Open Source Solar System


Distributed, or decentralised energy systems can be build with Open Source Renewable Energy Hardware. Within the Hamburg Open Online University project Collective Open Source Hardware, short cos(h), step-by-step instructions were created to build your own open source solar system. The tutorial is based on Libre Solar components and offers a modular system that can be set up, depending on power and storage capacity requirements. Basic understanding of electrical engineering and programming is required for a successful construction.

Manufacturing of a Solar Charge Controller

A charge controller feeds electrical power from solar panels (or wind turbines or bicycle generators) in the battery storage system. If electricity should be stored in batteries, a charge controller is always required, as it prevents the battery from overloading or overcurrent. Cos(h) created a manual that shows how to manufacture a MPPT (Maximum Power Point Tracker) charge controller. It is a PCB (printed circuit board) for running an electrical solar power system.

Click here to open the cos(h) tutorial and build your own MPPT.

Photos from the MPPT manufacturing:

Images by cos(h) is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

Assembly of a Solarbox

This tutorial shows you how to connect the previous constructed charge controller with solar panels, batteries and loads directly. However, a solarbox can be created individually.

Another cos(h) tutorial shows how to assemble a solarbox, which is a small scale mobile energy system (consisting of batteries, electric components like a charge controller and connectors for connecting power generation units like solarpanels)

Click here to open the cos(h) tutorial and assembly your own small scale solar system.

Libre Solar Box Overview by cos(h) is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

Other Open Source Hardware:

Global Village Construction Set: 50 different industrial machines: Open Source Ecology


More information:

Video: What is Open Source Hardware?

cos(h) Tutorial

cos(h) Git Lab

Libre Solar Website

Libre Solar Community Platform


DIY Rooftop Rainwater Harvesting


Harvesting rainwater is one of the most self-sufficient and environment friendly methods of using water. As much as 80 % of rainwater that falls onto your catchment area can be collected by applying simple methods. This DIY Rooftop Rainwater Harvesting handbook walks you through an easy  process of building a small rain barrel system. If you want to start small and inexpensive, this might be a good option for you.

DIY Rooftop Rainwater Harvesting by Sumbal Tasawwar and Ruth Schaldach is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

To get a better estimate of how much water can be collected from a rooftop, please have a look at our second Rainwater Collection Calculator (Rainwater Collection from Rooftops).

Some additional tips about at home rainwater harvesting to remember:
    • Never drink untested and unfiltered water. The rainwater collected using this method can be used for purposes such as watering your garden.
    • Never place your barrel close to utility services or septic tanks.
    • Drain your barrel once in a while.
    • You can place some pea gravel around your barrel. This will be helpful in case of overflow.
    • Consider installing a gutter debris filter.
    • Clean the gutters thoroughly before installing the rainwater barrel.
    • Consider installing a first flush diverter to reduce contaminants.
    • You can expand your rainwater collecting capacity by connecting an additional barrel.
    • Set up a seasonal maintenance schedule.

We hope you find this handbook useful and hope to hear from you in case you try out this solution.


Homemade Drip and Subsurface Irrigation


The benefits of drip and surface irrigation systems can be exploited also in domestic conditions through a homemade irrigation system. These systems are simple and inexpensive to install and also a great way to recycle items that may otherwise go to waste, such as plastic bottles. They are suitable for gardens, as well as potted plants. To learn how to make your own homemade irrigation system, have a look at this tutorial!

Homemade Drip and Subsurface Irrigation by Maria Monina Orlina and Ruth Schaldach is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.