Demand for 700-mile US wind power line exceeds five times capacity

The 4 GW Plains and Eastern line from Oklahoma to Tennessee is set to unlock $7 billion of wind power investments and has received 22 GW of demand from generators and industrial consumers such as Kellogg’s, General Motors and Unilever, project developer Clean Line Energy Partners told Wind Energy Update.

The U.S. installed 8.7 GW of utility-scale wind generation in 2016, accounting for 60% of total capacity additions. As growth continues in the coming years, new wind projects will become more dependent on long-distance transmission lines from high wind areas to major consumption markets.

In a major boost for developers, GE and Clean Line Energy Partners, a group of private investors, agreed in November to go ahead with the 4 GW Plains & Eastern Clean Line project, a 700-mile transmission project which will send wind power from the Oklahoma Panhandle region to consumer markets in the Mid-South and Southeastern U.S. Clean Line Energy Partners is developing the project and GE will supply the HVDC converter stations.

Demand from large utilities and industrial consumers supported development of the Plains & Eastern project, which will be the first overhead HVDC line in the U.S. in more than 20 years. Clean Line Energy estimates the new power line will support over $7 billion of new wind power investments.

Clean Line Energy Partners received over 22 GW of transmission capacity requests for the project, Ally Copple, spokeswoman for Clean Line Energy Partners, told Wind Energy Update in an email.

Kellogg’s, Ikea, General Motors, Sediver and Unilever are among the companies that have expressed interest in low-cost energy via the Plains & Eastern line, Copple said.

“The line will allow utilities in the Mid-South and Southeast to access renewable generation at scale that is very hard to develop locally in that region due to land constraints,” she said.

Construction of the Plains & Eastern line is expected to start in the second half of the 2017 and the line could be in operational by 2020.

                       Wind power share of total generation by US state

Source: American Wind Energy Association (AWEA), February 2017.

Shorter cuts

New transmission capacity in Western U.S. can could reduce total power generation costs by billions of dollars by reducing wind power curtailment and fossil fuel expenses, National Renewable Energy Laboratory (NREL) said in a study published in January.

“To overcome the chicken-and-egg conundrum around transmission and deployment of remote renewable energy, coordinated generation and transmission planning, which isn’t the practice in many regions today, is really critical,” NREL researcher Jennie Jorgenson told Wind Energy Update.

Utilities in the Mid-South and Southeast U.S. are currently importing wind energy across a series of lower-voltage alternating current (AC) lines, and congestion can cause curtailment of wind farms.

HVDC is proven to be the most efficient technology to reliably deliver large volumes of power, over such long distances, according to Patrick Plas, general manager of HVDC at GE, which will supply the three converter stations for the line.

The Plains & Eastern HVDC line will also impose a narrower right-of-way footprint than equivalent AC lines with the same transmission capacity, according to project files.

The project includes a converter station in Oklahoma that will be the link for most of the power plants, and two additional converter stations in Arkansas and Tennessee.

New power plants would need to be connected close to converter stations, Plats said.

“There is a limitation in the HVDC technology, which is you cannot connect power plants just anywhere,” he said.

Further buildout

Clean Line Energy Partners has spent almost a decade developing the Plains & Eastern project and invested more than $100 million.

“The magnitude of the project requires leadership and persistence. Our hope is that success will beget success in building interstate transmission lines, Copple said.

“We are pleased with President Trump’s willingness thus far to support infrastructure projects, and we hope he will continue to use the bully pulpit [agenda platform] to move infrastructure projects along,” she said.

The U.S. would need to build 33,000 circuit miles of new transmission lines at a cost of $60 billion to support the aggressive wind growth strategy of 35% wind power penetration by 2050 set out in the Department of Energy's 2015 Wind Vision Study.

NREL recently analyzed this scenario and found that curtailment of wind power generation could be reduced by around half to 7.8% by building four proposed transmission lines of combined capacity 10.5 GW.

These projects could reduce generation costs by $2.3 billion, NREL said in its study 'Reducing Wind Curtailment through Transmission Expansion in a Wind Vision Future.’

The first transmission line would see the greatest reduction in curtailment and "further transmission buildout continues to reduce curtailment and generation costs but with diminishing returns," NREL said.

    Total annual curtailment under multiple transmission grid buildout

The figure shows how annual curtailment, in terms of percent of renewable energy that is available but unused, reduces with increasing transmission expansion. The Reference represents the scenario with no transmission beyond what is currently planned; Transmission 1, 2, and 3 represent scenarios with increasing amounts of transmission builds; and Copper Sheet is a bounding scenario with unlimited transmission capacity between nodes.

Source: NREL study 'Reducing Wind Curtailment through Transmission Expansion in a Wind Vision Future.' (January 2017)

NREL also warned that transmission must provide flexibility by implementing efficient scheduling practices such as fixed bilateral contracts, to minimize the risk of curtailment.

The laboratory is now conducting two further studies on transmission expansion, Jorgenson told Wind Energy Update.

The Interconnection Seams Study is investigating opportunities to integrate the East and West grids by strengthening connections between these regions and using energy generation resources more efficiently.

A second study, which is the largest integration study NREL has undertaken, will evaluate the further interconnection of Canada, U.S. and Mexico power systems.

“Both of these studies will provide insight as to how upgrading our transmission grid infrastructure can provide increased affordability, sustainability, reliability and resiliency,” Jorgenson said.

NREL expects to complete the Interconnection Seams Study by the end of this year and plans to produce a final report on the Canada-U.S.-Mexico grid study by 2018-2019. Initial findings may be released in the interim, Jorgenson said.

By Anna Flavia Rochas

 

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