By Bruno De Wachter / Published on Tue, 2009-05-26 05:30
A Scientific American article provokes a lot of reaction
An article in the recent April edition of Scientific American discusses the statement of Jon Wellinghoff that the U.S. will never need to build another coal or nuclear power plant. He claims that all of the new capacity that is required could be delivered by new wind, solar, and biomass plants and — in a transition period — new natural gas plants. 'Nuclear and coal plants are too expensive,' he claims.
Jon Wellinghoff is the new chairman of the Federal Energy Regulatory Commission. With this statement, he goes beyond those of other Obama administration officials, who have strongly endorsed renewables and energy efficiency, but also say nuclear and fossil energies will continue to play a major role.
Scientific American noted that Wellinghof’s statement generated some sceptical reactions from leading experts at universities, research institutes, and energy associations. A lively debate on this topic has also taken off on the Power Globe expert forum (see April 2009 - Week 4).
Is baseload an anachronism?
Jay Apt, a professor at Carnegie Mellon University, reacted to Wellinghoff by saying renewables are not suitable for delivering baseload because of their intermittent character. This provoked Wellinghoff to respond that 'Baseload is an anachronism'.
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By Hans De Keulenaer / Published on Fri, 2009-02-13 13:16
Variability of weather and climate represents a significant source of risk to the electric power industry. Weather influences power trading, fuel acquisition, load forecasting, systems planning, hazard planning and a range of related tasks within the industry. Lead-times for weather and climate information range from minutes for rapidly changing hazard conditions and wind-power resources to decades for infrastructure planning. Demands on forecast accuracy are equally daunting.
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By Hans De Keulenaer / Published on Wed, 2008-10-15 13:01
A recent report from IEA explores how variable renewables can be integrated on a large-scale into the electricity system.
The report proposes to replace the term 'intermittency' with 'variability'. Calling renewables intermittent is misleading, since wind or solar power do not drop from full power to zero and vice versa - they are available at some level much of the time, and ramp up or down following gradients dictated by weather.
The main theme of the report is that hosting capacity of the electricity system for variable renewables can be much larger than previously reported, provided that a number of
measures are taken to increase system flexibility. The approach
recognises the problem, but offers solutions.
A number of
strategies are presented to smooth the effect of variability or to
increase flexibility of the electricity system to absorb it.
Smoothing factors:
- system-wide aggregation: aggregating wind or solar power over a wider area reduces variability
- Aggregation of the output of different generation technologies
- Better forecasting
Flexibility sources:
- Fast-response capacity in the generation portfolio
- Availability of storage
- Stronger interconnections of transmission systems
- Demand-side management and response
While there is no intrinsic ceiling to hosting variable renewables,
current networks may be inadequate for large-scale incorporation.
Substantial changes to networks and system operation will be needed.
And whatever the mix of above solutions adopted, there remains large
uncertainty on the cost and reliability of the resulting system.
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By Fernando Nuno / Published on Fri, 2008-04-04 14:16
Up to 40.8% of the overall electricity demand is supplied by wind power at some moments of the day in the Spanish electricity system. This record constitutes a real challenge for transmission system operators (TSOs).
In more general terms, renewable energy penetration strongly depends on the ability of TSO to evolve towards a new way of operating the system: dedicated predictability for renewable generation, voltage dip management and managing the power balance.
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By Bruno De Wachter / Published on Thu, 2007-11-15 08:30
Removing bottlenecks to allow free trade
Enhancing the European transmission grid is important for three closely interwoven reasons:
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To allow power transport to compensate for the intermittent output of renewable energy systems
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To enable free trade in electrical power within the EU
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To ensure a continuous power supply throughout the EU
In spite of the importance of these changes, grid enhancement is progressing very slowly. There are several reasons for this. First, current European regulations do not allow Transmission System Operators to build up the necessary investment capital to undertake large scale infrastructure works. Second, the environmental impact assessments of overhead lines take a great deal of time. The European landscape is already densely built, so it is normal that each new construction project must be thoroughly investigated regarding its necessity.
While many involved parties have recently been urging faster grid enhancement, this does not mean that no progress is being made at all.
New cross-border transmission lines
This month, the new 700 MW subsea interconnector between Norway and the Netherlands will be inaugurated.
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By Hans De Keulenaer / Published on Fri, 2007-03-09 17:41
During a very interesting webinar presentation last month, Mark Lively showed how market can contribute to improve operating conditions in the electricity system.
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By Bruno De Wachter / Published on Mon, 2007-02-26 08:30
New compressed air storage plant announced in Iowa
In Iowa, USA, municipal utilities have announced plans to build a 269 megawatt plant for compressed air energy storage underground. The goal is to overcome the constant variations in the output of wind turbines. Construction of the plant will begin in 2009 and be completed by the end of 2011.
Electricity generated by wind farms at remote sites will be used for driving giant compressors at the storage site. The compressors will pump air into the ground, where it will be stored in porous rock formations. The air will be converted back into electricity by releasing the pressure and allowing the air to drive generator turbines.
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By David Hirst / Published on Mon, 2006-03-20 10:39
Date: April 25, 2006 at 14h00 GMT+1
Duration: 1 hour
Speaker: David Hirst
Ambient generation is available when nature decides, not us. Therefore, its use requires actions to balance the electricity system. Up to now, ambient generation has been considered largely as negative load, simply adding to the variability of the daily load profile. The unbuffered use of ambient generation will be limited to a certain extent. Beyond this, more active approaches are needed, such as smart distribution grids and demand response schemes. This web event, part of Leonardo ENERGY's campaign on the 'electricity system of the future' present a promising scheme using system frequency to use the inherent storage capacity of domestic appliances.
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