Are We There Yet? Building the Grid of the Future
By David Rosenberg, Chemical Engineering, 2020
The 2015 Paris Climate Conference ratified a global consensus that coal, oil, and natural gas combustion will need to fall dramatically in the coming decades. Nevertheless, the debate over how to power an increasingly energy-hungry world continues to rage. Technologies that directly harvest sunlight and wind are some of the least controversial and best developed. While these provide far more energy than global demand requires, the power available at any location can change widely and rapidly. Adding variable sources into a grid built around easily controlled combustion will require an overhaul of energy collection and distribution. Fortunately, a wide variety of systems have been developed to meet this need by rethinking the way we handle transmission, communication, storage and consumption.
Though they seem spontaneous from the ground, wind and sunlight tend to move across the landscape. Distributing and linking power plants over a wide area ensures energy distributers have a more constant overall supply. Expanding the grid will also allow access to more concentrated and reliable energy resources in remote regions such as deserts and oceans. Alternatively, solar panels and small-scale wind turbines allow local communities and homeowners to produce their own electricity, further integrating power across regions with different climate conditions. To do this, generators will have to measure and communicate available resources much more frequently than in current networks and utilize more effective and standardized weather forecasting.
Even with perfect management, maintaining enough wind and solar plants to guarantee sufficient power in any conditions would be prohibitively inefficient and expensive. Fortunately, a wide variety of batteries have been developed that store electricity over various timespans and release it as needed. Cheaper but less efficient options include using heat or electricity to melt or boil substances that can later release that energy turning a generator or heating a building, and electrically forming hydrogen from water in a reaction that can be reversed in a fuel cell. Large scale and long term storage can be achieved by using excess energy to power a pump that moves water uphill for later release through a hydroelectric dam.
According to a 2015 Stanford study, with effective transmission in place the United States can meet about 55 percent of its total energy needs with wind and solar power alone, achieving 100 percent renewable energy using hydroelectric dams. Combining low-cost storage, enhanced transmission and flexible power usage by consumers and industry could enable global energy reform.
