You can use concrete blocks as an anchor point but you must dig them in the ground and compact the ground back around the block. The block should be dug into the ground 300mm to 400mm as a suggestion, but you must check this with the job engineer.
You can use a prop from the concrete block to back to the panel (horizontally) to help hold the concrete block from sliding away.

Concrete Deadmen Ref # Application Bar Size (mm) Bottom Cover (mm) Units in a Standard Pack