Bioenergy derived from agricultural, municipal and timber industry waste burnt in high efficiency furnaces has recently been mooted as an alternative to the energy presently generated from the burning of brown coal here in Australia.
To turn waste into energy is an attractive and decidedly more environmental friendly option to burying the rubbish in landfills or to let the waste pollute rivers and seas. The Nordic countries have been leading the world in the bioenergy field with highly efficient centralised power plants in use that burn waste materials at high temperatures since the 80s. These plants these days also come equipped with the latest technologies in removing harmful gaseous substances from the emitted flue gases including carbon dioxide.
Typically these regional power plants serve communities of up to 30,000 inhabitants in size with their day-to-day requirements of heating. They do so through the distribution of heated water to households surrounding the power plant. In addition in co-generation power plants the heat is also converted into electricity and fed into the grid supplementing the base load of hydroelectric and nuclear power in Sweden.
The Swedish countryside is traversed by numerous rivers and transmission lines running between the hydroelectric power plants situated by the rivers and the major cities along the coast of the Baltic and North Sea. Hydroelectric power accounts for 50 per cent of the total electricity production while the regional co-generation plants that are closer to the cities contribute 2.7 per cent of electric energy.
The energy produced in the regional power plants dotted around Sweden is used in the same way as electricity from hydroelectric and nuclear power plants in ensuring a secure source of base load energy. You can’t turn these power plants on and off since they are required to supply connected households with electricity for lighting and hot water for heating during the long and cold winters.
The successful development of a bioenergy sector in Sweden has required major public and private investment in infrastructure over decades. For instance specialised heavy machinery has been developed for the handling of agricultural and forest industry waste. An efficient transport system that ensures that the waste reaches its destination with minimal impact on the environment has also been considerd. Investment in public awareness raising campaigns have been required to educate the population of the benefits of the sorting of household waste into recyclable materials and into waste material suitable for destruction through burning.
The suboptimal “one bin fits all” schemes which presently operate in Australia where paper, glass , tin cans , plastic food and drink packaging is mixed into one recycling bin has in Sweden been replaced by neighbourhood recycling stations, often located close to supermarkets, where every household brings their rubbish and then sorts it into different containers. There are containers for coloured glass, clear glass, metal cans, newspapers, plastic coated paper, and different types of soft and hard plastics.
In addition glass bottles, aluminium cans and plastic bottles for soft drinks attract a deposit fee of 20 to 40 cents which you get back when you return the empty bottle or can to the shop. In every supermarket there is an empty bottle return machine that collects and counts the number of bottles and cans and prints a receipt for the value of the empties you have brought in that you can cash in at the supermarket.
There are clear public benefits of introducing these schemes. As an example 950 million aluminium cans are recycled every year in Sweden which is 87 per cent of the total drinks in aluminium cans consumed. To make a new can from recycled aluminium saves 95 per cent of the energy required to manufacture a new can.
Similarly 80 per cent of clear plastic drink bottles, which also attract a deposit, are recycled.
The Swedish Government target for recycling of drink containers is 90 per cent by 2015 when the recycling scheme with deposits on plastic bottles and cans will have been in place for 30 years.
However the recent down turn in consumption of discretionary food items due to the global financial crisis as well as the trend to use less packaging for foods and drinks in general is having an impact on the amount of waste available to the bioenergy sector in Sweden.
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