Page 39 - Applied Photovoltaics

terrestrial light, a standard solar spectrum is used to rate photovoltaic products. The
present standard for most terrestrial applications is the global Air Mass 1.5 spectrum
tabulated in Appendix A.

EXE RCI S ES
1.1 The sun is at an altitude of 30° to the horizontal. What is the corresponding
air mass?
1.2 What is the length of the shadow cast by a vertical post with a height of 1 m
under AM1.5 illumination?
1.3 Calculate the sun’s altitude at solar noon on 21 June in Sydney (latitude 34°S)
and in San Francisco (latitude 38°N).

1.4 The direct radiation falling on a surface normal to the sun’s direction is
2
90 mW/cm at solar noon on one summer solstice in Albuquerque, New
Mexico (latitude 35°N). Calculate the direct radiation falling on a surface
facing south at an angle of 40° to the horizontal.
1.5 To design appropriate photovoltaic systems, good data on the insolation (i.e.
amount of sunshine) is essential for each particular location. List the sources
and nature of insolation data available for your region (state or country).

REFE RE NCES
Updated World Wide Web links can be found at www.pv.unsw.edu.au/apv_book_refs.

ASTM (2000), ‘Standard solar constant and air mass zero solar spectral irradiance
tables’, Standard No. E 490-00.

ASTM (2003), G173-03 Standard Tables for Reference Solar Spectral Irradiances:
Direct Normal and Hemispherical on 37° Tilted Surface (www.astm.org).

Australian Bureau of Meteorology (2004) (www.bom.gov.au/weather/satellite).
Beyer, H.G., Reise, C. & Wald, L. (1992), ‘Utilization of satellite data for the
assessment of large scale PV grid integration’, Proc. 11th EC Photovoltaic Solar
Energy Conference, Montreux, Switzerland, pp. 1309–1312.
Blakers, A., Green, M., Leo, T., Outhred, H. & Robins, B. (1991), The Role of
Photovoltaics in Reducing Greenhouse Gas Emissions, Australian Government
Publishing Service, Canberra.

Bureau of Meteorology (1991), Australia.
Duffie, J.A. & Beckman, W.A. (1991), Solar Engineering of Thermal Processes, 2nd
Edition, Wiley-Interscience, New York.
Gast. P.R., (1960), ‘Solar radiation’, in Campen et al., Handbook of Geophysics,
McMillan, New York, pp. 14-16–16-30.

26