FAQ

What is heat power?

Heat power is utilizing already existing heat sources and making it in to clean electricity. Heat power primarily comes from two sources: the earth’s geothermal heat and industrial  heat. Geothermal Heat power and Industrial Heat power.

What isn’t heat power?

Nuclear energy and energy from fossil fueled power plants are not considered heat power. Although they both make electricity out of heat, they do not rely on pre-existing heat sources. Instead, the processes they use to generate power emit greenhouse gases in a non-sustainable manner or leave toxic, radioactive substances for future generations to take care of.

How do we create power from heat?

Heat is used to evaporate a liquid, water or benign organic medium, and drive a turbine coupled to an electricity generator. The gaseous medium is then cooled and converted into a liquid. The pressure difference in the machine is what drives the power generator. All power plants work according to this principle; the trick is to increase the efficiency to make the process economically viable.

Does the heat have to be a certain temperature?

Traditionally, geothermal heat power plants have been located over sources of heat with temperatures above 200 degrees Celsius. This limited heat power to specific places on the planet located along the edges of the tectonic plates, called the “Ring of Fire”. At these sites they sometimes even pump 90-degree water back into the earth. But new technologies are allowing us to harness from temperatures as low as 70 degrees Celsius.

Is one type of heat power better than the other?

No. Just like we need other renewable energies, such as solar and wind power, we need to take advantage of every source of heat power. While geothermal heat power is the core business of energy providers, industrial waste heat power is a non-core business for industries. However, you could say that capturing industrial heat power has the advantage of converting waste into a usable resource, while geothermal heat power is taking advantage of a massive, still mostly untapped resource. Industrial waste conversion also has the advantage of being easier to deploy, as geothermal sources require drilling to obtain a source.

What is the potential of heat power?

Consider that 50% of global energy waste is in the form of heat. Imagine if that energy could be put back into the grid. Even at 10% efficiency, it would immediately yield 5% more primary energy. On a much grander scale, the untapped heat under the earth’s surface could provide a constant source of 15,000 gigawatts for 200 years with a negligible cooling effect.

Who invented heat power?

You could say that the invention of the Organic Rankine Cycle is what initially made it possible to generate heat power. US-based Ormat and the Italian company Turboden pioneered the industry. Today they are the global leaders in the design, manufacture and maintenance of ORC systems.

Why is heat power not as well known as other renewable energies like solar or wind power?

The first reason has to do with efficiency. It is more efficient to generate power when there is a significant difference in temperature. Burning coal, oil and gas at high temperatures for power generation is cheap - as long as you can emit CO2 free of charge. Until recently, renewable heat power has not been economically viable, but the technology has improved. In fact,  all renewable energies are becoming more cost-competitive and we are seeing strong growth in the industry, albeit from a small base.

Secondly, in the geothermal field, the risks connected with drilling have been very high, especially if you wanted to find heat of above 200 degrees C. But with today’s superior drilling and exploration techniques, finding out what’s below the earth’s surface is not as much of a gamble or monetary hurdle.

The final reason is timing. New technologies are enabling us to transform low-temperature heat into energy at lower prices, like the machine developed by Swedish clean tech company Climeon. Ten years ago, if your heat source wasn’t at least 120 degrees, it was unusable.

Who is leading the world in heat power?

That depends on how you measure it. Right now more than 50% of the energy in Kenya comes from geothermal sources. Countries situated on the Ring of Fire are naturally ahead of the game when it comes to heat power; in Indonesia geothermal is $50-billion-dollar business. When it comes to harnessing waste heat, a few companies are leading the way, such as Virgin Voyages and Viking Line, both of which use heat power modules from Climeon to produce electricity from waste heat aboard their ships.

What is the main advantage of heat power over other renewables?

Solar power and wind power are important renewable energies, but they are intermittent. You can only produce solar electricity when the sun shines, and wind electricity only when the wind blows. We need electricity all the time. We therefore need a way to store that electricity, baseload power plants, or both.

Wind requires a lot of space. Hydropower is a terrific renewable energy but it's limited; we have already converted most rivers into power plants. The potential of biomass is limited for many reasons - competition with food production, carbon dioxide emissions (even if biomass combustion can be made to be CO2-neutral), and the slow growth of biomass.

The biggest advantages of heat power are:

  1. It can provide 24/7 baseload electricity.
  2. It does not require a lot of space.
  3. It reduces the carbon footprint of industries by converting waste heat to useful electricity.

In other words, heat power is the number one candidate for the transition to a sustainable, fossil-free energy system.

What companies provide heat power?

Ormat, Turboden, Devetec, Calnetix, Orcan, OpCon, ElectraTherm, e-rational, Exergy, Climeon and others are companies that operate in the field of heat power. But there are many more, such as Zuccato, Bosch, Triogen and others. Here's a longer list.