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Federal green grid vision gone missing in America

As the United States legislates for higher shares of renewables, the development of its straggling and disjointed grid network to match its clean energy ambitions is lagging behind

A market-orientated approach to modernising its power system infrastructure will only achieve so much without much more regulatory support from federal and state-level authorities

COMPLICATED NETWORK
The United States’s transmission systems are complex, with several stakeholders, making efficient planning and deployment more difficult

MARGINAL GAINS
As new transmission is difficult in the US, grid operators are finding new ways of pushing more power along the wires

KEY QUOTE
We need to improve America’s outdated and siloed electricity transmission system both to compete effectively in the 21st century economy and to properly tackle the climate crisis

America’s electricity network could be considered the oldest trans-continental grid in the world. Coast-to-coast electrification took place in the US well in advance of Europe. Many lines in operation are more than 90 years old, while the bulk of the network has been in use for half a century. PJM Interconnection, a regional transmission organisation (RTO) serving 13 states in eastern America has assets that date back many decades. Two-thirds of its infrastructure is more than 40 years old, while the other third has passed the half-century mark. Some local lines at voltages below 230 kV are approaching 90 years old. The US transmission grid is also as big as it is old. Hundreds of thousands of miles of high voltage power lines and millions of miles of low voltage distribution cables connect thousands of power stations to hundreds of millions of electricity consumers. There are more than 161,000 kilometres of transmission wires of 345 kV or greater. It would be tempting to assume that installation of new transmission lines as market demand drives growth is just an accepted way of life in the US. Unfortunately for the growth of renewable energy, that is not the case. Massive hurdles block the construction of a few high voltage super-highways, preventing the establishment of a nationwide macro grid to get renewables generation to demand centres and to ease the task of balancing their variable supply by opening access to power from a wider geographical area.

The demise in 2019 of Clean Line Energy, a private US transmission infrastructure developer, serves as a cautionary tale on how reliance on market forces can backfire. Led by wind industry veteran Michael Skelly, Clean Line had ambitions to develop five long distance, high voltage transmission lines to carry over 16.5 GW of renewable generation across the United States. Of its five projects, three were sold to renewable energy project developers, a fourth was shelved, and a fifth was blocked by legislators in Iowa. Clean Line Energy had received $100 million from investors, showing that money is not the answer to everything.

The US, despite the number and length of the wires criss-crossing the country, does not have a single interlinked electricity grid. PJM is part of the Eastern Interconnection grid, one of three major transmission system areas. The Eastern Interconnect stretches from the Atlantic coast to the Rocky Mountains. The Western Interconnect serves the other side of the Rockies, and the Electric Reliability Council of Texas (ERCOT) serves much of huge and sprawling Texas.

LABYRINTH WITHOUT STRENGTH

Each system operates independently, with no synchronisation of power flows between them. Alternating current (AC) power from one has to be converted to direct current (DC), transferred to the neighbouring interconnection before being converted back to AC. These compartmentalised, inflexible and poorly linked power systems are now struggling to deal with the demands of traditional thermal generation, let alone the increasing levels of variable renewables. The fragmentation runs deeper still. The company selling power can be a non-profit municipal utility, a member-owned cooperative, an investor-owned utility or a power marketer. Functions such as inter-connection oversight, balancing supply and demand, transmission, distribution, generation, and obtaining permits for system upgrades must negotiate a maze of local, state and federal authorisation instances.

Such a labyrinth of players also stands in the way of a renewables-rich grid. Fifteen states between the Rocky Mountains and the Mississippi River account for 88% of the nation’s wind potential and 56% of its solar potential. That same region is home to only 30% of expected 2050 electricity demand. A grid with a predominantly renewable future must be capable of freeing up those wind and solar riches. We need to improve America’s outdated and siloed electricity transmission system both to compete effectively in the 21st century economy and to properly tackle the climate crisis,” says Greg Wetstone from the American Council on Renewable Energy (ACORE), a non-profit organisation.

Some regional and state-level progress has been made in improving the fragmented US grid, with ERCOT recognised as a leader by example. The combination in Texas of a state government mandate and a market approach to getting new wires built opened the floodgates for wind generation. Texas designated priority renewable energy zones (CREZ) as transmission corridors to bring low-cost wind from the west to population centres in the east. Having established a route to market for the wind generation, it invited competitive bids for provision of the wires. In all, nearly 6000 kilometres of new transmission was built in short order at a cost of $7 billion, capable of carrying 20 GW. That rapidly made Texas the US market leader in wind development. As a state it hosts more than 29 GW of wind generating capacity, more than most entire countries have achieved, with the exception of China, Germany, and India.

The Midcontinent Independent System Operator (MISO), an RTO covering 15 Midwest states and part of Canada, is also making headway with upgrading its grid. MISO provides open access transmission service and high voltage transmission monitoring. It organised a Multi-Value Projects (MVPs) process and allocates funding to new infrastructure by assessing costs based on multiple values rather than one—the traditional approach that tends to throttle transmission funding in the rest of the country. MVPs took into account reliability, public policy needs such as state renewable energy goals, and regional economic value to fully assess the value of new transmission, opening the way for investment that was likely to yield a return. By broadening the scope for cost recovery for transmission line development, the approach resulted in an expansion of the grid network that has helped with the distribution of generation from this renewables-rich region.

The Western Interconnect hopes to add high voltage lines linking windy Wyoming and sunny South-western states, such as New Mexico, to population centres. The proposed TransWest Express Transmission Project would provide 3 GW of transmission capacity to deliver Wyoming wind generation to Arizona, Nevada, and southern California. But completion of the 1175 kilometre, 500 kV link is far from certain, stymied by wrangling over permitting between federal, state, local and native land jurisdictions. Enormous distances and mountainous terrain add further barriers. Militant local groups intent on stopping infrastructure projects around their towns, regardless of whether it is an oil pipeline or a wind transmission corridor, add to the litany of problems.

Within the Eastern Interconnect area, efforts to secure 80% of electricity from wind and solar generation by 2050 are underway, including tapping into offshore wind capacity planned off the Atlantic Ocean coastline. But generation from offshore wind projects will hit a transmission bottleneck unless investment in grid upgrades can be unlocked. Offshore areas have been leased for 29 GW of wind development along the east coast alone. New York has further issued a solicitation for 2.5 GW of offshore wind capacity and has legislated 70% clean electricity by 2030 and 100% by 2040. New Jersey plans a comparable amount of offshore wind and wants 50% of its electricity from wind power by 2030, while other coastal states have impressive wind power ambitions. Connecticut targets 100% by 2040; Maryland 50% by 2030; and Maine wants 100% of its electricity from renewable sources by 2050. If the almost 30 GW of offshore wind comes online, the current grid can accommodate less than a quarter of that at best. Lack of transmission is a mighty roadblock in the path of the states’ ambitions. Overall, there are plans to build about 214 GW of new generation in the US in the next five years, 80% of which will come from renewables. Without a major shift in the transmission picture, much of that power will have nowhere to go.

Under the Administration of Donald Trump, little help has been on offer from the Federal Energy Regulatory Commission, which regulates interstate power affairs. New orders to specifically direct it to facilitate transmission of renewable energy across America may be forthcoming from a government under the presidency of Joe Biden.

A strong grid will deliver massive economic and public health benefits for all Americans

BREAKTHROUGH EFFORTS

Multiple pieces of the power grid puzzle must fall into place to improve the situation, even when ignoring the political and human elements of the problem. Just making the right decisions on what wires to string up and where is a sizable challenge. Transmitting electrical energy at higher voltages not only reduces line losses, but can also reduce public opposition. A single 765 kV line on a 60-metre-wide right-of-way carries the same amount of power as 15,138 kV lines requiring a land corridor 450 metres wide causing fewer permitting headaches per MW of power transmitted. A federal instead of a state approach would make economic sense and likely speed grid modernisation. Advocacy groups ACORE and Americans for a Clean Energy Grid (ACEG) have launched the Macro Grid Initiative to build support for a nationwide, high voltage direct current (HVDC) network, optimised for the best wind and solar resources. HVDC line losses are 3.5% for each 1000 kilometres traversed, compared to 6.7% or more for AC lines at similar voltage levels, more than making up for the 1% of the AC to DC and back again converter station losses. An HVDC backbone for the US can be likened to the freeway system that spans every state and often rings major cities. That road network took federal government initiative backed by billions of dollars over many decades.

An alternative to immediate major investment in new transmission would see existing lines upgraded to higher transfer capacities, achievable using improved conductors or increasing voltage rating. Flow controllers could also be used to route power to less congested parts of the network, a relatively cheap option that is easily installed. In heavily populated areas likely to resist reconductoring”, or HVDC efforts, avoiding the permitting barrier can be a faster route to getting more renewable energy on the grid, but it is a limited and short term solution. Upgrading sub-stations to the latest standards and adding capacitor banks can also boost the transfer capacity of existing lines. The cost of such improvements to the existing system comes in at millions of dollars, an easier pill to swallow for utilities, both investor-owned and municipally owned, than development of multi-billion dollar HVDC lines.

A digital solution, called Dynamic Line Rating (DLR) technology, uses real-time monitoring to constantly calculate line rating variations (tension levels) on transmission lines. Pacificorp, a utility based in Oregon, gained around 100 MW of additional transmission capacity from using DLR. While the gains would be greater with a new transmission line, so would the cost. For comparison, a new 230 kV line would cost $50-to-$75 million and would have to jump through numerous approval hoops over many years, while Pacificorp secured its additional capacity for a modest cost of around $1 million. While HVDC may solve delivery of bulk power from massive wind and solar farms, the grid also needs to adapt to the growth of distributed energy resources (DERs). DERs feed into local distribution networks reducing demand on the high voltage transmission network. Yet traditional rules and restrictions often make it difficult for DER to access the grid. Financial barriers either prevent their creation or limit their ability to be compensated for any power they make available to the grid beyond their own needs. A new microgrid testbed known as DERConnect is using a $39 million grant from the National Science Foundation to validate autonomous grid operation technologies to optimise the use of DERs. The project encompasses an energy storage testing facility as well as more than 2500 DERs already existing on the University of California microgrid at the San Diego campus, a number of buildings, and 300 electric vehicle charging stations. It is just one of many initiatives attempting to increase the viability of DERs and evolve a smarter grid. But again, legislative barriers and utility resistance stand in the way of distribution-transmission systems becoming better coordinated so DERs can play a role in balancing load and meeting demand as well as reducing demand on the wider grid.

LESSONS LEARNED

The United States’ market-oriented approach to development of its power infrastructure works at regional and state level to control the cost of new build. But the piecemeal strategy stands in contrast to Europe’s increasingly holistic planning of a fully interlinked continental grid. Similar planning may be required at federal level in the US if the country is to reap the full advantages of its vast renewable energy resources, both to clean up its energy use and to reduce the cost of doing so. Wind energy development, often mandated by law, but with increasing frequency selected as the cheapest option for meeting demand, could be the driver for transmission build-out, though progress is likely to be slow without regulatory support.

Just as the Eisenhower interstate highway system unleashed US manufacturing in the 20th Century, a strong grid will deliver massive economic and public health benefits for all Americans in the 21st Century,” says Rob Gramlich at ACEG. States continue to set ambitious mandates for renewable energy and targets for when their energy consumption releases no more carbon emissions than they can offset by other means. Yet the number of kilometres of transmission capacity built has been in steep decline since the completion of the CREZ lines in Texas in 2013 and 2014.

The laws driving CREZ construction in Texas were passed in 2005 but it took years to lobby that legislation into reality and a decade to build. Similar Western Renewable Energy Zones (WREZ) were conceived in 2008 to facilitate high voltage construction, but nothing ever materialised. The TransWest HVDC line has been on the drawing board since 2005, unable to make it from paper to reality. Progress has been made but it will take years for the 600 kV line from Southern Wyoming to Nevada and California to traverse its 200-kilometre path. With luck, construction commencement will not be delayed beyond late 2021—its current estimate. Federal intervention into the transmission network appears more likely under the presidency of Joe Biden, where climate change mitigation through development of renewable energy is high on the agenda. On top of efforts at state level, one possible tool for the new administration is the issuance of an investment tax credit that would make investment in transmission a tax haven for corporations, doing for grid development what tax credits have done to drive wind and solar installations. Even so, without a strong political lead that gets the public behind grid modernisation, a long and rocky road lies ahead. Unless people understand the benefits that major grid upgrades will bring to them and their offspring, towns, county, state, and community activists are likely to contest every inch of progress.

TEXT Drew Robb ILLUSTRATION Hvass & Hannibal