Wind turbines — how do they work and what should you know about them?

Wind turbines — how they work and what determines their efficiency

Wind is considered a particularly valuable energy resource. It is:

• Renewable — it forms naturally and will never be depleted,
• Clean — it does not generate environmental pollution,
• Socially acceptable — wind power plants are far less controversial than, for example, nuclear energy,
• Economically competitive — once built, the infrastructure requires minimal maintenance, allowing for a satisfactory profit margin at relatively low cost.

The use of wind energy is not an isolated trend. The International Energy Agency points out that it is gaining momentum worldwide. By 2050, wind power is expected to cover nearly 20% of global electricity demand. Countries that particularly promote the use of this technology include China, the United States, Germany, India, as well as Spain and the United Kingdom.

Wind energy in Poland — the current situation

So, what does the use of wind turbines look like in Poland? As it turns out, not bad at all. Installed capacity in onshore wind power increased by 15% in 2023 compared to the previous year. The total installed capacity has exceeded 10 GW, but according to the company Polskie Sieci Elektroenergetyczne S.A., this is only the beginning. By 2040, installed capacity is expected to reach 22.1 GW—or even 41.4 GW—depending on the direction of legislative changes (the figures correspond to minimum turbine spacing of 700 m and 500 m, respectively).

Currently, the highest production levels are in the Pomeranian, West Pomeranian, and Greater Poland provinces.

How do wind turbines work? — the process of generating energy from wind

To better appreciate the potential of wind turbines, it is worth understanding the principle behind their operation. In the simplest terms, wind turbines use a two-stage energy conversion process. First, the kinetic energy contained in the stream of wind sets the rotor blades in motion, thereby generating mechanical energy. This mechanical energy is then used to drive a generator, which produces electrical power.

Although this mechanism may seem straightforward, it comes in several technical variations, which can be broadly divided into three categories:

• Horizontal Axis Wind Turbines (HAWT)
• Vertical Axis Wind Turbines (VAWT)
• Bladeless Turbines

In each case, the working principle of the turbine differs slightly. Moreover, within the first two categories, multiple technological approaches are applied. For example, HAWTs are subdivided into single-blade, double-blade, and triple-blade rotors, turbines with diffusers, and turbines that utilize the Magnus effect.

The first solution is especially widespread in European Union countries. These systems are known for their high efficiency, but they also pose significant challenges: they can endanger birds, produce substantial noise, and require specialized mechanisms for blade orientation, operational shutdown in high wind conditions, and braking systems.

By contrast, vertical-axis turbines are the oldest type known to humanity. They feature a simple design and lower construction costs. They are also easy to assemble and disassemble, and can operate across a very wide wind speed range—from as little as 2 m/s up to nearly 60 m/s. However, they are generally less efficient than horizontal-axis turbines.

Small wind turbines for homes — is it worth the investment?

Wind power is not only a “large-scale” commercial solution. Increasingly, it is also being used as a supplementary source of electricity in single-family homes. These turbines are mounted on masts several meters high and can operate even at low wind speeds. Such installations typically consist of several components: the turbine mounted on the mast, a meter, cabling, and an optional battery.

In practice, small wind turbines are often used to heat water in a central heating system. The electricity they generate can also be fed directly into the household grid to power everyday appliances and devices, while any surplus can be exported to the public power grid. For this purpose, an inverter with an MPPT (Maximum Power Point Tracking) system is used, much like in photovoltaic installations.

Small wind turbines as an alternative energy source — where do they work best?

Small wind turbines can be an efficient source of electricity, but unfortunately, they are not effective in every setting. Their efficiency depends primarily on consistent wind flow and sufficient wind speed. If wind gusts occur only occasionally or are very weak, the rotor blades will not spin fast enough to power the generator.

In practice, this technology works best on open flat areas or elevated terrains. If a home is located in a valley, surrounded by forest, or dense urban development, other renewable energy sources, such as small-scale photovoltaic installations, are usually more effective. In the case of solar panels, efficiency depends mainly on how well the silicon panels are exposed to sunlight.

The amount of electricity a wind turbine produces also depends largely on its capacity:

• A 3 kW turbine can supply basic household appliances and lighting.
• A 5 kW turbine should fully meet the average energy needs of a single-family household.
• Turbines with a capacity of 10 kW or more are better suited for small businesses or higher energy demand.

Subsidies for home wind turbines — how to get financial support?

In June 2024, applications opened for subsidies for small-scale home wind power plants. The program, called “My Wind Power Plant”, allows individual users to receive up to 47,000 PLN in support for the purchase of a turbine along with an energy storage system.

The funding covers the years 2024–2029, with a total budget of 400 million PLN. The first application round runs from June 17, 2024, to June 16, 2025, with an allocation of 50 million PLN for this stage.

Wind power plants can be an attractive solution for businesses and households located in areas with favorable wind conditions. They are efficient, relatively inexpensive to install, and nearly maintenance-free.