White paper · grid-connected concept

Demand Response Desalination

Utility-scale, grid-balancing

The 2015 grid-connected concept: replace one large pressure center with many small RO modules and vary how many operate.

Grid-integrated module proposed in the paper

Proposed 30 hp demand-response reverse-osmosis module from the original white paper

Calculated from the proposed module

A plant adjustable in approximately 22 kW steps

The paper envisioned plants containing 5-500 independently controlled modules. Every additional module would add or remove about 22 kW of load.

Source: Demand Response Desalination (2015), pages 9 and 11. Loads shown are arithmetic products of the paper's 22 kW module demand, not measured plant results. Original page.

The grid problem

Load, net load, wind and solar do not move together

The paper used this CAISO simulation to show the steep ramps a high-renewable grid must follow. It does not claim that desalination output traces an invented hourly curve.

Original white-paper Figure E, a CAISO simulation of load, net load, wind and solar profiles for January 2020
Power inexpensive or surplusMore modules operate
Power expensive or constrainedFewer modules operate
Water demand continuesStored permeate supplies it
Source: Demand Response Desalination, Figure E, citing the California Independent System Operator.

How it works

  • Many small, fully integrated modules replace a single large pressure center
  • The number of operating modules can respond to energy price and grid conditions
  • Stored permeate separates water delivery from the timing of water production
  • The paper analyzes potential demand-response and grid-balancing uses
Read the white paper