We’ll need huge desalination projects to meet the world’s future fresh water needs – but the energy to do it will be in short supply
Reducing the fossil energy needed in desalination is simply critical to a sustainable future, as we cover here, frequently, because the MENA nations are at the forefront of the issue: Saudi Options Narrow With Peak Water and Israel Commits Itself To More Desalination. But it comes with a huge energy cost, which is why “Desalination Should Be A Last Resort”.
So it was with excitement that I opened a Press Release from Israel’s IDE Technologies touting “the first green Reverse Osmosis system” for water desalination. Great! Who better to solve this crucial issue than a company has been around since the dawn of desalination? IDE Technologies is the grandfather of water treatment plants, with 400 desalination plants in 40 countries built worldwide since 1965.
So, is their new system solar or wind-powered desalination… like this example we’ve covered? Saudi Arabia and IBM to Develop Solar-powered Desalination
Well, no. It would be more accurate to describe their new system, IDE ProGreen, as slightly more energy efficient.
The company’s new product, IDE ProGreen just reduces energy use “by utilizing more highly efficient pumps” than are currently in use, “coupled with an energy recovery system”. No figure or percentage of energy reduction is offered in their Press Release to provide any evidence of any specifics, but the most efficient (reverse osmosis based) desalination plants typically need about 5 kwh of energy to desalinate every cubic metre of fresh water. This much energy expended to make each cubic metre of fresh water is completely unsustainable.
Reverse Osmosis is a more energy efficient desalination process using a semi-permeable membrane with tiny pores through which water can flow. The small pores of this membrane prevent all substances with a larger molecular composition than water from getting through. So salt and other minerals get siphoned off, as well as bacteria and disease-causing pathogens.
IDE Technologies’ new “Green” Reverse Osmosis system being offered at the end of 2011 is compact and flexible, which makes it easy to transport and install, and it reduces the impact on the environment by eliminating the use of chemicals in the pre-treatment and desalination processes.
But it is reducing the high fossil energy use in desalination that is critical. Soaring greenhouse gas emissions make desalination a technology that must innovate reductions in fossil fuel use. You’d think the grandfather of desalination could provide some hard numbers on this critical need.