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Copyright Michel Langhammer & Timm Wille   --- # Verbund offener Werkstätten (VoW) - Workshop "Power to the People" - VoW Veranstaltungslink: https://www.offene-werkstaetten.org/de/post/power-to-the-people - This document is created to exchange about Open-Source Hardware for Renewable Energy Systems at the Jahreshauptversammlung of Verbund offener Werkstätten, 11.11.2023 in München --- **Access Documenation / Presentation (read-only)**  --- # Personal Introduction - **Michel Langhammer** - researcher at **New Production Institute**, Helmut-Schmidt-University Hamburg - research field: **Open Source Hardware, Sustainable and Circular Manufacturing, Open Educational Resources** - (.01 - .10.2022) head of chair of **Fab City Hamburg (association/ e.V)** - (since 2017) member of **Open Source Ecology Germany (association/ e.V.)** - (since 2018) community of **Libre Solar project** (focus on Open Educational Resources (OER) and Nanogrid System) - (2010 - 2021) 11 years working experience in **manufacturing industry** (PLC programming, technical consultant for energy efficiency in production systems) - **background:** electrical engineering, focus factory automation systems --- # Theory: Replication of Open-Source Hardware ## Open-Source Hardware (OSH) "Open Source Hardware is hardware whose design is made publicly available so that anyone can **study, modify, distribute, make and sell** the design or hardware based on that design." [Ref: OSHWA definition](https://www.oshwa.org/definition/) - **OSH business model guideline:** https://gitlab.com/OSEGermany/osh-guideline-business-models - **Library of Open Source Hardware:** https://losh.opennext.eu/ - **OSH academy:** https://gitlab.com/osh-academy/osh-basics - **OSH Makers Curricilum:** https://curriculum.openhardware.space/ ## Using Open-Source Hardware for Distributed Manufacturing - basis Paper from Mariscal-Melgar, J.C, University Helmut-Schmidt (Hamburg, Germany) [Ref: Paper](https://www.repo.uni-hannover.de/handle/123456789/12269) - **Requirements for Distributed Manufacturing**  - **Distr. Manufacturing: Node-based concept** - production devided in tasks/ work packages / sub-assemblies - **nodes**: provide capacity, capability, flexibility, specialisation of manufacturing steps - framed as Fab/Open/Living/Green/...Lab or Microfactory - **sub-nodes**: taking over manufacturing tasks of nodes - **super-nodes**: capable of all manufacturing steps of an sub-assembly or end-of-line assembly  ## Replication of Open Source Hardware (OSH) through community-based OSH Build Workshops - basis Paper from Anoniou et al, University of Bath (Bath, England), University of Grenoble Alpine (Grnoble, France) [Ref: Paper](https://www.cambridge.org/core/journals/proceedings-of-the-design-society/article/identifying-the-factors-affecting-the-replicability-of-open-source-hardware-designs/02509F521214AFF0124B005C348875C7) - **What is Replication?** - Repeatability: Same community, same source - **Replicability**: Different community, same source - Reproducebility: Different community, different source (same hardware) - **Influancing factors of OSH replicability** - **Quality** - Doc standards: structure and format following template and guidelines - Doc dynamics: relates to latest development; external persons can participate in doc process - Doc accuracy: content clear, sufficient, rigor, correct - file formats: standard for using standard machines; readable open-source formats - design rules: rules that facilitate replicablity (fabricability, procurement) - **Completeness** - design rationale: key points to consider (risk, failure, trouble shooting) - design content: enough information to enable building a working version - **Accessbility** - project: easy to find - documentation: publicly published; freely accessible; multiple language; use of metadata - avalability of materials and equipment: required materials and equipment available to the builder - **Ease of manufacture and assembly** - knowledge and skllls: easy to build; level of skills; materials, tooling and processes needed - **(community-based) OSH Build Workshops** - local production by a community of practice gathering for manufacturing and assembly an OSH (tangible) object/ artefact - use of local supplier networks - performance of - local production - replicability - knowledge transfer ## Open-Source Hardware Building Blocks for Renewable Energy Systems: Libre Solar Project  website: https://libre.solar/ OER site: https://learn.libre.solar/ github: https://github.com/LibreSolar --- - **Context: Access to clean energy still not given to everyone**  --- - **What is Libre Solar? Open-Source Building Blocks for Distributed Energy Systems**  --- - **Open DC Nanogrid System Overview**  - The **main system level functions** of the grid are: - **Current routing** (wired connection between devices including switches and fuses) - **Voltage control** (e.g. to set correct battery charging voltages or needed load/ device voltage) - **Energy management** (e.g. management of the state of charge of the batteries) - Snapshot: **Conventionell Fossil Energy Systems**  :::info See, **http://cos-h.cc/education/energy_system_intro/** ::: --- - **Solarcharger - Maximum Power Point Tracker, example: Libre Solar MPPT1210HUS (12V, 10A(max), high-side load output, USB charging, serial port)**  - **Features:** - 12V battery voltage - 40V max. solar input (36 to 48-cell panels, ideally so-called 12V panels with 36 cells) - 10A max. charge current - 10A max. load output current - Low-power 32bit ARM MCU (STM32L072) - Expandable via Olimex Universal Extension Connector (UEXT) featuring I2C, Serial and SPI interface (e.g. used for display, WIFI communication, etc.) - USB charging, 2A max. - High-side load switching - Built-in protection: - Overvoltage - Undervoltage - Overcurrent - PV short circuit - PV reverse polarity - Battery reverse polarity (destructive, fuse is blown) --- # Introduction to Libre Solar Box 360 Design  ## Overall System Layout The overall system design consists of - **Electrical components** - (Solar)Chargecontroller (power electronic, DC/DC converter) - Battery - Photovoltaic panel (PV-panel) - Wires, Plugs - **Mechanical components** - Frame - Panel Covers - Handles ## Mechanical Frame Design ### Design Requirements The mechanical frame is very individual and does not effect the main functionality of the solarbox which is the storage and provision of electrical energy. The following requirements for the mechanical design can be considered: - mobile or stationary - weight - robustness (including waterproofness) - ease of assembly - ease of integration of electrical interfaces (plugs, switches) ### Design Concepts Our key requirement is to have a mobile energy station. We came up with following design concepts: 1. Simple wooden box design screwed together 2. optional Aluminium (B or T slot) profile design and eliminating heavy wooden panels, use of profiles for main structural support 3. Lasercut design with sandwich base design to support heavy battery. ## Electrical Design ### Requirements - Open Source Hardware based chargecontroller - use of lead-acid batteries (cheaper, lower energy denstity -> higher weight), no additional Battery Management System (BMS) needed. - standardized input/output plugs for PV input (MC4 plugs) and DC output (car cigarette plug) (automotive systems -> high availability) - modular and reconfigurable system layout -> ideally no direct soldering of cables ### Used Components - OSH Solarcharger: Libre Solar 12010HUS, currently available 12V. 10A -> defines the power limitations - flexible PV Panel: P=90Wp - Battery: C=360Wh ## Other OSH Solarbox Designs - The 1st Libre Solar Box prototyped in the Fab Lab St. Pauli in Hamburg, Germany, - project-link: https://ose-germany.de/projekte/libresolarbox/ - repo-link: http://cos-h.cc/hardware/solarbox_intro/ - repo-link: https://gitlab.opensourceecology.de/verein/projekte/libresolarbox ## Other OSH Hardware Projects related to Renewable Energy Systems - Electro Dacus: https://electrodacus.com/ - Open Nanogrid Project (OSEG): https://wiki.opensourceecology.de/OpenNanoGrid - OwnTech Foundation, http://www.owntech.org/en/home-en/ --- # Build Process - Step by Step Guide ## Collaboration / Iteration - **Sharing data, information and knowledge** is important for collaboration especially in the design and developing of hardware using **open-source principles**. Using digital tools to exchange information, a proper documentation builds the fundament. - **People** builds the fundament to **transfer this information into knowledge** and **share their knowledge within a community** so they can give it further to other people ("train the trainer") - To improve OSH documentation, the **iteration process** of documentation is essential - Sharing our experiences and requirements help us understand what we really need and how we can solve this --- ### Step: Getting to Know - Material **Electrical Components** - **Solarcharger** - Reference: https://learn.libre.solar/system/charge_controller.html - Deep-Dive: https://learn.libre.solar/development/dcdc_converter.html - System Layout of a Maximim Power Point Tracker (MPPT) chargecontroller  - Libre Solar 1210 HUS, User Manual: https://libre.solar/mppt-1210-hus/  - **Solarpanel** - Reference: https://learn.libre.solar/system/solar_panel.html   - **Datasheets** specify the following parameters - **V_oc: Open circuit voltage** is the **maximum voltage of panel** when it is not connected to an electrical circuit or system, i.e. when there is no current flow. It can be measured with a multimeter directly at the panel’s terminals or the ends of the attached cables. - **V_mpp: Voltage at maximum power point:** is the voltage at which the power output of the module is at its peak. See below graphs for better understanding. - **I_mpp: Current at maximum power point:** is the current corresponding to V_mpp - **I_sc: Short circuit current:** is the current measured when both terminals are connected to each other. In the characteristic curve, this point is where the voltage VV equals zero. - **Battery** https://learn.libre.solar/system/battery.html#charge-methods - **Datasheets** specify the following parameters: - **V_nom: Nominal Voltage:** The nominal Voltage describes the voltage level the - **C: Capacity:** It is display in [Ah] which means for how long [h] it can provide current [A] Combined with the V_nom (V_nom[V] * C[Ah]) you get the Capacity in [Wh, W=V*A] - **Miscellaneous** - Wires, Plugs, Fuse, Switch --- ## Step: Electrical Assembly - **needed tools:** screw driver - **needed materials:** - wires - conncectors: battery pole clamp, crimp-connector, solar connectors - fuse-holder - fuse - switch - **Electrical Layout:**  - **importan Informations** :::danger **WARNING** LIFE danger: DON'T conncet the plus and minus pole of the **Battery** ::: :::warning **WARNING** DON'T conncet the wires with **PV-MC4** connector yet as you can't disconnect after ::: ### Step: Wire components - connect together the electrical components using the electrical layout and following routing - **Connections:** - Bat(+) -> Fuse-Holder(no polarity) -> Switch(+), Switch(-) -> Solarcharger, Bat(+) - Bat(-) -> Solarcharger, Bat(-) - Plug-MC4(female) -> Solarcharger, PV(+) - Plug-MC4(male) -> Solarcharger, PV(-) - Plug-DC-Output(+) -> Solarcharger, Load(+) - Plug-DC-Output(-) -> Solarcharger, Load(-) - Optional: Parallel Connection of 2 Plug-DC-Output with clamp --- > [color=red] **FEEDBACK** > Which information is missing for you, please enter your feedback > - missing information X, if you want you can add your name so you are displayed as a contributer [name= example: Michel] > - missing information Y <details> <summary><b>Software Confifuration Steps </b></summary> ## Step: Software Configuration - **needed (digital) tools:** PC, ZephyrOS workspace, Visual Code Studio, Nucleo Board (ST-Link), - **needed materials:** - jumper wires (chargecontroller to nucleo board) - usb-cable type: USB 2.0 Mini-B - Reference: https://github.com/LibreSolar/charge-controller-firmware - Charge Controller Firmware Documentation: https://libre.solar/charge-controller-firmware/ The Firmware of the chargecontroller builds the brain to perform its functions. With beeing open-source you can adapt the functionality to every possible application possible with underlayer hardware. e.g. changing the charge algorithm to DC aligned wind-turbines or using the communication stack to integration data analyzing functions. The current software features are: - Running on [Zephyr RTOS](https://zephyrproject.org/) - one firmare for different chargecontroller hardware: STM32F0, STM32L0 and STM32G4 series MCUs - Different battery types supported (lead-acid, Li-ion, LiFePO4) - Maximum power point tracking (MPPT) algorithm based on Perturb and Observe (P&O) - PWM solar input (for certain hardware) - Load output with deep-discharge protection - Monitoring and configuration using the ThingSet protocol (mapping to MQTT, CoAP and HTTP possible) - Serial interface - CAN bus - OLED display support ### Step: Setup Up Digital Workspace - Reference: https://libre.solar/charge-controller-firmware/src/dev/workspace_setup.html ### Step: Connect Solarcharger with Nucleo Board (ST-Link) - connect the jumper wires - Reference: https://learn.libre.solar/development/flashing_debugging.html#programmer | Pin function | Nucleo board | Libre Solar board | |:----------------:|:--------------:|:-------------------:| | VCC | SWD pin 1 | SWD pin 1 | | SWCLK | SWD pin 2 | SWD pin 2 | | GND | SWD pin 3 | SWD pin 3 | | SWDIO | SWD pin 4 | SWD pin 4 | | NRST | SWD pin 5 | SWD pin 5 | | SWO (optional) | SWD pin 6 | SWD pin 6 | :::warning **INFO** Before you can flash the software, the device needs to be powered via the battery. The VCC from SWD does not provide power, it just detects the supply voltage of the target. ::: :::warning **INFO** consider the resistors of the nucleo board ::: ### Step: Costumization of Firmware - Reference: https://libre.solar/charge-controller-firmware/src/dev/customization.html# - Open the Terminal in VS Code, command: ```west build -t menucongif``` - changing battery type: we use a XXX - https://libre.solar/charge-controller-firmware/src/dev/customization.html#change-the-battery-type - You can look up the differnt battery types here: https://learn.libre.solar/system/battery.html#types-of-batteries -  - Zephyr also provides a more graphical user interface (GUI) with the command ```west build -t guicongif``` -  ### Step: Flash the Firmware - To flash the configured firmware use the command ```west flash``` - during flashing the Nucelo board is blinking </details> ## Step: Testing & Trouble Shooting --- Thank you! --- # How can we collaborate - Round Tables "Energiestammtisch" - Example Salem am Bodensee - Conrete Use-Cases - Gabelstabler/ Forklift -> connecting battery of mobile devices to grid, how can I connect the forklift with, - Knowledge about possible application - example: how can I charge devices with my exisiting PV Panels (800W), make it easy to use, simple, without all legal requirement, right now too complext - using recycled/ refurbished batteries, other RES components (Renewable Energy System) - connecting to orgas providing - who can give me qualitative feedback to usefullness - local "ambassador" for RES, having knowledge, sharing it, doing workshops - displaying/ mapping existing OSH projects, application, use-cases - feedback processes, how can we give feedback about our activities - consider the NOT technology part to integrate ALL people in the process - who is the target group? - how to communicate? - Funding of activities - VoW infrastructure: Co-Wiki, forming VoW group, matrix group # Open points - Name for VoW group - proposals - "Power to the people" (PTTP) - "New Energy at Home" - "Local Energy" + "Power to the People" - "Pirate Energy" - "Short Circuits" - "(Renewable) Power Platform" - "Fork Home Energy" - feedback to workshop - practical part: - different stations of actions would help: e.g. drilling, wiring, ... - having electrical layout would be nice , example: where to connect the battery - backround information would be helpful: what application possible, why 9V, ... - it was helpful to have experienced people in the groups to answers questions - it was very good that the design was simple, the thinkings of waterproof - general - was good that the practical was first and theory second - consider time, e.g. after lunch it was good to have practical part # Possible actities - workshops - developing - manufacturing - installation - maintenance