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Skip to 0 minutes and 5 seconds In this lecture, we will discuss the grid-scale application of battery storage. I will explain different services that batteries can provide on the grid. We will look at the barriers behind the wider deployment of batteries at the grid. The grid-scale application of battery storage refers to stationary batteries that are installed at different locations on the grid. In this application, batteries mainly deliver local support to transmission and distribution networks. This means that batteries can contribute to tasks and responsibilities of Transmission System Operators (TSOs) and Distribution System Operators (DSOs). Let’s look at services that batteries can provide at the grid to better understand their potential roles.

Skip to 0 minutes and 48 seconds Generally speaking, batteries can provide three main groups of services at grid: 1. Grid constraint management. 2. Power quality and reserve capacity and 3. Energy management Let’s go through them one by one. First, battery storage can support the management of existing or future grid constraints. What does this mean? A grid constraint is like a traffic jam in a power system, which means electricity cannot be transported where it’s needed because the grid is too small or congested. Battery storage can contribute to solving grid constraints through services such as performing capacity firming or congestion management. These services refer, for example, to a situation where batteries are used to locally cover load when the lines leading to that load are congested.

Skip to 1 minute and 41 seconds Traditionally, investments in grid was the main approach to ensure that there will be no grid constraints. But upgrading the grid networks requires large investments and battery storage can be considered as an alternative option. Overall, utilisation of battery can cause upgrade deferral at grid by mitigating grid constraints. The second group of battery services at grid is power quality and reserve capacity. For example, battery storage could be used for black-start which refers to the ability to restart the system in the case of an outage. Other possible services are frequency control or ancillary services which means balancing the grid in terms of power or voltage, at each moment of time. Finally, batteries can provide energy management.

Skip to 2 minutes and 28 seconds For example, they can contribute to peak shaving, load levelling, and energy arbitrage. In these services, it is possible to store electricity during low electricity prices or low loads and use that electricity during peak time or high load. We do this to avoide extra cost due to high electricity prices or grid fees or earning extra revenue. Energy management is a useful service for balancing intermittent nature of renewable energy during high and low loads. To understand these services better, I encourage you to go through the assigned reading material. The required technical characteristics of battery storage at grid depends on several factors. The most important characteristics of battery for the grid-scale application are power density, response time and discharge duration.

Skip to 3 minutes and 22 seconds These characteristics are critical because they play an important role in maintaining the security of supply at grid and keeping power quality. Characteristics such as energy density play a less significant role since the space is not an issue for this application. Today Power Hydro Storage (PHS) or Compressed Air Energy Storage (CAES) are most available storage technologies at the grid. Both of these technologies belong to the group of mechanical energy storage. The share of these two technologies together is more than 97% of all the installed storage capacity at the grid. But, in the recent years, batteries are becoming more attractive. For example, the share of Li-ion batteries worldwide for grid-connected applications is increasing.

Skip to 4 minutes and 8 seconds This share is estimated to be more than 1000 MW in the near future when in 2010 it was only about 100 MW. Li-ion indeed is suitable for a wide range of services at grid, including power quality control or energy management through balancing intermittent renewable energy generation. You may ask yourself if the application of batteries can facilitate grid services, why their deployment rate has been slow? Several barriers can explain this slow deployment. Let’s have a look at some of them. First, one of the main barriers is related to doubts about batteries’ ownership and operation. Limited or vague legislations make this more difficult in Europe.

Skip to 4 minutes and 55 seconds For example, in Europe for the development of grid-scale storage projects, one fundamental question is that whether TSOs or DSOs can build and operate the storage technologies or whether they can seek cost recovery through regulated as well as unregulated revenues? Currently in Europe, the existing policies hinder this ownership which to some extent challenges the development of storage as an alternative option at grid. The second reason is the high cost of grid-scale batteries. This high cost together with existing rules limit the profitability of battery storage projects. Third and last, batteries need to compete with other alternative flexibility options. For example, smart grids, demand management methods, or cheap gas-fired turbines.

Skip to 5 minutes and 43 seconds All of these options could provide similar services, to the ones of batteries at grid. Now that we discussed the barriers, let’s also have a look at the drivers behind the grid-scale application of battery storage. The first driver is the actual delay in the construction and reinforcement of the European grid infrastructure. In fact, about 50% of all projects on grid upgrade in Europe have been delayed or cancelled. These delays are happening in the time that the need for flexibility is increasing because of a larger share of renewable electricity. Given this delay and the urgent need for enhancing the grid network flexibility, battery storage can be considered as an alternative option.

Skip to 6 minutes and 29 seconds Batteries can provide similar services, and their installation process is much shorter than grid reinforcement. Besides, grid construction results in more transmission lines over the farms or landscapes, which influences the view, and this is not often desirable by the neighbouring society.

Skip to 6 minutes and 50 seconds Second driver is the standardisation of grid-scale battery storage system. This standardisation can influence installation, safety or recycling of batteries. Such standardisation will result in faster project development and at the same lower project cost. Third driver is the on-going innovation in the battery technologies. Innovation is bringing the cost of batteries down while at the same time is enhancing their efficiency, lifetime and performance. Finally, new business models are coming to the market which would allow further revenue generation from battery projects at the grid and as the results drive more investments in batteries. To summarize, in this lesson, you have learned about the grid-scale application of battery storage. You got an overview of different services that batteries can perform at the grid.

Skip to 7 minutes and 42 seconds You heard about main barriers and drivers of grid-scale application of batteries. Hopefully, now you know how batteries can effectively and efficiently contribute to the grid services, especially, when there is a large share of variable power sources in the electricity market.

Grid-scale application battery storage

Let’s start with the grid-scale application of battery storage. Watch the following video about services, drivers, barriers, suited technologies, and technical characteristics.

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This video is from the free online course:

Battery Storage Technology: Opportunities and Uses

EIT InnoEnergy