I have 25 solar dishes that track the sun throughout the day. I place these dishes in a 5x5 matrix form on the ground. The North-south distance is x and East-west distance is y. both x,y fall in the range of minimum 25 units and maximum 80 units.

If I keep the dishes closeby, i.e., x = y = 25 they project a shadow on the nearby dish and absorb less solar energy throughout the day. IF I keep them away, i.e., x = y = 80, they absorb more energy but occupy more land.

Energy absorbed throughout the day is a function of (x,y) and some other factors that remain constant throughout. Through programming, I have a way to calculate the energy absorbed per day. Also, apart from the range of x and y, the area is also constrained, let's say Max_Area.

As of now, I've been calculating energy for each value of x and y from 25.0 to 80.0 through an interval of 0.1, skipping the ones that have an area large than Max_Area, and finally comparing the energy, but that's 302500ish calculations, and I'm sure there might be better optimisation techniques in the literature.

So what should I learn to optimise such situation?