LED grow lamp used for for supplemental lighting

It appears that our cool cloudy summer is going continue into August, so I decided to add some supplemental lighting for the swiss chard.

The low wattage LED grow lamp has been suspended six to eight inches above the plants and a timer turns the lights on at 7 pm and off at 12 am. In the morning the light is turned on at 6 am and I remove the light when I open the greenhouse for the day.

I am not sure what, if any, effect it is having on the chard, however it really makes the greenhouse look like the Twilight Zone at night.