Energy Storage System E.S.S.

Switching from Fossil to Electricity: Renewable Energy is the Trend

Switching from fossil to electricity is the inevitable trend in the 21st century and modern cities are proactively looking into feasible, renewable and clean energy solutions, to help save the environment and to free itself from the dependence on fossil and its the ever-changing high cost.

Energy Storage System (E.S.S.) promotes the use of renewable energy, be it solar, wind, water, thermal or biomass. Once the energy is generated, it is captured and stored for use when in need. A reliable energy storage system is essential for the widespread of renewable energy usage, as we need to secure the source of electricity at the point of unfavorable environments (e.g. during gloomy days in case of solar).

MEC Energy Storage System – Key Applications:

  • Household Energy Storage System
  • Industrial Energy Storage System
  • Energy Storage System at Power Generation Plants (Solar, Wind, Water, Thermal, Biomass)
  • Microgrid Solution – Independent Off-Grid for Stable Power Supply
  • Solar Energy Storage-Charge System

Benefits of Installing an E.S.S.

Energy Cost Savings

Battery is charged during periods of lower electricity cost and deliver power from the battery during periods of high electricity cost

Storage of Renewable Energy

Compatible with all brands of inverters, for all types of renewable energy

Uninterruptible Power Supply
UPS Function

Switch Time ≤10ms for serving as an UPS

Peak Shaving

Reduce the peak demand by load management

Feed-in Tariff

Fully customized feed-in settings to optimize profits or for self-consumption

Power Reserve

Built-in backup power to be used during power outage

Types of E.S.S.

4 Types Available: On-Grid System, Off-Grid System, Retrofit System and Hybrid System

On-Grid System:

 

  • Feed-in Tariff
  • Less expensive than Off-Grid system
  • No batteries required
  • Supported by the Power Grid
  • No backup power during power outage
  • Anti-islanding protection included

Off-Grid System:

 

  • Energy stored in batteries and used at home
  • More expensive than On-Grid system
  • Batteries and controller required
  • Dependent on the provision of sunlight
  • Independent of the Power Grid
  • Anti-islanding not required

Retrofit System:

 

  • Feed-in Tariff
  • Energy stored in batteries and used at home
  • Backup power available during power outage
  • Anti-islanding protection included
  • Existing On-Grid Inverter can be retained
  • Batteries can be charged by the Grid
  • No charging of batteries from PV during power outage
  • Independent of existing PV panels

Hybrid System:

 

  • Feed-in Tariff
  • Energy stored in batteries and used at home
  • Backup power available during power outage
  • Anti-islanding protection included
  • Replacement of the existing inverter is required
  • Batteries can be charged by the Grid
  • Batteries can be charged from PV during power outage
  • Dependent of existing PV panels. PV panels match with the requirement of the Hybrid Inverter

Energy Storage Systems at a Glance

Work Modes of Retrofit E.S.S.

Self-Consumption Mode, Time-of-Use Mode, Back-up Mode & UPS Function

Self-Consumption Mode (Default):

On Sunny Days

  • PV powers critical and household loads first, then charges the battery.
  • The redundant power will be exported to the grid.

On Cloudy Days / At Nights

  • Battery discharges for critical and household loads first.
  • Grid will supply power when that from the battery is not enough or the battery reaches its minimum capacity.

Time-of-Use Mode:

 

  • Apply to areas that have peak and valley electricity price and feed-in tariff.

  • By setting charging and discharging power to the batteries, import / export of electricity from the grid can be controlled.

Example 1: Peak Hours

  • PV provides 100W power and Load consumes 400W power
  • Setting: Discharge Battery with 300W
  • Result: Import / Export 0W to Grid

 

Example 2: Off-Peak Hours

  • PV provides 100W power and Load consumes 400W power.
  • Setting: Charge Battery with 200W
  • Result: Import 500W from Grid

Back-up Mode:

  • Apply to areas that suffer from power outage regularly.
  • By setting battery state of charge (SOC) retention value in this mode, the battery is ensured to have enough energy to supply during power outage.

On Sunny Days: Operate as in Self-Consumption Mode

On Cloudy Days / At Nights:

  • Battery discharges for critical and household loads first.
  • Grid will supply power when that from the battery is not enough or when the SOC retention value is reached. 

UPS Function:

 

  • When power outage happens, system will switch to UPS Function automatically.
  • Battery supplies emergency power to the critical loads only until the battery reaches its minimum capacity.
  • Existing On-Grid system inverter will stop working to prevent islanding effect.

E.S.S. Protection Features

AC Surge Protection

Protect the system from inrush current

AC Short-circuit Protection

Protect against excessive current caused by abnormal connection between two nodes

Ground Fault Monitoring

Protect against excessive current caused by unplanned path to ground

Grid Monitoring

Monitor status, current, voltage and frequency of the grid

Anti-islanding Protection

Disconnect power to the grid in the event of a blackout

Over / Under Voltage Protection

Protect the battery from over-charge or over-discharge

Over-load Protection

Protect the battery from high C-rate discharge

Over-heat Protection

Protect the system from heat damage