Using a PV system to power an emergency water disinfection system Curt Elmore, Associate Professor of Geological Engineering Mariesa Crow, Director of the Energy Research and Development Center Matt Vitello, Graduate Student University of Missouri Energy Summit Columbia, Missouri April 23, 2009

!Emergency! Critical commodities – Drinking water – Electricity – Transportation (import) of supplies On-site treatment is the solution?

Drinking water treatment technologies Principal concern = ubiquitous contamination – Fecal pathogens Chlorination Ozonation Reverse Osmosis Ultraviolet light Others

Timing is everything Crystal ball needed? – Shelf-life = critical concern! Chemicals Fuel Energy storage

UV = good candidate! Infinite shelf life Commercial systems available NSF/ANSI certified No harmful residuals May also treat some pesticides, solvents, and explosive compounds

UV has some downsides … No residual Energy intensive Mercury in lamp

Pros > Cons

Renewable Energy System

Objectives Mobile – go to surface water sources Is self-powered by wind turbine & photovoltaic cells Supplemental power from portable electrical generator Can be towed by a standard pickup truck Can be set up & operated with little training Can be placed in storage for extended time periods Low-maintenance, no significant consumable supplies Affordable for municipal and regional civic entities that are tasked with addressing civil emergencies Has on-board test equipment to validate disinfection function

Concept

Reality

Performance Wind turbine redundant – Complexity – Cost – Weight – Safety – Personnel – Lightening – Visibility – Greater area of deployment

Performance Pumping/flowrate was the limiting factor – Proactive Environmental Products, Monsoon Model PRO10597: 48VDC:24VDC gpm Additional pumps/PV required for pretreatment

Performance Treatment averaged 2.4 gpm UV system operates for 19 min Continuous UV operation possible if sunny Single charge = 19 min of UV operation

Performance Disinfection met coliform standards for “natural” water Disinfection met coliform standards for spiked water Coliscan MF for colony enumeration IDEXX Colilert for presence/absence Other parameters OK

What would a production system look like? Use external pumps (think fire tankers) Larger elevated charge tanks Throughput goal = 10 gpm – Single UCAP charge (19 min) – 2 L/day – 360 people

Production Cost < $40K On-going work – Energy management – Uncertainty analysis – Commercialization Questions?