Solar Water Pump Engineering Challenge

• Corner A: A solar-powered fountain at the entrance
• Corner B: A rainwater collection system that feeds the garden beds
• Corner C: A pollinator water station for bees and butterflies
• Corner D: An interactive water-flow garden visitors can play with

• Corner A: Follow the instructions exactly
• Corner B: Sketch a plan first, then build it
• Corner C: Dive in and adjust as you go
• Corner D: Improvise with whatever’s around

• Corner A: Solar / renewable energy engineer — designing power systems
• Corner B: Water systems engineer — moving water across cities and farms
• Corner C: Agricultural engineer — irrigation, soil, growing systems
• Corner D: Environmental engineer — protecting ecosystems and resources

Watch this first — it shows how to read voltage off a multimeter.

Test procedure:

1. Clip one multimeter lead to the red (+) wire on your panel, the other to the black (−) wire.
2. Set your multimeter to read DC voltage — the V with a straight line above it, not the wavy one.
3. Take everything outside. Hold the panel flat in your hand and read the voltage.
4. Now tilt the panel toward the sun. Did the reading go up or down?
5. Move to a shaded spot and read again. Then back to full sun.

• Highest voltage you got and where/how the panel was positioned
• Lowest voltage and what changed
• Best angle to the sun — flat, tilted, or steeply tilted?

Watch this — it shows the connection.

Build procedure:

1. Fill your reservoir about halfway with water. Set it on the tray.
2. Drop the pump into the water — it has to be fully submerged to work.
3. Position the open end of the tubing so it points at the target cup.
4. Connect the panel to the pump: red wire (+) to red wire, black wire (−) to black wire. Take the panel into full sun.
5. If water flows: you’re a working engineer. If nothing happens: swap the wires (see warning above).
6. Build a structure with craft sticks, tape, and recycled materials to hold the tubing steady and support the target cup. Your system needs to run hands-free for one full minute.

Run 1 — 60 seconds:

1. Reservoir full. Target cup empty. Tubing pointed where you want it.
2. Hold the panel in full sun. Start the timer the moment water starts flowing.
3. After 60 seconds, disconnect the panel.
4. Pour the water from the target cup into your graduated cylinder. That number is your flow rate in mL per minute.

Pick one change, then run again:

• Shorten the tubing — less distance, more flow
• Lower the target cup — less lift, more flow
• Improve the structure — fewer wobbles, less wasted water
• Reposition the panel — find a better angle to the sun
• Seal a leak — every drop that misses the cup is wasted

Run 2 — same 60 seconds, same measurement.

One last 60-second run with your best design. Lock in your final flow rate.

Now walk into the gardens with your team. You’ve built a prototype — but where would it actually go? Look for:

• A garden bed where a small water feature would help pollinators or birds
• An area where drip irrigation would save staff time
• A spot where visitors would see your system working — and learn from it
• A place where your system couldn’t work — too shady, too far from water, too exposed to wind

Renewable energy engineers and water systems engineers design these systems for a living — at scales from a single pollinator water station to a thousand-acre solar farm pumping irrigation water across rural Iowa. Right now, Iowa is one of the biggest renewable-energy producers in the country, and engineers here are figuring out how to power farms, towns, and factories without burning anything. The prototype you just built — solar panel, pump, water moving without an extension cord — uses the exact same principles as systems running in fields and feedlots today.

1. What was your final flow rate?
2. What was the biggest improvement you made — and how did you know it worked?
3. Where would you install your design at Reiman Gardens — and what would you have to change?