Satellite Dish Solar Cooker or Solar Concentrator

Here I made solar concentrator using the small mirrors. This is basically first part of project called "integration of solar cooker/concentrator with biogas plant"

To built a solar concentrator from satellite dish you don't have to use any thing extensive. Just buy satellite dish, small mirrors/reflective material(Aluminum),Stand, sand paper, Silicone glue/ (ask an expert about best the glue). I brought almost 4.5 feet (diameter) long satellite dish and according to my calculations it was enough for me.

Remember that size of dish totally depends on your location on the globe. If you live near the equator, small sized dish can be enough, and if you live closer to poles you will need extremely larger one to fulfil your needs.

You can use different software like PVCDROM to get an idea of solar intensity at your location(by entering the latitude and longitude and GMT) and for angle of sun in different month of the year use SPOSI online software.

First, Calculate the area of dish using the Pappus's theorem. This will give you idea about how much reflective material you need. If you are using mirrors as reflective material. Then, you will need small pieces because you can't bend the mirrors like Aluminum. I used the small sized mirrors as reflector because its reflectivity is higher than Aluminum. (These were made on order according to my requirement).

Aluminum has 80 to 85% reflectivity but mirrors have 95+% of reflectivity. Furthermore, Aluminum paper/sheet are fragile, can be torn easily plus it loses its reflectivity with time.

Note: By installing the smaller mirrors me can maintain the almost perfect parabola bend of dish and it will give good focal point.

Start sticking mirrors in a row & avoid installing any damaged/ broken mirror, and remember to leave holes open for inserting the stand afterwards

or

You can first fix dish on the stand and then install the mirrors, its totally up to you.

Angle the center of dish directly towards the sun and steadily hold the paper/wood at focal point it will start burning in seconds.

To find the focal point you can do hit and trail method by placing the wood/paper at different Heights form the center. or you can calculate and get and idea form the this formula

F=((diameter)^2/16*depth)