Why Wave Power?
The obvious advantage of all forms of renewable energy (with the exception of bio-energy) is that no fuel is required, which eliminates the emission of carbon dioxide. However, it is not always mentioned that even renewable energy sources have a "cost" factor. Sometimes they require large areas and people living in the vicinity are affected in various ways. Renewable resources may also have an impact on their natural environment and on the organisms living there. The scale of these "costs" depends on the choice of the site and the type of energy production (amongst others). The potential of "green" energy sources varies as well, not in the least because of differences in energy content/energy density and in the amount of hours the energy source (sun, wind, waves, etc.) can be used during the year. When these and other physical/technical, economical and environmental factors are weighed up, wave energy stands out as being very competitive.
As the above figure shows, the energy content per unit increases in intensity from solar power, to wind power, to water. The reason for this is that nature concentrates solar energy in wind and then further amasses this energy in sea waves.
Direct use of solar power is limited because the degree of utilization is only 10-12 percent. Moreover, in Sweden the sun only shines 1000 of a year's 8760 hours. The rest of the time it is night, dawn, dusk or overcast.
Wind power plants are dependent on wind. The wind speed needs to be at least 13-15 m/s to fully utilize a wind power plant to its rated effect. For smaller types 10 m/s might suffice. Because it is not always windy, the degree of utilization is 25% on average (on land in Sweden ), going up to 30% if the plants are located at sea.
Waves continue to roll, even after the wind stops blowing, which leads to a higher degree of utilization than for wind power. The circumstances in Sweden , with moderate wave conditions, indicate a degree of utilization of 35% to 50% (depending on differences between the Baltic Sea and the west coast of Sweden ). However, in bigger seas and large oceans, this can go up to 70%. Furthermore, the energy density is a lot higher than for wind or solar power. The physical conditions for wave power are therefore very good and the relatively high degree of utilisation makes waves a predictable source.
Energy generation from wave power should thus have a considerable potential to contribute to our electrical energy production. This is especially the case along the coastlines of the big oceans, but is an option even for Swedish waters, provided that suitable technologies can be developed. About 70 percent of the earth's surface is covered by water. Various estimations show that the world's potential for wave energy is 10,000-15,000 TWh per year. That is about the same as the economic potential of hydropower in the world. In the Baltic Sea alone, the potential is calculated to be 24 TWh, which is much more than the planned Swedish development of renewable energy in the next 5-10 years.
Hydropower, which is based on stored, potential energy, is of course one of the best sources of renewable energy, since hydropower plants can be utilised close to 100 percent of time (provided it rains enough). This high degree of utilisation is not achieved that often, because hydropower is used to regulate the power production (i.e. adjust the production to the consumption which varies during the day). Fossil fuels, nuclear power and bio fuel are used in the same manner. Their energy generation is usually only interrupted because of maintenance or low energy consumption (e.g. during summer)
Direct use of solar power is limited because the degree of utilization is only 10-12 percent. Moreover, in Sweden the sun only shines 1000 of a year's 8760 hours. The rest of the time it is night, dawn, dusk or overcast.
Wind power plants are dependent on wind. The wind speed needs to be at least 13-15 m/s to fully utilize a wind power plant to its rated effect. For smaller types 10 m/s might suffice. Because it is not always windy, the degree of utilization is 25% on average (on land in Sweden ), going up to 30% if the plants are located at sea.
Waves continue to roll, even after the wind stops blowing, which leads to a higher degree of utilization than for wind power. The circumstances in Sweden , with moderate wave conditions, indicate a degree of utilization of 35% to 50% (depending on differences between the Baltic Sea and the west coast of Sweden ). However, in bigger seas and large oceans, this can go up to 70%. Furthermore, the energy density is a lot higher than for wind or solar power. The physical conditions for wave power are therefore very good and the relatively high degree of utilisation makes waves a predictable source.
Energy generation from wave power should thus have a considerable potential to contribute to our electrical energy production. This is especially the case along the coastlines of the big oceans, but is an option even for Swedish waters, provided that suitable technologies can be developed. About 70 percent of the earth's surface is covered by water. Various estimations show that the world's potential for wave energy is 10,000-15,000 TWh per year. That is about the same as the economic potential of hydropower in the world. In the Baltic Sea alone, the potential is calculated to be 24 TWh, which is much more than the planned Swedish development of renewable energy in the next 5-10 years.
Hydropower, which is based on stored, potential energy, is of course one of the best sources of renewable energy, since hydropower plants can be utilised close to 100 percent of time (provided it rains enough). This high degree of utilisation is not achieved that often, because hydropower is used to regulate the power production (i.e. adjust the production to the consumption which varies during the day). Fossil fuels, nuclear power and bio fuel are used in the same manner. Their energy generation is usually only interrupted because of maintenance or low energy consumption (e.g. during summer)