How EMMA GVS works

Manage the power you export to the grid to satisfy your DNO.

EMMA GVS (Grid Voltage Stabilisation) functions in the same way as standard EMMA but has the added ability to ensure that the amount of power you export to the grid at any one time is restricted to that permitted by your Electricity Distribution Network Operator (DNO).
It is typically used for larger micro/onsite generators which are on remote sites with high impedance grid-connections. For example, you want a micro-generator that is capable of producing, for example 11kW, but the electricity network you are connected to is only capable of handling 4 kW (the limit set by your Network Operator can be either a fixed maximum export current or capacity or an export current or capacity that varies depending on supply voltage).

Without EMMA GVS you would be restricted to a 3.5 kW micro-generator. With EMMA GVS, you can install a larger generator, confident that EMMA GVS will manage the export of electricity so it remains within your Network Operator’s limits. Any electricity in excess of this is used onsite.

The export threshold is managed by EMMA GVS using a thermal store (such as immersions in one or more hot water cylinders or a buffer tank or convection heaters). EMMA GVS varies the power to these devices to act as an overflow for any excess electricity above the permitted export threshold.

EMMA GVS also monitors the grid voltage and maintains it within the inverters operating range by varying power to the thermal devices. Should these primary loads reach their desired temperature EMMA GVS will switch to an alternative heating load.

For example, on a windy day, once all immediate appliance, space heating and hot water needs and export thresholds have reached their maximum safe temperatures/thresholds, the surplus electricity has to be diverted somewhere else. EMMA will switch from heating the water with the immersion at this point to an alternative thermal load. If for any reason the thermal store or the alternative loads malfunction, the EMMA GVS unit will isolate the supply from the renewable source by disengaging a contactor on the supply line from the renewable source.

We supply store/alternative load contactors as an optional/recommended extra with our EMMA GVS units. These switch from the primary load to the alternative load when the desired temperature is reached.

EMMA GVS also eliminates flicker – which is where rapid ramping up and down of voltage due to excess power from the renewable source which can cause for instance the intensity of lights to change.

ELITE Control

The ELITE is the latest addition to the EMMA product family. While we consider it to be the Elite of power diversion and monitoring it is in fact EMMA's little sibling or as we call it EMMA lite.


EMMA Cascade

The modular heating system that can grow and grow


EMMA with Export Control

EMMA with EC allows for installs to have a greater renewable output than the Max Export Capacity (MEC) on site by diverting excess energy to heat.