Mini Desalination Plants: Clean Water For All
We say access to clean water is a fundamental human right. However, nearly 2 billion people still don’t have access to this essential resource. Mini-desalination plants can help solve this global problem and provide safe drinking water for all. The technology behind these small but powerful plants is simple, effective and inexpensive.
How does desalination work?
Desalination is a process that removes dissolved minerals from unpalatable water, such as seawater, and creates fresh drinking water. The most common type is a Reverse Osmosis (RO) plant. RO plants use pressure to force untreated water through a semi-permeable membrane, leaving the dissolved minerals behind.
Mini Desalination plants are small-scale RO plants designed for domestic or small community use. They typically have a capacity of around 500 litres per day and can be powered by grid electricity, solar power, or even a car battery.
They can often be found on ocean-going vessels like sailboats with lower freshwater tankage capacity and are considered a reliable method of providing drinking water on month-long passages.
On land, Mini Desalination plants can be essential for increasing access to clean water in remote and rural communities and in emergencies where freshwater supplies have been contaminated or cut off. They can also be used to supplement existing water supplies during periods of drought.
The potential is huge; there is roughly 800 times more brackish water than fresh water in the ground throughout the United States. Brackish water contains far fewer dissolved minerals than seawater, meaning the desalination process is more cost-effective and results in less waste than seawater treatment systems. This huge amount of water only needs to be tapped and desalinated to provide water to drought-stricken places like Arizona and California. For example, despite a once in 1200-year drought, it is estimated Arizona has 600 million acre-feet of brackish water deposits that it could use for desalination purposes.
Benefits of Mini Desalination Plants
- They are much more affordable than traditional large-scale desalination plants.
- They are much easier to transport and set up, making them ideal for use in remote areas or disaster zones.
- They require far less energy and can operate on solar energy, making them more environmentally friendly.
- Because they can run on solar energy, they do not need a grid utility connection, which is ideal for remote locations.
- They can produce drinking water, irrigation water, or even water for industrial purposes.
- They can help to improve the quality of life for people who live in areas where clean water is not readily available.
Mini Desalination Plant Costs
The cost of installing a mini desalination plant will vary depending on the size and capacity of the plant. Generally, the larger the plant, the higher the initial investment cost. However, operating costs on a solar-powered system are relatively low, making it an affordable option for many communities.
The initial investment cost for a mini desalination plant can range from $500 for household-sized systems to tens of thousands for larger, community or resort-scale systems. The operating costs for a mini desalination plant are typically between $0.02 and $0.10 USD per gallon of water produced. These costs will vary depending on the type of plant, its location, and the cost of energy.
Mini-Desalination plants can provide a community with clean water at an affordable price and are a viable option for communities that are affected by drought conditions.
Mini Desalination as a Social Enterprise
While large-scale desalination plants have been in use for decades, mini-desalination plants are a newer technology that can be deployed in a social enterprise model and are already making a difference in many parts of the world.
In India, for example, a plant backed by brewing giant Carlsberg will provide subsidized clean drinking water to area residents and provide employment to more than a dozen local women. The company designing the system, Desolenator, provides a combination of solar-electric and passive solar systems to power the plant for little or no cost and with minimal environmental impact.
Looking ahead, it’s clear that mini-desalination plants will play an essential role in ensuring that clean water is accessible to all. As RO and solar technology continue to evolve and become cheaper and more efficient, mini-desalination plants will help us meet the challenges of a changing climate and ensure everyone has the water they need to lead healthy lives.