How to Build a Parabolic Solar Concentrator

  • 6-12 hours
  • Beginner
  • 500-1,000
What You'll Need
Concave mold
Loose fiberglass sheet
Fiberglass hardener
A medium sized brush
Chrome coated aluminum mirror sheets
Paper towel
Utility knife
Charcoal facemask

A parabolic solar concentrator is a device that focuses light on a point to heat an object. Usually used in collaboration with a heat exchange unit, a device that moves heat from the focused light to moving fluid inside the heat exchange, a parabolic solar concentrator can be made easily in your own backyard. To learn how to do this, read the article below.

Step 1 - Take Appropriate Precautions

The use of power tools requires you to wear gloves at all times so as to avoid any injuries. Wear a charcoal facemask while using the fiberglass hardener; cutting, trimming and buffing also require the use of a facemask as a means of protection against flying dust. Read the manuals provided with the power tools for maximum safety and take caution while using the utility knife. Wear only your working clothes at all times, and throw away any materials that came in contact with the fiberglass hardener. After you have noted down these precautions, move on to building a parabolic concentrator.

Step 2 - Making a Fiberglass Parabolic Dish

This is the structure that will house the reflective mirror surface. The process of making a fiberglass dish is a simple yet technical one. You need to be very patient while working with fiberglass in order to ensure a smooth finish. Use the underside of a steel dish or a concrete mold and layer on pieces of the loose fiberglass material. Apply a coat of fiberglass hardener after each layer of fiberglass and leave to dry for 12 hours. Pull apart the fiberglass dish from the mold and sand it with a grinder. After the surface has been sanded, polish the inner curve with a buffer and move on to the next step of applying the aluminum strips.

Step 3 - Cutting the Aluminum Strips

This step requires a bit more attention so as to ensure that 2-inch thick strips are cut from the chrome coated aluminum mirror sheets with accuracy. Use a meter rule and a very sharp utility knife to cut the aluminum sheets. After these have been cut, move on to the next step of applying these strips.

Step 4 - Applying Aluminum Strips on the Parabolic Dish

Aluminum strips that are used to create a mirror like surface have an adhesive layer on one side and a reflective layer on the other. Start applying this adhesive tape from the equator of the dish and move outwards. Take off the film that covers the adhesive layer and stick it using your thumb to push out any wrinkles or air bubbles.

When applying an adjacent strip, make sure that there is minimum overlapping so as to ensure a smooth mirror surface. Apply the second mirror layer after you are done with the first. The second layer is composed of aluminum sheets that much thinner and translucent than those used in the first layer and add to the reflective property of the parabolic concentrator. If any air bubbles do form, use the utility knife to make a small incision to let the air out.

Step 5 - Finishing Up

Use a paper towel to flatten the aluminum sheets and use a pair of scissors to trim any extra pieces of the material. This adds to the overall finish of your now completed parabolic solar concentrator.