Earlier this year, Representative Alexandria Ocasio-Cortez and Senator Ed Markey introduced a resolution to the US Congress that sought to achieve net-zero greenhouse gas emissions by 2030 and eventually power the the country with nothing but renewable energy. Known as the Green New Deal, the plan is as ambitious as it is fraught with political roadblocks from both sides of the aisle. But even if the Green New Deal can find support in Congress, it will still have to grapple with its biggest political, economic, and technical challenge: transmission lines. Hundreds—perhaps thousands—of miles of transmission lines.
The fundamental challenge with integrating solar and wind energy into the US electric grid is that the areas that are best for generating these types of clean energy are usually very remote. The Great Plains is the place to harvest wind energy, and the Mojave Desert gets sun 360 days a year, but these locations are hundreds—if not thousands—of miles away from America’s biggest cities, where clean energy is needed most. Piping this energy from wind and solar farms means building more interstate high-voltage transmission lines, which are expensive, ugly, and loud. Unsurprisingly, most people don’t want transmission lines near their homes, so new builds often face stiff political resistance from locals.
The design and management of the US electric grid itself doesn’t help. The national grid comprises three main regions—the Eastern, Western, and Texas interconnections—and each of these regional grids operates independently of the others. Within the three interconnections, there are a number of regional transmission organizations and independent system operators, which are nonprofit entities that manage the transmission and generation of electricity by utilities in their region. The Department of Energy and the Federal Energy Regulatory Commission, an independent agency within the DOE, are responsible for identifying when and where new transmission is needed, but it’s up to the states to pick the patch of dirt where the transmission lines are built, while the utilities within the states decide who will pay for them.
Even in the complex world of energy policy, placing new transmission lines is a gordian knot. “The transmission issue is a hybrid of a federal issue and a state issue, which makes it challenging from the standpoint of policy, because you have different jurisdictions for different things,” says David Hurlbut, a policy and economic researcher at the National Renewable Energy Laboratory. Furthermore, he says, transmission lines spanning several states raise complex questions about cost allocation, which requires determining who benefits most from the new infrastructure. Given the economic and legal complexities involved with interstate and inter-regional transmission, most of the new renewable energy sources that have been added to the US grid in the past two decades have been developed within individual states or regions. This simplifies the cost-benefit calculations and also makes securing the permits required to build the transmission lines much easier.
Although local renewable energy generation seems like an obvious solution to the problem of large-scale transmission projects, a DOE report found that in most cases it’s more economical to build transmission lines to pipe in the electricity from regions where the renewable source is cheap and abundant. (See Mojave Desert, above.) Distributing energy generation and transmission across states and regional boundaries has the added benefit of helping balance energy supply and demand, says John Hensley, vice president of research and analytics at the American Wind Energy Association. Even if the wind isn’t blowing at one generation facility, it’s probably blowing somewhere else, so being able to tap into far-flung renewable energy sources helps ensure the supply of electricity meets the demand.
The benefits of building new transmission infrastructure to integrate the grid across states and regions are well known within the energy industry. “It’s kind of a universal conclusion that larger grids are better,” says Paul Denholm, a principal energy analyst at the National Renewable Energy Lab. Although NREL and other labs have done a lot of work on simulating possible inter-regional transmission projects, and FERC has created policies that require transmission operators to cooperate across state and regional boundaries, these large-scale projects haven’t materialized. This has led some private investors to take matters into their own hands.
Earlier this year, two European companies announced they would be backing a $2.5 billion project to develop a 349-mile underground transmission line that pipes wind energy from Iowa to Chicago. While underground transmission lines avoid NIMBY naysaying, they also cost about twice as much per mile to build. In Wyoming, a company owned by billionaire Philip Anschutz is building a 3,000 MW wind farm and transmission system that would carry clean energy to Los Angeles. Wads of cash from a billionaire’s pocket solves the problem of who will pay for new transmission, but the company still must secure permission from each state where the lines will be built. Indeed, the wind farm has spent the past 10 years trying to secure the necessary permits to bring the project to life.
The good news is that increasing the amount of renewable energy on the grid doesn’t depend on sympathetic billionaires building a continental high-voltage transmission system—yet. The amount of renewable energy on the US grid has doubled in the past decade without interregional wires. At this point, nearly 18 percent of electricity in the US is produced by renewable energy sources like wind and solar, but most of this renewable energy stays in the region where it was generated. In short, pushing US renewable energy use to 40 or 50 percent, to say nothing of the 100 percent goal stated in the Green New Deal, will require more transmission lines to pump that clean energy into the largest cities. The path forward is clear, but one of the biggest obstacles to clean energy in the US is still a clear path for new transmission lines.