Renewable energy and grid stability: modern infrastructure challenges and solutions

Grid stability ensures a continuous supply of electricity to homes and businesses. A reliable source of energy has always been necessary to sustain cities and towns and facilitate economic activity, but new challenges continue to arise. Aging infrastructure, an increase in the number of extreme weather events and cybersecurity issues affect the already strained electrical grid.

Energy suppliers, governments, businesses and homeowners are all looking for ways to mitigate today’s energy supply risks and agree on the need for resilience to deal with today’s challenges. Alongside infrastructure upgrades and increased efficiency, renewable energy is an increasingly important solution for creating greater energy resiliency.

Renewables like wind, solar, geothermal and biomass power are cost-competitive and cleaner than fossil fuels. Renewable energy offers stability and reliability over the long term because it relies on natural elements like sunshine instead of finite resources like coal or natural gas. Also, solar panels or turbines can sit closer to end users, limiting the amount of energy lost in transmission and lowering the chance of infrastructure damage affecting the power supply.

Here is a closer look at the role renewable energy can play in improving grid stability and the challenges increased reliance on clean energy could bring to utility providers and customers.

The basics of electrical grid stability

The power grid consists of a network of power plants where energy gets created, distribution facilities that break electricity down into lower voltages and power lines that carry electricity to end consumers.

Grid stability requires balancing the supply of energy with consumption. A stable grid transmits the same amount of electricity as its users consume, and it supplies this amount of power without major interruptions. Here is a look at the key components necessary for grid stability.

• Supply and demand equilibrium occurs when the electricity produced and transmitted meets the needs of end users. This concept also involves stable pricing that helps maintain supply and demand equality.
• Frequency and voltage control are necessary to ensure a consistent flow of energy through the grid. The grid needs the ability to adjust frequency and voltage to deal with changes in supply or demand. Failure to make adjustments could lead to systemwide disconnections and blackouts.
• Grid inertia is caused by turbines or rotating generators in power plants. This equipment keeps spinning with inertia for some time even after losing propulsion, giving operators time to deal with system failures before total loss of power.

Renewable energy may complicate the current system for maintaining grid stability. For instance, renewable energy systems like solar arrays lack inertia, so the traditional system for balancing supply and demand may not function correctly and power can stop flowing immediately after a malfunction. The variable nature of solar or wind power makes this balancing act more complicated without proper management strategies.

Challenges with renewable energy and grid stability

Energy imbalances can occur based on fluctuations in, and differentials between, demand and power generation. However, renewables like solar can sometimes make these gaps larger. In the U.S., the largest grid imbalances occur in California and the Southwest, both of which rely more heavily on solar generation than other regions.

This is one of several challenges that utility-scale solar power producers have to contend with when adding renewable energy to the existing grid infrastructure.

Intermittent supply

Intermittency in renewable energy describes a power source that is not consistent or predictable. Wind turbines only produce power when the wind blows, and solar panels only convert rays to electricity during daylight hours. The output of both these power sources can vary depending on the weather.

Intermittent production is one of the biggest challenges of solar energy for homeowners, businesses and utility providers. Optimized design of utility-scale solar arrays can maximize solar panel efficiency and minimize fluctuations. However, even the most efficient layout and panel orientation won’t solve all intermittency issues.

While solar power does offer clean energy and lowers the daily output needs from other energy sources, utility providers may need to use other energy sources to meet non-daytime demand and provide backups should weather conditions cause lower solar or wind outputs.

Overload disturbances

While renewables may not produce any energy at some times, there are also scenarios where they overproduce such as on very sunny or windy days. Sudden spikes can cause issues controlling frequency and voltage in the system and exacerbate problems within the electrical infrastructure.

Transmission lines and substations in an aging grid system may not be able to handle the energy spikes. This can increase the risk of outages or require disconnecting energy generators altogether to avoid system-wide problems.

Balancing supply and demand

In some situations, peak renewable energy output aligns with energy needs. For example, buildings need energy to run air conditioners during hot summer days. However, homeowners also need electricity to power lights and appliances at night, and heating often requires a lot of electricity during the winter when solar output could be much lower.

In many regions, peak energy use is in the evening or early morning when solar panels are not producing power, so all power must come from other sources. However, these sources are not needed as much during the day when solar production peaks. A poorly planned grid can lead to chronic mismatches between supply and demand.

Not only does this oversupply or excessive demand affect grid reliability, but it can also cause electrical price fluctuations. Oversupply can lower prices during the day and high demand can cause higher peak rates after dark.

Solutions for grid stability with renewables

Solar, wind and other renewables require management approaches that account for intermittency and other complicating factors. Grid updates, energy storage solutions, smart grid technologies and government policies that account for renewables can help increase grid stability while embracing cleaner energy.

Updated planning and infrastructure

The electrical infrastructure in the United States is outdated and unable to withstand increasingly frequent severe weather and accommodate new additions like renewables. Local and regional regulators are reluctant to make upgrades that would involve major investments funded by rate increases that would be unpopular.

The solution could be to add grid-enhancing technologies (GETs) to help modernize the system and better integrate renewables. The U.S. Department of Energy is tapping private investors and using federal funds to speed up these upgrades.