Radiometer for concentrated solar radiation

Kurzfassung

An Italian research centre has developed and realised a radiometer that can be used for measurement of very high irradiances, especially conceived for applications in solar radiation 3D concentrators. Organisations dealing with optics or photovoltaic activities are sought for research/technical cooperation and for commercial agreement with technical assistance.

Details

An Italian research centre involved in R&D activities on photovoltaic technology has developed and realised a radiometer that can be used for measurement of very high irradiances, those typically achieved in systems for 3D concentrating solar radiation.
It has been designed in such a way as to be operated in different environments, at different attenuation ratios, depending on the intensity of the incoming light.
It is made of a prism inside which two spherical cavities were performed. The light is measured by a photodiode and spectrally analysed by a spectrograph through an optical fibre. The photodiode is thermally stabilised from 5°C to about 50°C. The radiometer has been calibrated by a flashed solar simulator with concentration. The current, measured by the photodiode, for a particular size of input and insert windows, can be correlated with the intensity (number of suns) of the input light.

Innovative Aspects:
No radiometers are available on the market, which can sustain the very high intensity of concentrated solar radiation produced in solar furnace, thermal and photovoltaic concentrators. The realised prototype is the first ready-to-use radiometer for concentrated radiation. It is able to measure solar light intensities as high as thousand of suns (hundreds of watts). A prototype of it has been realised at the research centre’s laboratories. Other prototypes, improved in the design, will be used in other solar concentrating systems in Italy. It is a tool with high flexibility, portable; moreover, it is a universal tool, operating with stationary radiation, and temperature-controlled.
This radiometer can be used: in all solar energy applications that exploit radiation concentration to reach higher efficiency in the electric, thermal or thermodynamic conversion process of the radiant energy; in all concentration plants that require control measurements of radiation, if the concentrator’s shape allows its employment (or it can be designed for a specific concentrator, for continuous measurement of the radiation); in all laboratory applications that require measurement of the total power or the irradiance distribution in a concentrated light bundle; for the calibration of concentration solar cells, particularly for accurate measurement of the total radiant power incident on a cell.