What is an Energy Storage Module (ESM) – Utility Scale?

An Energy Storage Module (ESM) is a packaged solution that stores energy for use later. The energy is usually stored in batteries for specific energy demands or to effectively optimize cost. ESM can store electrical energy and supply it to designated loads as a primary or supplementary source. Moreover, it provides a stable and continuous power supply regardless of the supply source status. Voltage and frequency regulation can also be improved by using ESM modules.

ESM has different applications within the distribution network aiming to improve the quality and continuity of the power at optimal cost. The main applications of the ESM are:

Load shifting / time of use management: The practice of altering the pattern of energy use so that on-peak energy use is shifted to off-peak periods.

Peak shaving: Peak shaving is related to Load Shifting. Both are part of the demand management in which the goal is to increase the load factor.

Renewable energy smoothing or ramp control: Reduces the impact of quick changes in renewable generation levels. It can be used to ensure that wind-farm ramp-rates (MW/min) are kept within design limits and to eliminate rapid voltage and power swings on the electrical grid.

Renewable capacity firming: Helps maintain the power output at a committed (firm) level for a period.

Frequency regulation: In this application, the ESM charges and discharges in response to analogue signals received every 1 to 4 seconds.

Spinning reserves: In this application, the ESM remains charged and responds in case of a generation or transmission outages. Depending on the application need, the system can respond within milliseconds or minutes.

Power quality: An ESM helps protect the loads further downstream against short-duration events that affect the quality of power delivered to the load.

Voltage and VAR support: An ESM can help to maintain the grid voltage by injecting or absorbing reactive power (VAR).

What is Behind the Meter Energy Storage Solution (BTMESS)?

BTM ESS means the energy storage system is installed on the customer’s property and on the customer’s side of the utility meter. The use of a BTM ESS energy storage system, therefore, can reduce the customer utility bill and the consumer is given the liberty to store the energy and sell it back to the grid at their convenience.

A BTMESS may consist of the following components:

a solar array to capture energy from sunlight
a number of wind turbines to capture wind energy
a storage system to store electricity from the RE components and any purchased from the grid
a control system to manage the production, storage and delivery of the electricity

By constantly determining the amount of electricity being drawn, being generated, 'state of charge' of the storage system and load variation with time BTMESS controls

energy received from the Renewable Energy sources (unless it is both dark and windless) to charge the batteries
energy supply from the storage system to the load (the equipment within your building)
electricity bought from the grid when the grid supply price for electricity is at its lowest

What are the advantages of BTMESS?

Reduction in the carbon footprint of the building by generating electricity 'locally' from renewable sources
Reduction in the amount of electricity purchased by the building
to provide power conditioning and UPS characteristics for the whole building
to eliminate blackouts to the building, providing uninterruptable power during grid failures
to eliminate the damaging effects of brownouts on the building
to buy electricity at the lowest possible purchase rates and sell at highest possible rates

What is Peak Shaving or Load Levelling?

Peak shaving is a technique that is used to reduce electrical power consumption during periods of maximum demand on the power utility and thus saving substantial amount in the form of peaking charges. The goal is to avoid the installation of capacity to supply the peaks of a highly variable load. Energy storage provides fast response and emission-free operation, making it the optimal solution for this application.

Load levelling usually involves storing power during periods of light loading on the system and delivering it during periods of high demand. During the periods of high demand, the energy storage system supplies power, reducing the load on less economical peak-generating facilities. Load levelling allows for the postponement of investments in grid upgrades or in new generating capacity.