Financial Times

The need for clean drinking water is increasing rapidly. Natural supplies can no longer cope, and shortages happen around the world - especially in tropical and developing counties.

There is often enough water available, but it is salty, brackish or dirty, and needs cleaning to make it safe to drink.

Governments, scientists and engineers are working on ways to do this, but existing methods such as 'multi flash distillation' or 'reverse osmosis' have many drawbacks. The equipment is expensive to build, is knowledge intensive and consumes a lot of energy. For many countries, these methods are simply not feasible. A solution is needed which is simple and reliable, and can be financed, build and operated locally. Until now, nothing like this existed.

Pyramid Water Systems has developed the Water Pyramid, a new drinking water concept for tropical, rural areas.

The Water Pyramid makes use of simple technology to process clean drinking water out of salt, brackish or polluted water.

Most of the energy needed to clean the water is obtained from the sun.

The application is designed for tropical or subtropical regions around the world, where flat ground space is available together with abundant radiation from the sun.

The Water Pyramid is designed following appropriate technology standards, and at present a patent is pending.

Since customers demand for more than technology alone, we offer important organisational tools, micro financial schemes, capacity building and help to setup a viable financial and economical application.

With this set of tools, we are committed to solve water problems in close cooperation with our customers.

Benefits
Benefits of Water Pyramid-concept, in short:

*Drinking water made easily available
* For remote and local application
* Low operational/ maintenance costs
* Can be used for income generation
* Workforce can be locally recruited and trained
* Water Pyramid can be locally produced
* Based on Appropriate Technology

How does solar distillation work?

The Water Pyramid is based on the principle of solar distillation which, over the years, has proven to be a highly efficient mechanism in cleaning up water supplies in order to provide safe drinking water.

The mechanism behind solar distillation is simple and effective.

Solar energy penetrates an airtight space through a transparent cover and is absorbed by the polluted water in the bottom of the space.

The water is heated to temperatures up to 50-70 degrees Celsius. Within the airtight space, polluted source water (e.g. salt water, brackish water, river water) evaporates and condensates simultaneously.

Within the airtight system, convection currents are formed between the cover and the water surface.

Over the water surface, the air is saturated with water vapour, and it moves upwards where it is cooled by contact with the cover. Here, its vapour partially condenses and is extracted from the system.

What is the quality of produced drinking water?

With the Water Pyramid purified high quality drinking water is produced. In the evaporation process, impurities such as salt, heavy materials and microbiological organisms are totally removed.

What is the life span of a Water Pyramid?

Although highly dependant on the specific climate conditions and the level of maintenance, generally speaking after three years of operations, the plastic foils have to be replaced with new ones.

Is pre-treatment of feed water necessary?

Dependant on the quality of the feed water, pre-treatment can be necessary. In that case we advise to use simple aeration and sedimentation, possibly in combination with Rapid Sand filtering techniques.

Is post-treatment of produced water necessary?

Yes, some treatment is necessary to demineralise the produced water. That can be achieved by passing the distillate over a calcium containing material of by adding salt tablets to the product water. If the produced water is being stored for longer periods, we advise dosing chlorine based chemicals to the system.

What parameters influence the production rate?

The water production is related to local climatologically conditions such as the intensity of the solar radiation, clouds, outside temperature, humidity and wind activity.

Further, regular operations, cleaning of Water Pyramid surface, and maintenance will contribute to a stable water production.

What is the maximum production of the Water Pyramid?

The water production is primarily related to the intensity of the solar radiation and the ground size of the Water Pyramid. In tropical regions, a water production of 4 - 5 litres a day per sq metres Water Pyramid is achieved. Thus, a Water Pyramid of 500 sq metres produces daily 2.000 to 2,500 litres of fresh drinking water.

What can be done if we need more water?

The Water Pyramid is designed using a modular concept leaving space for (future) expansion on demand. Water pyramids can be linked together to meet your specific water needs.

How environmentally friendly is the Water Pyramid?

The electrical energy necessary to produce drinking water can be obtained using solar panels in combination with battery back-up system. Reverse osmosis (RO) desalinators in the same production range usually require about 10 times as much energy to produce 1000 litres of water. And compared to the RO systems, the Water Pyramid produces hardly any brine.

Are consumer based applications feasible?

Physical laws require relatively large sizes for the Water Pyramid (200 sq metres minimum) to achieve competitive results. As a consequence, a reduction of size implies reduction of advantages, making the Water Pyramid less suitable for small scale domestic applications.

Requirements:
Region and location

Abundant sunshine is the key for producing water within the Water Pyramid. Therefore, we expect clients to be in tropical and subtropical (island) regions. For satisfactory operation, the Water Pyramid requires sufficient flat space, and the nearby presence of source water, such as salt water, brackish water or polluted river water.

Operations and maintenance

A well trained local workforce, in combination with back-up in the form of a technical service team play a vital role in the day-to-day operation and maintenance of the Water Pyramid. In our concept, the first line service work on the Water Pyramid is executed at the community level, sharing responsibilities and revenues.

Hygiene and Sanitation, training and capacity building

For successful application of the Water Pyramid, basic knowledge of hygiene and sanitation is vital. Further, it is advised to initiate a capacity building programme in cooperation with the local community, NGO’s and other appropriate partners.

Technical concept

The Water Pyramid is a uniquely designed foil structure, utilizing energy from the sun to evaporate dirty or polluted source water and to condense high quality drinking water.

The concept is primarily based on the solar still principle, but the Water Pyramid is the first, stable application optimised for large ground areas. Being able to cover large areas, allows the capturing of large amounts of sun-energy and subsequently the production of substantial amounts of drinking water. The Water Pyramid can provide communities of hundreds of inhabitants with enough drinking water to fulfil the basic water needs.

Hybrid system: solar distillation and rainwater harvesting

Apart from the solar driven type of water production, the Water Pyramid is a hybrid system in that it can also be used for rainwater harvesting if the climate conditions are such that a rainy season occurs. The harvested rain water is gathered in a large water tank and purified for drinking water- or agricultural purposes.

In operating the Water Pyramid; four types of water are produced:
* Drinking water, for direct and local consumption;
* Bottled water, to market;
* Water used for washing and cooking;
*Water for agricultural applications.

Easy to maintain, durable and flexible

The Water Pyramid is simple to install, to operate and to maintain. It can be operated by a locally recruited labour force. The technology used is sustainable and the materials used reflect the high quality of the design.

The Water Pyramid is designed using a modular concept leaving space for future expansion on demand. Clients have the flexibility to use salt water, brackish water or polluted river water as source water.

Appropriate Technology

Appropriate Technology (AT) forms the backbone of the Water Pyramid: The concept is environmentally friendly due to a very low energy consumption (the desalination process is solely driven by sun energy) and minimal production of air pollution and brine.

The Water Pyramid can be maintained by a locally recruited workforce and offers local communities the ability to increase their income.

Last but not least, due to the low operational cost, the Water Pyramid can easily compete with other desalination technologies.

Technical Details

A typical Water Pyramid, with a total area of 200 sq metres, situated in favourable tropical conditions, can produce 400 to 800 litres of fresh water a day, using the energy from the sun.

The need for energy is low: the desalination process is solely driven by sunlight and the electrical energy needed for pressuring the Water Pyramid and driving the water pumps can be obtained using solar cells in combination with a battery back-up.