Build a solar collector

With our last practical course, we should consider ourselves like one from simplest and build billgsten things a solar collector can. Nevertheless the solar collector should be able the water to heat up in such a way that one can shower thereby. Our consideration was the following: The water comes into an aluminum container, because some good heat leader is. On this container we paint a black point and with the help of a collecting lens the rays of light exactly on this point are then fokusiert. The reason is following: Black absorbs a majority of the heat energy of the rays of light and because also the rays of light are bundled, is still larger the effect