Years ago oil companies made billions by just selling oil, which was available for free. Sheiks and big oil field owners became the richest people of the world by just selling "mud". They simply turned dirt into money.

Now we are at the dawn of the solar age . Sun is for free. As a hacker you should use the free solar energy to produce. Please empower your 3D printer using sun at daytime. You must not store the energy. Just setup a timer and start the printing job if sunlight is available. Use the solar panel to detect light. If there is current, your print jobs starts automatically. Make your projects as cheap as possible. Don't use energy from the power outlet. Most devices have a 5V, 9V, 12V or 19V connector. All these devices can be powered using sunlight directly!

Try it. You don't need to invest much money. Solar panels are becoming cheaper and cheaper. Support CIGS panels. Buy CIGS cells, create your own solar energy module for your 3D printer. Load your laptop battery with your windowsill. Please use the sun to create the electricity for your devices. As soon as you start you will see this is addictive and feels great. Not only because you save the environment. Once you think "solar" you have a swarm of small devices which you can operate everywhere. You will become independent of the power company.