On a cloudy day you might want the charge to start even if there is less than 6A (~1.4kW) available as surplus from the local generation. That's where the Minimum Green Level (MGL) comes in. With MGL at 100% then Zappi will stop the charge is the surplus generation drops below 1.4kW. By reducing MGL, Zappi will allow some power to be drawn from the grid to top up the generation if needed. For example, with MGL at 50% Zappi will keep charging the EV until the surplus generation drops below 700W. At MGL = 1% the charge will continue until there is less than 14W of surplus generation. In practice this means Zappi will only stop charging if all local generation has stopped.