BESS stands for Battery Energy Storage System, a technology designed to store electrical energy in batteries and release it when needed. These systems play a crucial role in balancing supply and demand in power grids, improving energy efficiency, and supporting renewable energy integration.
Here's a deeper look at BESS
Key Components of BESS:
- Batteries: The core of BESS, typically made from lithium-ion, lead-acid, or other advanced chemistries. They store energy when there's surplus power and discharge it when demand is high.
- Power Conversion System (PCS): Converts direct current (DC) from the batteries to alternating current (AC), which can be used by most electrical systems or sent back to the grid.
- Energy Management System (EMS): Monitors and controls the operation of the BESS, ensuring optimal charging, discharging, and grid integration.
- Cooling System: Maintains the temperature of the batteries to improve efficiency and prevent overheating.
Applications of BESS:
- Renewable Energy Integration: BESS helps store excess energy generated by solar panels or wind turbines when production is high, making it available during periods of low production (e.g., at night or when the wind is not blowing).
- Grid Stability: By providing quick-response energy, BESS stabilises voltage and frequency in power grids, preventing blackouts or brownouts.
- Demand Response: BESS can discharge power during peak demand periods, reducing the need to ramp up less-efficient, fossil fuel-based power plants.
- Backup Power: BESS provides backup power during outages or in regions with unreliable grid connections.
- Electric Vehicle Charging Stations: BESS can support EV charging stations by storing energy when demand is low and releasing it when many vehicles are charging.
Benefits:
- Increased Efficiency: Reduces energy wastage by storing surplus power.
- Reduced Carbon Emissions: Enhances the integration of renewable energy sources.
- Cost Savings: Lowers peak demand charges and reduces the need for new power plants.
- Energy Independence: In remote or off-grid locations, BESS can provide reliable power without constant grid access.
Overall, BESS technology is essential in transitioning towards a more sustainable and resilient energy system, enabling efficient use of renewable energy sources and enhancing grid reliability.
How do we integrate BESS with power generation? 
When Battery Energy Storage Systems (BESS) are combined with diesel-powered generators, they create a hybrid power system that takes advantage of the strengths of both technologies. This hybrid setup offers increased fuel efficiency, reduced emissions, and improved operational flexibility. Here’s how BESS works with diesel generators:
- Operational Setup:
In a BESS-diesel hybrid system, both the diesel generator and the BESS work together to supply power. The system typically works in the following manner:
- Diesel Generator for Base Load: The diesel generator supplies power to meet the base load of a site or application. When demand is high, the generator runs at its optimal capacity to ensure steady power output.
- BESS for Peak Load and Energy Storage: The BESS stores excess energy when the generator produces more power than is required or when other renewable energy sources (like solar or wind) are generating power. When the load increases or the diesel generator reaches its maximum capacity, the BESS discharges power to cover the additional demand (peak shaving).
- Start/Stop Optimisation: During periods of low demand, the BESS can provide power instead of the diesel generator. This allows the generator to shut down or run at a lower output, avoiding inefficient operation at low loads (which typically consumes more fuel, increases CO₂ emissions and causes more wear and tear).
- Energy Flow and Management:
A sophisticated Energy Management System (EMS) monitors and controls the flow of energy between the diesel generator, BESS, and the load (power demand). The EMS ensures that:
- The diesel generator operates at its most efficient load point (typically 70-80% of its rated capacity), maximising fuel efficiency and reducing wear.
- The BESS charges during low-demand periods and discharges during peak demand, reducing the overall load on the generator.
- The system automatically switches between the BESS and diesel generator, ensuring seamless power delivery.
- Key Benefits of a BESS-Diesel Hybrid System:
Fuel Efficiency:
- Reduced Fuel Consumption: Diesel generators are most efficient when running at or near their optimal load. However, when operating at low load, they consume more fuel per unit of electricity generated. By using BESS to handle low or fluctuating loads, the diesel generator can run more efficiently, reducing overall fuel consumption.
- Peak Shaving: During periods of high demand (peak loads), the BESS discharges power to meet the increased demand. This reduces the need for the diesel generator to run at maximum capacity, improving fuel efficiency.
Lower Emissions:
- Reduced Generator Run Time: Since the BESS can provide power during low-demand periods or short bursts of high demand, the diesel generator doesn't need to run continuously. This results in lower emissions of carbon dioxide (CO₂) and other pollutants associated with diesel combustion.
- Smoother Operation: Generators running at optimal load emit fewer pollutants. The hybrid system minimises inefficient operation at low loads, which can cause incomplete combustion and higher emissions.
Reduced Maintenance and Operating Costs:
- Fewer Start/Stop Cycles: Frequent start/stop cycles on diesel generators lead to wear and tear, resulting in higher maintenance costs. BESS smooths out the demand fluctuations, reducing these cycles.
- Longer Generator Lifespan: Running the generator at its optimal capacity for a shorter period reduces wear and tear, prolonging its operational life and reducing the need for frequent maintenance.
Backup Power and Flexibility:
- Seamless Power Delivery: In the event of a generator failure, the BESS can provide backup power until the generator is restarted or repaired, ensuring continuous power supply, however only as long as the stored energy lasts
- Renewable Energy Integration: In some hybrid systems, BESS is combined with renewable energy sources like solar or wind. The diesel generator only runs when renewable energy is insufficient or BESS is depleted. This minimises the generator's run time and maximises renewable energy utilisation.
- Operational Scenarios:
Scenario 1: Load Shaving:
- During normal operation, the diesel generator runs and supplies power. If demand spikes, the BESS steps in to provide additional power, avoiding the need for the generator to ramp up beyond its optimal load.
- Once the demand subsides, the generator continues to operate at its optimal level, and the BESS can recharge.
Scenario 2: Low-Load Periods:
- If the power demand drops significantly (such as at night or during off-peak hours), the diesel generator can shut down, and the BESS takes over to supply power. This avoids inefficient generator operation at low loads, which would waste fuel.
- The generator restarts only when the BESS charge is depleted or when demand rises again.
Scenario 3: Renewable Energy Integration:
- In systems that incorporate renewable energy sources like solar, the BESS can store excess renewable energy during the day when solar output is high. The diesel generator can then be used as a backup when renewable energy and the BESS are insufficient to meet demand (e.g., at night or during cloudy weather).
- Example of a BESS-Diesel Hybrid Application:
- Remote Areas: In off-grid locations such as islands or rural communities, diesel generators are often the primary source of power. By integrating BESS, these systems can reduce fuel costs, emissions, and reliance on constant diesel generator operation.
- Construction Sites: Temporary construction sites often rely on diesel generators for power. A hybrid system with BESS allows the generator to run efficiently during peak times while using stored energy during low demand, cutting fuel costs and improving environmental impact.
- Mining Operations: In remote mining sites, hybrid systems are used to reduce the fuel consumption of diesel generators, especially during times when energy demand fluctuates.
A BESS-diesel hybrid system combines the reliability and power of diesel generators with the efficiency and flexibility of battery storage. This integration results in significant cost savings, improved fuel efficiency, lower emissions, and reduced maintenance, making it an attractive solution for off-grid or high-demand applications where consistent power is crucial.
