South Australia Vs. Too Much Home Solar

May 10, 2021 by Lewin Day 209 Comments

Once upon a time, the consensus was that renewable energy was too expensive and in too sparse supply to be a viable power source to run our proud, electrified societies on. Since then, prices of solar panels have tanked, becoming more efficient along the way, and homeowners have been installing them on their rooftops in droves.

Where once it was thought we’d never have enough solar energy, in some cities, it’s becoming all too much. In South Australia, where solar output can be huge on a sunny day, electricity authorities are facing problems with grid stability, and are taking measures to limit solar output to the grid.

Isn’t More Usually Better?

The problem faced by South Australian utilities is one of how to properly control an electrical grid with many thousands of distributed power sources. Typically, in conventional modern power grids, voltage and frequency is controlled within set limits by carefully matching the supply from major power plants with the demand from users. Fast-response plants can be brought online to meet shortfalls, and switched off when demand drops, and everything hums along nicely.

Unfortunately, solar power isn’t so easy to throttle, and even less so when it’s coming from thousands of separate households each with their own rooftop install and an inverter to feed back into the grid. This has led to authorities contemplating measures such as charging homeowners to export energy to the grid in peak periods in an effort to slow the huge uptake of home solar systems. Export limits have also been proposed for suburbs with the highest concentration of home solar, as substations in certain residential areas struggle to cope under the huge inflows of energy. Continue reading “South Australia Vs. Too Much Home Solar” →

Automate Your Poultry With CoopCommand

May 8, 2021 by Jenny List 24 Comments

A fresh egg taken from beneath a slumbering hen is something to which the taste of a supermarket equivalent rarely compares. The satisfaction of having a contented flock does come at a price though, in the form of constant monitoring and husbandry of your poultry’s well-being. It’s a problem that [hms-11] has tried to address with CoopCommand, a system to automate the monitoring of and environment within a chicken coop. It controls a light to counteract for shorter winter days, warms their water when it’s cold, has a fan for cooling and ventilation on hot days, and a camera to keep any eye on them.

At its heart is an ATmega328 controlling the coop functions, and an ESP32 camera board for network connectivity and visual monitoring. An alphanumeric LCD and a set or buttons provide the interface, and all is fitted on a custom PCB in a smart 3D-printed housing. Meanwhile all the files can be found in a GitHub repository.

A machine cannot replace human care and attention when it comes to good animal husbandry, as there’s always an essential need for the poultry owner to attend to the needs of their charges. But a system like this one can make an important contribution to their welfare, with a consequent increase in their laying ability.

Solar And Wind Could Help Support Ethiopia’s Grand Dam Project

April 29, 2021 by Lewin Day 22 Comments

Ethiopia is in the midst of a major nation-building project, constructing the Grand Ethiopian Renaissance Dam (GERD). Upon completion, GERD will become the largest hydropower plant in Africa, providing much needed electricity for the country’s growing population.

The project dams the Blue Nile, a river which later flows into neighbouring Sudan, where it merges with the White Nile and then flows on to Egypt. Like all rivers that flow across political boundaries, concerns have been raised about the equitable management of the water resources to the benefit of those upstream and down. Too much water dammed upstream in GERD could have negative effects on Egyptian agriculture reliant on river flows, for example. Efforts are ongoing to find a peaceful solution that suits all parties. Recently, suggestions have been made to supplement the dam’s power output with solar and wind to minimise disruption to the river’s users.

Continue reading “Solar And Wind Could Help Support Ethiopia’s Grand Dam Project” →

Blocking Out The Sun: Viable Climate Countermeasure Or Absolute Madness?

April 26, 2021 by Lewin Day 155 Comments

If there’s one thing humans hate, it’s exercising willpower. Whether its abstaining from unhealthy foods, going to bed early, or using less energy and reducing greenhouse gas emissions, we’re famously bad at it. Conversely, if there’s one thing humans love, it’s a workaround. Something that lets us live our lives as the carefree hedonists we are, and deals with the sticky consequences so we don’t have to.

One such workaround for the issue of climate change is a doozy, though — blocking out the sun’s rays in order to cool our warming planet.

Continue reading “Blocking Out The Sun: Viable Climate Countermeasure Or Absolute Madness?” →

“Paper” Bottles For Your Fizzy Drinks (And Bottle Rockets)

April 23, 2021 by Jenny List 144 Comments

A story that passed almost unnoticed was that the Coca-Cola company plan to run a limited trial of paper bottles. Wait, paper for a pressurized beverage? The current incarnation still uses a plastic liner and cap but future development will focus on a “bio-based barrier” and a bio composite or paper cap tethered to the vessel.

Given that plastic pollution is now a major global concern this is interesting news, as plastic drinks bottles make a significant contribution to that problem. But it raises several questions, first of all why are we seemingly unable to recycle the bottles in the first place, and given that we have received our milk and juice in paper-based containers for decades why has it taken the soda industry so long?

Plastic soft drink bottles are made from Polyethylene terephthalate or PET, the same polyester polymer as the one used in Dacron or Terylene fabrics. They’re blow-moulded, which is to say that an injection-moulded preform something like a plastic test tube with a screw top fitting is expanded from inside in a mould by compressed gas. As anyone who has experimented with bottle rockets will tell you, they are immensely strong, and as well as being cheap to make and transport they are also readily recyclable when separated from their caps.

Continue reading ““Paper” Bottles For Your Fizzy Drinks (And Bottle Rockets)” →

Parts of the automated soil moisture monitoring station

Solar Stevenson Screen For Smart Sprinkler

April 11, 2021 by Bob Baddeley 1 Comment

It’s not infrequent that we see the combination of moisture sensors and water pumps to automate plant maintenance. Each one has a unique take on the idea, though, and solves problems in ways that could be useful for other applications as well. [Emiliano Valencia] approached the project with a few notable technologies worth gleaning, and did a nice writeup of his “Autonomous Solar Powered Irrigation Monitoring Station” (named Steve Waters as less of a mouthful).

Of particular interest was [Emiliano]’s solution for 3D printing a threaded rod; lay it flat and shave off the top and bottom. You didn’t need the whole thread anyway, did you? Despite the relatively limited number of GPIO pins on the ESP8266, the station has three analog sensors via an ADS1115 ADC to I2C, a BME280 for temperature, pressure, and humidity (also on the I2C bus), and two MOSFETs for controlling valves. For power, a solar cell on top of the enclosure charges an 18650 cell. Communication over wireless goes to Thingspeak, where a nice dashboard displays everything you could want. The whole idea of the Stevenson Screen is clever as well, and while this one is 3D printed, it seems any kind of stacking container could be modified to serve the same purpose and achieve any size by stacking more units. We’re skeptical about bugs getting in the electronics, though.

We recently saw an ESP32-based capacitive moisture sensor on a single PCB sending via MQTT, and we’ve seen [Emiliano] produce other high quality content etching PCBs with a vinyl cutter.

Is It A Lawnmower? Is It An RPi IRC Server? It’s Both!

April 9, 2021 by Maya Posch 10 Comments

Although first presented to the world as an April 1st joke, [Jotun]’s IRC-enabled lawnmower began life as the result of casual bantering among folk on the Undernet IRC network. When the project worked out better than probably anyone could have expected, it was presented as the Green Future of Undernet on April 1st. Joking aside, the project actually is pretty interesting and well-executed.

At the core is a Remington RM110, a fairly basic gas-powered push lawnmower. After years of use it wasn’t running so well any more, so [Jotun] took it apart and cleaned the engine, despite never having done so before. With that grimy task completed, a subsequent remark in an Undernet channel about linking the lawnmower to Undernet led to a Raspberry Pi 4 and various other components being ordered.

The view from the driver’s seat with the server box installed.

The write-up by [Jotun] provides a pretty good overview of the project’s history: from getting the Raspberry Pi 4 working with a UPS add-on, to getting the IRC server software working and serving clients, and putting a weather- and dust-proof box together with enough filtered ventilation to ensure that the freshly mowed grass doesn’t clog up the Raspberry Pi while keeping everything cool.

As a bonus, the system tracks the wheel revolutions so that [Jotun] can keep track of the square kilometers of grass he has cut, and reports this with an IRC bot to anyone interested on Undernet, in the channel #lawnmower. The only thing that isn’t working well yet so far is the live camera feed from the lawnmower, due to the obvious vibration issues, but [Jotun] reckons that can be solved in time.