green hacks

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2022 Hackaday Prize: Get Your Planet-Friendly Power On!

April 27, 2022 by 5 Comments

Time flies! This weekend marks the end of the first stage of the 2022 Hackaday Prize, and your chance to enter your alternative-energy projects. There are ten $500 prizes up for grabs, and there’s still time to whip up a project page over on Hackaday.io to showcase it.

In this round, we’re looking for projects that harvest their own energy — solar, wind, heat, vibration, you name it — or projects that make it easier to collect, store, or use renewable energy. Whether this is microwatts or megawatts, the scale of the project is up to you! As long as it’s using or making it easier to use clean energy, we want to see it.

So far, we’ve seen some great projects, ranging from a optimizes the tilt angle of a home solar installation to a demonstration of using a new type of lithium-ion capacitor to add solar power to smaller projects. We really love [MartMet]’s simple Bluetooth thermometer hack, which adds a supercapacitor and solar cell to an outdoor thermometer, and then uses hacked firmware to log the charge status over a year of use! We’re suckers for good data.

The sun is not the only game in town, though. There are a surprising number of projects based on human energy production in emergency situations, from cranking to shaking. Thermionic converters were new to us, but we love explorations of fringe tech. Other traditional favorites like wind and water may make more sense for larger applications. And don’t forget how you’re going to store all this juice you’ve collected.

[Nick Poole]’s thermionic converter array
[Anuradha Gunawardhana]’s 18650 Pack

In short, we’ve got a bunch of great entries, but we’re still missing yours! There’s no minute like the last minute: if you’ve done some work in clean or renewable energy, set yourself up a Hackaday.io project page now. You’ll help make all our projects cleaner, and stand a good chance of taking home some real money to boot!

Once we’ve handled power, the next round is “Reuse, Recycle, Revamp” where any tech that uses recycled parts or facilitates reuse, repair, or recycling is fair game!

The HackadayPrize2022 is Sponsored by:

Ask Hackaday: Is It Time For Waste Heat And Cold Area Heating To Shine?

April 12, 2022 by 82 Comments

It’s difficult to escape the topic of energy supply at the moment, with the geopolitical situation surrounding the invasion of Ukraine leaving the natural gas supply to an entire continent in jeopardy. Fortunately we’re watching the green shoots of an early spring here in the Northern hemisphere so the worst of the winter weather is behind us, but industrial customers can take no such solace from the season and will have to weather whatever price hikes are to come. Every alternative idea for energy supply is on the table, and with the parallel imperative of decarbonising the economy this goes beyond the short term into a future without so much need to rely on gas.

The Future is Cloudy

A district heating plant in Vienna, Austria.
A district heating plant in Vienna, Austria. Joadl, CC BY-SA 3.0 AT

A collaboration between a Finnish district heating network and Microsoft caught our eye because the location of a new data centre for the tech giant was chosen specifically to supply waste heat to the network, rather than releasing it to the environment. It’s not uncommon at all for European cities to use district heating networks but they are normally supplied by waste incinerators, boilers, or combined heat and power stations. The use of data centre waste heat is a novelty, as is in particular the siting of the data centre being dictated by the network.
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A portable water quality monitor

Monitoring Water Quality Using Lots Of Sensors And Machine Learning

April 2, 2022 by 9 Comments

Despite great progress over the past century, more than a billion people still don’t have access to clean drinking water today. Much of the water on Earth’s surface is polluted, but it’s not always easy to tell a dirty stream from a clean one. Professional kit for water analysis can be expensive, which is why [kutluhan_aktar] decided to design a portable, internet-connected water pollution monitor.

A bowl of water with several sensors immersed in it, and a blue box connected to them
Calibrating the system using a bowl of clean water.

There is no single parameter that determines the quality of a water sample, so the pollution monitor has no less than five different sensors. These can determine the oxidation-reduction potential (a chemical indicator), the pH (acidity), total dissolved solids (mainly salts), turbidity (suspended particles) and temperature. To combine all these numbers into a simple “yes/maybe/no” indicator, [kutluhan] trained a neural network with data gathered from a large number of places around his hometown.

This neural network runs on an Arduino MKR GSM 1400 module. While not a typical platform for AI applications, the neural network runs just fine on it thanks to the Neuton framework, a software plaform designed to run machine learning applications on microcontroller systems like the Arduino. It also has a GSM/3G modem, allowing it to report the measured water quality to a central database.

All of this is housed in a 3D-printed enclosure that makes the whole setup easy to carry and operate in any location. Collecting data across a wide area should help to locate sources of pollution, and hopefully contribute to an improvement in water quality for everyone. Here at Hackaday we love citizen science initiatives like this: previously we’ve featured projects to measure things as varied as air quality and ocean waves.

Hackaday Prize 2022: Solar Harvesting Is Better With Big Capacitors

March 30, 2022 by 26 Comments

The sun is a great source of energy, delivering in the realm of 1000 watts per square meter on a nice clear day. [Jasper Sikken] has developed many projects that take advantage of this power over the years, and has just completed his latest solar harvesting module for powering microcontroller projects.

The concept is simple. A small solar panel is used to charge up a lithium ion capacitor (LIC), which can then be used to power other projects. We first saw this project last year, when it was one of the winners of Hackaday’s 2021 Earth Day contest. Back then, it was only capable of dishing out 80 mA at 2.2V.

However, the latest version ups the ante considerably, delivering up to 400 mA at 3.3V. This opens up new possibilities, allowing the module to power projects using technologies like Bluetooth, WiFi and LTE that require more current to operate. It relies on a giant 250 F capacitor to store energy, and a AEM10941 solar energy harvesting chip to get the most energy possible out of a panel using Maximum Power Point Tracking (MPPT).

It’s a useful thing to have for projects that you’d like to run off the sun, and you can score one off Tindie if you don’t want to build your own. We’ve seen [Jasper] pull off other neat solar-powered projects before, too. Video after the break.

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Custom Controller Ups Heat Pump Efficiency

March 25, 2022 by 59 Comments

Heat Pumps are an extremely efficient way to maintain climate control in a building. Unlike traditional air conditioners, heat pumps can also effectively work in reverse to warm a home in winter as well as cool it in summer; with up to five times the efficiency of energy use as a traditional electric heater. Even with those tremendous gains in performance, there are still some ways to improve on them as [Martin] shows us with some modifications he made to his heat pump system.

This specific heat pump is being employed not for climate control but for water heating, which sees similar improvements in efficiency over a standard water heater. The problem with [Martin]’s was that even then it was simply running much too often. After sleuthing the energy losses and trying a number of things including a one-way valve on the heating water plumbing to prevent siphoning, he eventually found that the heat pump was ramping up to maximum temperature once per day even if the water tank was already hot. By building a custom master controller for the heat pump which includes some timing relays, the heat pump only runs up to its maximum temperature once per week.

While there are some concerns with Legionnaire’s bacteria if the system is not maintained properly, this modification still meets all of Australia’s stringent building code requirements. His build is more of an investigative journey into a more complex piece of machinery, and his efforts net him a max energy usage of around 1 kWh per day which is 50% more efficient than it was when it was first installed. If you’re looking to investigate more into heat pumps, take a look at this DIY Arduino-controlled mini heat pump.

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Used Facemasks Turned Into Rapid Antigen Tests With Injection Molding

March 24, 2022 by 15 Comments

Here’s a little eye-opener for you: next time you’re taking a walk, cast your eyes to the ground for a bit and see how far you can go without spotting a carelessly discarded face mask. In our experience, it’s no more than a block or two, especially if you live near a school. Masks and other disposal artifacts of the COVID-19 pandemic have turned into a menace, and uncounted billions of the things will be clogging up landfills, waterways, and byways for decades to come.

Unless they can be recycled into something useful, of course, like the plastic cases used for rapid antigen tests. This comes to us by way of [Ric Real] from the Design and Manufacturing Futures lab at the University of Bristol in the UK. If any of this sounds or looks familiar, refer back to October when the same team presented a method for turning old masks into 3D printer filament. The current work is an extension of that, but feeds the polypropylene pellets recovered from the old masks into a desktop injection molding machine.

The injection molding machine is fitted with 3D-printed molds for the shells of lateral flow devices (LFD) used for COVID-19 rapid antigen testing. The mold tooling was designed in Fusion 360 and printed on an Elegoo Mars MSLA printer using a high-strength, temperature-resistant resin. The molds stood up to the manual injection molding process pretty well, making good-quality parts in the familiar blue and white colors of the starting material. It’s obviously a proof of concept, but it’s good to see someone putting some thought into what we can do with the megatonnes of plastic waste generated by the pandemic response.

Pedal Powered Power

March 14, 2022 by 19 Comments

When you have a solar-powered web server, where do you go next for a source of power? Instead of lazily mooching off the sun, you can use your muscle with a bike generator. [Ed note: The site is run on an entirely solar-powered server, so if it’s the middle of the night, you might have a better web experience here.]

We’ve covered bicycle generators before, so what’s new? For starters, the accessibility of chargers and batteries has changed significantly. Rather than just charging a phone or putting out a measly 5V, this bike can be integrated into an existing solar PV system and output many voltages. This guide goes over building one with hand tools with great detail.

It starts with a 1950’s vintage exercise bicycle, no hacksaw required. A friction drive connects a generator and makes for an incredibly compact generator/exercise machine. Calculating the correct gear ratio is crucial to getting the 12 volts out at an average pedaling speed. You want your range of voltages to be between 5 and 24 volts. With the help of a control panel provides 5v, 12v, 14.4v, and 220v to power a variety of devices. Boost and buck converters output these voltages (depending on whether the voltage needs to be set for a maximum or a minimum). A potentiometer allows you to dial back the power draw of certain appliances (an electric kettle, for instance), making a workout a tad easier on the human component of the generator.

Another key takeaway from this guide is using a wind charge controller to charge batteries. A solar charge controller will just cut the circuit when the batteries are full. A wind charge controller will increase the load until the motor breaks. Some controllers are also hybrid wind and solar, allowing you to connect a small panel like the one running the webserver this guide is posted on and then charge up the batteries when it has been overcast for a few days in a row.