• Managing System Failures: Constantly balancing electricity supply and demand can create pinches and cost pressures. Peak energy use times, like heat waves or cold snaps that require more heating or cooling, can lead to infrastructure failures that interrupt electricity service. Battery storage is starting to change this dynamic for the better.
• Reliability: The grid is vulnerable to several factors that can knock out power. First among them is the climate crisis, which is making extreme weather events more intense and more frequent, while being exacerbated by the grid itself. Another factor is aging infrastructure in need of modernization. Grid planners have failed to keep up with the pace of new resources coming online or design for a more connected grid between regions and sites of new clean energy development. Meanwhile, there is an ever increasing demand for electricity. Power outages have increased 64% from the early 2000s, and extreme weather-related outages — many driven by a worsening climate crisis — have increased 78%.
• Price Volatility & Costs: Fossil fuel prices can spike, burdening everyday people and small businesses who pay for electricity. For example, many parts of the U.S. electricity grid are heavily dependent on gas. Price spikes for gas directly impact electricity rates, and consumers notice it in their electricity bills. Today, the grid and the utilities that operate it are often monopolies at the local level, which makes fair pricing more difficult. Low-income households have an even harder time covering volatile electricity costs, as energy bills eat up a larger percentage of monthly income. Families of color have been found to have the highest rates of energy insecurity across all levels of income.
• Pollution: The electricity sector is one of the biggest sources of air pollution in the U.S. When we generate electricity with fossil fuels, the process releases toxic substances like SO2, NOx, particulate matter and mercury into the air. Those pollutants are linked to the development of heart and respiratory disease, more emergency room visits and hospital admissions, and premature death. Fossil fuel production facilities are more likely to be placed in low-income communities and communities of color — making the burden of these health impacts unequally felt.
• Equity in Service: Historic inequities in grid infrastructure have led to disproportionate negative impacts of grid failures on communities of color and vulnerable communities, including extended power outages and slower rebuilding timeframes.

Solar is the fastest growing power source in the U.S. Large scale solar facilities now produce the cheapest electricity today, closely followed by wind energy. 

Wind infrastructure is also being built out and improved upon rapidly. In many regions, onshore wind has become cost competitive with fossil fuels. Both wind and solar are expected to rapidly get cheaper over the coming years and decades. 

Coal’s share of power generation is falling. Coal-fired power plant pollution generates carbon pollution that exacerbates climate change and releases a host of toxic substances like mercury, arsenic, and soot that threaten public health. Today, coal is more expensive than renewables or even gas. Most experts say that coal’s time as a major energy contributor is coming to an end, but not soon enough for our health and environment.

Gas is still a major source of electricity, unlike coal. But issues with gas generation are coming into sharper focus. Gas-fired power plants — which are disproportionately built in low income communities and communities of color — emit toxic nitrogen oxides which drive instances of  heart or lung diseases like asthma and bronchitis, increase emergency room visits and hospital admissions, and even cause premature death. Gas is also increasingly unreliable. Gas-fired power plants have disproportionately failed across multiple recent extreme weather events, such as the 2021’s Winter Storm Uri or 2022’s Winter Storm Elliot, while renewables have stayed online longer and come back online faster. 

Oil powers transportation, but is not used at large scale in electricity generation in the United States.

It is crucial that we continue the transition from fossil fuel energy to clean, renewable energy sources at a pace that recognizes the urgency of the climate crisis while also ensuring that the grid remains reliable.

Progress has also been made to allow clean energy to power the grid throughout the day and the seasons. Solar, wind and battery storage is a powerful combination. Solar and wind often occur at different and highly complementary times, while batteries can hold electricity for peak moments. Connecting different regions and types of clean energy sources makes for a strong and reliable mix.

Most experts believe that the ability to power the grid with a majority of clean energy is already available with our current technology and a regular pace of grid updates, and that the ability to power the grid with all clean energy is rapidly approaching. To get there, the grid needs significant deployment of new transmission infrastructure and other investments to bring on more clean energy and to meet the electricity demand of the future.

• Large scale batteries are being installed together with major energy sources like solar farms. They are the size of shipping containers and can combine to store several hours of energy for use when demand is up or generation is down.
• Home batteries can be installed in homes or businesses, and allow users  to store energy from solar or other sources for emergencies or during peak times.

The ability to store energy at more points in the energy system allows for more use of clean energy and more resiliency in the face of weather extremes and demand fluctuations. For example, in April of 2024, batteries in Texas storing solar-produced energy stepped in when other sources like coal and gas plants were offline, delivering four percent of Texas’ electricity at one point, enough to power a million homes.

Grid Structure

The U.S. electrical grid is divided into three major interconnections, which link local grids together at a synchronized frequency:

• The Eastern Interconnection
• The Western Interconnection
• The Texas Interconnection (ERCOT)

These interconnections operate largely independently, with limited power transfers between them. Within each interconnection, there are numerous local and regional grids interconnected to form larger networks for reliability and commercial purposes.

Regulatory Oversight

Several entities are responsible for regulating and overseeing the grid:

• Federal Energy Regulatory Commission (FERC): Oversees interstate electricity sales, wholesale power markets, and transmission.
• North American Electric Reliability Corporation (NERC): Ensures grid reliability and security, overseeing six regional reliability organizations.
• State Public Utility Commissions: Set rules for utilities operating within their states, approving capital expenditures and rates.

Operational Management

The day-to-day operation of the grid is managed by:

• Balancing Authorities: These entities, often electric utilities, ensure that electricity supply constantly matches demand within specific parts of the power system.
• Regional Transmission Organizations (RTOs) and Independent System Operators (ISOs): Manage transmission infrastructure and operate wholesale energy markets in their geographic regions.
• Utility Companies: Operate the supply chain (generation, transmission, and distribution) in the public interest. They can be public, cooperative, or investor-owned.