question

kubaros avatar image
kubaros asked

Solar yield monitoring with MPPT and without a battery

I am planning a solar energy project and am reaching out to you for your expertise and to find the most suitable product for its implementation. The aim of the project is to compare the total power output (in Wh) of two identical solar panels (each 120Wp, 12V) over a period of one month. I intend to repeat this comparison over a six-month period. The focus is on testing a soiling prevention technology for the surface of the solar panels. I plan to operate one panel without and another with this technology to determine the percentage increase in efficiency at the end. For the comparison, data logging with at least daily resolution is required. The test will be conducted in a remote region (island operation) and monitored monthly, which is a desert area with high temperatures in summer.

My question to you is:

  • How can I reliably and realistically measure the performance of both modules and store the data, especially considering that the technology will be used under maximum load in solar installations?

Currently, a setup with an MPPT charge controller (SmartSolar MPPT 75/10) without a connected battery and a resistive load (e.g., a heating element with higher consumption than the maximum panel output) seems most logical to me. Would an MPPT controller with the right settings fulfill this task? If not, why, and what alternative would you recommend? The load should be continuously active, so that the solar power is constantly consumed. This assumes that the charger does not lose the data when it is completely switched off at night and reactivated at dawn.

I look forward to your response and thank you in advance for your support in this exciting project.

MPPT SmartSolarbatterymonitoring
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4 Answers
Justin Cook avatar image
Justin Cook answered ·

An MPPT requires a battery to be connected first, then the PV, as detailed in the "Connection" section of the user manual. Please do not operate the MPPT without a battery connected.

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kubaros avatar image kubaros commented ·
okay i see. What alternative would you recommend in order to realise this test setup?
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regman54 avatar image
regman54 answered ·

How about running identical setups side-by-side simultaneously, one operating with this new technology the other without?

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kubaros avatar image kubaros commented ·
yes that is exactly how i want to do it. the question is hot to measure the power output ?
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klim8skeptic avatar image
klim8skeptic answered ·

@kubaros You can buy solar panel testers. example tester They do the mppt thing and display the max panel output.

Maybe you could use an energy meter between the panel and tester to count the energy produced during the day?

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kubaros avatar image kubaros commented ·

hey thanks, that might be a easy work around. do you know if an victron mppt charger with a battery but without any load still meausre and log the max power output of the panel correctly even the battery is 100% full?

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ejrossouw avatar image
ejrossouw answered ·

@kubaros There are also good scientific papers published on the effects of soiling which may save time and effort depending on the actual objective. Large solar farms are greatly impacted by soiling and there are many interesting solutions out there already.

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kubaros avatar image kubaros commented ·
hey yes thanks i am already very aware of existing technologies and did read many papers already. i have invented a new technolgy and would like to compare it to others.
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Related Resources

MPPT product page

VictronConnect manual

PWM or MPPT

MPPT calculator

MPPT codes

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