This is clearly a major "sticking point" for growing these forms of renewable energy. Do some traditional plants need to be "backed off" to increase demand for renewable energy? This solution is not likely because the dispatchable power plants are not going to voluntarily give up revenue in an effort to help their competitors, the renewable energy companies, more useful to electricity consumers.
What is the greater demand - Clean renewable energy or 'cheap' energy at the expense of the environment?
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Wind and solar power companies in Ontario say they’re about to be penalized $100 million by the agency that runs the province’s electricity market.
The renewable energy firms say that’s how much they’ll lose if the Independent Electricity System Operator (IESO) restricts the flow of wind and solar power onto the electricity grid when the demand for power is low, but winds are high.
The companies have filed an application with the Ontario Energy Board asking it to force the IESO’s to review its new rules, which they brand as discriminatory and “nothing less than a reversal of government policy.”
The new rules, they say “are designed to fundamentally change the bargain” for renewable energy firms.
The IESO, for its part, has estimated that there will be a general benefit to all electricity users of as much as $225 million a year if its new rules go into effect.
The dispute centers around the way most wind and solar power flows onto the grid.
Most electricity generators are “dispatchable,” which means they tell the IESO at what price they’re willing to sell power into the market.
As demand rises, the IESO calls for increasingly expensive generators. As demand dwindles, the IESO tells the most expensive generators to shut down.
Wind and solar firms, by contrast, are not dispatchable. Their power flows into the system whenever the wind blows or sun shines.
Increasingly, the province has faced times when demand is low but winds are blowing strongly. That can create surplus power, which may have to be exported at very low prices.
At times, the IESO has had to pay neighbouring provinces or states to take Ontario power, with the cost borne by all customers. At other times, it has had to shut down a nuclear unit, which then can’t be restarted for several days, even if demand rebounds sharply.
Meanwhile, encouraged by provincial policy, more renewable power is coming into service: An additional 3,000 megawatts of wind power alone is due to start up in the next 18 months.
“The new rules will allow the dispatch of wind,” said Terry Young, vice president of the IESO.
That’s a sharp change in direction, the companies argue.
“It is nothing less than a reversal of government policy with respect to encouraging the use of renewable power,” they say in their application to the energy board.
Having output reduced is one thing. The question is:
If the output is scaled back, how much – if anything – should the energy firms get paid?
The companies say they’ll be heavily penalized if they’re simply cut back without compensation.
“The Renewable Energy Supply Generators estimate the potential cost of this change to them is in the order of $100 million over the next five years,” they argue.
They want the energy board to send the new rules sent back to the IESO for revision.
The question of compensation falls to the Ontario Power Authority, which holds the contracts with the renewable energy companies.
Compensation talks with the energy firms are under way, said Kristin Jenkins, vice president of the power authority.
“The approach is to say there’ll be a cap,” she said.
The wind and solar firms would be paid for lost output only up to a maximum amount.
Limits would be set both for compensation to be in a single year, and over the life of the 20-year contracts, but no agreement has yet been reached.
Source:
Wind and solar power firms fight $100 million rule change | Toronto Star John Spears Business reporter, Published on Fri Feb 01 2013
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Dispatchable generation
From Wikipedia, the free encyclopedia
generating plants that can be turned on or off, or can adjust their power output on demand.
This may be contrasted with certain types of base load generation capacity, such as nuclear power, which may have limited capability to maneuver or adjust their power output, or variable renewable energy sources such as wind power which cannot be controlled by operators.
The time periods in which dispatchable generation plant may be turned on or off may vary, and be considered in time frames of minutes or hours.
In general the only types of renewable energy which are dispatchable are biofuel, biomass, hydropower with a reservoir, and concentrated solar power with thermal storage.
The main reasons for which dispatchable power plants are needed are:
- Load matching - slow changes in power demand between, for example, night and day, but not to short-term ones, require changes in supply too, as the system needs to be balanced at all times (see also Electricity).
- Peak matching - short periods of time during which demand is above load matching plants output; generation capable of satisfying these peaks in demand is implemented through a quick deployment of output by flexible sources.
- Lead-in times - periods during which an alternative source is employed to supplement the lead time required by large coal or natural gas fueled plants to reach full output; these power sources that can be deployed in matter of seconds or minutes to adapt to rapid shocks in demand or supply, which cannot be satisfied by peak matching generators.
- Frequency regulation or intermittent power sources - changes in the electricity output sent into the system may change quality and stability of the transmission system itself because of a change in the frequency of electricity transmitted; renewable sources such as wind and solar are intermittent and need flexible power sources to smooth out their changes in energy production.
However in practice, large-scale storage technologies other than pumped hydro remain in an early stage of development and are expensive.
See also
Vanadium redox batteryReferences
- ^ Cooper, Duncan (22 March 2012). "Johnson’s Energy Club Competes in Renewable Energy Case Competition". Samuel Curtis Johnson Graduate School of Management. Retrieved 29 August 2012. "Most conventional energy sources are dispatchable, meaning that they can be turned on or off according to the demand for electricity. The amount of electricity they produce can also be turned up or down so that supply of electricity matches the amount demanded by users"
- ^ Electricity Grid: Key Terms and Definitions
- ^ Welcome to First Hydro
- ^ Why solar energy?
- ^ How can renewables deliver dispatchable power on demand?
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