As Distribution Network Service Providers (DNSPs) increasingly explore transitioning fringe-of-grid customers to Stand-alone Power Systems (SAPS) to reduce costs and improve reliability, it’s critical to address a key factor that can significantly impact system performance: parasitic loads. These often-overlooked energy demands, combined with inefficient component choices, can undermine the cost-effectiveness and sustainability of SAPS. Here’s why choosing low-parasitic-load components matters, along with insights into leveraging efficient HVAC systems and energy management strategies.
What Are Parasitic Loads?
Parasitic loads are the constant energy demands from system components, even when they are not actively in use. These can include:
- Standby power consumption of inverters, chargers, and controllers.
- Self-consumption of monitoring equipment and communication devices.
- Idle energy draw from auxiliary systems like cooling fans or sensors.
In a SAPS environment, where every watt counts, parasitic loads can erode the overall efficiency of the system. This leads to increased energy generation requirements (increased solar array or genset having to run more often), larger battery storage needs, and ultimately, higher costs.
Why Low-Parasitic-Load Components Matter
- Optimised Energy Use: Components with low parasitic loads minimize unnecessary energy consumption, ensuring more power is available for essential loads and reducing the strain on energy generation and storage systems. Valen Power has seen savings of over 4kW parasitic consumption reduction per day by simply using a suitable Inverter/ Charger/ MPPT system.
- Cost Savings: By reducing parasitic loads, DNSPs can decrease the size and cost of batteries and solar PV arrays required to support the system, reducing TCO and making SAPS more financially viable.
- Improved System Lifespan: Lower parasitic loads mean less cycling/ DoD of batteries and other critical components, extending their operational life and reducing maintenance and replacement costs.
Efficient HVAC Systems: A Game-Changer
One of the most significant contributors to energy demand in SAPS is heating, ventilation, and air conditioning (HVAC). Choosing the right HVAC system can drastically reduce parasitic and operational loads.
- Inverter-based HVAC Systems: Unlike traditional fixed-speed units, inverter-based HVAC systems adjust their speed to match cooling or heating demand. This reduces standby power consumption and improves overall energy efficiency.
- Pre-loading Cooling with Excess Solar: Advanced Energy Management Systems (EMS) with smart scheduling capabilities can use excess solar generation during the day to pre-cool or pre-heat enclosures. This proactive approach reduces the overall cooling or heating demand during peak times, lowering energy usage and reliance on batteries.
The Role of an Intelligent Energy Management System (EMS)
An EMS is the backbone of an efficient SAPS. When designed with advanced functionality, it can:
- Monitor and Minimise Parasitic Loads: Continuously track the energy consumption of all components and identify opportunities for optimisation.
- Integrate HVAC Pre-loading: Use real-time solar generation data to schedule HVAC operations, maximising the use of renewable energy and reducing battery reliance.
- Optimize Component Performance: Ensure inverters, MPPT controllers, and other components operate at peak efficiency with minimal standby losses.
A Path Forward for DNSPs
Transitioning fringe-of-grid customers to SAPS offers tremendous potential for cost savings and improved reliability. However, success hinges on the careful selection of components and strategies to reduce parasitic loads. By prioritizing low-parasitic-load components, leveraging efficient inverter-based HVAC systems, and deploying advanced EMS solutions, DNSPs can create SAPS that are not only cost-effective but also sustainable and resilient.
The move to SAPS is not just about replacing grid connections; it’s about rethinking how energy is managed and consumed. By addressing parasitic loads and optimizing efficiency, DNSPs can lead the way in delivering energy solutions that meet the demands of tomorrow.
