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Quenching the Middle East's thirst responsibly

Desal Association president: Regional water use must get sustainable

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Desalination plants must get more sustainable in their energy consumption.
Desalination plants must get more sustainable in their energy consumption.

The International Desalination Association’s President, Corrado Sommariva, discusses strategies for implementing sustainable solutions to keep supply ahead of demand

For nearly half century, desalination has provided a reliable source of fresh water to the growing population and economies in the Gulf region. No real development in society or industry in the area would have been possible without the parallel implementation and development of desalination.

Clearly desalination is a critical component of sustaining life and economy in the Gulf region: some countries in the Gulf rely on desalination to produce 90 per cent or more of their drinking water, and the overall capacity installed in this region amounts to about 40 per cent of the world’s desalinated water capacity.

Desalination plants are strategic assets requiring large investments, and with an often abrupt growth pattern, desalination planning is very difficult.

The planning of a desalination project is extremely delicate process. Generally, the period between the initial inception of a project – covering the feasibility, technical specification, tendering, etc. – and the first water production requires a minimum of three to a maximum of eight years.

In this scenario, increasing capacity is a process that needs to be explored well in advance, and proper master planning is essential.

As for the power generation industry, development of a desalination plant needs to consider parallel requirements. For example, long trunk lines are often required to transport and distribute the product water to the various utilities.

The commercial lifetime of a desalination plant can be very long – from 20 to 40 years depending on the technology – but generally, concessions aim at amortizing the investment cost over the time span of 20 to 25 years. The emphasis here is on predicting the right technical solution for such long lifecycle in a fast technological development scenario.

This imposes a great responsibility on all strategy planners. Desalination technology is rapidly changing, and many technical parameters that may have an influence on today’s decisions can drastically change during the asset’s lifetime. These include the cost of energy, cost of chemicals, availability of steam and power, and level of O&M expenditures.

Furthermore, in addition to the quantifiable parameters in the decision-making process, there are also important non quantifiable aspects that that are going to be extremely sensitive in the lifecycle terms and need to be given serious consideration.

A typical example is the level of impact on the environment. Impact levels are going to be perceived differently during the long lifetime of the assets, and some solutions that are taken today may be superseded by more advanced environmental solutions before the end of the project’s lifetime.

Generally speaking, the desalination industry is committed to improving its environmental stewardship, and the IDA is indeed playing an important role in the matter.

In December 2010, IDA held the first Environmental Symposium on the relationship between meeting the growing water needs in the Gulf region while at the same time safeguarding the environmental wellbeing of this unique and critically important body of water.

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The resulting Blue Paper provides a strategic roadmap with suggested strategies for mitigating potential effects of desalination, and discussions are continuing to help encourage implementation of these measures.

Most importantly, with such long asset life it should be considered that the technology that has been selected may become prematurely obsolete. Therefore, it is essential that planning considers the possibility of retrofit with more efficient solutions as time goes by.

In this scenario, satisfying the growing demand for water in a sustainable way is a major challenge for the desalination community. Reducing the cost of water in the given energy footprint is the greatest challenge that all Middle East countries will face in the next 20 to 25 years, as the region uses energy-intensive technology for water desalination.

Improving energy consumption is essential to face the issues related to sustainability, but it will not have a significant impact on water tariff for the time being.

Particularly in the Middle East, the price of energy used for desalination technologies is very low, and with such a low price the installation of more sophisticated energy-efficient strategies becomes commercially unattractive.

Here IDA can play an important role both in encouraging policies that promote energy savings and the correct application of energy tariff in desalination technology. In this manner, contractors and developers would be incentivized to develop more sustainable solutions in our business.

A special task force has been created by the IDA to investigate further what strategies can be adopted to mitigate the environmental and energy effect of desalination and how government and stakeholders can work together towards an inclusive and integrated process.

To date, some progress has been made in reducing the carbon footprint of desalination, but the overall goal of making desalination more affordable can be only achieved by a coordinated teamwork between all stakeholders operating in the sector, aiming at encouraging efficiency both in the implementation and promoting advanced and emerging technologies for green desalination.

In this respect, there is a very strong connection between the industry’s capacity to accommodate growing water demand needs and at the same time, mitigate environmental impacts. The response lies in the capacity of the technology not only to generate more innovative solutions, but also to implement them in real applications.

Energy consumption is a typical case where innovation has been playing an important role in the desalination industry in the last decade.

The energy consumption of seawater reverse osmosis (SWRO) technology has dropped to levels in the range of four to five kwh/m3 thanks both to the adoption of more sophisticated energy recovery devices and also the development of membranes that can operate at higher recovery and better flux.

Reverse osmosis (RO) technology is continuously improving in the field of both reliability and energy efficiency. It is essential that planners aiming at keeping supplies ahead of demand are aware of the sensitivities that energy cost will play over the long term in the overall water tariff, so that possibility of retrofitting more energy efficient solutions could be designed at this stage for long-term implementation.

If, on one hand, developments in thermal desalination technology have not been as evident as those in reverse osmosis, the advances that have been introduced in the field have, nevertheless, been substantial.

The two major thermal desalination processes are Multi-effect Distillation (MED) and Multi-stage Flash (MSF). MED technology is substantially more energy efficient than MSF technology and in some cases, also more energy efficient than RO.

For many years, MED technology could not find an entry point in the implementation of large scale projects, but it has now found its way through the market as there is a serious technology drive towards increasing the distillers’ performance ratio. Whereas 10 years ago, one distiller could produce seven kg of distillate water per kg of
steam, the trend is now more towards nine or 10.

There has also been a strong drive towards the development of solar desalination in the region. This has been moved forward by a generally more environmental and energy conscious approach to the power and desalination market in the region.

The successful application of renewable energy in the region will depend on several factors, and primarily the capacity of creating a strong platform of interest that involves both researchers and investors as well as the governments and includes a set of policies that seriously promote this application further.

A great contribution to this improvement in the Middle East has been made by the privatisation of the water generation sector and by the introduction in the market of private entrepreneurship, which is focused on technology efficiency to gain a competitive edge aligned in the development of projects in the region.

Clearly, careful planning aiming at keeping supplies ahead of the demand cannot exclude a significant action on water conservation and wastewater reuse that could be implemented in the region with regard to water distribution, consumption, treatment, recycling/reuse and disposal.

This approach could bring about significant savings both in the production water costs and also in the overall water sector’s energy footprint.

Water conservation must start with education, and must include the provision of suitable monitoring and water regulating devices as well as the application of realistic water tariffs that reflect accurately and without subsidies the cost of water production.

Water tariffs in the Gulf region, and particularly in the Kingdom of Saudi Arabia, are among the cheapest in the world and the price for consumption is negligible.

Water utilities are often located in inland areas where, in addition to the high energy production cost, a substantial cost and energy input is required for long water
transmission pipelines.

Water is essential to growing population and economies. It must be affordable, but the tariff also needs to be structured to encourage conservation and the wisest use of this precious resource.

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