Solar Plastic Molding:  Key to Improved Water Security and Sanitation in the Developing World

Emerging markets face chronic shortages in plastic tanks for water storage, water processing, and septic and sewage treatment.  These critical tools can improving health outcomes for millions of people, yet are unavailable or unaffordable in much of the emerging world.

The problem is manufacturing.  Plastic tanks are typically made using rotational molding – a 50-year-old process that requires a factory with a reliable energy supply (typically natural gas and grid-tied electricity), a building and other infrastructure, and a substantial investment in molding machinery.  Suitable factory sites often don’t exist in developing regions, and if they do then political or other factors may make the investment unappealing.   The result is that most locations that can support a traditional tank manufacturing facility already have one – and many of these locations are far from the under-served markets.

Why not simply ship the tanks to where they’re needed?  The challenge is logistics. Tanks are big, hollow, and relatively low in value.  For the cost to transport a single water tank to a remote area you could ship hundreds of mobile phones.  The cost of a water tank might double once delivered 300 Km from the factory, while the cost of a mobile phone might only increase 5%.

So this is the problem:  tanks are desperately needed in developing regions, it’s hard to put new factories in or near these areas, and it’s too costly to ship the tanks from factories to these remote areas.

The solution is Solar Rotational Molding.  This recently developed technology (patents and other IP information here) packs an entire molding factory into a single shipping container, and can be setup in any sunny location in a few days.  The factory in a box – a Solar Rotational Molding or ‘SRM®’ system – molds water and septic tanks up to 4150 liters (1100 gallons), without the use of fossil fuel energy or external electricity. 

  • SRM systems come with an easy to deploy array of LightManufacturing’s H1® Heliostats  The heliostats focus intense light and heat on rotating molds in the molding mechanism – free, safe, and clean solar heat.
  • The factory sets up in as small an area of 30m x 30m – and no concrete foundation, metal building or other infrastructure is required.  
  • Only two workers are needed to operate the factory.
  • Parts can be molded from standard polyethylene or polypropylene resins.
  • Optionally, parts can be molded with a high percentage of recycled mixed plastics (2,4, 5 and other types) using the LightManufacturing Solar Shredder – a high capacity shredder pulverizer which operates off grid from a dedicated Photovoltaic array.
  • Using the solar shredder, useful objects can be molded from landfill, shoreline, or ocean-collected waste.

Solar Rotational Molding offers several benefits to developing regions:

  • Distributed manufacturing, decoupled from major industrial centers
  • Local employment
  • Ingestion / recycling of local or regional waste
  • Low cost water tank and septic tank production, made near the point of use
  • Redeployability in case of political unrest or bad weather conditions
  • Disaster recovery – systems can be deployed post-earthquake, post tsunami to help supply critical water and sewage management tools.

SRM systems have produced thousands of parts for industrial and government customers, and have operated commercially since 2014.   The process can be deployed in most sunny regions of the world – over 49% of the earth’s land area.

Molding Range – 49% of Earth’s Land Area

If your project would benefit from improved access to water tanks, septic tanks, or similar products in the developing world, please contact us.