This system allows you to ‘UNplug’ from the grid during the day and re-plug at night.
In today’s ‘always on’ era, there are over 100 million refrigerators, Internet modems and laptops running on fossil fuels in the United States alone, all of which adds roughly 33 billion pounds of CO2 to the atmosphere annually. That is the equivalent of four coal burning power plants, just to put things into perspective. As a way to curb this never-ending problem, Markus Löffler has developed a solution that starts with taking essential household appliances off the grid during daylight hours.
The idea for this project first came about after the Maker and his family suffered a power outage that left his home in total darkness and their refrigerated food spoiled. Upon brainstorming, he decided to absorb the endless sun of Southern California through a series of solar panels and take his refrigerator off the grid during peak hours of the day, which also happen to be when energy costs and greenhouse gas emissions are the highest. What’s more, the aptly named UNplug system automatically reverts back to electricity at night.
Now live on Kickstarter and a recent entry in this year’s Hackaday Prize, UNplug supplies automatic uninterrupted power with built-in surge protection by controlling the power source that goes to an appliance, switching between the grid, solar power and batteries. Meaning, should a thunderstorm, hurricane or a tree falling on a line cause a power outage, the solution is capable of switching back via battery. This lets users keep their most critical home equipment up and running in a time when they’re needed most, whether it’s the lights, security monitors, smoke detectors or phone chargers. One solar panel is enough to take a refrigerator, laptop and modem off of the grid.
The unit is comprised of three main functional blocks: a120V AC unit, a 12/24V DC unit, as well as the sensors and microprocessors. Speaking of which, two configurations are available. The first employs an Arduino-compatible ATmega328 controller without the need for a Wi-Fi signal, while the second uses a Spark Core to wirelessly send data and sync with IFTTT recipes.
“The UNplug firmware will be pre-installed onto the processors so each unit is ready right out of the box. But you can even go ‘fully hacker friendly’ and download and compile your own programs. There is an Arduino and Spark compatible C-library that allows you to program your own functionality and go be beyond the intended use. There are two interfaces (Serial and I2C) to wire connect the unit to other hardware like the Raspberry Pi,” Löffler writes.
In order to completely construct the appliance power system requires a 12V or 24V power inverter, batteries and at least 250W of solar panels. An online dashboard allows the user to monitor energy usage, cost savings and other metrics from just about anywhere. These algorithms and programs are all open source and available on Github.
“UNplug is essentially an Automatic Transfer Switch that switches a load between two sources. It automatically switches when it senses one of the sources has lost power,” the Maker notes. “The ATS will automatically tell the inverter to start. Once the ATS sees that the inverter is ready to provide electric power, the ATS breaks the home’s connection to the utility grid and connects the inverter. The inverter supplies power to the electric load, but is not connected to the electric utility lines.”
What’s nice is that thanks to its modular design, each component can be updated independently. This includes adding more solar modules and batteries, replacing the inverter with a more more efficient unit, swapping out the universal socket MCU with a Bluetooth-enabled controller, integrating a cellular network, and receiving automatic firmware updates via Wi-Fi.
UNplug isn’t only limited to in-home use either; in fact, it can be implemented pretty much anywhere, from RVs and campers to boats and cabins. Head over to its Kickstarter campaign, where Löffler is currently seeking $55,000. Delivery is slated for October 2015.