NEW ENERGY’S PLACE ON THE WIRES
Bill Opalka, March 4, 2009 (Michigan Green)
The power industry is preparing to answer consumer demand, state policy requirements and political pressure for climate change action by providing increased portions of their electricity from New Energy sources.
The power industry’s biggest concern is not New Energy supply but transmission reliability due to inadequate capacity on the wires and aging technology.
Planners and advocates are beginning to formulate a strategy to integrate ever larger supplies of New Energy into the transmission system.
Part of the challenge is developing a system capable of interacting with intermittent home rooftop solar systems of 3-to-5 kilowatts and intermittent multi-thousand megawatt wind installations in addition to the gigantic coal, natural gas and nuclear plants currently online.
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Another part of the challenge is delivering electricity generated from local solar energy and electricity from wind and solar projects 1000 or more miles distant to energy-hungry and ever-greener city consumers.
Among the policy initiatives in the works that will impact this process are (1) a national Renewable Electricity Standard (RES), (2) a transmission bill funding new wires, smoothing regulatory disputes and requiring states to create Renewable Energy Zones (REZs) pre-establishing rights-of-way (ROWs) and (3) the re-organization of power markets into regional transmission organizations (RTOs) with central "balancing authorities."
Improving day-ahead and real-time forecasting is a necessary factor for New Energy to continue coming onto the transmission system without reducing reliability.
Forecasting is getting ever better. (click to enlarge)
Newest computer hardware, pushed by the Federal Energy Regulatory Commission (FERC) and National Electricity Reliability Corporation (NERC) in recent years, makes integrating the myriad of factors coming into a balancing authority feasible.
Studies in the U.S. and Europe show there are no technical barriers to bringing New Energy up to 20% or more of grid power. An Xcel study showed the cost would be $5 per megawatt-hour (~10% of wind’s wholesale price).
Solar power plants will not present transmission system difficulties different than those already faced and resolved by the wind industry but solar power plants already face Bureau of Land Management (BLM) site-approval considerations for the 200+ megawatts of planned projects and the large land tracts needed for them.
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Reliability is not a term of art in the power business, it is the essence of the job.
The effectiveness of state Renewable Electrricity Standards (RESs) at driving utilities and power companies to develop New Energy and plan for integrating it into their supply is obvious. Where there are standards, utilities are acquiring New Energy resources. Where there are carve-outs specifying New Energy sources or distributed generation, investment is driving those industries. Regardless of the particular New energy, be it solar in the Southwest, wind on the Great Plains, biomass in the Southeast or ocean energies in the Pacific Northwest, one part of the planning is constant: Preparing the transmission.
In a regional transmission organization (RTO), a “balancing authority” can control and facilitate integration of New Energy while handling the many varying supply and demand factors popping up throughout a system moment by moment.
The advantage: Variations of power supplies like wind intermittencies or coal plants suddenly going offline would, in the control of a big balancing authority, not be anymore problematic than any number of other ramping events. In a small system, however, any such event could be problematic or even trigger a brownout.
The newest high-capacity wires will preserve the landscape while facilitating transmission and integration. (click to enlarge)
Contemporary wind equipment is an indication of what 21st century technology can mean in a relationship between grid operators and New Energy. Not long ago, turbines were forced to go offline during severe whether conditions. Newer turbines have sophisticated gearing and the capacity to stay online and drop voltage 10%. This keeps the supply of wind-generated electricity to the grid steadier and reduces the grid operator’s need to shuffle supplies.
New developments and technologies informed the U.S. Department of Energy’s official conclusion that it is feasible for the nation to get as much as 20% of its power from wind by 2030. This official finding of feasibility no doubt informs the widespread belief that the grid can also get 10% of its power from solar energy, 10% of its power from ocean energies and a similar portion from geothermal energy in the foreseeable future.
Full system integration, the ultimate goal. (click to enlarge)
- Charlie Smith, executive director, Utility Wind Integration Group (UWIG): "I prefer to call it a variable output resource. Intermittent implies it comes and goes rather quickly and that's not the case. While an individual turbine or turbines may stop spinning, the output over an entire area in the aggregate tends to balance the load…"
- Brian Parsons, National Wind Technology Center (NWTC) at the National Renewable Energy Laboratory (NREL): "The hardware is getting more grid-friendly. Perhaps the greatest example is in the old days if there was fault the entire system would go off. Now, low voltage raided through is developed into all hardware."
- Mike Taylor, Solar Electric Power Association (SEPA): "Photovoltaic, prior to 2006, was about 99 percent distributed and almost all of that less than a megawatt or two…"