3. Fundamental optimization strategies of an EWQMS
The primary goal of an energy and water quality management
strategy has been to minimize energy costs without compromising
on the water quality. Recently, the energy price escalation and
volatility has created budgeting difficulties for utilities [NYSERDA,
2010]. Hence, to reduce energy bills, water utilities have engaged
in a broad array of programs based on energy efficient practices, the
use of alternative and cleaner energy sources, and/or onesite
generation [Bunn et al., 2006]. In particular, the shift of the electrical
load (e.g., for pumping) to lower cost tariff periods has been
advantageous for those utilities that are subject to timeeofeuse
(TOU) charges by electricity providers [Raucher et al., 2008]. An
EWQMS provides a framework to implement water utility's energy
management strategies on a real‒time basis, which to date has
been achieved with optimization steps taking as little as thirty
minutes. Further details on energy cost reduction opportunities
that have been considered in EWQMS operations are discussed
below.