To get the energy we use nearly everywhere, people rely on the electricity grid. Most electricity distribution systems were laid down long before renewables were viable. As cleaner sources of power, such as wind and solar, become competitive, utilities have adapted their grids to incorporate them. In fact, despite our traditional association of solar with panels connected to a building producing its own electricity, utilities are the largest users of solar and wind energy worldwide.
As the mix of available methods to generate electricity continues to expand, different alternatives to the traditional, centralized grid are emerging. Some wind mills and solar installations, for example, power a limited number of buildings, constituting microgrids. Traditionally, microgrids were built as back-up systems for the primary grid and relied on diesel generators (most microgrids around the world still do). With the growth of clean energy microgrids, it has been easy to assume they are the future when it comes to distributed renewable power generation. However, technological progress and the fact that utilities have embraced renewables relatively fast could make it possible for the emergence of “macrogrids” that can transport renewable energy across vast distances.
Exporting sun: Macrogrids could make it possible to take solar energy from a place like this one―where it is plentiful year-round―to cities like Oslo in winter, where it is non-existent.
Green Energy of the Future, Brought to You By “Macrogrids”?
A few weeks ago, Futurism published an interesting article that explored how macrogrids could be where renewables get a boost in the near future. “While micro grids are in the public eye as a solution to power remote communities with solar, wind and other forms of renewable energy,” the article states, “the transformative potential of macro grids utilizing vast electric lines often falls off the radar.” The article points to several advances in DC current technology that can potentially “revolutionize the way we transport clean electricity from the places where it’s produced to where it’s needed the most, solving the problem of intermittent power supply that still holds back the mass deployment of renewable infrastructure.”
This is an interesting angle to a problem that dates back to the days when Nikolai Tesla’s AC and Thomas Edison’s DC currents were competing head to head for dominance. AC current won the battle as the better system to use for distributing electricity to cities, in part because it is a system where electricity flows in both directions, as opposed to the one-way flow of DC systems. AC’s two-way flow is the reason why excess solar power produced by a building can be put into the grid for distribution elsewhere.
DC current, however, is better at transporting energy over long distances without loss. The Futurism article points out, “DC is now making nationwide, high-voltage transmission lines possible because DC can reliably carry a lot of power over greater distances, reducing energy losses typically occurring with alternating current systems.” The article further cites several examples of places experimenting with DC technology this way.
Wind from Wyoming Powering Homes in California
One of the projects under construction using DC power to enable renewable power to travel long distances is the TransWest Express Transmission project. According to their charter, this project “will provide the transmission infrastructure and 3,000 MW of capacity necessary to reliably and cost-effectively deliver approximately 20,000 GWh/yr of clean and sustainable electric energy generated in Wyoming to the Desert Southwest region, which for the purposes of the project is Arizona, Nevada and southern California.”
The TransWest project is an interesting solution to the problem of variability that renewables like wind and solar have. We have written extensively about how a diversified mix of energy sources can mitigate the intermittency problem. This project approaches the problem from a different angle to achieve a similar result, “using Wyoming wind to help fill in the times when California’s wind isn’t blowing or the sun isn’t shining. The TransWest project put it this way: “Many experts recognize that providing more connectivity between geographically diverse and complementary renewable resources can help smooth grid operations as the grid grows greener.”
Interestingly, projects like TransWest were given a green light based on a 2015 authoritative paper by Nature Climate Change which concluded, “When using future anticipated costs for wind and solar, carbon dioxide emissions from the U.S. electricity sector can be reduced by up to 80% relative to 1990 levels, without an increase in the levelized cost of electricity. The reductions are possible with current technologies and without electrical storage. Wind and solar power increase their share of electricity production as the system grows to encompass large-scale weather patterns. This reduction in carbon emissions is achieved by moving away from a regionally divided electricity sector to a national system enabled by high-voltage direct-current transmission.” One of the authors, Christopher Clack, from the Cooperative Institute for Research in Environmental Sciences at the University of Colorado summarized it by saying, “We’re basically getting that big battery we want for free.”
Renewables on the Rise
Similar projects to move renewable energy across vast distances are already underway. The Nature Climate Change article points to a project in China, where an investment of $88 billion for ultra-high-voltage, direct-current lines is being implemented to carry 12,000 megawatts of renewable energy across distances of more than 3,000 kilometers.
There is a greener future for all of us when technology makes it possible to have many solutions to the problem of wind and solar energy variability. Whether it is by expanding the geographical reach of transmission power, making for a smarter mix of energy sources, or even creating batteries that can store excess power, renewables are the future of energy.
As the Hydrogen 2.0 ecosystem gains momentum, we’ll be sharing our views and insights on the new Hydrogen 2.0 Economy. We also update our blog every week with insightful and current knowledge in this growing energy field.