At the exhibition, held concurrently with the World Future Energy Summit, Joaquin Konow, Development Manager, Crystal Lagoons Corp, spoke to B Surendar about the technology, benefits and application of the concept.

When was Crystal Lagoons Corp set up, and what is its scope?

We started in 2008 with a project and created and developed technology that allows you to build and maintain in limited sizes of crystal clear water lagoons at very low cost. We have created the biggest swimming pool in the world; this is in Chile.

How many projects have you handled so far, and what kind of projects are you scouting for?

We have done 180 projects in 45 countries. We are growing fast in the real estate sector, doing large lagoons. One and a half years ago, we started looking at applications in two areas:

1. Pre-treatment for RO
2. Cooling for thermal power plants, data centres and, eventually, district cooling.

This has been catching up very fast. We are working with major energy companies in Chile. We are creating large water bodies that will act as heat sinks. It works out to be less expensive, as we don’t use much energy, because there are no fans involved.

What would qualify as a large lagoon?

In our estimate, two hectares of space would qualify as a large lagoon. It will hold approximately 40,000 cubic metres of water.

Our model is similar to a cooling tower. We are talking about the same parameters here. And we can achieve the same temperature that a cooling tower can achieve. The lowest temperature a cooling tower can achieve is driven by the wet bulb temperature.

What are the cost and environmental factors involved?

Our system is less expensive to operate. We use less water, because there is no drift, and therefore, the evaporation is less. This is because, all that we evaporate is the heat that comes out of the lagoon.

What kind of water do you use, and what about its treatment?

We can use any kind of water, be it brackish or seawater. We use seawater and brackish water directly. However, we haven’t used TSE (treated sewage effluent). Depending on the use of water, we use different treatments. We use PVC, stainless steel or alloys for the heat exchangers.

We always keep salinity levels at an acceptable level, because the volume of water we have in a lagoon is very large –10,000TR = 35 MW. If you are planning to cool 35MW, you will need at least 25 hectares of lagoons.

Can the lagoon go deeper?

Yes, one solution is to go deeper. Similarly, we use spray system. When the wet bulb temperature is close to the lagoon temperature, we need to use spray to take out the heat.

What is the structure of the lagoon?

We use special type of linings as a base.

In which case, you cannot exchange heat with the ground?

Yes, so we use spray.

What about the heat?

The heat is removed from the lagoon through evaporation and conduction. We have a model where we simulate five times the life period of the lagoon, and we obtain temperature data that allows us to ascertain surface depth of the lagoon. One of the advantages of this is that we can manage the water quality.

In your estimate, what is the capex?

It will depend on the earthworks, which are different from area to area. Roughly speaking, for a standard project, it would work to USD 180,000 per hectare of lagoon. This cost will fetch a turnkey solution. It includes the earthworks, spray system, structure and lining and the circulation system. Most of the material can be procured locally.

What projects have you executed in the MENA region?

We were to be working on a project in Dubai, which has stopped at present. In Sharm-el-Sheikh, in Egypt, we have completed a 12-hectare lagoon. And then, there is the Dead Sea Lagoon in Jordan, which is for amusement purposes. In Saudi Arabia, we have a project for cooling. Though the project itself is huge, the cooling part is small.

What are the other applications of the concept?

The lagoon can be used for aesthetics and recreation and not just for cooling. It can also be used for industrial purposes. Taking advantage of the heat in the water, you can do district heating and desalination. We are taking advantage of thermal gradient to produce fresh water. We pass the hot water from the lagoon through pipe, which has a membrane in between, with cold water on the other side. Consequently, we can produce fresh water at a very low cost. As of now, there is no pilot project for desalination, but it is at the development stage.