DER Integration

Overview - Increase in DERs in the Australian Energy Market

As the volume of distributed energy resources (DERs) including electric vehicles, solar photovoltaic generation and behind-the-meter battery storage systems rapidly increases, networks need to adjust to accommodate this uptake. This has involved a fundamental switch in mindset from considering low voltage networks as ‘fit and forget’ infrastructure carrying unidirectional power flows to a more actively managed system that has conditions varying across the day and the seasons.

It’s vital that networks integrate DERs quickly, cost-effectively and safely as this represents an important step in the decarbonisation journey and the road to net zero.

EA Technology has experience in performing LV network modelling and monitoring for the efficient integration of DERs into the network.

Modelling
Monitoring
Software Solutions
Case Studies

Modelling

DER Hosting Capacity Assessment

Conducted by EA Technology to understand the hosting capacity limits of distribution networks with respect to DER.
Determine the most cost-effective investment strategies, in order for the grid to sufficiently meet demands of the future.

Australian DNSP 1: Hosting Capacity

Hosting capacity (kW export per customer) for different LV network types.

At present, the approach is to permit 5kW export per customer, but it is clear that the hosting capacity on a per customer basis is considerably less than 5kW for the majority of the network types present in the network and in some cases the capacity can be as low as 1 – 2 kW.

Australian DNSP 1: LV Management Strategy

Cost-benefit performance of each strategy in base case conditions.

This chart shows that when considered against a base option of imposing static limits on DER export, the strategy that generates the greatest level of benefit for customers is the Dynamic Limits (Template model) approach.

Cost of Augmentation – We obtain the costs associated with network interventions (transformer upgrades, new circuits, etc.) / year
Interventions Applied – We obtain the specific interventions that are applied / year / network architecture type
Demand / Generation curtailment – Where a strategy allows for the curtailment of generation or demand, we capture the magnitude and cost associated with this / year
Enablers – Where specific items of enabling infrastructure are required (i.e. monitoring, substation automation, etc.), this is captured based on the year it is required and associated cost / network architecture type

Australian DNSP 2: Hosting Capacity - Solar PV

The circuits with fewer customers tend to be able to accommodate a greater capacity of PV generation.

Utilising the volt-var characteristic for AS/NZS 4777.2 : 2020, compliant inverters increase the potential kW export at the expense of increased losses.

Graph on the right shows the effect of absorbing vars as would be case with the volt-var characteristic on the kW export limits. Adjusting the operating voltage of the network potentially increases the available capacity further for the same increase in losses.

Absorbing vars to reduce the network voltage and facilitate increased kW export comes at the expense of increased losses over and above those associated with the increased kW export.

Australian DNSP 2: Hosting Capacity - EVs

Lowering the LV voltage either by changing the tap position of the HV/LV transformer or by changing the set point of the HV voltage regulation equipment or some combination of both offers a significant increase in the available capacity of the LV network to accept PV generation.

Monitoring