Types of Export Restriction

Here are examples where there is roof space available for 8kW of solar panels, but National Grid has required export to be restricted to 6kW. The restriction is often required since there is little investment to upgrade the National Grid to support solar panel installation.

The ideal solution would be to install 8kW of solar panels; however, since the National Grid has imposed a 6kW export restriction, we reduce the size of the solar system to 6kW and don’t benefit from 2kW of potential solar generation.

In this solution we install the full 8kW of solar panels; however, since the National Grid has imposed a 6kW export restriction, we reduce the size of the inverter to 6kW.  This means the full 8kW of solar can be used most of the time in the home, but in the middle of summer when generation is above 6kW, 2kW is wasted.

In this solution we install the full 8kW of solar panels and an 8kW inverter.  However, since the National Grid has imposed a 6kW export restriction, we install an export meter to ensure no more than 6kW is exported to the grid.  This means the full 8kW can be used in the home all the time.  In the unlikely event 8kW is not being used in the home or stored in batteries, 6kW will be exported to the grid and 2kW wasted.

This is the best form of export restriction, but can be more expensive to install.