  Heat resources of small temperature difference are easily accessible, free
and unlimited on earth. Thermoelectric effects provide the technology for
converting these heat resources directly into electricity. We present designs
of electricity generators based on thermoelectric effects and using heat
resources of small temperature difference, e.g., ocean water at different
depths and geothermal sources, and conclude that large-scale power plants based
on thermoelectric effects are feasible and economically competitive. The key
observation is that the power factor of thermoelectric materials, unlike the
figure of merit, can be improved by orders of magnitude upon laminating good
conductors and good thermoelectric materials. The predicted large-scale power
plants based on thermoelectric effects, if validated, will have a global
economic and social impact for its scalability, and the renewability, free and
unlimited supply of heat resources of small temperature difference on earth.
