End to central planning
Sunday, 8 July 2007
Rebecca Bream
N most parts of the world, electricity is generated by large power stations and transmitted along high voltage networks, sometimes over long distances, to centres of industry and population that are hungry for power.
This was the logical way to organise electricity networks in the past, when governments were the main builders of power stations and energy efficiency was not a big concern.
Customers had supplies of power they could rely on and they did not need to know how or where they were generated. Large power stations were built out of town, and locations were determined by access to fuel rather than access to customers.
But increasingly this largescale, centrally-planned model looks inefficient and out of date.
Climate change has become a mainstream political issue, and energy customers are aware of the need to cut energy use and switch to cleaner forms of electricity generation to limit carbon emissions.
This has led to arguments that large power stations burning fossil fuels should give way to smaller, renewable energy units sited closer to where the power is used. Energy is lost when electricity is transmitted over long distances, and traditional power stations -- whether coal or gas -- only capture part of the calorific value of their fuel.
The waste heat is usually sent up a chimney and into the atmosphere. More than 60 per cent of the total energy in coal or gas can be lost at the power station, and 3.0 to 4.0 per cent is wasted during transmission.
The alternative is forms of "distributed energy", from microgeneration, such as solar panels and wind turbines for individual houses, to medium-sized combined heat and power (CHP) plants that supply factories, hospitals or housing estates.
CHP captures the waste heat produced by gas- or coal-fired power plants and uses it to provide steam for industrial processes, such as paper manufacturing, or to heat and cool buildings.
Nick Otter, director of technology and external affairs at Alstom Power, which manufactures power generation equipment, says CHP plants are up to 80 per cent efficient and therefore lead to significant reductions in carbon emissions. "It is a really efficient way of using the primary energy source."
CHP is more common in eastern Europe than in western Europe and the US, and is well-suited to densely-populated urban areas where heat can be easily piped to households. Mr Otter suggests that getting planning permission for such plants could be tricky in the UK, where people are not used to having power stations in residential areas, but that incentives such as subsidised heat could help overcome opposition.
In the UK, CHP is more common as a source of power and heat for industry. The UK government has set up a task force to look at removing barriers to investment in CHP, and is encouraging renewable CHP projects such as those that burn biomass - wood chips for instance.
Rory Tait, UK head of energy at law firm Eversheds, predicts that a sizeable number of CHP schemes will be rolled out in the UK over the next few years. He says plants can range in size from less than 1.0MW to about 30MW, with the larger plants usually linked to industry.
New rules governing property developments in the UK mean that developers need to obtain at least 10 per cent of their energy from renewable sources in order to secure planning permission. Mr Tait says CHP plants would be better suited to developments in urban areas than wind turbines, which might not get enough wind to work properly.
Although the technology is still relatively expensive, households are increasingly investing in wind turbines and solar panels in order to produce their own renewable electricity and heat.
Distributed energy enthusiasts are also promoting the idea of household boilers that contain fuel cells and can generate electricity as well as heating water. While they would still burn natural gas, they would be much more efficient than traditional boilers and could one day eliminate the need for large power stations. These "micro-CHP" boilers are already proven technology but need more work to make them small enough and cheap enough to appeal to consumers.
Distributed energy makes sense in theory, but there are practical barriers. Moving from large- to small-scale generation would require big changes to countries' electricity and gas infrastructure and could cause problems to the smooth running of their national grids.
Colette Lewiner, in charge of energy, utilities and chemicals for Capgemini Group, says the need to centrally-regulate power supply is a big barrier to the spread of distributed energy. "It is very difficult to manage a grid if you have a lot of small generators."
And microgeneration will only work if households install "smart meters" to allow accurate tracking of how much energy they produce as well as consume, and allow consumers to sell excess electricity back to the grid.
Smart energy meters are being rolled out in several parts of the world but many companies complain that they are too expensive.
Although there are hurdles, distributed energy looks set to grow in the coming years, however. The need to move away from fossil fuels and increase energy efficiency should push governments and energy companies towards embracing decentralised forms of generation.
Large power plants are likely to continue to play an important role in countries' energy mix, but, in 20 years' time, the present model may look very dated.
(Under syndication arrangement
with FE)
N most parts of the world, electricity is generated by large power stations and transmitted along high voltage networks, sometimes over long distances, to centres of industry and population that are hungry for power.
This was the logical way to organise electricity networks in the past, when governments were the main builders of power stations and energy efficiency was not a big concern.
Customers had supplies of power they could rely on and they did not need to know how or where they were generated. Large power stations were built out of town, and locations were determined by access to fuel rather than access to customers.
But increasingly this largescale, centrally-planned model looks inefficient and out of date.
Climate change has become a mainstream political issue, and energy customers are aware of the need to cut energy use and switch to cleaner forms of electricity generation to limit carbon emissions.
This has led to arguments that large power stations burning fossil fuels should give way to smaller, renewable energy units sited closer to where the power is used. Energy is lost when electricity is transmitted over long distances, and traditional power stations -- whether coal or gas -- only capture part of the calorific value of their fuel.
The waste heat is usually sent up a chimney and into the atmosphere. More than 60 per cent of the total energy in coal or gas can be lost at the power station, and 3.0 to 4.0 per cent is wasted during transmission.
The alternative is forms of "distributed energy", from microgeneration, such as solar panels and wind turbines for individual houses, to medium-sized combined heat and power (CHP) plants that supply factories, hospitals or housing estates.
CHP captures the waste heat produced by gas- or coal-fired power plants and uses it to provide steam for industrial processes, such as paper manufacturing, or to heat and cool buildings.
Nick Otter, director of technology and external affairs at Alstom Power, which manufactures power generation equipment, says CHP plants are up to 80 per cent efficient and therefore lead to significant reductions in carbon emissions. "It is a really efficient way of using the primary energy source."
CHP is more common in eastern Europe than in western Europe and the US, and is well-suited to densely-populated urban areas where heat can be easily piped to households. Mr Otter suggests that getting planning permission for such plants could be tricky in the UK, where people are not used to having power stations in residential areas, but that incentives such as subsidised heat could help overcome opposition.
In the UK, CHP is more common as a source of power and heat for industry. The UK government has set up a task force to look at removing barriers to investment in CHP, and is encouraging renewable CHP projects such as those that burn biomass - wood chips for instance.
Rory Tait, UK head of energy at law firm Eversheds, predicts that a sizeable number of CHP schemes will be rolled out in the UK over the next few years. He says plants can range in size from less than 1.0MW to about 30MW, with the larger plants usually linked to industry.
New rules governing property developments in the UK mean that developers need to obtain at least 10 per cent of their energy from renewable sources in order to secure planning permission. Mr Tait says CHP plants would be better suited to developments in urban areas than wind turbines, which might not get enough wind to work properly.
Although the technology is still relatively expensive, households are increasingly investing in wind turbines and solar panels in order to produce their own renewable electricity and heat.
Distributed energy enthusiasts are also promoting the idea of household boilers that contain fuel cells and can generate electricity as well as heating water. While they would still burn natural gas, they would be much more efficient than traditional boilers and could one day eliminate the need for large power stations. These "micro-CHP" boilers are already proven technology but need more work to make them small enough and cheap enough to appeal to consumers.
Distributed energy makes sense in theory, but there are practical barriers. Moving from large- to small-scale generation would require big changes to countries' electricity and gas infrastructure and could cause problems to the smooth running of their national grids.
Colette Lewiner, in charge of energy, utilities and chemicals for Capgemini Group, says the need to centrally-regulate power supply is a big barrier to the spread of distributed energy. "It is very difficult to manage a grid if you have a lot of small generators."
And microgeneration will only work if households install "smart meters" to allow accurate tracking of how much energy they produce as well as consume, and allow consumers to sell excess electricity back to the grid.
Smart energy meters are being rolled out in several parts of the world but many companies complain that they are too expensive.
Although there are hurdles, distributed energy looks set to grow in the coming years, however. The need to move away from fossil fuels and increase energy efficiency should push governments and energy companies towards embracing decentralised forms of generation.
Large power plants are likely to continue to play an important role in countries' energy mix, but, in 20 years' time, the present model may look very dated.
(Under syndication arrangement
with FE)