Grass absorbs about 10 percent of the energy from the Sun, while of that 90 percent is lost as heat.
The plants, whether monocot or dicot use light energy from the sun to produce food. However, for this plants only absorb a small amount of energy from the Sun, that is, about 10 percent for the process of photosynthesis.
In the food chain, only approximate 10 percent of the energy is passed on to the next level, while the rest is lost mainly in the form of heat.