Any fan of westerns will have the image etched into their memory: a farmhouse dominated by a solitary windmill, creaking ominously as a harbinger of approaching outlaws. Such solutions were used long before electricity became widespread, mainly to pump water from wells as a primitive form of self-supply. Today, some contemporary farms — now safe from bandits — incorporate modern mini-generators capable of covering part of their renewable energy needs. Now attention is turning to urban settings, with a new generation of home wind turbines that are more compact, quieter and more efficient. One German company’s design has just achieved a pioneering certification that could start putting this technology on the map.

Before examining the latest advances in this field, it is worth briefly reviewing the different options available in the residential wind energy sector, also known as small-scale or micro wind. These systems do not replace other energy sources such as photovoltaics, but complement them thanks to their ability to generate power at night or in periods of low sunlight.

While the market continues to evolve, several families of wind turbines account for most home and small building solutions currently available. Each type responds to different needs in terms of space, local wind conditions and architectural integration. Unlike conventional wind power, which has traditionally favoured ever-larger turbines, this segment prioritises smaller sizes and discreet design. Three main approaches are in use. 

1. Horizontal-axis wind turbines (HAWTs) are the most traditional models, visually akin to large windmills. They tend to offer higher performance in areas with relatively steady, unobstructed winds, which is why they are usually mounted on masts or towers.
2. Vertical-axis wind turbines (VAWTs) emerged as an alternative for urban environments or areas with frequent turbulence. Unlike horizontal models, they do not need to be oriented to face the wind and can be integrated into rooftops or building structures. Their peak efficiency tends to be lower than that of HAWTs, but they can be attractive where winds are variable and space is limited.
3. An emerging category is bladeless turbines, which use vibration, oscillation or novel aerodynamic capture rather than a conventional rotor as discussed in this article. Although their performance is still undergoing commercial validation, these designs exemplify efforts to find quieter, more compact solutions for self-generation.

Although this model was first introduced in 2009, it has only now secured certification from the ICC Small Wind Certification Council (SWCC) following two years of tests for durability, power output and safety carried out in Utah. Certification provides independent verification of performance and gives consumers confidence in reliability. Each unit currently retails at just under €3,000.

Progress is also being made on efficiency. Researchers at the Fraunhofer Institute for Applied Polymer Research, in collaboration with an engineering firm, have developed a high-efficiency small turbine that can begin generating power in winds as low as 2.7 m/s, lower than typical thresholds for similar devices. In tests with winds of 10 m/s, prototypes have reached around 450 revolutions per minute and output about 2.5 kW.

The key to this design is a hollow rotor manufactured via 3D printing, which produces a lightweight, flexible structure that can harness gentle breezes while adapting to strong gusts without damage. Unlike the NG turbine, this concept is still in the research phase.

Home wind turbines are still far from becoming a mainstream self-generation solution, but recent advances offer grounds for optimism. What is clear is that the future of renewable energy lies in the multiplication and diversification of sources—from large-scale wave energy plants to the smallest triboelectric devices—without forgetting its two fundamental pillars: wind and solar power.

Source:

• Fraunhofer Institute
• New Atlas