Our society's environmental impacts are the additional heat, the greenhouse gases and the heavy metals.
Additional heat is produced by burning fossil fuels when generating the power or heat we need. This additional heat, that would not be produced naturally, raises the temperature of the Earth and induces changes in the climate.There is no additional heat produced when we use solar energy because that heat would be produced naturally anyway.
Greenhouse gases (mainly CO2) are produced when generating heat by burning fossil fuels. These gases thermally insulate the Earth and create climatic disturbances. About ten times more heat from fossil fuels is needed for an electric heater than to obtain the same heating from a solar heater.
Heavy metals - copper, zinc, tin, chromium, nickel, silver - are the most important metal pollutants and, unfortunately, are still the main materials used in the manufacture of classical solar heaters. We changed that by using mainly polymers (plastics) which can be obtained from renewable organic compounds, and they can be recycled.