Wind is one of the oldest sources of technologically usable energy, from its traditional role powering aquatic vehicles — application in which it was unsurpassed for thousands of years — to the first mechanical devices in widespread use not powered by a biological source. But there is more than historical interest in wind as a source of energy. As all energy sources except nuclear ones, it’s ultimately a form of solar energy, but it’s one in which energy is collected at a geographical scale. It is eminently renewable and clean, and based on robust and well understood engineering principles, all very important characteristics in a world that is undeniably, beyond a temporary respite because of the global economic crisis, facing both finite reserves of fossil fuels and the high cost of their environmental side effects. Yet predictions from the International Energy Agency indicate that wind power, under current circumstances, will not grow to cover more than 2% of the global energy demand by 2030. A recent working paper from the World Bank explores the reasons behind this.
It is not a matter of its potential as an energy source. According to studies mentioned in the working paper, even exploiting a 20% of the potential wind power available in the planet would be enough to satisfy the entirety of our energy needs at the present. On the other hand, this is an staggering statistic: despite the unevenness of the economic development of mankind, implying that large populations have access to much less energy than others, our usage of energy is still in a certain way planetary in scale. A more realistic scenario than the exhaustive exploitation of the wind resources of the planet would see wind power supplying up to a third of the global energy needs by 2050, playing a key role in the world economy.
There are, however, economic and engineering problems that still delay the widespread use of wind power, accounting for its current relative unimportance as an energy source. One of them is cost. Wind power can, depending on the zone, be much cheaper than nuclear or solar power, but issues of energy distribution make this advantage only applicable to those areas. And it is still, even at last year’s peak prices, more expensive than forms of electricity generation based on fossil fuels (although this is only so because so far the very economically concrete environmental costs of burning fossil fuels haven’t been incorporated into their price, one of the market characteristics responsible for the climate change crisis).
Wind power is also more capital intensive than other forms of energy generation, requiring large capital expenses in both turbines and the electricity grid. Compounding this problem, the energy output of a wind farm is fairly uneven, depending on variable atmospheric conditions, particularly wind speed, that are impossible to control or predict accurately. As investments, then, wind farms are both relatively large and uncertain, making them more difficult to finance by the private sector.
Beyond these economic issues, the biggest engineering problem is perhaps that of the irregularity, sometimes minute to minute, in the output of a wind farm. It is an usually ignored fact that our technology is much better at generating energy than at storing it — something that is readily seen in the relatively slow pace of progress in the batteries of consumer electronics, despite the sustained improvement in their energy efficiency — and that we presently lack any way to store electric power in a large scale. So the variable output of wind farms, when plugged into the overall grid, induces significant engineering costs related to the smoothing of that input in order to make the total available energy reliable (also an important factor in the large-scale deployment of solar energy). Simply stated, there is still no workable universal solution to this problem, although it is also true that the global energy grid is far less capable and flexible than it could be, even with current technology .
Overall, wind power has the potential to become a key part of the world’s sustainable energy portfolio, but, at least under the current economic conditions, or even those prevalent in 2007, its financial and engineering characteristics won’t make the transition automatic at the global scale. It is certain that wind power will continue to expand, specially in zones where it makes the most sense from a geographical and economic sense, but its large scale application will require substantial infrastructural and financial investments.