The United States lacks coordinated renewable energy infrastructure planning, keeping carbon emissions high. A more unified plan could leverage geographic diversity by connecting renewable energy production areas with major population centers via long-distance transmission lines. Researchers propose a HVDC transmission network across the US to connect solar, wind, and hydroelectric resources, reducing carbon emissions by 80%. Pilot projects should test localized connections first to provide momentum for wider applications.

1. AMORE PERFECT ENERGY UNION
Challenges and Opportunities for Renewable Energy Infrastructure in the United States
Kevin Rushton, June 2018
In its transition away from reliance on fossil fuels, the United States suffers from a lack of
coordinated infrastructure planning. A number of unfortunate policy and business decisions have
resulted, keeping carbon emissions high and perpetuating the rapid consumption of natural
resources. A more unified energy infrastructure plan can help the nation leverage its geographic
diversity to overcome these inefficiencies.
THE PROBLEM
Designing a power grid around renewable energy is more complicated than it is with fossil fuels for
several reasons. First, renewable sources do not provide consistent levels of energy over time. The
output of solar farms and wind turbines depends on the weather, while hydroelectric output
fluctuates seasonally. In the current system, fossil fuel redundancies make up the difference; this
requires the facilities to run at suboptimal levels much of the time, increasing waste and
undermining the benefits of renewable energy.
Location also complicates infrastructure design. Not all geographic areas hold the same potential
energy output from a given source (National Renewable Energy Laboratory n.d.): sunlight is
abundant in the deserts of the American Southwest, but more moderate at higher latitudes and in
colder climates; the powerful winds that blow across the Plains States and off the coasts are impeded
elsewhere by mountains and forests; hydroelectric power depends on proximity to major waterways.
Additionally, some of the most fertile grounds for renewable energy production are far away from
major metropolitan areas. Building power plants where they would be most productive is often
impractical, because the existing power infrastructure relies on alternating current (AC) lines which
lose significant amounts of power over long distances.
Both temporal and locational factors have been problematic for renewable energy in the United
States. Different geographical regions develop in isolation, often in contradictory ways. Southern
California’s solar farms are inadequate for peak power consumption and must be supplemented with
fossil fuels; yet at other times Californians must pay neighboring states to take their excess power to
avoid transmission overloads. This disincentivizes further solar development, leaving much of the
desert’s potential untapped (Penn 2017). Meanwhile in cloudy New England, solar development is
flourishing—at the expense of existing farmland and undeveloped wilderness (Carini 2018) (Chesler
2016). The irony of sacrificing green space in the name of green energy while other power sources go
unharnessed illustrates the need for appropriate policy and engineering solutions.

2. CURRENT POLICY SOLUTIONS AND THEIR LIMITATIONS
The most obvious solution to the problem of fluctuating output is to store extra energy during peak
production times for later use. Unfortunately, widespread energy storage is still cost-prohibitive
(Rhodes 2018). Even once technological advances drive down prices, energy storage cannot address
regional differences in potential energy output; solar panels in New England will always be less
productive than those in the California desert.
Interconnectivity is the key to turning this geographic diversity into an advantage. Alternatives to the
current AC power grid do exist, as in the Pacific Intertie, a high-voltage direct current (HVDC)
power line that stretches 846 miles from the Washington-Oregon border to the Los Angeles area
(Bonneville Power Administration 2010). Usually the Pacific Intertie sends excess hydroelectric
power southward, though occasionally the surplus flows the other way. HVDC technology allows
large amounts of energy to be transmitted across long distances with relatively low energy loss. In
order to be used it must be converted to traditional alternating current (AC), which requires
expensive equipment; however, the amount of energy transferred across the Pacific Intertie since its
debut in 1973 has more than compensated for this expense.
China has been employing similar technology to transmit electricity from power plants in the
interior to the major population centers along the coastline. In fact, China is currently pioneering
more advanced ultra-high voltage (UHV) technology, using either AC or DC power depending on
the transmission distance (Center for Energy, Environmental, and Economic Systems Analysis
2015). However, most of the energy transported along these lines still comes from coal; the main
goal at this point is not so much to promote renewable energy as to improve urban air quality by
keeping smokestacks far away from the people (Downie 2018).
POLICY RECOMMENDATION
Researchers at the Earth System Research Laboratory (ESRL) proposed using the HVDC technology
of the Pacific Intertie to build a network of major transmission lines across the contiguous United
States (MacDonald, et al. 2016). Using sophisticated cost-optimization software, the researchers
estimated that the nation’s carbon emissions could be reduced by almost 80% using existing
technologies. Such a system would connect consumers across the country to solar farms in the
California desert, wind farms in the Plains states, and hydroelectric plants in the Pacific Northwest.
When output is low in one area of the system, other areas can compensate. Significantly decreased
fossil fuel operations would provide an additional buffer until energy storage technology can assume
that role.
Of course, the entire nation’s energy infrastructure cannot—and need not—be overhauled all at
once. A practical next step would be to identify areas that currently have a large renewable energy
capacity, such as South Dakota and Iowa, and connect them to areas where support for renewables is

3. high but capacity is low, such as New England (National Renewable Energy Laboratory n.d.) (Yale
Program on Climate Change Communication 2014). Success on a smaller scale would provide
momentum for more widespread applications.
It is also worth noting that the ESRL study used HVDC technology, as opposed to China’s cutting-
edge UHV. Further studies should be completed to confirm the results of the study and to expand
upon it by exploring other emerging technologies. Researchers should also identify the most
promising locations for more localized pilot projects. More specific policy and engineering steps can
then be detailed, and the United States can begin to move toward a more unified and efficient
renewable energy strategy.
REFERENCES
Bonneville Power Administration. 2010. "Direct current line still hot after 40 years." BPA Newsroom. May 26.
Carini, Frank. 2018. "A Contentious Debate: Green Energy vs. Green Space." Eco RI News, March 17.
Center for Energy, Environmental, and Economic Systems Analysis. 2015. Power Play: China’s Ultra-High Voltage Technology and
Global Standards. Chicago: Paulson Institute.
Chesler, Caren. 2016. "The Green Roller Coaster." Slate, June 20.
Downie, Edmund. 2018. "Sparks fly over ultra-high voltage power lines." China Dialogue, January 29.
MacDonald, Alexander E., Christopher T. M. Clack, Anneliese Alexander, Adam Dunbar, James Wilczak, and Yuanfu Zie. 2016.
"Future cost-competitive electricity systems and their impact on US CO2 emissions." Nature Climate Change, January 25: 526-
531.
National Renewable Energy Laboratory. n.d. Geospatial Data Science: Maps. Accessed June 8, 2018.
https://www.nrel.gov/gis/maps.html.
Penn, Ivan. 2017. "California invested heavily in solar power. Now there's so much that other states are sometimes paid to take it." LA
Times, June 22.
Rhodes, Joshua. 2018. "Energy Storage Is Coming, But Big Price Declines Still Needed." Forbes, February 18.
Yale Program on Climate Change Communication. 2014. Estimated Support for Renewable Energy Funding. New Haven: Yale Climate
Opinion Maps.