Why geothermal energy is taking the spotlight
The potential for geothermal energy in supplementing global power supply is real. How can government around the globe overcome current impediments to scale-up the adoption of geothermal energy?
Last year, governmental ministers and 29 partner institutions from the private sector signed the Florence Declaration, committing to a 500% increase in global installed capacity for geothermal power generation by 2030.
Although the target 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.
This is despite its huge potential - for both lowering greenhouse gas emissions and saving money. Geothermal is one of the lowest-cost energy sources available, after start-up costs are met. The global potential for geothermal is estimated to be around 200GW (gigawatts).
“Geothermal’s vast potential is currently untapped,” says Italian environment minister Gian Luca Galleti who made a presentation at the Florence summit. “We must develop new technologies and encourage new investments to ensure we cover this gap.”
The summit in Florence, Italy, was organised by the Global Geothermal Alliance, which was launched at the United Nations climate summit in Paris in 2015. Entitled: ‘Working Together to Promote Geothermal Energy Towards a Sustainable Energy Future’, the conference brought together private and public sector representatives to address and overcome barriers that have hindered the deployment of geothermal despite its vast potential.
Geothermal energy is energy in the form of heat within the sub-surface of the Earth that is carried up to the surface as water and/or steam. Depending on its characteristics, geothermal energy can be used to generate clean electricity, or in direct use applications such as heating, cooling, the agribusiness and in industrial applications, to name a few.
The global potential for geothermal is estimated to be in the region of 200 gigawatts. Countries in the GCC are already considering it a viable option for alternative energy as the region increasingly looks beyond fossil fuels for its power plants.
Dubai in the United Arab Emirates is already considering the use of geothermal energy to provide power needs in desalination plants, with preliminary studies into the energy source already showing promising results.
Dubai Electricity and Water Authority (Dewa) is requesting proposals for an early-stage feasibility study on producing electricity from geothermal energy and its use in desalination.
The study will also include exploring the potential for tidal, wave and ocean currents as a source for power generation.
According to experts, geothermal is more suitable for applications such as desalination rather than power generation since UAE’s temperatures are below 200°C, the minimum temperature required for power generation from geothermal energy, which is a result of heat from beneath the Earth’s surface.
Steve Griffiths, the vice president for research at Abu Dhabi’s Masdar Institute says that the GCC’s geothermal resources are only suitable for low-temperature applications, averaging about 100°C.
“Geothermal energy from beneath the Earth’s surface, the heat that creates hot springs, needs to be at temperatures of more than 200°C to be a prime candidate for power generation. The UAE’s temperatures are much lower than this, making geothermal more suitable for applications such as desalination rather than power generation,” says Griffiths.
“While UAE has the advantage of exploiting geothermal energy in the same drilling techniques used to explore oil and gas, it is yet to take advantage of the greater potential presented by the sea to generate electricity on a large scale.”
The European Commission estimates that 0.1% of the energy in ocean waves could be capable of supplying the entire world’s energy needs five times over.
Neighbouring Saudi Arabia is eyeing geothermal power as part of its strategic energy plan that also includes massive use of solar energy and wind farms.
Speaking last year at the World Future Energy Summit in Abu Dhabi, Saudi energy minister Khalid Al Falih highlighted the Kingdom’s rich geothermal resources, which are located mainly in the country’s western region. Saudi Arabia’s geothermal resources are related to the general tectonic activity of the Red Sea and associated with a series of volcanic rocks and ridges.
The Jizan area is considered as a promising geothermal system that includes a number of structural-related hot springs.
Analysis of available satellite images, geo-indicators and performing 2D electric geophysical survey had given experts a clue on Saudi Arabia’s geothermal reserve potential for possible energy production.
One study revealed the presence of many good geothermal “anomalies” in Jizan province, of which Al Khouba geothermal resource is considered the most important.
Researchers found good surface petro-thermal properties (high temperature, up to 78 °C and good flow rate) and subsurface characteristics — good vertical and lateral extensions — as well as potential thermal properties in these sites.
A good geothermal potential of 17.847 MWt is estimated for Al Khouba hot spring, providing a reservoir area of 1.125 km2.
In the Western region near Jeddah and Makkah, there are large volcanic areas — known as “harrats”, which are formed by volcanic activity. The volcanic eruptions of harrat near Madina area, for example, are recorded in the year 1256 AD.
Experts have seen at least six thermal springs in Jizan and four in Al-Lith area and temperatures at some of these locations found to be around 120°C.
In Saudi’s north-west region, there are other volcanic regions like Harrat Al Shamah, Harrat Al Raha and Harrat Uwayrid near Tabuk, and Harrat Ithnayn.
The gathering of political leaders from 25 countries at a sumptuous palace in Florence last month is expected to try and speed up deployment of geothermal energy with the facilitation of the International Renewable Energy Agency (IRENA). But significant hurdles remain.
To get heat from the layer of hot and molten magma under the Earth, water is pumped down an injection well. Then it filters through the cracks in the rocks where they are at a high temperature.
The water then returns via the “recovery well” under pressure in the form of steam. That steam is captured and is used to drive electric generators or heat homes.
Italy wanted to host last month’s summit because it is keen to increase its use of geothermal energy. Delegates were able to tour Italy’s first-ever geothermal energy production plant in Lardarello, not far from Florence.
Italy has had the historic misfortune of being situated above some very hot earth - resulting from tectonic activity that causes earthquakes and volcanic eruptions. But that heat underground can also be harnessed to generate power.
Across the world, 90 countries possess proven geothermal resources with the potential to be harnessed, and they are mostly located in regions of tectonic activity. That means that the potential is low in most of Europe, but huge in the Asia-Pacific region.
Yet capital for funding projects in this region has been hard to come by, especially for projects at this scale.
“Right now, we may only be harvesting 6% of proven geothermal energy potential,” says IRENA Director-General Adnan Z. Amin.
He called this last months’s Florence Declaration “a milestone that, in the strongest possible terms, demonstrates renewed will to unlock the potential of geothermal.”
Following the signature of the declaration, IRENA released a new report, which found that access to capital for surface exploration and drilling remains the main barrier to geothermal development.
The report also found that more transparent government regulations that avoid delays are needed to provide a stable environment for developers and investors.
Representatives of African Union countries, as well as the AU’s commissioner for infrastructure and energy Amani Abou-Zeid, were at the Florence summit pledging to provide this transparency. Abou-Zeid said the technology can help Africa decarbonise, while also providing jobs.
“Geothermal energy is emerging as a hidden gem of Africa’s renewable energy resources and we must work together, across nations, to ensure this resource achieves its potential,” says Amin.
One country in which investment commitments are not lacking is Indonesia, which is planning 4,013 megawatts of additional capacity in the coming years.
This puts it far ahead of all other countries. The United States, Turkey and Kenya follow, with a little over 1,000 megawatts of additional capacity each planned.
Amin says such government commitments can encourage private investment in developing these energy sources, which is capital-intensive at the start.
“If we can identify and implement mechanisms that deliver a greater level of certainty to investors and developers, then we will move beyond meaningful dialogue to decisive action,” he says.
If the various government representatives that gathered in Florence last year maintain their commitments and follow them up with concrete plans of action, geothermal energy could play a significant role in the GCC’s ongoing push for renewable energy.