Salvo wrote:
You would get a failing grade if that was an exam question. When using mppt, temperature is a killer . You didn't account for it. At 1000W/m^2 irradiance, the panel will be fairly hot.
The math has been done many, many times. mppt should have about 5% advantage.
Well I would think you would earn a failing grade as well.
How hot is "fairly hot"? As you well know cell temp is dependent not only on irradiance but also ambient temp, wind speed and panel mounting. I am certain that my panel cell temp in Colorado even at only 5000' elevation is much lower than it would be in Arizona or SoCal at an equal irradiance of 1000 W/m^2.
You also know that the advantage of MPPT is not only dependent on cell temp, but also battery SOC and battery voltage and a corollary to that on how long the controller stays in bulk. MPPT has quite an advantage at lower SOC with corresponding lower battery voltage.
To cherry pick the worst possible scenario for MPPT then say the math is done and the advantage is only 5% is frankly irresponsible.
No doubt there are times then the advantage is only 5%, but to be fair if you are going to assert that, you also need to state the conditions under which that is true.
Did you view the
link in a previous thread in which side-by-side tests were done using identical panels with different controllers? His results showed a better than 20% advantage for MPPT over week long testing. Granted his conditions were ideal for MPPT, but that's my point. There's no math that says MPPT has only a blanket 5% advantage for everyone everywhere.
