Which are The Factors To Be Considered While Selecting Energy Storage Device?

Today, as the global energy storage market grows, national markets are recognizing the value of battery storage systems, especially in the solar power market, which is increasingly becoming part of the grid. The intermittent nature of solar power makes its supply unstable, and the use of can provide frequency regulation to balance grid operations. In the long run, energy storage devices will play a greater role in providing peak capacity and deferring more expensive investments in other power assets, such as distribution, transmission, and generation facility upgrades and retrofits.

Over the past decade, solar power and battery storage systems have both seen significant price declines. In many markets, renewable energy applications are undercutting the market competitiveness of traditional fossil and nuclear power generation. Whereas in the past, the cost of renewable energy generation was considered by many to be high, today the cost of fossil energy is much higher compared to some renewable energy generation.

At the same time, solar+energy storage devices can provide electricity to the grid and replace natural gas-fired power plants. The investment costs for solar power facilities are significantly lower than they were a few years ago, and no fuel costs are incurred over the life of the solar+energy storage device, so it provides energy at a lower cost than conventional energy sources. When solar power facilities are combined with battery storage systems, their electricity is available at specific times and the immediate response time of the batteries allows their projects to be flexible to meet capacity or ancillary market needs.

Currently, nickel-cobalt-manganese (NCM/nickel-cobalt-aluminum (NCA)-based lithium-ion batteries have come to dominate the energy storage market, and these types of batteries have achieved their goals of lower cost and increased energy density through simple and durable engineering to optimize production methods, tooling, speed, and efficiency, rather than through technological breakthroughs to outperform competitors (as shown in Figure 1).

At the current rate of development, the price of nickel-cobalt-manganese (NCM)/nickel-cobalt-aluminum (NCA) lithium-ion batteries will drop to $100/kWh and energy densities will reach 300 Wh/kg by 2030. these ratios are developing linearly, and these targets will be achieved sooner if technology is developed more rapidly. Increasing battery production driven by the automotive industry is the main driver of this progress. Lithium-ion batteries reduce costs and increase energy density through simple and durable engineering optimization.

Factors to Consider When Deploying an Energy Storage Device

There are many factors to consider when deploying an energy storage device. The power and duration of the battery depends on its purpose in the project. The purpose of the project is determined by the economic value. Its economic value depends on the market in which the energy storage system participates. This market ultimately determines how the battery will distribute energy, charge or discharge, and how long it will last. Power and duration determine not only the investment cost of the energy storage system, but also the operating life.

The process of charging and discharging the energy storage system will be profitable in some markets. In other cases, only the cost of charging will be paid, and the cost of charging is the cost of conducting the energy storage business. The amount and rate of charging is not the same as discharging.

For example, in a grid-scale solar+ energy storage device, or in the application of a customer-side energy storage system using solar energy, a battery storage system uses electricity from a solar power facility to obtain so that it qualifies for an investment tax credit (ITC) benefit. For example, there are nuances to the concept of paid charging for energy storage systems in regional transmission organizations (RTOs). In the Investment Tax Credit (ITC) example, the battery storage system increases the equity value of the project and therefore increases the owner's internal rate of return. In PJM's example, the battery storage system pays for charging and discharging, so its return compensation is proportional to its electrical energy throughput.

It seems counterintuitive to say that the power and duration of a battery determine its operating life. The multiple factors of power, duration and lifetime make energy storage technology different from other energy technologies. The heart of a battery energy storage system is the battery. Just like solar cells, their materials degrade over time and will degrade performance. Solar cells lose power output and efficiency, while battery degradation loses the ability to store energy. While solar power systems can continue to operate for 20-25 years, battery storage systems typically only last 10 to 15 years.

Replacement and replacement costs should be considered for any project. The potential for replacement depends on the project's throughput and the conditions associated with its operation.

The Four Main Factors that Contribute to Battery Degradation Are?

1. Battery operating temperature

2. Battery current

3. Average battery state of charge (SOC)

4. the "oscillation" of the battery's average state of charge (SOC), i.e., the interval between the battery's average states of charge (SOC) that the battery spends most of its time in. The third factor and the fourth factor are related.

There are two strategies for managing battery life in a project. The first strategy is to reduce battery size if the project is supported by revenue and to reduce future replacement costs in the program. In many markets, the program's revenue can support future replacement costs. In general, the reduction in future costs of components needs to be considered in the estimate of future replacement costs, consistent with market experience over the past 10 years. The second strategy is to increase the size of the battery so that its overall current (or C-rate, simply defined as charge or discharge per hour) is minimized by implementing parallel cells. Since batteries will generate heat during charging and discharging, lower charge and discharge currents tend to produce lower temperatures. If there is excess energy available in the battery storage system and less energy is used, it will reduce the amount of battery charge and discharge and extend its life.

Battery charge/discharge is a key term. The automotive industry typically uses "cycles" as a measure of battery life. In stationary energy storage applications, batteries are more likely to be partially cycled, which means they may be partially charged or partially discharged, with each charge and discharge being insufficient.

Available battery energy. It is possible for an energy storage system application to have less than one cycle per day, and depending on the market application, it is possible to exceed that metric. Therefore staff should determine battery life by evaluating battery throughput.

Energy Storage Device Lifetime and Validation

There are two main elements to the testing of energy storage devices. First, testing at the cell level is critical to assessing the life of a battery storage system. Cell-level testing reveals the strengths and weaknesses of the battery cells and helps inform the operator how their batteries should be integrated into the energy storage system and whether the integration is appropriate.

The series and parallel configuration of battery cells provides an understanding of how the battery system works and is designed. Battery cells in series allow for the stacking of battery voltages, meaning that a battery system with several cells in series has a system voltage equal to the individual cell voltage multiplied by the number of cells. The battery-in-series architecture has cost advantages, but it also has some disadvantages. When batteries are connected in series, the individual cells draw the same current as the battery pack. For example, if a battery cell has a maximum voltage of 1V and a maximum current of 1A, 10 cells in series will have a maximum voltage of 10V, but their maximum current will still be 1A and their total power will be 10V * 1A = 10W. When connected in series, the battery system faces voltage monitoring challenges. To reduce costs, voltage monitoring can be performed on series-connected battery packs, but it is difficult to detect damage or capacity degradation of individual cells.

On the other hand, paralleling cells allows current to be stacked, which means that the voltage of a parallel pack is equal to the individual cell voltage and the system current is equal to the individual cell current times the number of cells in parallel. For example, if the same 1V, 1A cells are used, two cells can be connected in parallel, which reduces the current by half, and then 10 pairs of parallel cells can be connected in series to achieve 10V at 1V voltage and 1A current, but this is more common in parallel configurations.

This difference in battery series and parallel methods is important when considering battery capacity guarantees or warranty policies. The following factors flow down through the hierarchy that ultimately affects battery life: market function ➜ charging/discharging behavior ➜ system limitations ➜ battery cell series-parallel architecture. Therefore, battery nameplate capacity does not indicate a possible overbuild in a battery storage system. Whether or not there is overbuilding is important to the battery warranty because it determines the cell current and temperature (cell residence temperature in the SOC range) and daily operation will determine the operating life of the battery.

System testing is an adjunct to battery cell testing and is usually more applicable to project requirements that demonstrate proper battery system operation.

To fulfill their contracts, energy storage battery manufacturers often have factory or field commissioning test protocols that verify system and subsystem functionality, but may not address the risk of battery system performance exceeding battery life. A common discussion regarding field commissioning is capacity test conditions and whether they are relevant to the battery system application.

The Importance of Battery Testing

After DNV GL tests a battery, the data is included in an annual battery performance scorecard that provides independent data to the battery system purchaser. The scorecard demonstrates how the battery will respond to four application conditions: temperature, current, average state of charge (SOC), and average state of charge (SOC) oscillation.

The test compares battery performance to its series-parallel configuration, system limitations, charge/discharge behavior in the market, and market functionality. This unique service independently verifies that battery manufacturers are responsible and correctly estimate their warranties so that battery system owners can make an educated assessment of their exposure to technical risk.

Energy Storage Device Vendor Selection

To achieve the battery storage vision, vendor selection is critical - so partnering with a trusted technical expert who understands all aspects of utility-scale challenges and opportunities is the best recipe for project success. Selecting a battery storage system supplier should ensure that the system is UL9450 compliant, has been tested in accordance with UL9450A, and has a test report available for review. Any other location-specific requirements, such as additional fire detection and protection or ventilation, may not be included in the manufacturer's base product and will need to be identified as a required add-on component.

In summary, utility-scale energy storage devices can be used to provide electrical energy storage and support load pockets, peak demand and intermittent power solutions. These systems are used in many areas where fossil fuel systems and/or traditional upgrades are considered inefficient, impractical or too expensive. Many factors can affect the successful development of such projects and their financial viability.

It is important to work with a reliable manufacturer of energy storage equipment. BSLBATT ESS barrery, a market leading provider of smart battery energy storage solutions, designs, manufactures and delivers advanced engineering solutions for specialized applications. The company's vision is focused on helping customers solve the unique energy problems that affect their business, and BSLBATT's expertise can provide fully customized solutions to meet customer goals.