in a field dominated by Kenya. The $115 Geothermal Risk Mitigation Facility (GRMF) fund is administered by the African Union. Further applications for funding from Tanzania, Uganda, Zambia and Ethiopia are due for consideration for multiple projects to be implemented by both government-owned agencies and the private sector, in the last quarter of 2016. Following the approval of the grants, newcomers should start generating power from steam in the next three to four years, with the majority benefitting from Kenya’s 20 years’ experience in geothermal development, as well as from the government of New Zealand, which has offered to avail technical expertise to the newcomers. link

June 2016: Japan’s rich reserves of geothermal power. Resource-poor Japan, which last year spent $174 billion in 2015 importing fossil fuels, has the world’s third-largest geothermal reserves, representing an estimated 23GW of power, according to the International Energy Agency.  Less than 600 MW, or about 2% of that capacity is being used at the moment. This would equal a rich reserve of power equivalent to about 20 nuclear reactors. At the end of 2015, Japan had about one-third the installed geothermal capacity of Indonesia and one-fifth the U.S., according to Bloomberg New Energy Finance data. Moreover, Japan’s geothermal capacity has been little changed since at least 2000. linkMay 2015: Japan looks to possible geothermal expansion. Japan has recently turned toward its abundant reserves of geothermal energy expecting 380 to 850 MW of new installed geothermal capacity by 2030. As Japan continues to bounce back from the Fukushima nuclear disaster in 2011, it has focused on renewable energy to lessen its reliance on nuclear and carbon-heavy fossil fuels. One major obstacle was due to, of all things, environmental considerations. Nearly 80% of Japan’s geothermal resources are located within national parks or protected hot springs, areas designated as restricted “zones” with limits on the type and location of work that can be done in them. Japan set a moratorium on geothermal production within these parks, with heavy restrictions even on light research. In 2012, the Ministry of the Environment relaxed the rules for each zone, and the government also increased funding for geothermal exploratory drilling from $15 million to $90 million. link

May 2014: Indonesia to start work on world’s biggest geothermal plant. Southeast Asia’s largest economy, home to the world’s largest geothermal resources, is racing to meet power demand growth of more than 7% a year, with plans to add 60 gigawatts of capacity to its existing grid by 2022. link

East Africa
February 2016: World’s largest geothermal plant opens in Kenya. Kenya’s 280MW Olkaria plant, the world’s largest, began commercial operation today. The plant (pictured) will provide almost 20% of the nation’s total power capacity. Kenya is among the world’s most active regions for geothermal development, and figures from the national statistics bureau showed that 381.6MW of geothermal power was generated in December alone. Geothermal power now accounts for 51% of the nation’s installed power capacity, displacing hydropower as the top energy source. linkOctober 2013: East Africa sees 20GW of geothermal available. Reykjavik Geothermal, the Icelandic company that’s helped build power plants in more than 30 countries, agreed to develop as much as 1,000MW of projects in Ethiopia over the next 10 years. About 10MW will be in operation by 2015, with a total of 500MW by 2018. The Great Rift Valley in East Africa, which spans eight countries, may have as much as 20 gigawatts of potential geothermal energy, according to data compiled by Bloomberg. Ethiopia’s Prime Minister Hailemariam Desalegn said “My vision is that over 30 years we will harness the 80,000MW of renewables that we have,” including hydroelectric, wind and solar, today. linkFebruary 2011: Potential 15,000MW in Eastern Africa. link

Geothermal energy in the USA –  link

September 2013: New Zealand gets world’s biggest geothermal plant. The 100MW Ngatamariki plant in New Zealand is the biggest “singular binary power plant” ever constructed. Built in a record 24 months by Omat Technologies, Ngatamariki generated 150 gigawatt hours (GWh) during commissioning. It’s expected to reach 700 GWH of annual electricity production, equivalent to that used by 80,000 households. Over the past 25 years, Ormat has installed about 350MW of geothermal across 14 power plants in New Zealand. link

Iceland is often considered a country run on geothermal energy as it fundamentally sits on a volcanic base (like Hawaii), and virtually every building in the country is heated with hot spring water. In Reykjavik, for example (population 115,000), hot water is piped in from 25 kilometers away, and residents use it for heating and for hot tap water. (Iceland is almost completely powered from renewable sources – 73.4% from hydropower and 26.5% geothermal.)

April 2017: Iceland magma drilling project may revive giant UK power cable. Scientists will study the possibility of producing geothermal energy from magma for the first time, in a $100 million project in Iceland, which if successful could produce up to 10 times more energy than from a conventional well. Producing geothermal energy from magma would enable Iceland to export more energy and could also revive a plan to build a power cable from Iceland to Britain (delayed due Britain’s vote to leave the EU) to provide power to British homes, in what would be the world’s longest power interconnector. link

Iceland technology to assist Europe.

May 2014: Iceland closer to providing Europe with geothermal energy. Iceland is moving closer to plugging European homes into the volcanic island nation’s geothermal and hydropower reserves via what would be the world’s longest power cable, according to the country’s largest energy producer. “The more we look at this project, the more positive feedback we get,” said CEO of Landsvirkjun which produces more than 70% of Iceland’s power. “Over the past two years we’ve moved closer to this project becoming a reality.” link

July 2012: Iceland technology on geothermal planned for U.K.  Hot rocks technology, which uses the heat of the Earth’s core to generate power, will soon become a reality in Britain. Plans have been unveiled to tap into geothermal resources at five sites, including one in Manchester with the potential to heat 7 million homes. And planning permission has been granted to two projects in Cornwall, considered to be the leading county in hot rocks technology. link

May 2010: Geothermal could meet all Canada’s energy needs. Canada could technically meet all its electricity needs and dramatically lower greenhouse-gas emissions if it moved aggressively to develop enhanced geothermal power projects, according to the first comprehensive assessment of the country’s deep geothermal resources. The study found that the most promising Canadian sites are located in parts of British Columbia, Alberta and Saskatchewan. link

South America.
(August 2012) South America has largely relied on hydropower, but its capacity is weakening. Geothermal presents a major opportunity throughout South America, but exploratory drilling has been limited. According to the ESMAP (Energy Sector Management Assistance Programme) report, the range of geothermal capacity estimates is quite broad. Though expectations may be uncertain, many regions are hopeful that exploration will reveal something more. The most viable resources are thought to be located along the Pacific Rim, which ranges from Mexico to Chile. Key spots in the Caribbean islands also carry some potential, according to researchers. link

Central America: 
2015: Geothermal energy in Central America. Central American countries have indeed been in the vanguard in their use of geothermal energy. In El Salvador, 24% of electricity comes from geothermal. That figure places it second out of all countries in the world in its level of reliance on this power source. (Iceland is tops.) Meanwhile, 15% of Costa Rica’s electricity comes from geothermal, as does 10% of Nicaragua’s and 5% of Guatemala’s. Compare those numbers with the worldwide figure of 0.3%. The basic reason for Central America’s geothermal energy riches can be summed up in one word: volcanoes. link

Australia.   Geothermal energy is an emerging industry in Australia, with exploration being conducted in all states and the Northern Territory. While significant resources have been identified and there are several companies in advanced stages of exploration, presently there is no commercial production of geothermal energy in Australia. That said, there is significant potential for geothermal energy in Australia. It is estimated that one per cent of the geothermal energy shallower than five kms and hotter than 150°C could supply Australia’s total energy requirements for 26 000 years (based on 2004-05 figures).  link  In Australia, there are two types of geothermal projects are being developed – enhances geothermal systems and hot sedimentary aquifers. link

While much of the future supply of geothermal in Australia is expected to come from HFR (hot fractured rock) the Birdsville geothermal power station in western Queensland  is the only one of its kind in Australia at present, but gets its small output from hydrothermal power. The small Birdsville geothermal power station was built in the early 1990’s and remains no more than a pimple on Australia’s vast geothermal energy resources. link 

July 2016: Turkey’s geothermal pollutes more than coal. In Turkey, because of a quirk in the geology, some of the geothermal wells pollute as much as coal-fired power plants. The nation has a layer of subterranean limestone, which lets loose CO2 when it comes in contact with steam as hot as 280C. The results mark a rare example where renewable energy is producing a greenhouse gas. They’re disputed by at least one of the companies singled out in the EBRD [European Bank for Reconstruction and Development] report and have prompted the industry to search for ways to pare its emissions. They’ve also put a spotlight Turkey’s ambition to boost geothermal capacity 60% by 2023, making it one of the world’s top markets for the technology. link

 The future of geothermal energy

Geothermal energy has the potential to play a significant role in moving the United States (and other regions of the world) toward a cleaner, more sustainable energy system. It is one of the few renewable energy technologies that – like fossil fuels – can supply continuous, base load power. The costs for electricity from geothermal facilities are also declining. Some geothermal facilities have realized at least 50% reductions in the price of electricity since 1980. New facilities can produce electricity for between 4.5 and 7.3 cents per kilowatt-hour, making it competitive with new conventional fossil fuel-fired power plants.

January 2016: Future of geothermal industry becomes clearer. The current expectation of global geothermal energy through the end of the decade is that annual capacity installations will bring the existing approximately 12.6 GW to nearly 21.5 GW, with smaller increases in 2016-2017 giving way to larger annual increases from 2018-2020, according to data presented during the 2015 World Geothermal Congress. The U.S., Indonesia and Mexico have the potential to continue their positions as leaders in the industry, while current activities in the Caribbean, Chile and Kenya show that these up-and-coming regions also could do their part to drive new developments in the years to come. link

August 2015: Geothermal industry has high price tag. The geothermal industry may need as much as $73 billion in public financing, almost 10 times current spending levels, to meet developing countries’ electricity targets, according to a new report. Countries such as Kenya, Papua New Guinea and Indonesia have huge geothermal potential but face challenges attracting capital to develop it. Countries are collectively aiming to deploy 23 gigawatts of power from geothermal sources by 2030. The world’s largest project to date is the Sarulla power plant in Sumatra, Indonesia, with 330 megawatts. link

 Is there a downside to Geothermal energy?

December 2009: Geothermal project in California shut down. The collapse of AltaRock project in California comes a day after Swiss government officials permanently shut down a similar project in Basel, because of the damaging earthquakes it produced in 2006 and 2007. Taken together, the two setbacks could change the direction of the Obama administration’s geothermal program, which had raised hopes that the earth’s bedrock could be quickly tapped as a clean and almost limitless energy source. link  

December 2009: Swiss geothermal project shut down. A $60 million project to extract renewable energy from the hot bedrock deep beneath Basel, Switzerland, was shut down permanently after a government study determined that earthquakes generated by the project were likely to do millions of dollars in damage each year. The AltaRock project in California is the Obama administration’s first major test of advanced geothermal energy and like the Basel project, the plan is to drill miles underground, fracture hot bedrock and circulate water through it to generate steam. link

September 2009: German geothermal plant could be cause of earthquakes. Landau in der Pfalz, a small city in Germany, is currently undergoing government inspections about earthquakes potentially caused by a geothermal plant. The government is still trying to determine if the plant is safe enough for the area. By digging two miles deep to pull up the heat, it provides for tremendous energy results, but scientists suggest it also causes seismic problems. link  (Update June 2013 – The Landau geothermal plant may be closed as its due to excessive costs. link)