This tutorial by KidWind provides details for making a solar boat for a class or hobby project.

Build the best boat you can and race your friends!

Step 1: Solar Power Basics

This boat is powered by solar panels or solar cells, which harness light energy from the sun to produce electricity. When light from the sun reaches the solar cells (photovoltaic cells) electrons are released through the cells and into an electrical circuit. This electricity will be used to power the motor of your boat.

This information comes from the NEED project. Click on the link to learn more about solar energy : NEED Website

Step 2: Materials Needed

(1X) Solar Panel (we used 1.5 V | 500mA)
(1X) DC motor (check your local hobby/surplus store)
(2X) Alligator clips
(2X) 4" of 22 gauge wire
(1X) Material such as pink foam to make boat hull (The hull can be made from whatever material you think will be most buoyant and hydrodynamically efficient)
(1X) Motor clips (To attach the motor to the deck)
(1X) Plywood deck (Explained in later steps)
(1X) 5/64" Steel Driveshaft (4" length)
(X) Propellers
(1X) Mounting tape (18")
(2X) 2" screws or hot glue to attach the motor clips to the deck
(1X) Pieces of balsa or other material for rudder
(1X) Protractor (to optimize solar panel angle)
(2X) 2" lengths of 1/8" diameter tubing (to connect the driveshaft to the motor and the propeller to the driveshaft)

You will need scissors or a hobby knife, duct tape, a screwdriver, wire strippers, a marker, glue (optional), and plastic bottles (optional)

Some of these parts may be challenging to find, but you should be able to find most things you need between a hardware store, hobby shop, and/or surplus store. You can always check out our website if you really want a specific part. You can use this list as a guide and a basis on which you can adapt your own model.

Step 3: Building the Hull

There are many ways to design the hull for your solar boat. To begin, use the pink foam or material you found for the hull. You should use a material that will float well. Use a marker to draw a boat design. Any design will work, but for an optimal boat design, see the tips about drag discussed later. Make sure it is large enough to float the motor and solar panel! Be creative! **ADULT HELP NEEDED!!** Using a hobby knife or serrated blade, cut out your boat shape.

Step 4: Preparing the Deck, Motor, and Driveshaft

1. Now cut the material you have for the deck (plywood, or something light and easy to puncture, but durable enough to last) into a shape that will fit on the hull. Then puncture a few holes in the deck as shown in the image below. Then cut a slit at the back end of the deck where your driveshaft will go through.

2. Look at the plywood deck and the drilled holes. The holes are used to secure the motor clip to the deck. You may attach your motor mount at any of these points except the slit at the back end of the deck. Place your foam hull under the plywood deck, securing it with one or two strips of double-sided tape. Be sure that the slit at the back of the deck is unobstructed because your driveshaft must slide through this hole to get to the water!

NOTE : You can bypass the hole cutting (except the slit at the edge of the deck) by hot gluing the motor clip to the deck. If you do this, ignore step 3. If you choose to hot glue the motor mount, and want to attach a rudder to the bottom of the hull, you will have to find a different way to attach the rudder to the hull, since there will be no screw end sticking out the bottom.

3. Using the screw, attach the motor clip to any of the mounting holes you created. If you can, drive the screw straight through the hull so it sticks out the bottom. This can serve as your rudder mount. As you screw down on the motor clip, the clip will tighten and change shape. Test your motor in the clip as you tighten to make sure it fits securely. If it does not fit, slide some paper or other material inside to make it snug.

4. Push a 1" piece of rubber tubing onto the driveshaft of the DC motor. Do not push the rubber tubing all the way to the bottom of the driveshaft, or it can drag on the motor and slow down.

NOTE : If you cannot find 1/8" diameter tubing, try to find a material that will connect to both the driveshaft of the motor and the driveshaft you will attach to the propeller. It will have to be able to bend and spin around with the motor while mostly staying in place.

5. Find a material to make a propeller and attach it to your 4" steel driveshaft. You can seach google for a variety of small propellers.

6. Slide the other side of the driveshaft up through the slit in the back of the deck (make sure your propeller is facing down into the water). Fit the driveshaft with the propeller into the rubber tube you have attached to the motor. You will need to push and twist a little bit, but it is important that this is a tight connection.

7. Clip the motor into the clip and double-check that it fits tightly. If it is too loose, you can turn the screw to tighten the clip. If it is too tight and the motor does not fit, loosen the screw.

Step 5:

1. Position the solar panel where it will catch the most sun. The top deck of your boat is a perfect place. The solar panel can be attached to the wooden deck using the two sided mounting tape. One experiment you can try is to change the angle of the solar panel on the deck. You want the sun's rays to hit the solar panel at a 90 degree angle (perpendicular), so before you tape the panel on the deck, set your angle where you want it.

2. You need to attach wires from the motor to the solar panel. The solar panel has two terminals positive and negative. Slide one of your stripped wires from the motor through the positive lead and the other through the negative lead. Loop the wires over themselves, but DO NOT ATTACH THEM PERMANENTLY! Depending on which wire you attach the motor will spin clockwise or counter-clockwise. If you want your boat to go forward using the propellers included, they have to spin counter-clockwise. Test the boat in the sunlight to get this right. If your motor seems to be spinning the wrong way, simply switch the wires at the solar panel.

3. At this point, your boat is nearly complete! It will have about 1" of a screw poked out of the bottom. This is a perfect place to mount a rudder. A rudder will keep your boat going straight as an arrow. Without a rudder, you may find your boat turning around willy-nilly through the water. You can use whatever you want for a rudder, as long as it is straight. The small pieces of balsa wood included in your kit are perfect for making a rudder. You can also design your own rudder using another material.

4. To attach the rudder, use a small strip of duct tape and wrap it around the screw onto the rudder. You can also try using glue or mounting tape, but make sure it is secure, even when wet.

5. Now double check that everything on your boat is ship-shape! If so, take it outside to some water (or under a VERY bright light) and begin testing, experimenting, and racing your solar sea-faring vessel!