The most commonly utilized solar technologies use inert materials found at every building site including silicon (glass), aluminum (frame) and copper (wiring).
Although thin film photovoltaics do contain some heavy metals, including cadmium, numerous studies (e.g. the Sustainability of Photovoltaics and Life Cycle Impact Analysis of Cadmium in CdTe PV Production) have found that these metals do not leach from the modules into the environment under normal conditions or anticipated accidents such as storm damage or fires. Heavy metals used in thin film systems do need to be mined, but that process creates less environmental damage than mining for coal or uranium for use in electricity generation.
While generating electricity, a solar plant produces no emissions or waste. Emissions from a coal plant cause harmful air and carbon pollution, while nuclear power creates waste product that remain extremely toxic to humans for millions of year.