03-10-2018, 05:40 PM
If batteries were cheap I would just put everything at whatever the angle was that gave me the most Kwh for the day and store it. Panels tend to be cheaper now so virtual tracking is used to spread out the PV production so more of the power is used as it is produced, both earlier in the morning and later in the afternoon.
The sine of 30 degrees is .5. That would correspond to the panel being 60 degrees from horizontal. Two panels leaning against each other with each panel forming one leg of an equilateral triangle would produce the same power as a single panel laying flat if the sun were directly overhead. My brother, being an astronomer, drones on about "atmospheric extinction" and how that makes it unproductive to put the panels that steep but part of the problem is how to fit that many panels on your roof to get sufficient power when the sky is cloudy but at the same time not get too much power (having bought all those panels) when it is clear. With all those panels you won't suffer too much from attenuation due to the sun passing through so much atmosphere when it is clear. You will make it up rapidly when the sun gets a little higher. Also on cloudy days the light is coming from the clouds which are very near so extinction is not so much an issue.
It all depends on the relative cost of panels vs batteries. If I had infinite storage I would save energy in the summer for use in the winter. As it is on any day that your charge controller goes into float, you would have benefited from trading overall production for earlier/later production.
The sine of 30 degrees is .5. That would correspond to the panel being 60 degrees from horizontal. Two panels leaning against each other with each panel forming one leg of an equilateral triangle would produce the same power as a single panel laying flat if the sun were directly overhead. My brother, being an astronomer, drones on about "atmospheric extinction" and how that makes it unproductive to put the panels that steep but part of the problem is how to fit that many panels on your roof to get sufficient power when the sky is cloudy but at the same time not get too much power (having bought all those panels) when it is clear. With all those panels you won't suffer too much from attenuation due to the sun passing through so much atmosphere when it is clear. You will make it up rapidly when the sun gets a little higher. Also on cloudy days the light is coming from the clouds which are very near so extinction is not so much an issue.
It all depends on the relative cost of panels vs batteries. If I had infinite storage I would save energy in the summer for use in the winter. As it is on any day that your charge controller goes into float, you would have benefited from trading overall production for earlier/later production.