How do the Affinity Laws help operators reduce pump energy use in hydronic systems?

The Affinity Laws show that small reductions in pump speed can significantly lower energy consumption. For example, reducing pump speed by 1/2 reduces energy use to 1/8 of the original energy use. The law states that P2 = P1(N2/N1)^3, Where P1 and P2 are the inital and new power use, and N1 nad N2 are the initial and new pump speed. Similarly, small increases in pump speed can significantly increase energy use.