Geothermal Heat Pumps in the U.S. and Europe

Already back in 1852 the concept of moving heat from a place of lower to higher temperature was invented and the first sketches of the heat pump were laid out. However, it wasn’t before a century later, an inventor with the name Robert Webber, coined the technology known as geothermal heat pumps (GHP).

Since then, commercial popularity has increased tremendously. The technology has a worldwide annual growth of 10% – one of the fastest growing ways of harnessing renewable energy. Since geothermal heat pumps only require temperatures in the range between 5 and 30 degrees Celsius, they can essentially be utilized in almost all parts of the world.

Worldwide geothermal installations

Source: Curtis, et al. World Geothermal Congress, 2005.

The majority of the growth happens in the United States and Europe, but countries such as Japan and Turkey are starting to show interest in the technology as well.

The U.S. is on top when it comes to installed capacity – almost two thirds of the total capacity of the world. About 80.000 new geothermal heat pumps are installed in this country every year. This might look impressive at first glance, but lets look a bit closer at the numbers:

Geothermal capacity in Europe

Source: EurObserv’ER 2007

Sweden, at the very top in Europe, has 20% of the worldwide capacity. This country only has a population size of 9,4 million (as opposed to the population in the U.S, which now has surpassed 314 million).

In other words, every person in Sweden has an average GHP capacity over ten times greater than in the U.S.!

Looking from this new perspective, why is the capacity in Sweden that much higher than in the U.S.?

United States

Most GHPs in this country are made for peak cooling, which means they are oversized for heating (with the exception of the northern states). Over 600 schools in the state of Texas have now installed geothermal heat pumps where the main purpose of the technology is cooling.

The annual full-loading heating hours are therefore drastically reduced (as opposed to GHPs in climates that need heating) – only 1000 hours per year.

Europe

Most countries in Europe, and certainly Sweden at the top of the list, install geothermal heat pumps first and foremost for heating. In these environments, air conditioning is rarely required.  Most units are designed to provide the base load of heat, while often fossil fuels such as natural gas is used for peak demand. This translates to full-load operation somewhere between 2 300 hours annually – over twice the amount of the GHPs in the U.S.

Because of the rise of commercial and industrial applications of geothermal power, the number of GHPs sized for cooling is on the rise in Europe as well.  In the early 1980’s the popularity of geothermal heat pumps started catching on in Sweden. Within five years 50 000 units had been installed in Swedish homes. There are three main reasons that explains the popularity of geothermal heat pumps in this country:

  1. The climate and need for heating brings the costs down (as discussed above)
  2. Public awareness
  3. Financial incentives

Ground source or geothermal heat pumps can be used virtually everywhere and can bring great benefits to the table whether it is for heating or cooling – or both.

Galt House East Hotel in Kentucky houses one of the largest geothermal installations in the country, supplying a combined space of 161,650 square meters with heating and air conditioning needs. This brings in $25,000 in savings every month!

It should be clear that there is a lot of potential both for geothermal heating and cooling in the U.S. Both the government and states needs to get better at creating public awareness of the technology and its benefits.

This article was written by EnergyInformative, a company that spreads information about renewable sources of energy such as geothermal.

Source: U.S. Department of Energy

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