Solar Collector Losses Summary: Difference between revisions
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(New page: =Introduction= When considering the overall performance of linear slat collectors for a linear Fresnel solar concentrator system oriented in the E-W direction, several losses must be cons...) |
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=Introduction= | =Introduction= | ||
When considering the overall performance of linear slat collectors for a linear Fresnel solar concentrator system oriented in the E-W direction, several losses must be considered. For the case of a 4:1 aspect ratio array, such as a 15 foot wide array that stretches for 60 feet in the E-W direction. For this case, if we use 6" slats, we can fit about 16 slats in this area, or a total of 480 square feet of solar intercept. We have about 5 kWhr/day per square meter in Maysville, Missouri - from [http://en.wikipedia.org/wiki/File:Us_pv_annual_may2004.jpg] | When considering the overall performance of linear slat collectors for a linear Fresnel solar concentrator system oriented in the E-W direction, several losses must be considered. For the case of a 4:1 aspect ratio array, such as a 15 foot wide array that stretches for 60 feet in the E-W direction. For this case, if we use 6" slats, we can fit about 16 slats in this area, or a total of 480 square feet (45 sq meters) of solar intercept. We have about 5 kWhr/day per square meter in Maysville, Missouri - from [http://en.wikipedia.org/wiki/File:Us_pv_annual_may2004.jpg]. We summarize our losses. This includes air mass losses and averages over the seasons - because we are taking empirical data. We are assumining a collector tube with a single layer of insulating glass on the surface. | ||
#Edge Lossses | #Reflection losses from mirrors - 1%, assuming 99% reflective mirrors - and assuming that 4% reflection from glass is reflected back at the collector tube | ||
#Edge Lossses - 10% - from [[Solar_Collector_Calculations#Losses_due_to_edge_effects_only]] - about if we consider the 6 hours of highest sun during the day, or from 9:30 AM - 2:30 PM | |||
#Reflection from collector tube glass - 4% loss | |||
#Radiation losses from collector tube - 25% losses using selective coating as calculated in [http://openfarmtech.org/index.php?title=Solar_Collector_Calculations#Theoretical_maximum_achievable_temperature] | |||
Revision as of 14:59, 31 January 2009
Introduction
When considering the overall performance of linear slat collectors for a linear Fresnel solar concentrator system oriented in the E-W direction, several losses must be considered. For the case of a 4:1 aspect ratio array, such as a 15 foot wide array that stretches for 60 feet in the E-W direction. For this case, if we use 6" slats, we can fit about 16 slats in this area, or a total of 480 square feet (45 sq meters) of solar intercept. We have about 5 kWhr/day per square meter in Maysville, Missouri - from [1]. We summarize our losses. This includes air mass losses and averages over the seasons - because we are taking empirical data. We are assumining a collector tube with a single layer of insulating glass on the surface.
![[1]](http://en.wikipedia.org/wiki/File:Us_pv_annual_may2004.jpg){kind=link}
- Reflection losses from mirrors - 1%, assuming 99% reflective mirrors - and assuming that 4% reflection from glass is reflected back at the collector tube
- Edge Lossses - 10% - from Solar_Collector_Calculations#Losses_due_to_edge_effects_only - about if we consider the 6 hours of highest sun during the day, or from 9:30 AM - 2:30 PM
- Reflection from collector tube glass - 4% loss
- Radiation losses from collector tube - 25% losses using selective coating as calculated in [2]