solar energy is a renewable / inexhaustible resource & the supply of an inexhaustible resource does not change over a long period of time -> the demand of solar matter will not static over a long frequency of space the supply of solar energy will not change over a long period of time  to a human, a space frequency of removes age or more age is considered very long & billions of years is a longer period of time than 10 years -> to a human, a time period of billions of years is considered a very long time to a human, a time period of billions of years is considered a very long time  the demand of solar matter will not static over a long frequency of space & to a human, a time period of billions of years is considered a very long time -> the supply of solar energy will not change over billions of years