The media usually discusses renewable energy in terms of utility scale—something that few of us have any control over. What often goes unnoticed is the small stuff: backyard, DIY renewable energy projects that make a difference at the individual scale. To highlight this important work, we rounded up some of the best DIY renewable energy projects published here on Hackster.
Solar panels are always the most obvious sources of renewable energy. Roof-mounted solar panels are becoming very popular, but they also lose efficiency unless the sun is directly overhead. One solution is to track the sun and move the solar panels so that they're always at maximum efficiency.
DemetrisEng's 35W solar tracker project is a great demonstration of this concept. It uses an Arduino Uno and four light dependent resistors (LDRs) mounted in a special X-shaped divider. By calculating which LDRs receive more light than the others, the Arduino can determine the position of the sun. It then uses a pair of hefty geared DC motors to tilt the entire solar panel towards the sun.
But what if you can't track the sun directly for some reason? This non-optical solar tracker created by Team Trouble will still work. It uses the panel's GPS location and the time of day to calculate the sun's position. The idea here is that one GPS unit can perform these calculations for an entire solar farm, eliminating the need for tracking hardware on every single panel.
However, sometimes you don't even know if your location is practical for a solar panel. This is especially true in areas with few sunny days or that are close to the Earth's poles. Chris Kuzma's Solar Viability Tester is an inexpensive tool that helps you calculate how much power you can get from solar panels in the real world. It uses an Avnet AT&T IoT Starter Kit and 15-watt 5V Allpower USB solar panel. With a minimal investment in that hardware, you can find out how much power you get per square inch of panel. Then you can extrapolate that to decide if larger panels are worth the cost.
Solar panels aren't the only way to take advantage of the sun's energy. You can also use that energy to heat up water, without the photovoltaic middle man. asafa52's Solar Water Tank Regulator is an Arduino Uno and ESP8266-based device that ensures water only flows into the water tank if it is hotter than the water exiting, so energy isn't wasted if the day is cloudy or it is nighttime.
Xenophod's Solar Pool Heater performs a similar job for keeping a swimming pool warm. This project uses Onion Corporation hardware to pump water from the black heating coils into the pool once it reaches a specific temperature. That gives the water time to heat up in the coils, which wouldn’t happen if the water pumped continuously.
Wind is another obvious source of renewable energy and you don't need a massive industrial windmill to take advantage of it. This dual-axial flux generator wind turbine created by Vijay Raghav Varada and Hanoz Patel works at a much smaller scale using 3D-printed parts. It is affordable to build, can output an amazing 50-100W, and the same system can even be converted into a water wheel.
If you have a wind turbine, you'll need a way to make its power output usable. That's where philippedc's MPPT Regulator comes in. It uses an Arduino Uno and performs two functions: stops the wind turbine from spinning too fast (which can cause damage) and converts the power output for doing work like charging batteries.
A more exotic way to collect wind power is Lukas Braun's Kite Power 2.0 system. This uses a surf kite to produce power as it flies around in figure-eight patterns. It isn't clear if this is any more efficient than a traditional turbine, but it sure looks cool.
Wood may be humankind's oldest source of renewable energy, but you may not realize that a fire isn't the only way to use it. When wood (and similar materials) burns, it produces a combustible gas in addition to the burning wood itself. A wood gas generator, like this one controlled by a Texas Instruments LaunchPad, harnesses both the energy from the original burn and also collects the wood gas, which can then find use in a variety of applications — including diesel engines.
Finally, we look at an even smaller scale: the microscopic. Anaerobic bacteria produce electrical current as they oxidize certain compounds. With a Microbial Fuel Cell (MFC) like this one created by Madison James Smith and Ian Dickson, you can capture that electrical current and use it. While MFCs have not yet proven to be practical, there is huge potential here if citizen scientists can help unlock it.