Global IssuesCLIMATE CHANGE: Negawatts and Smart Grids
Electricity is indispensable to modern life, but its generation is responsible for 40 percent of the carbon dioxide emissions that cause global warming and climate change.
While wind and solar energy are carbon free, they are heavily dependent on weather conditions. No wind blowing or no sun shining means no electricity - and this simple equation becomes more apparent as the use of wind turbines and solar power plants grows.
Renewable energy sources are valuable in meeting electricity demand during periods of ‘high base load demand’ - the amount of power required to meet minimum demands based on estimations of consumer requirements.
As yet, this base load supply is met by power generated at plants that run continuously on environmentally questionable sources - nuclear or coal.
Better weather forecasting is one way to harness wind and solar power more efficiently. But researchers now talk about ‘smart grids’ and ‘negawatts’ - expressions that were current at the Nov. 26-27 conference in the German capital of Berlin on the ’Smart Revolution of Electricity Management’.
'The grid that distributes electricity today is a dumb one,' said Eicke Weber, in charge of solar energy systems at the Frauenhofer Gesellschaft, the leading, state-owned, German institute on scientific research.
'This grid works in one way only - electricity flows from giant power plants to consumers,' Weber said. 'In the near future, however, electricity will be generated in small plants and it will flow in both directions - from generators to consumers and back. It will be consumed when it is the cheapest, and can be stored.'
'To manage this changing landscape of electricity supply, and at the same time solve the challenge of climate change, we need smart grids,' Weber said.
The smart electricity grid of the future will use digital technology to monitor all electricity supply flowing into the grid while controlling the consumer's demand right down to household appliances to save energy, reduce costs, and increase reliability of supply, he explained.
In addition, a smart grid will use superconductive lines to increase the efficiency of transmissions and improve the capacity of the system to store electricity which is not being consumed and deliver it at periods of peak demand.
Storage capacity constitutes a salient feature in the management of fluctuating supply generated by solar and wind sources. Electricity that is not used immediately and stored for use during periods of peak demand is called negawatt.
Ulrich Foeken, manager of the regional German electricity provider EWE, which operates a wind turbine park in northern Germany, demonstrated how negawatt works.
Foeken cut off a wind turbine providing electricity to a model cold storage used by local fishermen and automatically, the cold storage reduced its electricity consumption. 'Normally, the storage house is cooled to minus 25 degrees Celsius,' Foeken said. 'But actually, we only need temperatures of minus 18 degrees Celsius for preserving the fish.'
The negawatts - the electricity the cold storage does not need to immediately consume - allow energy providers to avoid using a carbon or a nuclear fuelled power plant to meet peak base load demand, thus helping them to reduce greenhouse gas emissions.
'Peak electricity demand is particularly expensive, and from an environmental viewpoint, particularly dirty,' Ludwig Karg, director of the German state-led programme E-energy, told TerraViva.
E-energy, organiser of the conference on the smart revolution of electricity management, has started six energy model regions in Germany, aimed at 'demonstrating how the immense potential for optimisation presented by information and communication technologies can … enhance the efficiency and environmental compatibility of the power supply and ensure supply security,' Karg said.
'We want and need to create the Internet of electricity, for a flexible management of supply and demand,' Karg told TerraViva.
'All actors of the sector, from the generators to the consumers, passing through the operators of the grid, must be linked to each other. Every device, every appliance at the consuming end shall be connected to all electricity providers' regulating mechanism, as in a plug and play system, supported by smart meters, to monitor consumption and ponder supply and prices at any given moment, to constitute a smart grid,' Karg added.
That means that household appliances such as washing machines can be started or stopped according to the availability of cheaper electricity supply.
Smart grids need accumulators to store the electricity provided by fluctuating sources at moments of peak supply, and deliver it at moments of high demand. Such accumulators could be used in the electric cars of the future.
But smart grids have a downside. They intrude into consumers' privacy through devices controlling practically all aspects of a household's life.
'Electricity is not just another merchandise,' Georg Stark, a psychologist working for a private market research agency in Cologne, some 300 km south of Berlin, said at the conference.
'You have to be aware that electricity is a particular good. Consumers blindly trust their electricity provider. When they go to the toilet in the middle of the night and switch on the lights, they do not think about anything,' Stark said. 'Now you want to invade this privacy with your smart grids. Better think twice about it.'
(*This story appears in the IPS Terra Viva daily online newspaper published for the COP 15 in Copenhagen)
© Inter Press Service (2009) — All Rights ReservedOriginal source: Inter Press Service