BESS (Battery Energy Storage) Solution to counter Grid Imbalance and ancillary services

BESS Solution to counter Grid Imbalance and ancillary services

India has cumulative installed power generation capacity of 409 GW which is primarily contributed through Fossil fuel based power generation, primary coal (58%), Hydro (11%) and RE Sources (Wind, Solar & Other RE) 29%. The increasing penetration of RE (Renewable Energy Sources) although contributes towards Green Energy but at the same time will also raise challenges for the transmission network.

India RE installation is projected to grow to 500 GW by 2030 which means effectively 40 GW-45 GW gets added each year. Unlike conventional energy sources where the grid inertia is generally high to maintain a dynamic balance between production and consumption, RE Energy sources (solar /wind) are intermitted in nature and eventually will raise different set of challenges for the transmission network.

As per the estimate 400 GW ( approx ) capacity will need effectively 10 GW of grid inertia to maintain the healthiness of the Transmission and generation network. In other words for an active possibility of Grid outage or Blackout, there should be sudden increase or decrease of demand by 10 GW. In case of such situation the Grid may face outage or Blackout. The country has seen two severe?power blackouts which affected, most of?northern?and?eastern India?on 30 and 31 July 2012.?The 30 July 2012 blackout affected over 400 million people and was briefly the largest power outage in history. An estimated 32 GW of generating capacity was taken offline.

?Generally there is a healthy balance between demand and supply and similarly between the active and reactive power. In case increase of load or drawing of more from the grid other than allocated or projected capacity , the Circuit Breaker (CB) may trip adding additional stress on the transmission and distribution network. The sudden decrease/ decrease of load may lead to frequency variation (as power is majorly fed through synchronous generators) and will lead to shutting down of the synchronous generators. This phenomena may have cascading effect on other generation sources leading to failure and grid outage also known as BLACK OUT. With fast load changes and high flexibility and in order to use its benefits, it is necessary that the amount of electricity in the grid corresponds to actual consumption.

?In case of RE sources the Grid may not provide the requisite inertia unlike conventional Energy sources raising issues of Power Quality , Frequency and voltage regulation ,Overloading of existing transmission lines and providing reactive power.

BESS (Battery Energy storage system) integrated with RE sources can be a way forward to provide Ancillary services (frequency and voltage regulation, Energy shifting /arbitrage, peak demand reduction /peak load saving). Also most of the power generation station are maintaining spinning reserve of 5% of the installed capacity which can be made free to further monetize on the opportunity. The BESS system can deliver 98% CUF apart from providing load support in case of decrease of load demand again proving the active grid support.

?THE MAJOR CHALLENGES with Distributed RE sources to overcome with BESS

1. Power quality issues

Major power quality issues are voltage, frequency fluctuations, and harmonics.

?While integrating renewables, providing constant and reliable frequency and voltage, especially in unfavorable weather conditions could be extremely challenging. Voltage and frequency fluctuations are caused by the unpredictable nature of the renewables thus leading to grid disturbances in the form of Harmonics.

2. Overloading of existing transmission lines

The variable nature of Wind and Solar adds problems for balancing supply and demand. During peak hours, the existing transmission network faces challenge to match the inflow and outflow of power. The distributed nature of these energy resources adds complexity to the existing grid infrastructure. A surge might occur when producers generate too much power without warning, and the entire system would shut down. A transmission line has a specific capacity, and if this limit gets passed, thermal loads will lead to grid outage. If case of transmission line outage the reactive power supply would be challenge as the Transmission lines are active generators of Reactive Power.

3. Electro-mobility

Charging vehicles takes a significant amount of time especially when we need to use a supercharger which consumes an extremely large amount of energy. To compare, one full charge using a supercharger equals the launch of 70 air-conditioning units at once. Such an instant change in power demand is a huge problem to the grid. The increasing demand of electrical vehicles adds additional challenges.

#renewables #batterystorage #gridmodernization #solarenergy