Federal report claims 20% wind power penetration feasible

January 20, 2010

Wind farms in the Great Plains enjoy 7-9% higher capacity factors, the NREL report states

Federal government research has suggested that some 20% of electricity supplies for states east of the Rockies could come from wind farms by 2024.

However, the analysis from the National Renewable Energy Laboratory warned that “significant” expansion and upgrades to the grid in the eastern US would be needed to support such a scenario.

The organization warned that any future scenario would require upgrades to the Eastern Interconnection network, and called for an immediate start to planning such requirements.

The two-and-a-half year “Eastern Wind Integration and Transmission Study” claimed that wind power was a “highly cost-effective way to reduce carbon emissions”.

It suggested that cost savings from reduced coal consumption would make up for the costs of upgrading grid infrastructure suitable for a wide adoption of wind turbines.

Up to the middle of 2009, the US had installed nearly 30 gigawatts (GW) of wind power capacity. To generate 20% of the eastern US power demand, around 225 GW of wind capacity would be needed.

The NREL report said that by developing wind turbines over a very wide area of the US, the system would be protected from the intermittency of wind power generation. While one region might be experiencing a dip in wind speeds, other areas would make up for it to balance the system and ensure electrical reliability, the study suggested.

“Ambitious”

“Twenty percent wind is an ambitious goal, but this study shows that there are multiple scenarios through which it can be achieved,” said David Corbus, NREL project manager for the study.

“Whether we’re talking about using land-based wind in the Midwest, offshore wind in the East or any combination of wind power resources, any plausible scenario requires transmission infrastructure upgrades and we need to start planning for that immediately.”

The study team behind the EWITS report included Knoxville-based consultancy EnerNex Corporation, the Midwest Independent System Operator (Midwest ISO), and Atlanta-based Ventyx. Wind modelling for the report was carried out by Michael Brower of New York consultancy AWS Truewind.

Scenarios

The study team took a the current state of wind development in the US, along with wind developments currently in the queue for grid connections, as being their “reference scenario”.

They then compared four possible scenarios for future wind power in the Eastern US:

Scenario 1 – achieving a 20% market penetration with high capacity-factor projects in the Great Plains region where good wind resources exist and capacity factors are 7-9% higher than further east.
Scenario 2 – achieving a 20% penetration through wind projects in the Great Plains and further east, along with some East Coast offshore wind projects.
Scenario 3 – again, achieving a 20% penetration but with more onshore wind farms further east, closer to population centers, along with an “aggressive” pursuit of offshore wind resources.
Scenario 4 – pushing for a 30% penetration, with both aggressive onshore and offshore development.

The study’s conclusions were that a high penetration of the electricity system by wind was “technically feasible” with the required transmission upgrades.

Upgrades to the Eastern Interconnection grid would be needed for any of the scenarios studied – even the existing situation, the researchers pointed out.

And, it claimed that integrating 20% to 30% of wind on the transmission system would end up costing about $10 per megawatt-hour (MWh) of wind generation – or less than two tenths of a cent per kilowatt-hour unit of electricity used by customers.

The report posed some big questions, such as whether that level of wind power and its associated transmission facilities could ever get through the permitting process in such a timeframe.

“To put the scale of this study in perspective, consider that just over 70 percent of the US population gets its power from the Eastern Interconnect. Incorporating high amounts of wind power in the Eastern grid goes a long way towards clean power for the whole country,” said Mr Corbus.

“We can bring more wind power online, but if we don’t have the proper infrastructure to move that power around, it’s like buying a hybrid car and leaving it in the garage.”