Renewable energy technologies have an enormous potential in the United States and that potential can be realized at a reasonable cost. Market research shows that many customers will purchase renewable power even if it costs somewhat more than conventional power.[1]However, both economic theory and experience point to significant market barriers and market failures that will limit the development of renewables unless special policy measures are enacted to encourage that development.[2]<span> These hurdles can be grouped into four categories:</span>
In the earliest stages of development, all four organisms have a knobby head, gill slits, and a tail. These similarities tell us that all four of these organisms have a common ancestor.
