Saturday, 25 January 2014

Forget Intermittency: NREL says wind energy can boost grid reliabilit

We’ve all heard the warnings about how intermittent renewables could “crash” the grid if for instance all of a sudden the wind stops blowing and grid operators are left in the lurch for power when they need it. But what if wind turbines actually improve grid reliability?

May sound far-fetched to some people, but that’s exactly what the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) reports in the new study Active Power Controls from Wind Power: Bridging the Gaps. 
Previous studies have focused on wind energy forecasting as the key to balancing wind’s availability and the power grid’s demand, but this new hypothesis could vastly expand the relationship between wind turbines and the grid.

How Does Wind Perform With The Grid?

 

NREL undertook the study with the Electric Power Research Institute, an organization comprised of more than 1,000 members (most of whom are electric utilities) and the University of Colorado, so renewable energy naysayers will be hard pressed to dismiss this study as an environmentalist pipe dream.
Analysts studied multiple power system simulations, control simulations, and field tests at NREL’s National Wind Technology Center to determine how if wind could provide ancillary services in wholesale electricity markets, how wind farms affect system frequency in the Western U.S. grid system, and if using wind farms to actively provide power control to the grid affects turbine performance and structural integrity.
And the outcome of all these studies? Wind energy can not only support the grid by ramping power output up and down to enhance system reliability, but that using wind farms to provide active power control is economically beneficial, all with negligible damage to the turbines themselves.

Wind Energy, Making The Grid Stronger and Cheaper

 

These are potentially game-changing findings. “The study’s key takeaway is that wind energy can act in an equal or superior manner to conventional generation when providing active power control, supporting the system frequency response, and improving reliability,” said Erik Ela, NREL analyst.
Active power control helps grid operators balance system demand with generation at various times throughout the day, helping prevent power flow above or below the ideal grid frequency and involuntary load shedding – preventing both potential blackouts and turbine damage.
Making America’s grid more flexible and integrating renewables is an important imperative. Without long-overdue transmission system investments, grid operators are often forced to use high-cost (and typically fossil fuel) “peaker” power plants when demand surges or baseload power plants go offline.

Intermittency Mitigated By Recent Developments

 

The traditional issue facing wind energy in this context is that it can’t be “turned on” by grid operators whenever they need it. Unless the wind is blowing, turbines can’t generate electricity.
But wind has shown its chops in helping keep the lights on as extreme weather has hit the U.S. in recent memory – just consider the fact that wind energy was credited with preventing blackouts in Texas and parts of the Midwest when the polar vortex spiked power demand and forced some power plants offline.
NREL’s report also notes that almost all grid operators across the U.S., as well as many power systems outside the areas covered by regional grids, are using wind farms in dispatch procedures to manage transmission congestion at five-minute intervals – meaning it’s now a generation resource to be dispatched (for free) when needed.
“Utilities and independent system operators are all seeking strategies to better integrate wind and other variable generation into their electric systems,” said Ela. “Few have considered using wind power to support power system reliability.”
Wind energy has become one of the fastest-growing sources of electricity in America, and it’s a critical source of generation if we’re going to decarbonize our economy and slow climate change. With NREL’s report, perhaps grid operators will start to see wind energy as an energy system imperative, not just an environmental imperative.
Read more at http://cleantechnica.com/2014/01/24/forget-intermittency-nrel-says-wind-energy-can-boost-grid-reliability/#3IYcV037xrKOYc0p.99

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