Geothermal Energy – Enough for next 5 billion years!

Available 24/7 unlike solar and wind.

Renewable Energy – Part 3.

It is an inexhaustible resource. It would take 5 billion years for the heat at the Earth’s core to run out, which is the life span of the earth. The Earth itself is a renewable energy source, its heat is always available; it doesn’t go away when the sun goes down. It can play a big role in the energy transition by providing reliable, 24/7 clean energy, and it can do so much more than people think.

And geothermal is already widely used in places like Iceland. They power two-thirds of their homes with it. Almost 100 percent of their heat comes from geothermal.

If Iceland is doing it, why not everyone else?

The reason is, Iceland just happens to have very unusual geology with a lots of active volcanoes. So the geothermal heat comes up very close to the surface there. In other places, you would have to drill quite deep to get it.

Geothermal is used in a few places in the US on a small scale. It had a bit of a moment in the 1970s when oil prices were very high. That had built interest in funding geothermal research, but then that fizzled out after shale boom. And since then, wind and solar are the focus.

The core of the Earth is essentially a nuclear reactor that produces massive amounts of heat, enough for humankind’s energy needs forever. And we have just started from scratch with geothermal.

Geothermal has been overlooked for a lot of reasons historically. It’s been underfunded and it’s been under-resourced. Because of the shale boom, wind and solar, geothermal fell out of favor because geothermal is complicated and there are challenges that have to be solved to get it to work.

Wind and solar

• It is intermittent
• It can not be produced at all places.
• Large scale wind and solar affects ecology.
• Wind and solar is not a completely clean industry, because for us to make renewable energy work, we need massive amounts of grid storage. And at the moment, the best options for grid storage are batteries, and those require a lot of lithium and other elements, and that means a lot of mining, which is not environment friendly.

Rising Interest in Geothermal

Geothermal energy has waited a long time for policymakers and politicians to notice it. Now it seems that they cannot get enough.

Many factors account for this interest. They range from serious attempts to meet the Paris Agreement’s net-zero emission reduction target to many local authorities grappling with the removal of fossil fuels from their heating systems, with local and competitive energy sources; the increased value of lithium; as well as Russia’s invasion of Ukraine.

Unlike its more popular cousins – solar photovoltaic (PV) or wind – geothermal provides firm and flexible power. Its average capacity factor is higher than 80%, with some plants running at 100%. This means that an MWe capacity of geothermal is an order of magnitude different to its variable kin.

For example, in Croatia, a single 16.5 MWe capacity powerplant produced nearly as much renewable electricity as the 309 MWe of installed solar PV.

Around the world, nations are more interested in geothermal energy than ever. Across Europe, for example, Denmark, France, Germany, and Italy are expanding geothermal capacity to replace natural gas for electricity and heating. Advanced geothermal technology companies are multiplying, with new players like Fervo, Quaise, and GreenFire Energy pursuing commercial-scale projects.

Benefits of Geothermal

• Most geothermal power plants can run at greater than 90% availability (i.e., producing more than 90% of the time), which means that costs can be recouped more quickly.
• It is clean energy that can be extracted without burning fossil fuels.
• Geothermal power is “homegrown,” offering a domestic source of reliable, renewable energy.
• Geothermal energy is available 24 hours a day, 365 days a year, regardless of weather. Geothermal power plants have a high-capacity factor—typically 90% or higher—meaning that they can operate at maximum capacity nearly all the time. These factors mean that geothermal can balance intermittent sources of energy like wind and solar, making it a critical part of the national renewable energy mix.
• Geothermal energy can also be used to heat and cool homes and businesses, either with geothermal heat pumps or through direct use.
• Low emissions from electricity generation. Geothermal power plants largely release only excess steam.
• Geothermal energy offers homes and businesses low-carbon and energy-efficient heating and cooling options.
• Comparably low water use. By 2050, geothermal energy could represent 8.5% of total U.S. electricity generation while being accountable for only 1.1% of power-sector water withdrawals. The majority of this growth could be supported using non-freshwater sources.

Where can it be used

Ground source heat pumps can be used almost anywhere, while direct use and deep systems are currently limited to regions with naturally high geothermal activity.

What is Hampering Geothermal Growth?

While the potential for geothermal energy is significant, it remains largely untapped in most areas of the world due to the technological limitations.

Currently, geothermal is used where the locations are suitable. We do not have the technology to use it at anyplace. But research is progressing to solve this problem.

Upfront capital costs—including expenses for the initial stages of exploration, drilling, and construction—can be massive. The overall costs for a geothermal plant can total around $1,870–$5,050/kW, with more challenging geography increasing development costs.

Another difficulty is risk for investors, with exploratory drilling requiring approximately 15% of the total investment costs upfront. Yet in the exploratory phase, there is a high degree of uncertainty that the geothermal source will be commercially viable.

Understanding Geothermal Technology

Geothermal energy, which utilizes heat originating in the Earth’s core, provides a steady, non-intermittent source of renewable energy.

Heat is just 10ft below

If you were to journey to the centre of the Earth, you would find it is as hot as the surface of the sun.

Luckily, we do not need to get to those 9,000°F temperatures to tap into geothermal energy. Geothermal power plants can run off temperatures ranging from just 250° to 700°F; heat can be used directly from temperatures ranging from 100° to 300°F for space heating, industrial, and agricultural uses; and the consistent 50°–60°F found only 10 feet underground can heat and cool buildings and communities of all sizes.

Geothermal technology harnesses the Earth’s heat. Just a few feet below the surface, the Earth maintains a near-constant temperature, in contrast to the summer and winter extremes of the ambient air above ground. Farther below the surface, the temperature increases at an average rate of approximately 1°F for every 70 feet in depth. In some regions, tectonic and volcanic activity can bring higher temperatures and pockets of superheated water and steam much closer to the surface.

Three main types of technologies take advantage of Earth as a heat source:

1. Ground source heat pumps
2. Direct use geothermal
3. Deep and enhanced geothermal systems

Geothermal energy is considered a renewable resource. Ground source heat pumps and direct use geothermal technologies serve heating and cooling applications, while deep and enhanced geothermal technologies generally take advantage of a much deeper, higher temperature geothermal resource to generate electricity.

1. Ground source heat pumps

A ground source heat pump takes advantage of the naturally occurring difference between the above-ground air temperature and the subsurface soil temperature to move heat in support of end uses such as space heating, space cooling (air conditioning), and even water heating. A ground source or geoexchange system consists of a heat pump connected to a series of buried pipes. One can install the pipes either in horizontal trenches just below the ground surface or in vertical boreholes that go several hundred feet below ground. The heat pump circulates a heat-conveying fluid, sometimes water, through the pipes to move heat from point to point.

If the ground temperature is warmer than the ambient air temperature, the heat pump can move heat from the ground to the building. The heat pump can also operate in reverse, moving heat from the ambient air in a building into the ground, in effect cooling the building. Ground source heat pumps require a small amount of electricity to drive the heating/cooling process. For every unit of electricity used in operating the system, the heat pump can deliver as much as five times the energy from the ground, resulting in a net energy benefit.  Geothermal heat pump users should be aware that in the absence of using renewable generated electricity to drive the heating/cooling process (e.g., modes) that geothermal heat pump systems may not be fully fossil-fuel free (e.g., renewable-based).

2. Direct Use Geothermal

Direct use geothermal systems use groundwater that is heated by natural geological processes below the Earth’s surface. This water can be as hot as 200°F or more. These groundwater reservoirs can reach the surface, creating geysers and hot springs. One can pump hot water from the surface or from underground for a wide range of useful applications.

The water from direct geothermal systems is hot enough for many applications, including large-scale pool heating; space heating, cooling, and on-demand hot water for buildings of most sizes; district heating (i.e., heat for multiple buildings in a city); heating roads and sidewalks to melt snow; and some industrial and agricultural processes. Direct use takes advantage of hot water that may be just a few feet below the surface, and usually less than a mile deep. The shallow depth means that capital costs are relatively small compared with deeper geothermal systems, but this technology is limited to regions with natural sources of hot groundwater at or near the surface.

3. Deep and Enhanced Geothermal Systems

Deep geothermal systems use steam from far below the Earth’s surface for applications that require temperatures of several hundred degrees Fahrenheit.

To access this deep heat, at least two wells must be drilled. It can involve drilling a mile or more below the Earth’s surface. Cold water is injected from one well, it is heated by the rock and is extracted from the other well. The two wells are typically 800 to 1000m apart. In such a system, the water will travel from one well to the other only if the rock between the wells is sufficiently permeable.

Natural rock permeability is not high enough but can be enhanced by well-established oil and gas engineering techniques. These systems are called Enhanced Geothermal Systems (EGS).

As the water rises to the surface, the pressure drops and the water vaporizes into superheated steam. Geothermal steam can be used to spin a turbine and generate electricity.

Once the heat is utilized, the now-cooler water is pumped back underground.

EGS is not viable at present at all places because of high costs of drilling and exploration.

Triggers for Growth – Anywhere Geothermal

Currently the Geothermal is only tapping the low hanging fruits, places like Iceland where you’ve got everything you need is just lying at the surface.

But the main growth will come when we have technology to use geothermal anywhere. The earth heat is everywhere but the cost of utilizing it has to come down.

What are the best investment opportunities?

There are global companies that have been working for decades to build their competitive advantage in this field, few of them will be the shining stars in this long-term growth story. Visit Trikaal Resources page to explore the best companies – not just in geothermal, but in other exciting sectors as well.