Understanding the electrical IV characteristics of your solar panel is essential for assessing its real-world performance and comprehending its interaction with your charging circuit.

Voltaic Systems is a full-service provider of remote charging solutions, with end-to-end power solutions for IoT devices, is at the forefront of harnessing solar energy efficiently.

Solar panels are integral components of renewable energy systems, and their efficiency is vital to harnessing solar energy effectively. Whether you are designing IoT devices, solar-powered gadgets, or remote charging solutions, understanding your solar panel’s behavior is essential.

IV Curves – components and definitions

An IV curve, also known as a current-voltage characteristic curve, is a visual representation that illustrates the relationship between the voltage applied to an electrical device, such as a solar panel, and the current it produces.

IV curves can help you understand how much power the panel can generate at a given light level and at what voltage; which will influence the design of your device since you want your device to capture as much energy as possible in the expected environment. To create the curve, you apply a series of voltages to the solar cell while it is under illumination, a task that is quite simple since Otii hardware is portable and easy to use for field studies.

Quality Control with IV Curves using Otii Ace

Field testing becomes effortless with Otii. IoT devices are often located far from your office desk, and solar panels are typically positioned outdoors. Otii draws power from your computer, so you can set up a testing environment anywhere by simply connecting a laptop, Otii hardware, your device, and the IoT solar panels. Conducting measurements on the go is a breeze – just pack everything into your backpack. Your laptop supplies approximately 15 W, which is sufficient for numerous measurements.

Voltaic Systems generates IV curves almost daily as part of its quality control (QC) process. They go outdoors and generate IV curves for two randomly selected panels. They utilize the collected data to calibrate their lightbox and subsequently conduct an indoor constant voltage test.

The hardware design comes in pocket size, making field studies a breeze

Voltaic Systems recently started using Otii Ace Pro to generate the IV curves. To get the right light, tests are performed in the middle of the day in Spring and Fall, and also wintertime, even though it might be more challenging finding the time and place where the sun generates close to 1,000 W/m^2 in the Winter.

Before Voltaic Systems started using Otii Pro, they created IV curves manually. The method was very slow. Voltaic Systems has also have had other workarounds like BK Precision 8542B  with a MATLAB script that sweeps through the voltages. The downside to this is that Voltaic Systems need more precision with lower panels, especially when doing low light testing. This is where Otii Ace comes in, with its high accuracy and very low current measurement resolution.

The manual set-up (Before) and the automated, compact and portable set-up with Otii Ace Pro (After)

Image copyright: Voltaic Systems

Voltaic Systems´s setup for generating the IV Curves with Otii Ace Pro

• Solar Intensity Meter, Voltaic Systems used the TES 1333 Solar Power Meter
• Qoitech’s Otii Ace Pro with Otii Automation Toolbox
• Voltaic Systems Solar Panel
• USB-C cable
• Multimeter leads

Check out the steps from connecting the hardware to visualising the IV curves at Voltaic Systems blog post.

In summary, understanding the electrical IV characteristics of your solar panel is crucial for optimizing its real-world performance. Whether you’re designing IoT devices, solar-powered gadgets, or remote charging solutions, comprehending your solar panel’s behavior is essential for success.

If you’re interested in learning more about utilizing Otii for field studies or have specific questions about energy optimization, don’t hesitate to reach out to us. We’re here to help you harness the full potential of solar energy.

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