Can Our Electricity Grid Run on Alternative Energies?

An electricity grid, or power grid, is a network of systems that generate, transmit, and distribute electricity across regions or even continents.

Elements of the power grid, such as power stations and power lines, are often highly visible. The grid is essential to the daily operation of most communities, providing for conveniences such as lighting, heating, and cooling, as well as crucial resources such as public safety and health care.

Power grids must ensure that the amount of electricity in the grid corresponds with consumption needs. Current grids can be challenged by deterioration due to age, new requirements due to renewable energy sources and climate change, changing regulations, and threats such as terrorism.

Can we run power grids entirely on renewable energy?

To address climate change, humans need to reduce the amount of fossil fuel burned to produce energy.

But connecting renewable, or alternative, energy sources with the grid presents both opportunities and challenges.

• Conventional grids have relied on coal-fired or nuclear power stations located near areas of high electricity demand. Renewable energy generation systems like solar panels and wind turbines are often located in open spaces far away from urban areas, thus creating a need for more storage (e.g., pumped hydroelectric energy storage or batteries) and transmission (e.g., power lines) capability.
• Renewable energy sources, especially wind and solar power, fluctuate more than conventional sources. This can cause an imbalance between the amount of electricity available on the grid and the amount needed.
• Home solar panels position some consumers to contribute power back to the grid, requiring new economic models.
• The increasing use of electric vehicles and other technology requires that the grid of the future can grow to accommodate them.

Scientists and engineers are identifying technological and policy solutions to these challenges:

• Researchers use computer models to test the feasibility and estimate the cost of renewable electrical systems. Models calculate potential production from different technologies and demands over time. A model can reveal which combination of electricity sources and energy-storage systems has the lowest cost while always meeting demand. A 2012 modeling study conducted by the National Renewable Energy Laboratory determined that renewable energy resources accessed with commercially available technologies could supply 80 percent of the total generated electricity in the U.S. by 2050.
• A Caltech group led by Resnick Sustainability Institute researcher Steven Low developed and installed adaptive charging stations on campus for electric vehicles. The stations use smart algorithms to coordinate charging schedules with the Institute's existing electrical infrastructure to minimize the total charging cost.
• Researchers at Caltech and the Carnegie Institute for Science examined energy-storage options and multiple decades' worth of data on wind and solar availability to identify obstacles standing in the way of a transition to renewable energy. They determined that currently available battery technology is prohibitively expensive for long-term energy storage. Technologies that can store energy for entire seasons or even multiple years may be the key to building affordable, reliable renewable electricity systems.
• An interdisciplinary group of Caltech researchers, along with partners including Southern California Edison and the Department of Energy, are developing the devices, systems, theories, and algorithms needed to create a "smart grid": a dynamic and responsive system that incorporates intermittent energy production while meeting power demands.