One of the most important aspects of the transition to renewable energy is increasing the resilience of the power grid. It is also often one of the most overlooked aspects of our energy future. The distributed generation of energy that is becoming more and more prevalent creates a number of issues that conventional energy generation does not. In this article, we will explore these challenges, and look at some of the steps that have been, and can be, taken to avoid these issues from causing trouble in the future.
One major issue that comes from the addition of distributed generation to the electrical grid is the quick variation of output from renewable energy sources. Unlike conventional power plants, energy sources such as wind and solar do not output constant power, and can vary drastically in a 24-hour period. Currently, the power grid is built according to "a one-way model of the past" [1]. Energy along the existing grid was originally designed to move in one direction, from the generator to the consumer. However, as the grid begins to rely more and more on small-scale power systems, the line between "consumer" and "generator" becomes increasingly blurred [1]. Quick changes in available load, combined with changes in power demand, make it very hard to balance these dynamic systems.
In order to continue to incorporate the increase of distributed energy sources on the grid, utilities have begun to transition to a "smart grid" allowing for greater ability to monitor the demand and availability of power, as well as provide "greater responsiveness" of the grid [2]. This essentially refers to a "suite of technologies... that allow for two-way communication between the utility and its customers" [2]. This can include smart meters that constantly monitor the supply and demand of energy, sensors along transmission lines that measure the flow of electricity through the grid in real-time, smart appliances that can shift energy usage to off-peak times, and utility-scale battery storage that can take energy off of the grid when it exceeds demand, and push it back onto the grid when demand exceeds the supply of the generators. The combination of all of these technologies can provide a safer, more reliable grid for the future [3].
There have been times during the electrical grid's history when issues have arisen. For example, during the 1990s to early 2000s, the state of California served as a prime example of what could happen due to grid neglect. Starting in 1994, the California Public Utility Commission (PUC) began the process of restructuring California's energy market, attempting to increase competition between utilities in the state, deregulate the market, and decrease energy prices for consumers [4]. In the process, they encouraged utilities to sell off their fossil-fuel generating capacity, forcing them to rely on other sources [4]. The policies enacted ultimately led to the bankruptcy of one utility, rolling blackouts along the grid from 2000-2001, and a massive increase in electrical energy prices within the state. One of the major issues that the market faced was an increased demand on the grid, combined with an inability to meet it. From 1999 to 2000, total personal income in the state, a major contributor to electrical energy demand, increased by 9% [4]. As this was happening, the state was experiencing some of the hottest months of the last century, increasing demand for cooling, while also vastly decreasing the capacity of hydropower within the state [4]. While the effects of the restructuring plan played a major role in the unreliability of the grid at this time, California utilities would have had issues meeting demand even without the policy changes [4].
The issues that occurred in California in the late '90s and early 2000s are an extreme example of what can happen if a grid is not prepared for the demand of its customers. If a utility relies on exclusively distributed generation or variable energy sources for its energy supply, weather patterns and increased demand can quickly cause issues, leading to blackouts, and high energy prices. In order to avoid this, utilities must be actively adopting"smart-grid" technologies and striving for a safer, more reliable grid.
Photograph: Namaste Solar Blog, "Are Solar Panels Worth it for your Home?"
Sources
"Microgrids and Backup Power Systems" Idaho National Laboratory. A. Todd and K. Myers. 2021. https://factsheets.inl.gov/FactSheets/Microgrids%20Backup2021.pdf [1].
"How does the US Power Grid Work?" Council on Foreign Relations. J. McBride and A. Siripurapu. 14 May 2021. https://www.cfr.org/backgrounder/how-does-us-power-grid-work [2].
"Grid Modernization and the Smart Grid" Office of Electricity. https://www.energy.gov/oe/activities/technology-development/grid-modernization-and-smart-grid [3].
"Causes and Lessons of the California Electricity Crisis" Congressional Budget Office. Sept. 2021. https://www.cbo.gov/sites/default/files/107th-congress-2001-2002/reports/californiaenergy.pdf [4].
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