Water and energy are two utilities that are inextricably linked in a factory. For proof, when an osmosis unit, heat exchanger or cooling tower are fed poor-quality water, their energy efficiency plummets. What better raison, then, to keep a close eye on “water efficiency” in industry? Stéphane Gilbert, Chairman of the Management Board of Aquassay, a company specialised in efficient water use, couldn’t agree more.
Everyone is familiar with the concept of energy efficiency. But what exactly is water efficiency?
Stéphane Gilbert – You’re right, water efficiency is still something of an unknown. It’s a very recent concept that first emerged in the early 2010s and springs from the firm belief that water is an invaluable asset, but one that can be spoilt, is in limited supply and is costly. In practice, water efficiency is a comprehensive approach aimed at optimising the management of both water quality and quantity in industry. The point of water efficiency is to use less water, improve the production process and discharge fewer pollutants. We use science and digital technology to achieve data-driven water efficiency and, in so doing, tailor the way water is used in the water cycle.
How are water and energy connected in industry?
SG – I often say that water efficiency and energy efficiency in industry are two sides of the same coin. The main reason for this has to do with physics and chemistry: water has a tremendous ability to store energy. More specifically, it acts as a heat vector that can be used to either heat or cool. Water therefore plays a key role in industrial processes, for producing electricity or steam, for example.
So it is easy to see how the quality of the water will affect the quality of the process output. Just imagine what happens when water that is too calcareous is used in a heat exchanger. In hot water, the calcium content precipitates out and forms a layer of limescale on the sides, which acts as an insulator. This can lower the exchanger’s energy performance by up to 40%. Not only that, but the manufacturer will have to bear the maintenance costs for removing the limescale. These expenses will, however, be accounted for as energy-related costs. And yet the sole factor responsible for these mediocre performances is the poor-quality water.
We recently conducted an audit to identify the water costs in a factory and found that the costs attributable to water had been grossly underestimated. They are in fact up to 10 times higher than the visible costs of water, i.e. the combined cost of the water supply and waste water treatment.
What are the benefits to be gained by using a digital solution that links water and energy?
SG – You need to see the factory as an integrated system that uses energy, water and air, produces manufactured goods, and generates and discharges waste. Advances in science and digital technology mean it is now possible to collect, sort and collectively analyse all types of data, from a variety of digital platforms, in a single database.
So a manufacturer can study all of the factors interacting in his factory to get a better picture of their complexity, and turn that knowledge gained into added value. This new, holistic view makes it possible to optimise production, even when everything seems to be working well.
For example, by simultaneously monitoring the water cycle and the steam boiler in a dairy factory, we found a cold water backflow in the condensates. The customer had no idea it even existed! By preventing the cold water backflow, the customer saved the equivalent of €10,000 per year in energy. Proof that monitoring water management and energy management together leads to the right solutions and very fast returns.
So the idea is to monitor the industrial system as a whole. Is that all?
SG – No, there’s more. The factory has to be supervised as an integrated system, as we have just shown, but that’s not all. It must also be monitored continuously, since water quality varies constantly. The thermal inertia of the water and the inertia associated with its mass must also be taken into consideration. This means that the water’s influence on energy performance and industrial performance must be studied together in real time and over time.
This allows the technicians to adjust the processes and detect incidents early, thanks to the predictive calculations based on data historisation. This way, manufacturers can optimise their production and also save energy and water. Contrary to what people sometimes think, water is neither free nor in endless supply, and its quality is not unwavering. We would even say that monitoring water management is a civic issue that should not be glossed over!
Aquassay in brief
2015 – founded in July
22 facilities equipped in 5 countries: Algeria, Bulgaria, Egypt, France and Switzerland
A vital partnership
by Tanguy Mathon, CEO Blu.e by Engie
“Manufacturers are aware now that optimising their energy use is an essential part of managing their performance and their costs. What they don’t know yet is that optimising their water use is just as important. With Aquassay, we want to highlight the indirect costs of water, which, even if they don’t show up on the manufacturer’s bill, are far from negligible. The goal is to improve our customers’ performance. We are working together on three projects, one of which is the production of baby formula. This leads to the production of what is called “cow’s milk”, which the customer would like to recycle to fuel its steam boiler. However this cow’s mile contains proteins, sugars and fats that could melt or cook in the boiler and reduce its energy efficiency. It is these elements that our joint Aquassay/Blu.e digital platform is going to investigate.”