Megabatteries: The Nexus for Renewable Energy

Discussing renewable energy encompasses not only the technologies facilitating its generation but also its distribution, storage, and utilization. This includes everything from solar panels and wind turbines to innovative approaches like V2G technology, which enables electric vehicles to feed energy back into the grid from their batteries, as well as the deployment of home-based battery systems. When we scale up this concept, we encounter the emergence of megabatteries, a key component in the evolving sustainable economy.

Transitioning from coal and gas plants to wind and solar installations is only part of the equation. Equally critical is reconfiguring the electrical grid to seamlessly integrate a substantial influx of clean energy sources, which are inherently variable. Unlike fossil fuels, wind and solar power generation is immune to geopolitical tensions and supply disruptions, solely reliant on natural phenomena like wind patterns and sunlight.

Energy storage systems are the solution here, offering a suite of technologies designed to stockpile energy when surplus is available and dispatch it when demand spikes, ensuring the electrical grid remains stable and operational. This involves balancing energy input and output in real-time to maintain essential grid parameters such as voltage and frequency, preventing outages and other disruptions, even in times of insufficient wind or sunlight.

 

 

Megabatteries: A paradigm shift in storage

Historically, pumped-storage hydroelectric facilities have dominated energy storage, using off-peak electricity to elevate water for later energy generation. However, this piece highlights an emerging and rapidly expanding technology: large-scale stationary battery systems (BESS) that interface directly with the power grid, either absorbing or supplying energy based on systemic needs.

Predictions by S&P Global anticipate a 57% surge in grid-connected battery storage capacity by 2023, reaching 40 gigawatts (GW), with expectations of continued robust growth to approximately 70 GW by 2030. China and the US are spearheading this expansion. Bloomberg NEF's projections extend further, estimating global energy storage installations will hit 1,091 GW/2,850 GWh by 2040 — a substantial increase from the 9 GW/17 GWh recorded in 2018, necessitating an investment of $662 billion.

The role of megabatteries

The hallmarks of a reliable electricity system — flexibility, stability, reliability, and security — have traditionally been met with fossil fuel generation. The new challenge lies in achieving these standards within a renewable-dominant grid without CO2 emissions, ensuring power is available whenever and wherever needed.

Electricity storage is pivotal for maximizing the integration of variable renewable sources like wind and solar into the grid. It enables rapid absorption, storage, and redistribution of energy, aiding in the smooth operation of the electrical system. Megabatteries connected to the grid provide numerous services, enhancing efficiency and offering economic benefits. These include:

1. Operating reserve

Megabatteries can quickly respond to any potential technical imbalance in the system, such as frequency variations due to unexpected surges in electricity demand. Given that wind and solar generation possess less inertia or kinetic energy compared to traditional energy technologies, they are more susceptible to sudden mismatches between supply and demand. Despite significant advancements in forecasting wind or solar generation, these predictions are less precise than those for conventional technologies. Megabatteries offer essential reserve capacity to swiftly restore balance in such situations.

2. Ramping

In conventional electricity systems, the daily demand curve resembles a camel's hump, with peaks in the morning as people prepare for their day and in the evening when they return home. In a renewable-powered system, this curve morphs into a 'duck curve,' primarily because solar energy peaks during midday and drops sharply as night falls. Storage systems, including megabatteries, provide a quick response to these abrupt changes or ramps in electricity production, eliminating the need for additional generation capacity.

3. Arbitrage

Arbitrage involves supplying energy to the grid during high-demand, high-price periods and storing it during low-demand, low-price times. Megabatteries excel at this role, enhancing system flexibility and smoothing out fluctuations in electricity production. This process helps avoid the necessity of constructing new facilities solely to meet peak demand, thus moderating electricity price volatility.

4. Smoothing

Megabatteries can mitigate sudden voltage or frequency fluctuations in the grid, such as those occurring when solar output changes due to cloud cover or wind output varies with gust intensity. In doing so, they support grid operators in maintaining the system's technical equilibrium.

5. Savings in transmission and distribution investments

By employing megabatteries, it's possible to circumvent the need for new transmission and distribution infrastructure designed to handle congestion when production is high and existing networks lack the capacity to manage the load. This approach also results in a reduced environmental footprint compared to constructing new power lines.

6. Peak shaving

In renewable energy systems characterized by high variability in generation capacity, there may be a need to build new fossil fuel power plants solely to address potential peak power demands, ensuring reliability and security of supply. Megabatteries address this need by providing a viable alternative, thus obviating the requirement for new backup generation facilities.

Beyond the six key functionalities that megabatteries provide to power grids, they also offer significant benefits in various other settings such as off-grid locations, island environments, or smaller grids, enabling reliable system management without relying on fossil fuel solutions. Additionally, there are valuable applications behind the meter, where consumers can leverage these systems to decrease their reliance on the grid and even supply services back to it at certain times.

The largest battery in Texas

A prime example of the potential large battery technology holds for grid services is illustrated by the recent agreement by the Spanish company ACCIONA Energía. This deal involved the acquisition of the largest battery in Texas, alongside a portfolio of six other developmental projects totaling 1.23 gigawatts of power—equivalent to the output of a medium-sized nuclear power station.

The most advanced among these projects is Cunningham, located 21 miles from Dallas. Scheduled to become operational in the first quarter of 2023, it will stand as the largest grid-connected battery in Texas. With a capacity of 190 MW and an energy storage capability of 380 MWh, it occupies approximately 6 hectares. The other projects are slated for completion within the next three years, further enhancing the region's renewable energy infrastructure.

 

Source:

• IRENA

Photos:

• ACCIONA