Difference between revisions of "Insolation"
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[[Category:PV source]] | [[Category:PV source]] | ||
[[File:Irradiancegraph201029.png|thumb|right|'''Example of irradiance for a location under different weather conditions.''']] | [[File:Irradiancegraph201029.png|thumb|right|'''Example of irradiance for a location under different weather conditions.''']] | ||
| − | A Peak Sun Hour (PSH) is a standardized unit that is used to quantify the amount of solar energy that a location receives during an day, month or year. A Peak Sun Hour is defined as 1m² receiving sunlight with a [[Solar PV module#Standard test conditions|irradiance (sunlight intensity)]] of 1000 W/m² for 1 hour. The average PSH value for a given location will largely determine the amount of energy that a PV system produces, therefore it is a very important value for PV system design. The PSH value is based upon real world testing and observation and can be calculated for a particular day as follows: | + | A Peak Sun Hour (PSH) is a standardized unit that is used to quantify the amount of solar energy that a location receives during an day, month or year. A Peak Sun Hour is defined as 1m² receiving sunlight with a [[Solar PV module#Standard test conditions|irradiance (sunlight intensity)]] of 1000 W/m² for 1 hour (which can also be defined as 1000Wh/m²). The average PSH value for a given location will largely determine the amount of energy that a PV system produces, therefore it is a very important value for PV system design. The PSH value is based upon real world testing and observation and can be calculated for a particular day as follows: |
| − | '''Peak Sun Hours (PSH) = sum of | + | '''Peak Sun Hours (PSH) = sum of hourly insolation values ÷ 1000 W/m²''' |
::'''Example 1:''' An irradiance testing station gives you the following data for a particular day. What is the PSH value for this day? | ::'''Example 1:''' An irradiance testing station gives you the following data for a particular day. What is the PSH value for this day? | ||
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|17:00 | |17:00 | ||
|- | |- | ||
| − | ! | + | !Hourly insolation value |
| − | |200 | + | |200 Wh/m² |
| − | |300 | + | |300 Wh/m² |
| − | |500 | + | |500 Wh/m² |
| − | |800 | + | |800 Wh/m² |
| − | |1000 | + | |1000 Wh/m² |
| − | |1000 | + | |1000 Wh/m² |
| − | |800 | + | |800 Wh/m² |
| − | |500 | + | |500 Wh/m² |
| − | |300 | + | |300 Wh/m² |
| − | |200 | + | |200 Wh/m² |
|} | |} | ||
| − | ::::Peak Sun Hours (PSH) = (200 + 300 + 500 + 800 + 1000 + 1000 + 800 + 500 + 300 + 200) W/m² ÷ 1000 | + | ::::Peak Sun Hours (PSH) = (200 + 300 + 500 + 800 + 1000 + 1000 + 800 + 500 + 300 + 200) W/m² ÷ 1000 Wh/m² |
| − | ::::Peak Sun Hours (PSH) = 5600 | + | ::::Peak Sun Hours (PSH) = 5600 Wh/m² ÷ 1000 W/m² = 5.6h |
==Estimating PV production with PSH== | ==Estimating PV production with PSH== | ||
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::::PV source production estimate = 100 W x 4 PSH | ::::PV source production estimate = 100 W x 4 PSH | ||
::::PV source production estimate = 400 Wh | ::::PV source production estimate = 400 Wh | ||
| + | |||
| + | ==Notes/Resources== | ||
| + | [https://pvpmc.sandia.gov/PV Performance Modeling Collaborative] | ||
Revision as of 10:57, 29 October 2020
A Peak Sun Hour (PSH) is a standardized unit that is used to quantify the amount of solar energy that a location receives during an day, month or year. A Peak Sun Hour is defined as 1m² receiving sunlight with a irradiance (sunlight intensity) of 1000 W/m² for 1 hour (which can also be defined as 1000Wh/m²). The average PSH value for a given location will largely determine the amount of energy that a PV system produces, therefore it is a very important value for PV system design. The PSH value is based upon real world testing and observation and can be calculated for a particular day as follows:
Peak Sun Hours (PSH) = sum of hourly insolation values ÷ 1000 W/m²
- Example 1: An irradiance testing station gives you the following data for a particular day. What is the PSH value for this day?
Time 8:00 9:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 Hourly insolation value 200 Wh/m² 300 Wh/m² 500 Wh/m² 800 Wh/m² 1000 Wh/m² 1000 Wh/m² 800 Wh/m² 500 Wh/m² 300 Wh/m² 200 Wh/m²
- Peak Sun Hours (PSH) = (200 + 300 + 500 + 800 + 1000 + 1000 + 800 + 500 + 300 + 200) W/m² ÷ 1000 Wh/m²
- Peak Sun Hours (PSH) = 5600 Wh/m² ÷ 1000 W/m² = 5.6h
Estimating PV production with PSH
The power rating of PV modules is determined by testing under standard test conditions, one of which specifies that the test be performed with light of an irradiance (sunlight intensity) of 1000 W/m². A basic calculation of energy production for a PV system can be performed using the power rating of the PV source and the PSH value for the location during a given period. Note: additional PV module loss factors must be taken into account to arrive at a realistic estimate of production under real world conditions. The losses due to these factors can be substantial.
PV source production estimate = PV source power rating × Peak Sun Hours
- Example 1: You have a 100 W PV module. It will be installed in a location without shade that has an average daily Peak Sun Hour value of 4. Without accounting for loss factors, how much energy will this module generate on average per day?
- PV source production estimate = 100 W x 4 PSH
- PV source production estimate = 400 Wh
- Example 1: You have a 100 W PV module. It will be installed in a location without shade that has an average daily Peak Sun Hour value of 4. Without accounting for loss factors, how much energy will this module generate on average per day?
