While reactive power has no value in powering electrical devices, it does perform valuable functions to help power move more efficiently. An RPC setting of 0.9 lagging or lower is mandatory on all exporting inverters rated above 2kVA and up to 30kVA and connected to Ergon Energy’s main network (not SWER or isolated networks). A lagging fixed power factor ‘absorbs’ reactive power to reduce the amount of voltage rise attributed to the power generated by the PV system. Although it operates whenever the array is generating, it will only impact the generation amount (kW) when the PV system is generating at its maximum. For example, with a 0.9 lagging setting on a 5kVA inverter, the kW capacity is only reduced when it exceeds 4.5kW. By throttling back the kW capacity at peak PV generation times, the voltage rise to the network attachment point is reduced, thereby reducing the likelihood of the inverter’s maximum voltage trip point being reached. This in turn means the inverter will not trip off as often as it may have, which will result in more kWh being generated over a typical day, as illustrated by the green line in Figure 1.
Figure 1. Typical PV Generation profiles

Figure 1. Typical PV Generation profiles

RPC also benefits the local network and neighbouring PV systems, in that the reduced upward pressure on the network voltage will allow other PV systems sharing the transformer to operate without tripping off (other than in necessary circumstances), or at least operate for longer before tripping off. As more of your customers have RPC enabled, more inverters will operate more effectively. A key benefit of RPC enablement is that PV applications on premises on Ergon Energy’s main network which include RPC and undergo assessment are more likely to be approved. Also, the higher proportion of inverters with RPC on a local network, the more applications we’ll be able to approve on that network. Installers are encouraged to activate RPC on existing PV systems to help address voltage-trip issues. In a small proportion of cases, where there is a robust local network and few or no other PV units connected, the total kWh generated by a PV system with RPC may be a few per cent less annually than it would be without RPC. We’re confident that RPC provides holistic benefits for PV customers, the network and the PV industry. To minimise any downsides, we have allowed for dynamic RPC settings under the new (draft) Connection Standard that is currently open for feedback. Source: Ergon Energy