A distributed energy resource (DER) is a small-scale electric generation or storage system located close to the point of consumption rather than at centralized power plants. DERs include solar arrays, wind turbines, fuel cells, microhydro systems, and battery storage units ranging from kilowatts to low megawatts. These systems reduce grid congestion, improve reliability, and enable local energy independence.
Technical Details
DERs operate interconnected to the distribution grid or as microgrids serving specific facilities or communities. Typical residential DERs include 3 kW to 10 kW solar systems and 5 kWh to 15 kWh batteries. Commercial DERs scale to 50 kW to 500 kW capacity. Interconnection standards including IEEE 1547 and UL 1741 establish safety and performance requirements. Most DERs employ grid-interactive inverters supporting voltage-frequency ride-through and anti-islanding protection.
Practical Significance
DERs reduce peak demand pressure on transmission systems, deferring costly grid upgrades worth billions across utility territories. They improve grid resilience by distributing generation and enabling localized power supply during main grid disruptions. Owners achieve energy cost savings of 20% to 40% while utilities benefit from deferred infrastructure investment. Policy support through renewable energy targets and interconnection reforms drives rapid DER deployment growth of 15% to 25% annually.