Vegetable Garden Watering System

Second Place Winner

Middle School Competition

Congrats to Katie for winning second place in the Virginia Solar Challenge for Middle School!

Her project is also featured on the national KidWind site at

Why filter stream or pond water before watering vegetable gardens?

When a plant is watered, it absorbs the water through its roots, moves up the plant and into its stems, leaves, buds and fruit. When water is contaminated, it gets dispersed throughout the entire plant.

Katie wanted to investigate how solar panels could be used to power water pumps to move water from ponds and streams through a filter to clean water from sediment and harmful contaminants, then transfer the clean water to gardens to water plants.

100 watt lightbulb

First she had to determine how much energy can be produced by one then two solar panels in series when exposed to a 100 watt lightbulb.

Direct Sunlight in early afternoon

She also took the solar panels outside to measure the energy of one and then two solar panels in series when exposed to direct sunlight.

Making Calculations

She then had to do a series of calculations to determine if the energy produced by the solar panels would be enough to power the water pumps.

Setting up water pump

Katie tested one and then two solar panels to determine how many panels would be needed to generate enough energy to move water from a glass through the fish tank filter (using a charcoal filter). See this movie that shows two solar panels are needed to move the "dirty" water through the filter tank and into a clean water holding tank.

Katie then discovered that she only needed one solar panel to generate enough energy to transfer the cleaned water from its holding tank through a tube to the plant.

Setting up the Solar Panels

Katie created this adjustable structure to hold the solar panels. The panels move up and down dowels so she can adjust the tilt angle of the structure at different times of the year.

In order for the solar panels to get their best performance during the different times of the year, Katie began with her home town's latitude (Sterling, VA= 39 degrees) and added 15 degrees (39+15= 54 degrees). 54 degrees is the tilt angle that the solar panels should be set for winter. For summer, she needed to subtract 15 degrees (39-15=24). Since it is presently summer, Katie set the tilt angle of the structure at 24 degrees.

water filtration system

The Watering System

This movie was taken before Katie mounted the solar panels on the tilting structure.

tilting solar panel structure

For the future, Katie wants to learn how to use the KidWind switch so she can turn the filtration system on/off. After all, she does not want to over water plants! See Katie's video of her entire project.

KidWind switch