The role of battery storage in the renewable energy transition

Battery energy storage systems (BESS) are key to making renewable energy a reliable resource for power providers. Batteries can store wind and solar electricity supply for utilities to use to meet demand during non-generating times, giving them the same dispatchability as traditional sources like diesel and coal.

Likewise, EV charge point operators (CPOs) can also benefit from their own onsite battery energy storage systems with stable power, lower operating expenses, and additional revenue generated by providing ancillary services to the grid.

For these reasons, energy storage adoption is expected to continue to grow. Here’s a closer look at the role of storage in the renewable energy transition and the opportunities it affords EV fueling stations, fleets, and other enterprises.

Challenges to renewable energy adoption

While political and other obstacles exist, basic grid infrastructure barriers impede the transition to green energy. One primary challenge is the variability of these energy sources. Unlike traditional power plants, which can produce a steady and predictable output, wind and solar energy generation fluctuates based on weather conditions and time of day, this intermittency can create imbalances between supply and demand, leading to potential reliability issues and the need for backup power sources to maintain grid stability. Additionally, the existing grid infrastructure may not be designed to handle the rapid changes in power flow associated with renewable energy, requiring upgrades and enhancements to ensure effective integration.

Another challenge is the geographic distribution of renewable energy sources. Wind and solar farms are often located in remote areas, far from population centers where energy demand is highest. This necessitates the development of extensive transmission networks to transport the generated power to consumers, which can be both costly and time-consuming. Moreover, the current grid system may lack the flexibility needed to accommodate the decentralized nature of renewable energy, requiring a shift from a centralized to a more distributed grid model. These challenges highlight the need for innovative solutions and investments in grid modernization to facilitate the integration of renewable energy sources.

Benefits of utility-scale renewable energy storage

Battery energy storage systems offer a promising solution to the challenges of integrating intermittent renewable energy into the grid. By storing excess energy generated during periods of high renewable output, batteries can provide a buffer that smooths out fluctuating supply. This stored energy can then be dispatched during times of low generation or high energy demand, ensuring more consistent and reliable power. This capability enhances grid stability and reduces the reliance on fossil fuel-based backup power sources, helping to maintain a cleaner energy mix.

Moreover, battery storage systems can increase grid flexibility by providing ancillary services such as frequency regulation, voltage support, and load balancing. These services are essential for maintaining grid stability and reliability, especially with the increased penetration of renewable energy. Batteries can respond quickly to changes in grid conditions, helping to mitigate the effects of sudden drops or spikes in renewable generation. Additionally, battery energy storage can defer costly grid infrastructure upgrades by optimizing the use of existing assets, ultimately facilitating more efficient and cost-effective integration of renewable energy sources onto the grid.

Both short and long-duration energy storage solutions will be needed for renewable integration. Short-duration storage, typically provided by lithium-ion batteries, is crucial for addressing immediate and short-term fluctuations in power generation and demand, offering rapid response capabilities for frequency regulation and grid stability. However, long-duration energy storage is equally important to manage prolonged periods of low renewable generation, such as extended cloudy or windless days. Technologies, like pumped hydro storage, flow batteries, and emerging solutions such as hydrogen storage, can provide this extended energy reserve, ensuring a reliable power supply over days or even weeks. Combining both short and long-duration storage systems allow a more resilient and flexible grid, capable of accommodating the variable nature of renewable energy and supporting a consistent and reliable energy supply.

Battery storage and renewables on EV charging sites

Electric vehicle CPOs can learn from and participate in the grid benefits of energy storage. Having the ability to store energy in a BESS greatly increases site versatility, which offers a number of advantages. Adding onsite renewables along with a BESS only enhances the value of each.

Reduce operating costs

Power from the grid costs more at some times than others depending on time-of-use rates (TOU). With a battery, you can store utility electricity when it’s less expensive and discharge the power to your EV charging site when prices rise. Strategically moving around when you’re using grid energy in light of utility TOUs can help you better manage electricity expenses.

Increase profit margins

Demand charges are typically based on your highest level of grid use during a billing period. Switching to using battery power when you’re getting close to your grid limit can lower your peak level of grid demand. Using your resources more efficiently helps avoid utility charges, reducing operating costs and improving the profitability of your charging network over time.

Get more customers through

When you don’t have enough available grid energy to supply your site loads, your BESS can provide a boost to generate the extra electricity you need. The ability to supplement grid power and maintain reliable charging where your capacity is limited allows more customers to charge up quicker without making expensive infrastructure upgrades.

Capture your own sustainable energy

Adding renewable energy like a solar array to your EV charging site along with a battery enables even more benefits. Charging your battery with solar power offers a cost-effective alternative when the price of grid electricity peaks. Batteries coupled with renewables can also increase the resiliency of your site by islanding (disconnecting from the grid) through grid outages. Plus, powering EVs with renewables demonstrates your commitment to environmental responsibility, which resonates with environmentally conscious EV users.

Generate revenue through ancillary services

Current grid infrastructure can only support so much power. Sometimes energy demand outweighs what the grid can supply, which can result in grid instability and increased risk of outages. To help balance supply and demand, utilities or grid operators offer demand response programs to incentivize customers to be flexible with their energy consumption during peak demand hours or when certain grid conditions occur.

• U.S. customers in some territories can participate in demand response programs in which they are compensated for curtailing their electricity use during periods of high power prices or compromised grid reliability.
• European customers can participate in the fast frequency response and frequency containment reserve markets where balancing service providers prevent grid instability and power outages.

This gives EV charge point operators, fleets, and other charging site owners an opportunity to increase the value of their onsite renewable energy, EV chargers, and energy storage system to generate additional revenue.

The multiple use cases available for battery energy storage systems on EV charging sites make them increasingly valuable to CPOs.

Orchestrating your energy

While adding a battery to your EV charging site offers many potential benefits, a good energy management system (EMS) is critical to getting the most value from your storage system. An EMS can automatically optimize your battery charging and discharging based on varying time-of-use rates, perform peak shaving in light of your grid limit, and align grid conditions with your electrical load to maintain cost-effective and reliable charging.

For example, Sparkion’s vast experience with and deep understanding of electrical infrastructure allowed us to design the SparkCore™, a better EMS including software and controller. Our product provides the most value when a battery is onsite, ensuring that all site assets work together optimally with the grid for 100% system uptime and maximum revenue. Just as residential IoT devices like Amazon’s Alexa can integrate with household appliances for intelligent communication, fostering optimal function according to the homeowner’s goals, Sparkion’s EMS can connect with all site assets from EV chargers to renewable energy, energy storage, and more. Sparkion’s SparkCore™ can facilitate seamless and continuous communication between these devices and the grid for multiple use cases—performed automatically and simultaneously—resulting in high value for site owners.

Boosting sustainability with second-life EV batteries

The benefits of renewable energy battery storage are spurring increased use of these systems. However, their growing popularity, along with more EV adoption, will require more batteries and their critical raw materials. Demand for graphite, lithium, and cobalt is expected to increase by nearly 500% by 2050. Relying on new batteries alone will not satisfy market needs nor make progress on creating a more sustainable future.

Used electric vehicle batteries still maintain 70-80% of their capacity—enough to power onsite commercial battery storage systems. Such second-life batteries can provide a viable supply for rising market demand while adding further value to charge point operators. Furthermore, auto manufacturers and fleets have a unique opportunity to repurpose their own batteries in depot battery storage for EV charging to add economic and environmental benefits.

Still, second-life storage solutions come with challenges. Second-life EV batteries often have different thermal characteristics, cells with different degradation levels due to varying usage histories and more sensitivity to overcharging and discharging. As cells age, their capacities and internal resistances can vary widely, which can lead to uneven wear that could jeopardize the overall life of the battery pack. Second-life batteries must be properly managed continuously to function optimally in their new roles in stationary energy storage or grid support and adhere to safety standards and regulations.

That’s why a good battery management system (BMS) is essential for ensuring the safety, reliability, performance, and longevity of second-life batteries. By managing and monitoring the diverse and potentially degraded cells in these batteries, the BMS helps mitigate risks, optimize usage, and extend the economic and functional viability of second-life battery packs.

However, not all battery management systems can provide the same value from second-life batteries. Typically, in a conventional EV battery storage unit, the weakest cell drags down the usable capacity of the entire battery pack, decreasing economic efficiency.

Renewable energy integration supported by second-life battery systems provide a clear pathway toward global emission reduction goals, while providing significant advantages for charge point and fleet operators.