Follow our illustrated blog on Embedded Software Architecture

How to build a hybrid solar/wind energy harvester?

Webshop opening

VN:F [1.9.22_1171]
Rating: 10.0/10 (1 vote cast)

Sales promotion in Our webshop!

1. The square meter 2 blade H-rotor

H-rotor in our webshop!



  • 12V generator
  • 2 wing hub
  • 2 darrieus blades

We recommend the 2 wing economical H-rotor, and although in theory this is not 100% self-starting – as can be proven in a wind tunnel – it always starts on all the real sites we tested. The construction manual can be found here.

Specs, Power yield:

Wind speed at rotor height

Yield towards 12V battery bank

4 m/s

5 W

5 m/s

12 W

6 m/s

17 W

7 m/s

25 W

8 m/s

32 W

10 m/s

50 W

12 m/s

70 W

15 m/s

110 W

(very conservative estimated yield depending on good wind conditions and air flow quality)

Combined with our custom-made 12V generator, the turbine is designed to reach battery charging voltage at about 120 to 150 rpm which is reached at a wind speed of around 4m/s.

2. Darrieus blade kit

Kit for 1 meter height, including arm support for 1 meter diameter blade. You need to assemble the blade yourself (easy assembly).

Weight: 4 kilo each, the blade includes the support arm!

3. Three blade hub

A hub for 3 blades; the center hole of the hub fits a 20mm axle.

4. Two blade hub

A hub for 2 blades; the center hole of the hub fits a 20mm axle.

Inquiries and orders

Check Our webshop

Or please contact us by email:

Or use the form in our contact page.

VN:F [1.9.22_1171]
Rating: 10.0/10 (1 vote cast)

Green4 power controller: remote control with Raspberry Pi

As long as real-time control and fail-safe operation is not a strict requirement, the GUI or another PC application could be used to control the Green4 via our rs232 serial protocol. The target software simply executes what is being demanded by the … [Continue reading]

The embedded hierarchy – Part3

Linux-based software platforms Linux kernel In this section the Linux kernel part of an embedded software platform is discussed. Compiler While FreeRTOS (see Part2) has support for several compilers, the Linux kernel community has chosen GCC. … [Continue reading]

Responsive software design without threads — Part 1

responsive event-based I/O design

We need a GUI thread. a common developer's reaction when the application only responds slowly to user clicks. The developer might be right: when some (gui) events require a lot of processing then having more than one thread, e.g. a GUI thread … [Continue reading]

Green4 serial test protocol and GUI

Introduction For most embedded projects it is good practice to have basic tooling for testing I/Os. I/O primitives such as 'read gpio', 'set pwm duty cycle', 'read adc', not only allow engineers to verify hardware and software drivers, it might also … [Continue reading]

The red-black tree and hash table

red-black tree The even more advanced container we look at now is the red-black tree, which is a type of self-balancing binary search tree. Especially, interesting is the time complexity in big O notation: Action/Subject       Average          … [Continue reading]

3D printing of enclosures

Having the correct and proper enclosures, is a mechanical (and also a marketing) problem many electronics projects suffer from. It is also related to anticipated sales numbers. For big numbers, a custom enclosure which is produced with an injection … [Continue reading]

Vector, list and tree

Choice of containers Information technology, even embedded devices, is about information gathering, processing or calculation, and control. Input and data needs to be juggled around and maybe sorted. In this article, we want to point out some … [Continue reading]

Priority inversion

I found the inspiration for this article while working on a consultancy job: Priority inversion. In computer science, priority inversion is a (potential) problematic scenario in scheduling in which a high priority task is indirectly preempted by a … [Continue reading]

Progress update

Time for another update. The Green4 project is progressing steadily. In the last few months, we have been busy preparing the Green4 prototypes. Test software has been developed which is already very usable, but it is still in a state of flux as we … [Continue reading]