The Challenges

/The Challenges
The Challenges 2017-05-29T07:17:11+00:00
There is an increased awareness on the importance of the renewable energy sources to satisfy the energy and low carbon goals Europe is fostering, although the sector has to overcome these main barriers identified for the penetration of this technology in urban and peri-urban areas, where the exploitation potential and benefits for society are seen as the most promising ones.

Cost of technology

The future of the small and medium size wind industry depends mainly on the cost of the technology, the evolution of the fossil fuel prices and investor interest. The energy experts anticipate high growth rates for the production of Small Wind Turbines (SWTs) if the awareness rises and then the consumer demand increases. Nevertheless, cost remains to be the most influential factor for the deployment of SWTs.

In Europe, the installed cost of a SWT ranges from 2.100 to 7.400 € per kW and the electricity production cost between 0,15 to 0,30 € per kWh. Within this spot, competitiveness of the sector is linked to the possibility of reducing the technology costs and be in such parity with the energy trading, so that the SWT technology is attractive to the targeted market. This is something possible, as, for example in China, the trend is the opposite, where the cost of an installed device is one-third of the technology in Europe, being clearly competitive.


Wind resource assessment

Wind resource assessment stands a delicate drawback for SWT. Accurate prediction of the wind speed is essential to calculate the electricity output of a wind turbine, representing the basis for economic performance. Wind evaluation currently presents challenges for the small wind industry due to the expensive wind measurement tools in urban environments.

The shading and turbulence effect of surrounding obstacles produces inconsistent and unpredictable wind patterns below 30 m. As a result, the vast demand for inexpensive and efficient methods of predicting and collecting local wind data is another key driving factor that requires further innovation and cost reduction in the technology.


At the end of 2009, a cumulative total of 521.102 SWTs were installed worldwide, over 60.000 of which were newly installed that year with a sales revenue of over 160 M€ worldwide. Until the end of 2010, the world total cumulative installed of such systems reached 656.084 units, meaning a 26% growth from 2009 and generating approximately a total of over 382 GWh in annual energy production in the world, reaching a total installed capacity of 443,3 MW.

Despite the described demand of SWTs observed in developed countries, the market remains fragile. In addition, as mentioned before, the main application of these systems is not in the urban and peri-urban areas, where the maximum potential for the technology is. Currently, the fully competitive wind markets are rather found in the developing countries, where off-grid and micro-grid applications prevail.

The sector is at the mercy of the regulation, as it is completely dependent of it. In this sense there is a light hint at the front, as European directives and the transpositions in the EU Member States are opening the path for the implementation of these systems in urban and peri-urban areas, opening the door to auto-consumption in households and other applications, such as the integration in districts. The steps that Europe is making in favour of this energy concept mean a definitive opportunity for the SWTs

Social acceptance and safety

Wind energy, being a clean and renewable energy source in a global context of increasing social concerns about climate change and the energy supply, is traditionally linked to very strong and stable levels of support. Several studies suggest that over 80% of the population is favourable to big wind farms providing clean energy to the electrical grid. Although the scenario is established this way for big wind energy generation installations, there is a lack of experience in the massive deployment of small wind turbines at urban and peri-urban areas. Nevertheless, everybody agree that it is necessary to have social acceptance for the successful development of wind projects. Although social perception is, a priori, in favour of these kinds of systems, there is a need to ensure this at urban level, as well as guaranteeing the health and safety issues around the technology and quality of life. These two topics should be at the core of the future developments, as are the points that may jeopardize the public awareness, and therefore the success of the technology.

Aesthetic, noise and vibration

Small wind turbines are favoured renewable and sustainable energy. In many countries, noise radiation is considered as the major limitation in the development of wind energy over the last years. Therefore, noise emission is one of the major concerns in wind turbine industry, especially SWTs one, which are mostly erected into the urban areas. Tonal noise emitted from the wind turbine installations, such as gearboxes or electrical power transmission parts, poses a serious environmental problem to the surrounding community, which is still a crucial point concerning the acceptance of WTs.

Tonality is a feature that may increase the adverse impact of a given noise source, and its evaluation is of high importance. Vibration is another factor to address within SWTs, due to the impact they may have depending on the location where the device is installed. The primary vibration excitation mechanism is resonance of the dominant whirling mode of the turbine, with the operating blade pass frequency. In addition, resonance of the airfoil support struts at higher frequencies too. Vibration transmitted to the anchorage of the WT might be dangerous depending on the supporting infrastructure.

Finally, aesthetic issues are key enablers for the social acceptance of these systems. Current society perceives beauty as a driver for the installation of anything in their close environment. Therefore, as social acceptance is key, aesthetics must be carefully treated.

Wind market / user friendliness

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The wind energy market has benefited from the traditional global trend of feed-in tariff (FITs). This scheme has fostered the technology development and integration of high energy generation rates in the system, being the main beneficiaries the wind farms that have been erected throughout Europe and worldwide. The FITs scheme in the small wind turbines sector has been absent and it is not envisaged in many countries, being the challenge to achieve competitiveness with current energy prices without external incentives. This barrier is closely related with the cost of technology, being the main aim of the SWIP project to achieve a product that is cost competitive in the market.

A market forecast from World Wind Energy Association states that in the long term, the global small wind industry might even slowly evolve from a policy-driven model to one that is based on the productivity and affordability of the turbine itself, in which SWIP is focused. Recent trend of the small wind industry has shown an aggressive annual 35 % increase in the global installed capacity for the past years. The rate of growth is anticipated to continue until 2015, reaching an annual installation of 288 MW of SWTs. Based on a conservative assumption, the market could subsequently see a steady compound growth rate of 20 % from 2015 to 2020. The casual practice of the industry describes small wind turbines as those ones with rated capacities from 6 watt to 100 kW. These figures could seem too small, but taking into account that a European household demands only a 4 kW turbine to cover its consumption in a whole year, the scenario turns promising.

Moreover, proximity of society to information and communication technologies, mainly given by the wide use of smartphones, tablets and web support, needs to be exploited and taken as an advantage for the integration of new systems into society and their day-to-day life. Small and medium size wind turbines market must take advantage of this situation in order to bring nearer the consumer, the benefits the renewable energy sources have as well as enabling an easier understanding and use of the systems.
As shown before, there is a challenging approach for the future deployment of small and medium size wind turbines in urban and peri-urban areas, being the main conditions the successful assessment and associated developments to overcome the barriers previously exposed. There is a close relationship between all the barriers that currently slow down the market uptake of the technology, and there is a need to tackle them from a holistic perspective, which this project offers. SWIP project is built upon a high experienced consortium that aims to address and get over these barriers.