Vattenfall - Future production technology

Future production technology

The proportion of renewable energy sources in the generation system will increase. To be able to deliver energy at a cost that society can afford, availability and economic limitation requirements must also be taken into account.

In one of our development programmes, we are studying generation sources that have not yet been commercialised. The focus is on energy sources that have the potential for becoming important in the longer term, such as wave power. We are also following other energy sources, such as solar energy and geothermal energy.

Wave energy

We are assessing several ocean power technologies, such as wave power, salinity power, tidal and marine current technologies. Substantial research is in progress and considerable demonstration activities are initiated around the world. Most of the attention is focused on wave energy, which is judged to be the next renewable technology to be commercialised (after wind power). It has been estimated that the total wave energy resources of all European coastlines are around 1000 TWh per annum. The economic potential depends on costs of the specific techniques, the transmission costs and the efficiencies. Most wave power concepts are being developed for the high-energy wave conditions along the European west coast, and the most interesting markets right now are in Portugal and the UK, due to the generous subsidies. There are few technology options available for moderate wave conditions such as those outside Sweden, Denmark, Germany, Poland, etc. However, Uppsala University, Sweden, has developed an interesting concept based on a permanent magnet linear generator driven by a buoy at the sea surface.

Full-scale test

Vattenfall is funding a considerable part of a full-scale test at Islandsberg on the Swedish west coast, and the theoretical calculations of power output have been confirmed.
Vattenfall and the Seabased Industry AB company, together with the Swedish Energy Agency, are planning a 10 – 15 MW demonstration plant based on Uppsala University technology. The wave energy park – the Bohus project – will consist of buoy clusters and will produce approximately 50 GWh annually.

Solar energy

The sun is the origin of most of the energy sources we employ. However, when talking about "solar energy", we usually mean the utilization of direct solar radiation in solar cells and solar collectors.

• Electricity is generated in solar cells
• Heat is generated in solar collectors

Since the early 1990s, we have been participating in various international research programmes concerned with solar electricity. We have been developing the solar heat technique since the end of the 1970s. The objective of our continued work on solar energy has been to increase our knowledge of the technical and economic conditions, particularly for solar electricity.

Solar cells for electricity

Today's solar cells have a maximum efficiency of 15 percent. This means that 15 percent of the solar energy impinging on the solar cell is converted into electricity. Our energy demand is at its highest when the solar intensity is at its lowest. In the longer term, local small-scale power generation may become an attractive alternative to centrally generated electricity for certain applications and in parts of the world in which solar radiation is stronger that in northern Europe. But heavy subsidies will be needed for many years before the technique is sufficiently cost effective.

Solar collectors for heat

A solar collector absorbs solar heat in a system of tubes carrying water. Solar collectors are often mounted on roofs and the solar heat they collect is transferred to water heaters. The use of solar heat in northern Europe is limited, since the number of hours of sunlight is a minimum when the heat demand is at its maximum. In Scandinavia, Vattenfall has decided to await developments without investing its own efforts, since we cannot see any opportunity for being able to deliver solar heat at prices that would be attractive to customers, not even if we view optimistically the prospects of future development.

Geothermal energy

Geothermal energy uses the elevated temperatures in the earth’s interior to generate heat and electricity, and this heat is available continuously. It has excellent potential base load properties and is globally one of the most widely used sustainable energy sources, mainly in countries in which surface volcanic action is present. Geothermal energy has huge potential. But very costly deep drilling is needed to achieve even moderate water temperatures in central and northern Europe (except Iceland). As a result, the utilization of geothermal energy has so far been of minor interest in the countries in which Vattenfall has operations. However, the geological conditions in Poland and Germany are much better than in Scandinavia. The procedure for extracting heat consists of establishing a flow of water between at least two boreholes drilled down to a depth of 3-5 km and interconnected by natural or created fissures. Since there are no dependable methods for assessing the nature of the rock at great depths, there is considerable risk of poor results, with low energy output from the boreholes, or none at all. The low water temperatures achieved result in low efficiency of the conversion of heat to electricity which, combined with the high costs and risks, have so far limited the use of geothermal energy in the Vattenfall market area. Nevertheless, Vattenfall is actively following developments, and operates a geothermal CHP (Combined Heat and Power) plant in Neustadt-Glewe in Germany, which generates 210 kW of electricity and 6500 kW of heat. The second geothermal power plant with an electric power output of 750 kW is under construction in Gross Schönebeck, north of Berlin.