Low power home DC electrical system - 5th iteration

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The problem

Nowadays, Installing solar photovoltaic panels on big city buildings is limited to the roof area of the building. This means little power generation capabilities for energy savings when considering each individual apartment.

The idea

The idea of this "Smart Home Solar Power Management" Project is to develop simple components and accessories that enable easy, "for dummies" kind of installation of solar photovoltaic cells. For that to happen is required installation of additional wiring in the apartment electrical network. Staring with a 5V DC wire, suitable for most small home appliances such as vacuum cleaners, smartphones, tablets, and any other smart device or technology. And another with 12V DC suited for computers, gaming consoles, and OLED TV displays. This can be achieved by installing "power delivery" technologies, common in USB-C power solutions.

Energy storage methodology follows a decentralized architecture of installation, where each individual room or compartment has its own "independent" battery storage upwards 40.000mAh. All connected to a Smart Home device I made available on my Github.

The solar panels can be assembled in a Lego-style kind of way. Due to the reduced size of the photovoltaic solar cells, can be assembled into any shape or area. For instance glass door windows and doors. For instance in a terrasse or a terrasse exterior wall regardless of floor area shape.

The Power Wall

On the 4th iteration of the power wall, all 20,000mA power banks, with quick charge, have arrived from AliExpress, and the hardware electronics on my test Power Wall was simplified to the maximum and has now a storage capacity of 60A. See my previous article about the 4th iteration of this project below:

https://www.hackster.io/mtpsilva/ultra-low-power-home-dc-electrical-system-4th-iteration-d8294a

In this 5th iteration for this project I'll be CNC machining a piece of wood made to fit my existing balcony window wood frame, where i will assemble solar cells into four solar arrays, each for a maximum output of 5V 5.2A DC (see photo below). I will also be conceptualizing, designing, and fabricating a small lithium battery power wall that will serve as a power buffer between the solar energy harvested and the main "power delivery" DC line (see photo below).
This iteration , is not a project suitable "for dummies" as it requires machinery and intensive labor work to fabricate a solar panel made to fit a balcony window. That said, this fabrication step, can be easily replaced with existing and commercial solar panels selling on the internet. The only downside is, won't look as good as this one when finished.

Fabrication and assembly of the solar array

To allow assembly of individual solar cells, i used my CNC machine to drill and carve into the piece of wood the solar cell conductive tracks. Next i added a strong glue to the CNC'd surface where i placed all individual solar cells to form a photovoltaic solar array composed of 10 individual cells each. A total of 4 solar arrays were assembled and corrected in parallel for a maximum solar power output of 5V DC and 5,2A.

Installation on my balcony window

After all cut and drilled, the solar panel fabricated can be installed directly into the balcony window, without requiring any modifications of change to the existing window wood frame (see photos below).

For now, this will be a temporary installation, so i can remove it during the prototyping phases, every time i need to make some change. When is all done and completed, It will need to be painted to match the existing wood color on the balcony window frame and to be properly fixed to the window frame, using for instance, a silicone glue with a color to match the existing brown color.

Designing the Power Wall Buffer

Conceptualization of the "Power Wall Buffer" was made using two 17.38 W.h lithium batteries i have from an old Macbook laptop. added the usual battery protection circuitry where i connected a DC to DC boost converter and also a MPPT solar battery charger. The very first PCB prototype for a Power Wall Buffer already installed into the wall can be seen on the photo below.

The main function of this power wall buffer is to enable energy harvesting for solar outputs as low as 2V DC, store it on the local lithium batteries and output a stable DC power to my main "power delivery" DC line. In practical terms, this means my solar panel is able to produce energy on a rainy day, and it rains quite a lot of time here, where i live, in Belgium. Another important functionality that is going to be added is in the ability to act as a sensor to detect energy radiation the solar panel is absorbing during the day and during the night, every time someone passing by decides to target the window with some kind of radiation. For instance using an array of laser diodes. For instance using an array of LED didoes, in particular the ones operating in the invisible light spectrum.
More about this soon.
In the meantime the reader can visit my "mental health" GitHub repository below:

github.com/aeonSolutions/PCB-Prototyping-Catalogue/tree/main/Home%a20Automation%20Safety%20%26%20Health

a repository where I have smart devices able to detect, for instance, electromagnetic radiation targeting a bedroom window.

Conclusions

This solar panel assembly is not intended to produce a lot of energy. Is intended to produce what is possible to produce and add it to the distributed power DC power line, so it can be stored on any of the distributed power walls installed on any room or compartment. Another key functionality of this solar panel is on the ability to act as a sensor to detect the energy radiation the solar panel is absorbing during the day and during the night, every time someone passing by decided to target the window with some kind of radiation this solar panel is able to absorb.

Visit the GitHub repository for this project below: https://github.com/aeonSolutions/AeonLabs-Distributed-Power-Solutions-Smart-Distributed-DC-Power-Management

Next Iteration of this Project
In the Next Iteration of this project I'll be designing and prototyping in KiCad a Smart Distributed DC Power Management and Charging Device that has the purpose to charge 5V DC battery walls and power packs from the main 220V AC line at home. The innovation of this power charging device is in the ability to schedule charging to specific times during the day and night according to the price of electricity change. It can be programmed using machine learning to connect to a electricity market data source and calculate the best time to schedule battery charging according to the price variations on the electricity markets. Link to the 6th iteration of this project:
https://www.hackster.io/mtpsilva/smart-distributed-dc-power-management-5v-dc-30w-fe61b1

#openInnovation #DIY

one final note about the author

The PCB Design Files I provide on GitHub for anyone to use are free. If you like this Smart Device or use it, please consider buying me a cup of coffee, a slice of pizza or a book to help me study, eat and think to work on new PCB design files.

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