High PV Penetration

Support high PV penetration by reducing voltage volatility and injecting vars dynamically at the Grid Edge

Voltage can be driven to unacceptable volatility or out-of-range values by today’s PV solar systems, when installed in high concentration on an individual power network. Utilities can apply Varentec’s ENGO+GEMS solution to support the integration of distributed PV solar on their grids. The solution’s key functionality is ensuring the reliability and efficiency of the distribution system when hosting PV, even at high levels of PV penetration. The solution can help utilities meet their targets for integrating renewables, improving grid efficiency, and reducing carbon emissions, while helping address society’s need for a better performing and “green” grid. Utilities that deploy the solution for PV support also gain the technology’s other important functionalities, including grid-edge support and visibility, peak demand reduction, energy savings, grid-edge Volt-VAR control, and extending the life of primary grid assets.

Key Benefits

  • Eliminate adverse effects on the grid due to PV integration
  • State-of-the-art tools to manage consumer PV penetration
  • Reduce voltage fluctuations due to PV and improve customer satisfaction



Utilities need a solution to support PV integration because the intermittent power contributed by PV creates adverse grid impacts that limit its uptake. Impacts include rapid and extreme voltage fluctuations caused by solar intermittency and changing irradiance; reverse power flow, which creates high-band voltage violations under peak conditions and interferes with grid equipment operations; and difficulties controlling PV inverters to meet local as well as system performance objectives. As PV penetration reaches 50% of line capacity, utilities will also need tools to address the sudden ramp-up of traditional system demand in early evening when PV users naturally switch from solar to grid-based supply.

Traditional, centralized control technologies can’t effectively address these various, distributed and dynamic issues or manage the extreme voltage fluctuations to ensure compliance of local and system voltages. Further, the voltage fluctuations caused by PV can span the entire compliance band, undermining utility strategic initiatives for Volt-VAR control or conservation voltage reduction (CVR).

ENGO+GEMS can be employed to address all of these needs and enable PV to reach 50% of feeder capacity. The fast-acting VAR-injecting ENGO devices, installed on the secondary side of the distribution grid, smooth the voltage fluctuations caused by solar PV. With feeder voltage flattened, utilities can operate as shown below, all field devices with a lower system voltage, in coordination with an existing SCADA system, to avoid over-voltages caused by the reverse power flow associated with high solar PV:

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The approach also facilitates management of PV inverters as part of the grid ecosystem to ensure grid reliability and stability.

ENGO+GEMS provides additional, important functions even when enabled in the presence of high PV penetration. These functions include its ability to reduce technical volt and watt losses on distribution feeders to increase grid efficiency, save electrical energy, and optimize power factor to improve the quality of the power supply. Utilities can also apply the solution as a CVR tool by operating at the low end of the acceptable voltage supply to shave peak demand or reduce consumer energy consumption on a 24/7/365 basis.

Generally, with high penetration of PV solar on the distribution system, the life of primary assets is expected to degrade. This degradation is due to an inordinate increase in the number of operations needed to manage fluctuations caused by solar PV—an operational requirement that these primary assets were never designed to handle. With ENGO+GEMS employed, the life of primary-side assets is improved and actually extended. Utilities can also apply the technology as a complete grid-edge voltage and VAR control solution to manage system performance and costs.

Deploy ENGO+GEMS at your utility and realize even more benefits.

Find out more about how ENGO+GEMS can benefit your utility.

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