Combined solar/thermal (CHP) heat and power for residential and industrial buildings

摘要

A solar powered generator (100) has thermoelectric elements adjacent to and below solar cells. Concentrated sunlight is provided. A heat sink (104), which can be variable in temperature or efficiency, is in contact with the cold junction (108) of the thermoelectric device (103). The thermal resistivity is designed in relation to the energy flux, whereby the thermoelectric device (103) develops a gradient of several hundred Kelvin. Preferably the solar cell comprises a high band gap energy semi-conductor. The generator (100) maintains relatively consistent efficiency over a range of cold junction (108) temperatures. The heat sink (104) can be a hot water system. High efficiencies are achieved using nanocomposite thermoelectric materials. Evenly but thinly dispersing the thermoelectric segments in a matrix of highly insulating material reduces the amount of material required for the segments without sacrificing performance. A unitary construction of the solar cell and thermoelectric elements provides further advantages.

主权项

1. A solar powered generator comprising:
a solar panel having a top side and a bottom side and being functional to generate electric power from sunlight; a thermoelectric device adjacent to and below the solar panel, the thermoelectric device comprising a hot junction and a cold junction, the hot junction being in close thermal coupling with the bottom side of the solar panel, the thermoelectric device being functional to generate electric power when the hot junction is hotter than the cold junction; and one or more electrical connections for electrically coupling to and drawing electrical power from the solar panel and for electrically coupling to and drawing electrical power from the thermoelectric device; and a solar concentration system configured to concentrate sunlight onto the top of the solar panel, the system having a maximum solar concentration factor, f; wherein the thermoelectric device comprises n-type legs configured to conduct heat from the hot junction to the cold junction and p-type legs configured to conduct heat from the hot junction to the cold junction, the n-type and p-type legs having a height and the thermoelectric device having an average thermal resistivity through the height of the n-type and p-type legs; the n-type legs comprise one or more segments of n-doped semi-conductor materials; the p-type legs comprise one or more segments of p-doped semi-conductor materials; at least one of the segments is formed of a nano-composite material in which quantum confinement of carriers substantially reduces the segment's thermal conductivity; and the height of the legs, the solar concentration factor of the solar concentration system, and the average thermal resistivity of the n-type and p-type legs are independently selected such that sunlight incident on the solar concentration system with an intensity of 1.3 kW/m2 is operative to heat the solar panel to temperatures in excess of 575 K with the ambient temperature at 300 K while the cold junction is maintained at or below a temperature of 100 C.