Maximizing a Solar Panel

Solar panels seem like simple devices: light in and electricity out, right? If you don’t care about efficiency, it might be that simple, but generally you do care about efficiency. If you are, say, charging a battery, you’d like to get every watt out of the panel. The problem is that the battery may not draw all the available current, basically leaving capacity on the table.

The solution is a technique called MPPT (Maximum Power Point Tracking). Despite sounding like a Microsoft presentation add on, MPPT uses a DC to DC converter to present a maximum load to the solar cell while providing the desired current and voltage to the load. MPPT is what [Abid Jamal] implemented to manage his solar charger.

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Omaha Mini Maker Faire: Recycle All the Things

A young maker named [Allie] drew a lot of attention at the 2nd annual Omaha Mini Maker Faire. Her booth was full of the various creations she has designed and built herself throughout the course of her short life. The biggest draw was her green design dollhouse, which focuses on environmentally friendly living. With the exception of the LEDs lighting the interior, some tape, and the requisite bit of hot glue, the entire structure and its contents were made from recycled materials.

green-dollhouse-thumbThe cardboard structure features a kitchen, living room, bedroom, bathroom, and attic. Every piece of furniture and all the decorations are made from salvaged materials and packaging. One side of the roof holds a Snap Circuits board with a solar panel that powers some blue LEDs on the bedroom wall. [Allie] poured water down the other side of the roof to demonstrate the rain water collection system. The house’s rain barrel was made from a grated parmesan cheese container, which is perfectly designed for the airline tubing running into it from the recycled plastic guttering.

owl-says-noOne of [Allie]’s other projects is a disagreeable owl fashioned from cardboard and a salvaged canister. Hidden away beneath the owl’s platform lies a simple gear system attached to a key on the front. Turning the key causes the owl’s head to swivel back and forth. We tried to make it spin all the way around, but the full range of motion is about 270 degrees. She also brought Mountain Dew, a hummingbird model made from a spark plug and other metal bits and bobs, including a pair of soda can wings.

mountain-dew-hummingbirdIn addition to her crafty skills, [Allie] is one well-spoken tween. She was more than happy to discuss her creations in detail to anyone who would listen, which included at least two local journalists and this impressed reporter. We learned through a bit of light research that a robot [Allie] built a few years ago inspired a British toy company to produce a new doll, the Robot Girl Lottie. She’s an inspiration to makers of all ages.

Using The Sun To Beat The Heat

It’s practically May, and that means the sweltering heat of summer is nearly upon us. Soon you’ll be sitting outside somewhere, perhaps by a lake, or fishing from a canoe, or atop a blanket spread out on the grass at a music festival, all the while wishing you had built yourself a solar-powered personal air conditioner.

[Nords] created his from a large insulated beverage vessel. The imbibing spout offers a pre-made path to the depths of said vessel and the heart of this build, the ice water refrigerant. [Nords] fashioned a coil out of copper tubing to use as a heat exchanger and strapped it to the fan that performed best in a noise-benefit analysis.

A small USB-powered submersible pump moves the ice water up through the copper tubing. Both the pump and the fan run off of a 5V solar panel and are connected with a USB Y cable, eliminating the need for soldering. Even if you spend the summer inside, you could still find yourself uncomfortably warm. Provided you have access to ice, you could make this really cool desktop air conditioner.

[via Embedded Lab]

2015 THP Inspiration: Renewable Energy

Most of our energy comes from dead algae or dead ferns right now, and we all know that can’t continue forever. The future is by definition sustainable, and if you’re looking for a project to change the world for this year’s Hackaday Prize, you can’t do better than something to get the world off carbon-based fuels.

mhqyqz7The simplest solar builds can be as fun as a redneck hot tub – a solar thermal water heater repurposed into a heated swimming pool with the help of a pump and JB Weld. You can even build a hose-based version for $100. They can be as useful as a Maximum Power Point Tracking charger for a solar setup – a few bits of electronics that ensure you’re getting the most out of your solar cells. You can, of course, access solar power in a roundabout way with a wind generator built from a washing machine and a 555 timer.

carben-mainGetting energy from the sun is one thing, and putting it to use is another thing entirely. We spend a lot of energy on transportation, and for that there’s a solar power bike, an electric scooter, or a completely open source electric car.

Building the machines that make sustainable energy possible or even just the tools that will let us use all that energy are just a few ideas that would make great entries for The Hackaday Prize. You could go another direction and build the tools that will build and maintain these devices, like figuring out a way to keep these batteries and generators out of the landfill. Any way you look at it, anything that actually matters  would make a great entry to The Hackaday Prize.

THP Semifinalist: Solar Energy System

Building a solar power installation isn’t as simple as buying a few panels, wiring them up to a battery, and putting an inverter in the mix. To get the most out of your pricey panels, you’ll want to look at something called Maximum Power Point tracking. Solar panels have an IV curve, and this changes with how much sunlight they’re getting. To get the most out of a set of cells, you need make sure you’re drawing the maximum amount of power out of your cells.

[Nathaniel]’s Solar Energy Generator does just that. It can handle up to 500 Watts, sucks power down from a bank of solar cells and spits that out to a battery. That’s not everything; the project also has a microcontroller for measuring and displaying all the pertinent info, and some terminals to plug in a few DC loads.

While the Solar Energy Generator is designed for off the grid applications, this could easily augment a home installation on the cheap. If you want more than 500 Watts or so, you’ll want to look at a larger controller, but for anything under that, [Nathan] has you covered.

Videos below.

SpaceWrencherThe project featured in this post is a quarterfinalist in The Hackaday Prize.

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Solar Energy Provides An Outlet For Hurricane-Related Woes

Hurricane season in the US Atlantic region officially began on June 1st. While [mikesoniat] is hoping for a mild one in his Gulf Coast town, he’d like to be as prepared as possible in the event of a power outage. He’s been experimenting with solar power lately, and while he’d love to go all out with some hefty system that could keep all his appliances running, solar outlethe’s not quite ready for that kind of investment. While thinking about this dream system, he noticed all the phone jacks around his house that he hasn’t used for several years. After consulting the phone company and researching the capabilities of 22-26AWG POTS copper lines, he devised a solar-powered system to provide enough power to run lights, fans, and a couple of phone chargers.

At the heart of this hack are two 12V solar panels, two 12V batteries in a weatherproof junction box, and a 100W solar charge controller.  He started by re-wiring Ma Bell’s junction box up to the panels with thermostat wire. After prying out the RJ11 jack panels all over his house, he wired in regular outlets and marked them as 12V solar to avoid confusing his house guests. He was able to find 12V LED bulbs with standard bases, so all he has to do is screw in these bulbs and plug the lamps into his solar outlets. He also installed a floodlight outside and ran all of the wiring through the floodlight box.

To soak up more sun for this or any other solar hack, try a 2-axis solar tracker.

The Phidgets Solar Powered Weather Station


Yes, it’s a weather station, one of those things that records data from a suite of sensors for a compact and robust way of logging atmospheric conditions. We’ve seen a few of these built around Raspberry Pis and Arduinos, but not one built with a Phidget SBC, and rarely one that has this much thought put in to a weather logging station.

This weather station is designed to be autonomous, logging data for a week or so until the USB thumb drive containing all the data is taken back to the lab and replaced with a new one. It’s designed to operate in the middle of nowhere, and that means no power. Solar it is, but how big of a solar panel do you need?

That question must be answered by carefully calculating the power budget of the entire station and the battery, the size of the battery, and the worst case scenario for clouds and low light conditions. An amorphous solar cell was chosen for its ability to generate power from low and indirect light sources. This is connected to a 12 Volt, 110 amp hour battery. Heavy and expensive, but overkill is better than being unable to do the job.

Sensors, including temperature, humidity, and an IR temperature sensor were wired up to a Phidgets SBC3 and the coding began. The data are recorded onto a USB thumb drive plugged into the Phidgets board, and the station was visited once a week to retrieve data. This is a far, far simpler solution than figuring out a wireless networking solution, and much better on the power budget.

Via embedded lab