Increasing PV Solar Cell Efficiency Through Cooling

An unavoidable aspect of photovoltaic (PV) solar panels is that they become less efficient when they warm up. [Tech Ingredients] explains in a new video the basic reason for this, which involves the input of thermal energy affecting the semiconductor material. In the subsequent experiment, it is demonstrated how cooling the backside of the panel affects the panel’s power output.

There are commercial solutions that use water cooling on the back of panels to draw heat away from panels, but this still leaves the issues of maintenance (including winter-proofing) and dumping the heat somewhere. One conceivable solution for the latter is to use this heat for a household’s hot water needs. In the demonstrated system a heatsink is installed on the back of the panel, with fans passing cool air over the heatsink fins.

On a 100 Watt PV panel, 10 W was lost from the panel heating up in the sun. After turning on the fans, the panel dropped over 10 °C in temperature, while regaining 5.5 W. Since the installed fans consumed about 3 W, this means that the fans cost no extra power but resulted in increased production. Not only that, but the lower temperatures will in theory extend the panel’s lifetime. Though even with active cooling, even the best of PV panels will need to be replaced after a couple decades.

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Mini PC with the mod described, a large tower fan sticking out of a hole in the top cover

MiniPC Surgery Makes It 50% Cooler

[G3R] writes to us about a mod they did on a HP ProDesk/EliteDesk 400 G3 miniPC they use as a home emulation center. The miniPC would overheat as soon as the CPU load increased, resulting in frame drops and stutters, as well as throttling CPU. [G3R] took the original cooling solution, threw out half of it and modified the remaining half to accept a tower CPU cooler.

The modification is invasive in all the right ways. [G3R] shows how to de-fin the current heatsink and smooth it over with a… welder? Our guess is that the heatsink fins were soldered to the heatsink base, and in that case, a heat gun should also work. Afterwards, you’re supposed to cut a hole in the upper case, then re-wire the fan connections, and create custom brackets to attach the tower fan – [G3R] explains how to do it all and what to watch out for.

The results are fascinating. After performing the mod, both idle and under-load temps got cut down by 50%! Idle temps went from 50 to 25 °C, and under-load temps dropped from 79 to 40 °C – surely, with way less throttling involved. Not only this lets [G3R] play Breath Of The Wild without hiccups, it also certainly improves overall lifespan of the mini-PC, despite the intervention being mechanically harsh.

Making our devices, quite literally, cooler is a venerable tradition of hackers. Just a few weeks ago, we covered a simple 3D printable LGA 1700 CPU bracket which can gain you some much-desired thermal contact. Sometimes we encounter proprietary and weird cooling fans that fail, and then we understand their workings and build a substitute. And, even if your GPU was never meant to have a fan, you can add one anyway!

A GPU card with a home-made fan assembly

3D-printed Fan Mount Keeps Server GPU Cool In Desktop Case

Most readers of Hackaday will be well aware of the current shortages of semiconductors and especially GPUs. Whether you’re planning to build a state-of-the art gaming PC, a mining rig to convert your kilowatt-hours into cryptocoins, or are simply experimenting with machine-learning AI, you should be prepared to shell out quite a bit more money for a proper GPU than in the good old days.

Bargains are still to be had in the second-hand market though. [Devon Bray] chanced upon a pair of Nvidia Tesla K80 cards, which are not suitable for gaming and no longer cost-effective for mining crypto, but ideal for [Devon]’s machine-learning calculations. However, he had to make a modification to enable proper thermal management, as these cards were not designed to be used in regular desktop PCs.

The reason for this is that many professional-grade GPU accelerators are installed in rack-mounted server cases, and are therefore equipped with heat sinks but no fans: the case is meant to provide a forced air flow to carry away the card’s heat. Simply installing the cards into a desktop PC case would cause them to overheat, as passive cooling will not get rid of the 300 W that each card pumps out on full load.

[Devon] decided to make a proper thermal solution by 3D printing a mount that carries three fans along with an air duct that snaps onto the GPU card. In order to prevent unnecessary fan noise, he added a thermal control system consisting of a Raspberry Pi Pico, a handful of MOSFETs, and a thermistor to sense the GPU’s temperature, so the fans are only driven when the card is getting hot. The Pi Pico is of course way more powerful than needed for such a simple task, but allowed [Devon] to program it in MicroPython, using more advanced programming techniques than would be possible on, say, an Arduino.

We love the elegant design of the fan duct, which enables two of these huge cards to fit onto a motherboard side-by-side. We’ve seen people working on the opposite problem of fitting large fans into small cases, as well as designs that discard the whole idea of using fans for cooling.

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Exploring An Aftermarket LED Headlight Retrofit Kit

There’s plenty of debate about drop-in LED headlight bulbs, especially when they’re used with older reflector housings that were designed for halogen bulbs. Whether or not you personally feel the ultra-bright lights are a nuisance, or even dangerous, one thing we can all agree on is that they’re clearly the result of some impressive engineering.

Which is why we were fascinated to see the teardown [TechChick] did on a “Ultra 2 LED” retrofit from GTR Lighting. Apparently one of the diodes was failing, and as part of the warranty replacement process, she was informed she had to make it completely inoperable. Sounds like a teardown dream come true. If a manufacturer ever told us we needed to take something apart with extreme prejudice and provide photographic evidence that the deed was done, we’d be all too happy to oblige.

The driver itself ended up being completely filled with potting compound, so she doesn’t spend much time there. Some will no doubt be annoyed that [TechChick] didn’t break out the small pointy implements and dig all that compound out, but we all pretty much know what to expect when it comes to driving LEDs. The real interesting bit is the bulb itself.

As is common with these high-output automotive LEDs, the Ultra 2 is actively cooled with a small fan that’s actually enclosed within the heatsink. With the fan and the two-piece heatsink removed, she’s able to access the LED module itself. Here, two PCBs are sandwiched back to back with a hollow copper chamber that leads out of the rear of the module. When [TechChick] cut into the copper she said she heard a hiss, and assumed it was some kind of liquid cooling device. Specifically we think it’s a vapor chamber that’s being used to pull heat away from the diodes and into the heatsink at the rear of the module, which speaks to the advanced technology that makes these bulbs possible.

While laser headlights are arguably the future of automotive lighting, it’s going to be quite some time before they trickle down to those of us that don’t own supercars. Until then, when used responsibly, these LED retrofits can inject a bit of cutting-edge tech into your old beater without breaking the bank.

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