This desalination technology evaporates saltwater using electrical energy and condenses the vapor back into freshwater. Heat exchangers, pressure optimization and efficient process control can reduce energy demand. However, compared to RO or MSF, the ratio of input power to freshwater output is worse and economically hardly viable.

The situation changes fundamentally once second hand PV is used. Worldwide, millions of tons of old but still functional PV modules are discarded every year. Less than 10 percent of these modules are reused today, even though together they could provide the energy production of several nuclear power plants per year.

Combined with three practically unlimited resources:

• an enormous number of decommissioned PV cells
• unlimited seawater
• vast areas of dry sunny land

a system emerges that suddenly becomes economically and ecologically viable. PV thermal desalination uses energy that would otherwise be lost unused. This turns an energy intensive process into a solution that operates with almost no grey energy and unlocks enormous global potential.

HOW in the global desalination market

The global desalination market is built around large, energy intensive plants. These systems are operated by governments, corporations and high tech firms – and they function only where money, electricity and trained personnel are available.

Hand on Water offers something entirely different:
decentralized, solar powered, repairable water and agricultural systems that work without a power grid, without membranes and without complex technology.

This closes the gap between expensive high technology and regions that lack access to reliable water infrastructure. Our systems use old PV modules, provide shade for agriculture, produce water and can be operated locally.

HOW is not a competitor to conventional desalination plants.
HOW is the alternative model for regions where conventional desalination does not work.

Operation

Hand on Water provides systems designed to operate with minimal service.

Simple technology
HOW systems can be operated locally and maintained with basic tools. This reduces downtime and enables stable operation even without technical infrastructure.
Operation is limited to cleaning, salt removal and simple visual inspections. We train local teams so that all maintenance steps can be carried out without external specialists.

Adaptable
Because our systems use recycled PV modules they require neither grid power nor specialised components. They can be integrated directly into agricultural workflows and support reliable operation in remote regions.

Sustainability

Hand on Water builds systems without grey energy.

HOW systems use only photovoltaics. The grey energy of PV modules is amortised after a few years of operation. Since HOW uses only recycled modules, our systems operate practically without grey energy.
Each system is built from materials whose CO₂ footprint has already been absorbed — an advantage no other desalination system can offer.

Minimal resource consumption
While other systems require new energy, new materials and create new emissions, HOW relies on existing resources and avoids any additional production energy. This results in water with the smallest CO₂ footprint in the entire sector.

Agri PV
When the systems are used in an agri PV setup (the PV cells shading the crop area), multiple benefits arise at once. The modules reduce direct sunlight, lower soil temperature and decrease plant water demand. At the same time they generate the electricity needed for water production.
This solves two needs at once: energy and water are produced exactly where they are needed, with positive side effects such as more stable yields, better microclimate and significantly higher resource efficiency.

Salt as a byproduct
During operation the salt is automatically separated from the water. Depending on the application it can be cleaned and processed for resale. This turns a waste stream into a locally usable raw material.

Clean operation and circular economy
No chemical wastewater is produced, material use is low and all components can be easily reused or recycled at the end of their lifetime.
PV modules can already be recycled at around 95 percent, and the global recycling infrastructure is growing rapidly. By recovering aluminium, copper and other materials, there is even a financial return at the system’s end of life.