What does voltage impacts refer to?
Voltage spikes can impact the hosting capacity and safety of a distribution network and therefore are an important metric to measure for assessing network impacts.
Generally, the closer a neighbourhood battery is connected to the distribution substation, the less impact it can have on voltage. A neighbourhood battery connected at one of the furthest locations from the substation, i.e. at the end of the feeder, generally can have the greatest impact on voltage management for that part of the network. At the end of the feeder, however, the neighbourhood battery will have much more constrained import/export limits (that will impact its ability to perform services like energy arbitrage) compared to one close to the distribution substation.
A neighbourhood battery is therefore probably best located somewhere in the middle of the distribution network, however this will vary for each distribution network. Where the neighbourhood battery can be located will also, and importantly, be constrained by the physical sites available where it can be placed. Due to this, the ability for the neighbourhood battery to have a significant, if any, impact on network voltage is highly dependent and likely, in most cases, to be limited.
Metric for assessing voltage impacts
A battery’s meter may be able to monitor power quality at its connection point to determine if it is supporting the network. For example, during high load times the voltage would be low and during high export times the voltage would be high.
To assess if the battery is impacting network voltage, the daily range of low to high voltage experienced at its connection point could therefore be used according to the following relationship:
To reduce the daily range, a neighbourhood battery can optimise its real power importing/exporting and providing of reactive power at times of low or high voltage.
Another metric that could be used for assessing voltage impacts, which is currently being trialled by several DNSPs (e.g. AusGrid), includes their response to “peak events.” In such trials, the neighbourhood battery is rewarded for providing network support (real or reactive power) during those times. How often and the extent to which the neighbourhood battery can respond to those peak events could therefore be a quantifiable metric for estimating the impact the neighbourhood battery is having.
Data
- Battery meter voltage data
- Household meter voltage data