Feasibility studies

With the exception of EVs, all distributed energy resources (DERs) investigated have characteristics and capabilities that could support an electricity system restoration service.  

EVs aren’t yet prolific enough to be considered viable in this context.   

Much uncertainty surrounds the resource availability of battery storage (the state of charge at the time of shutdown) during electricity system restoration.  

This uncertainty can be reduced by providing a route to market for DERs, so these sites are incentivised to always ensure a minimum level of charge. 

There are concerns around the uncertainty of wind and solar resource.  

Some of this uncertainty can be mitigated through better modelling tools. This can increase confidence and provide a minimum level of assurance that this resource will be available when required. 

The majority of converter‑connected DER sites operate with grid‑following inverters, rather than grid‑forming inverters. This means they cannot generate their own voltage signal for the purposes of network energisation and creating a power island.  

Instead, the grid‑following inverters require a voltage signal to latch onto, which must first be created by a site with grid‑forming capability. Upgrading this capability is straightforward if the necessary incentives are put in place. 

A common issue throughout all DER sites is the resilience of the communications infrastructure. Currently, this is typically not adequate to meet the requirements for an effective electricity system restoration service. 

A minimum level of resilience is stipulated in Connection Agreements. Sites are rarely incentivised to provide more than this minimum level. A route to market for DERs would encourage more sites to incur additional costs to meet the necessary resilience requirements.