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 SummitColumbia, 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

• 4 min @ 3.6 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?