Reducing energy footprint of water desalination is priority, say experts

Dr Corrado Sommariva, managing director of ILF Consulting Engineers in Abu Dhabi, claims desalination technologies are too energy-intensive to be coupled effectively with solar power sources.

To reduce the energy footprint of water desalination, the Government should follow the policies European countries have used to encourage renewable energy, experts have said.

This reduction, as well as the switching to the use of renewable energy to power water production, was identified as water resources strategy goals for the capital during the recent Abu Dhabi Sustainability Week.

But, according to Dr Corrado Sommariva, managing director of ILF Consulting Engineers in Abu Dhabi, even with improvements over the past 50 years, existing desalination technologies are too energy-intensive to be coupled effectively with solar-power sources.

“Energy intensity at the moment is so high that to have one cubic metre per day of desalinated water, it would take you 50 square metres or more of solar panels,” he said, explaining that this means a commercial-scale plant will have huge requirements for space.

Emerging technologies that are able to separate the solids dissolved in sea water while using less energy will offer a more comfortable fit with solar power. But they need support, he said.

“At the moment all these technologies have very big development and engineering costs, which in the normal course of events they would not have, so they cannot be compared with the state-of-the-art [improved existing] technologies on a commercial basis,” said Dr Sommariva, who is former president of the International Desalination Association (IDA).

One way to tackle the issue would be for the Government to create a small market of up to Dh55 million a year, for new technologies. The approach, said Dr Sommariva, could be similar to the one used in some European countries to create a market for renewable energy technologies.

“They created 30 years ago a market whereby every company producing energy has to have a portfolio of 3 or 5 per cent of renewable energy,” he said.

“Policymakers should have the same strategy here for water,” he said. “They have to create a niche market for water whereby every developer must have a portfolio, maybe of 1 per cent or 2 per cent of their water produced in a renewable manner.”

Dr Abdullah Al Alshaikh, the IDA president and deputy governor for planning and development of the Saline Water Conversion Corporation in Saudi Arabia, also said government support was necessary to encourage the use of solar power in desalination in the Arabian Gulf.

“I think it needs some subsidies in the beginning,” he said.

Saudi Arabia is already coupling desalination technology with solar photovoltaics but it is relying on conventional technologies in a new facility being built on the border with Kuwait and expected to come online in two years’ time.

When it comes to the advancement of innovative desalination technologies, a first step has already been taken by Masdar. Last year, it announced a collaboration with IDA to build several pilot-scale desalination plants completely powered by clean energy.

These will help to inform them about building a large-scale, commercially viable facility by 2020.

The project is “going very well” and Masdar has already shortlisted bidders with an expected five projects to be announced next month, said Dr Sommariva, who is also consulting Masdar on desalination issues.

“The capacity is ranging between 1,000 cubic metres a day to – the smallest one – 200 cubic metres a day,” he said.

Among the possible innovative technologies are forward osmosis, low-temperature distillation and membrane distillation. Another concept involves the use of a solar pond to heat sea water and drive a more conventional thermal desalination process. The facilities could be operational this year and could offer important lessons to commercialising some of the new technologies.

“By the end of the year, we should have the first feedback in terms of reliability, confirmation of the energy footprint, costs of operation,” said Dr Sommariva.

It is these questions about plant performance and costs of building and operation that will determine the attractiveness for investors.

“So that is the question mark. But after this pilot, I am sure, many more investors will be interested to invest in these technologies,” he said.

Abu Dhabi produces more than 90 per cent of its water in combined-cycle electricity and water plants powered by natural gas, which are responsible for nearly a third of the country’s greenhouse gas emissions.