Geology, energy use and climate are closely interrelated. Geological knowledge and information helps us, for example, to locate various energy raw materials and to see traces of previous climate changes.
Globally, fossil energy sources are still dominant, and this affects the climate in various ways. In 2011, about 80 per cent of the world's energy supply came from fossil fuels such as coal, oil and natural gas.
In Sweden, the situation is better, but our energy supply today is still to some extent dependent on imported crude oil and petroleum products. This is despite the fact that Sweden has exceptional conditions for producing energy in a manner that is sustainable and has less impact on the climate.
Geology for energy
Knowledge and information about soil, rock and groundwater is often crucial to the environmentally adapted expansion and conversion of the energy supply.
Use of peat for energy production
Sweden is one of the world's most peatland-rich countries. The most significant use of peatlands through history has been in forestry and agriculture. Other significant applications of peat are and were as fuel, culture media and as litter peat. SGU has a great deal of information about Sweden's peatlands and guidance on what to consider when planning for the cutting of peat.
An expansion of wind power on land has a major impact on the environment, locally due to foundations and arrays, and locally or elsewhere due to the quarry operations required for the production of concrete aggregates and road materials.
Gravity foundations require considerable quantities of aggregate materials. SGU advocates the use of bedrock foundations if the bedrock is of sufficiently good quality and if it is close to the surface.
A number of shoals and offshore bars within Sweden's territorial waters and economic zone are of interest for the establishment of large-scale wind farms at sea.
In these areas, marine geological information is needed to determine the location and type of foundations for the wind turbines, and also to assess the impact on the habitat of marine organisms.
Geothermy and ground source heat pumps
In Sweden, the conditions for geothermal energy are considered to be best in areas with high groundwater assets at great depths (2–3 km), i.e. areas with thick strata of sedimentary bedrock or fault zones such as Vättersänkan. The largest commercial geothermal plant at present is in Lund, 30 per cent (250 GWh) of whose district heating needs are covered by 20-degree water from sedimentary strata at a depth of approximately 700 metres.
The upper layers of the ground store heat from the sun, which can be harnessed. The temperature of the soil and rock layers from which the heat is taken is usually about the same as the annual average temperature. There are currently more than 300,000 ground source heat pumps in Sweden, which are mainly used to heat homes. The advantage is that it is possible to heat a house using less electrical power than when heating it with electricity directly.
Greater use of biofuels requires extensive knowledge of the production characteristics of forest and agricultural land. Consideration needs to be given to water and nutrient conditions, bearing capacity and accessibility, protection against soil pollutants and groundwater protection. The maps and databases of soil types and soil geochemistry contain valuable information on matters concerning intensified production on forest and arable land.
Carbon capture and storage (CCS)
One way to reduce carbon dioxide emissions into the atmosphere from the burning of fossil fuels is to separate and store carbon dioxide in the bedrock.
In most contexts, Swedish hydropower is considered to have reached full development. However, there will always remain questions of dam safety, efficiency and the small-scale expansion of environmentally adapted hydropower. In the longer term, due to increased and more intensive precipitation, new questions concerning erosion and flooding may arise. Soil geology information is used for assessing erosion risks.
Other energy sources
In Sweden, the availability of fossil energy raw materials, such as oil and coal, is very limited. Shale gas is a form of energy that is arousing increasing interest, above all internationally but also to some extent in Sweden.
Geological information is needed both for locating uranium, which is used as fuel in nuclear reactors, and for storing the spent nuclear fuel.