Introduction

Date: 2015-10-07; view: 480.

FUTURE POWER SOURCES

Task 8

Read and translate the text.

Scientists and engineers are devoting an increasing amount of at­tention to what are commonly called "new" or "unconventional" power sources. The impetus for this development effort stems from many things. In a general way, the continually increasing demand for electric power, and the eventual inability of present energy sources to supply our needs are the dominant factors. However, there are others — the need for specialized power plants to serve in space or in remote land areas, to name one.

Four of the most promising of the "new" power sources - ther­moelectric, thermionic and magnetohydrodynamic generators, and fuel cells — are discussed in the following pages. As most readers will recognize, none of these power generation methods are new in prin­ciple. The concept of thermoelectric devices dates back to 1822; the thermionic principle to 1878; magnetohydrodynamics to about 1835, and, the fuel cell to 1802. However, only recently have these prin­ciples come in for serious attention as the basis for large-scale power generators. The present interest stems largely from a better under­standing of the physics and chemistry involved, and our ability to de­velop new materials to meet the unusual requirements.

In these articles no particular attempt has been made to evaluate each new generating method fully. At this stage of development, any general evaluation would be impractical, because much remains to be learned about each method.