Geothermal Engineering

Geothermal energy (from the Greek roots geo, meaning earth, and thermos, meaning heat) is power extracted from heat that is stored in the earth.

Our planet is a huge source of energy. In fact 99.9% of the planet is at a temperature greater than 100 degrees Centigrade, so geothermal energy is a significant renewable resource. This energy comes in the form of heat, hence ‘thermal’, and it comes from the ground, hence ‘geo’, as opposed to energy that comes from the sun, wind, water, or carbon deposits.

In some places the natural groundwater, heated by this geothermal energy, finds its way to surface and emerges in hot springs or steam geysers, which have been used by humans for bathing and agriculture since pre-history. So geothermal energy has been used to provide heat for as long as people have been around to take advantage of it.

Today, geothermal energy can be used to provide larger-scale heating, and to generate electricity. In Iceland, which has abundant geothermal energy resources, the resource is used to provide the majority of the electricity and heating demands of the country. Geothermal energy is an obvious source of clean and renewable energy.

Geothermal energy is not new. It has been around as long as there have been people to harness it.

The American Paleo-Indians were the first known humans to use geothermal energy, over 10,000 years ago. They used hot springs to bathe and heat their settlements, and there is evidence they also used them as a healing source.

Prince Piero Ginori Conti tested the first geothermal generator on 4 July 1904, at the Larderello dry steam field in Italy in 1904.

In 1922 the USA produced its first geothermal electricity plant which output 250 kilowatts to light the streets and buildings in the area, but it wasn’t until the 1960s that it constructed the first large-scale industrial geothermal energy plant, producing 11 megawatts of environmentally friendly, renewable, geothermal electricity.

This was a huge step, and helped inspire other organisations and governments to look seriously at geothermal energy. There are now geothermal energy plants in over 22 countries throughout the world, and as the technology improves, and the environmental benefits become clearer, it is still regarded as a major source of clean power for the future.

Hot water or steam is pumped from the Earth and used to drive turbines to create electricity.  The used water is then pumped back into the ground where it is reheated by the Earth.  It is then pumped again and the recirculation continues.

Power plants usually take two to four years to complete, depending on the geological conditions.  Once they are completed they continue to run for at least 25 years.

Geothermal energy will be available for as long as the Earth maintains a hot core. This is, to all intents and purposes, for ever.

There are three major areas where we can benefit from geothermal energy:

1. The opportunity for Cornwall to lead the Country in the development of renewable energy
2. The chance for Cornwall to develop its low carbon economy by capitalising on renewable heat for either industry, agriculture or the development of sustainable communities
3. The possibility for Cornwall to establish a global centre of excellence in geothermal engineering

Environment

Geothermal energy is a renewable source with a minimal footprint and produces low or zero emissions.

The processes used to extract geothermal energy produce low - or even zero - CO2 emissions. Once the geothermal energy power plant has started there is no need for fuel transportation to the site or waste removal from the site. And there is minimal impact, with no unsightly wind turbines, windmills or chimneys.

In addition to electricity, geothermal plants produce large quantities of renewable heat. The use of renewable heat is seen by the UK government as a key element in reducing CO2 emissions.

Energy

Geothermal energy has been used for millennia for bathing and agriculture, so we already know that it can be used as a source of readily available, clean power.

However, it is no secret that we are in an energy crisis, with current methods slowly draining the earth of its carbon resources and unstable energy costs. Geothermal energy is part of the solution and already supplies 10 GW of electricity Worldwide.

Right now, new techniques are enabling deep geothermal energy resources to be developed. In the US, for example, the extractable deep geothermal energy reserve is estimated at 2,000 times the current total annual domestic electricity demand (MIT, The Future of Geothermal Energy, 2006).

In addition, The Economist said in June 2008 on deep geothermal energy: “it has got the lot. No unsightly turbines. No need to cover square kilometres of land with vast mirrors. And it is always on.”

Economy

Economies depend on energy. Unlike wind or solar, geothermal plants do much more than just export electricity. The renewable heat produced by the plants can provide a source or both energy and employment to the local community, whether in industry or agriculture. Geothermal plants are unique in this respect. Whole communities can spring from a geothermal heat supply such as Bath did in Roman times.

Fossil fuels take resources from the planet and produce CO2, a greenhouse gas, as well as nitrous oxide and sulphur.

Wind and water power are very clean sources of power, but they are subject to changes in weather and climate. Geothermal energy is always on – 365 days a year, 24 hours a day.

Geothermal energy plants tend to be very localised – that is, the energy is produced on-site – so they don’t incur the transport costs and increased road traffic of other energy sources.

The renewable heat generated by the plants provide local employment opportunities.

President Obama said: “We can hand over the jobs of the future to our competitors, or we can confront what they have already recognized as the great opportunity of our time: the nation that leads the world in creating new sources of clean energy will be the nation that leads the 21st century global economy.”
Source: US Department for Energy

Mr Cameron said: “It's (geothermal energy) been talked about for years, but now it could be within our grasp. And if you look at the geothermal maps of where the suitable locations are in the world, Cornwall really stands out. There's absolutely no reason why we shouldn't be tapping into this. Experts think that, if we really got our act together, deep geothermal technology could meet as much as 10 per cent of our electricity needs, so it's not a trivial issue.”
Source: Thisisdevon.co.uk

“David Cameron yesterday vowed that a Conservative government would increase financial incentives for geothermal energy projects in the UK, promising to accelerate the rollout of feed-in tariffs for ground source heat pumps and introduce new support for larger-scale deep geothermal plants.”
Source: Businessgreen.com

Geothermal electricity generation is a safe and well established technology.  Most plants operate by abstracting water and re-injecting water to the earth to ensure that the natural equilibrium is not disturbed.  Minor earth tremors have been caused by this process but it is very rare for such an event to be felt at the surface.  Geothermal Engineering will be working with local academics and experts from Imperial College, London to ensure that the planned system is correctly monitored and managed. They will also work closely with the local community to keep them involved and informed at each step of the development.

No. The earth’s core is extremely hot and much, much deeper than any geothermal system. In geological terms, the power plant only scratches the surface, using heat that is transmitted into the earth’s outer crust. Thus, with properly managed use of water resources, the source of geothermal energy – The Earth’s heat – will be available indefinitely.

Parts of Cornwall have geothermal gradients (the difference between the surface temperature and the temperatures at depth) and heat flows that are well above the worldwide average and among the highest in Northern Europe outside zones that contain volcanoes. This makes it well suited for geothermal energy production.

Geothermal Engineering is working very closely with local agencies and the community to make sure it offers as many benefits as possible to the locality. This includes looking at the environment, the local infrastructure, energy requirements and the effect on the economy.

All the geothermal energy information on this website is free for you to use. You can also download a lot of information from the geothermal energy downloads page.

If you want to talk to someone about geothermal energy generally, or Geothermal Engineering specifically, please use the contact page. We’ll happily talk to you!

The benefits are threefold:

1. The opportunity for Cornwall to lead the Country in the development of renewable energy
2. The chance for Cornwall to develop its low carbon economy by capitalising on renewable heat for either industry, agriculture or the development of sustainable communities
3. The possibility for Cornwall to establish a global centre of excellence in geothermal engineering

The first plant should be operational by 2012-13.  If the project proves successful then additional plants will be rolled out over the course of 20 years.

Funding for the geothermal energy project will come from a combination of private finance and the Low Carbon Industry Fund. The private finance is being raised in conjunction with an investment bank.

The first plant will cost approximately £40 million to build and represents a substantial investment in Cornwall

The sound produced by drilling will be heard as approximately 43 decibels (dB) when standing 250 metres away from the site. This noise diminishes with distance.  Normal conversation, heard from a distance of one metre is approximately 50 dB, while a car driving past someone standing 10 metres away will be measured at approximately 70 dB. The noise will be mostly caused by the generators that power the drill (rather than the drilling process itself), and these generators will be well-insulated to further reduce sound. The drilling for the first well will continue for approximately 4 months.

Iceland is a major user of cheap, clean geothermal energy. It is such a volcanic area that the geothermal energy potential is vast. So, it has five major geothermal plants which produce a significant proportion of the country’s electricity, and nearly nine in ten buildings take their heat directly from geothermal heating.

In fact, Iceland’s geothermal energy is so inexpensive that some pavements in Reykjavik are heated!

On the other side of the world, New Zealand has played an important role in the development of geothermal energy. Its 1958 Wairakei plant was the second major geothermal energy facility after Larderello in Italy.
The country’s volcanic regions produce over ten percent of its electricity, and this is set to grow significantly with several major new geothermal energy projects under way.

Globally, 24 countries generate electricity from geothermal energy resources and there are deep geothermal systems currently being developed and tested in France, Australia, Japan, Germany, the U.S. and Switzerland as well as the UK.

It all depends how deep you wish to go.  With current technology depths of approximately 5kms are considered accessible.  If in the future, as is expected, drilling technologies improve, many areas of the UK could be favourable.

Geothermal Engineering Ltd is a renewable energy company formed to develop the UK's first commercial geothermal power plant, to be based in Cornwall. The power output from the plant developed by Geothermal Engineering Ltd will be greater than any other plant in the UK. The plant has been designed to be of commercial scale to prove that geothermal power is a serious competitor in the renewable energy market. Additionally, the potential for geothermal power in the UK would mean that the need for unsightly wind turbines in the countryside could be reduced.