Q: How can the water sector improve efficiency through power generation?
A: When you think about the water sector, you’ve got to remember that the water sector is a process that starts off with the rain and we’re then purifying that water, feeding it through, storing it, pumping it, and then feeding it out the other end.
So, let’s look at not just the pumping process, but also the treatment process, and the wastewater treatment process - because it’s a complete cycle - otherwise you can’t discharge it.
On the front-end side of things there are definitely things that you can improve, and the first thing would be, reduce the power that’s needed to do whatever it is you’re trying to do.
Let’s say you’ve got a pump room; you could have a diesel engine feeding a pump. We can now electrify those. So now you’ve got an electric motor feeding a pump which is much more efficient.
And you can keep going with that….
There’s normally nobody in that pump room, so we can switch all the lights off. When it’s summertime, we can switch off the anti-condensation heaters. There are all these peripheral things that can be switched off to reduce energy consumption.
The next thing is to improve is the motor. If you look at a motor today versus 15 years ago, the efficiency of the motors has been incrementally improving, the pumps are incrementally improving, even the bearings are improving. The lesson here is to make sure you’re making improvements to each one of those stages.
Once you’ve put in the new motor, now you need to monitor it. Because as it wears, its efficiency is decreasing. And in the worst case scenario, if you just leave it to carry on wearing and eventually it goes out of balance and breaks, now you’ve got some serious damage.
Now your carbon cost is not just what happened on the pump, it’s now all these people running backwards and forwards trying to fix it.
So monitor it, improve it, reduce.
Q: How can we improve efficiencies in water treatment?
A: When we look at the water treatment, there are ways of reducing the chemicals that are used, and even by doing that, you’re reducing your carbon footprint.
It’s not just about the electricity or the immediate, apparent energy, it’s about everything else that’s in the process.
If you reduce the chemicals, you reduce your cost, you make it more sustainable, there’s less wastage; so, don’t over-dose. You can use some sophisticated automation to actually measure what is necessary and then only add what’s needed.
When you then go right through to the other side of it and you look at the wastewater treatment there’s a couple of different options there.
Some wastewater treatment plants extract the solids, and they process it. So now the nitrogen and the phosphate can be sold as fertiliser. Now, instead of being a waste product that you’re trying to get rid of, it now becomes a saleable commodity.
The other thing that people may not be aware of is that, off that brown water, you get a fermentation process, and you have bacteria that are operating, and you get biogas that comes off it. That biogas has a methane content.
This allows you to extract that gas and feed that into a local generator, and then you use the local generator to supply some of your local power requirements.
When it comes to improving sustainability in the water sector, maybe somebody’s not sitting there adding up the carbon, but what they are doing is adding up the saved cost.
