Why isn't it possible to generate all of our energy from wind power?

One question that frequently arises from those beginning to explore environmental issues is why we can't generate all the electricity we need from wind. At first glance, it may seem like an obvious solution: we're already generating clean power with wind turbines, so why not just increase their numbers until we have enough energy to replace the dirty power plants?

Unfortunately, the situation is more complicated than it seems. To answer this, we must first gain a better understanding of how wind power functions and how a power grid operates. Let's dig into it, shall we?

How Does Wind Power Function?

So far so good, but here’s the real obstacle: Wind is unreliable. Sometimes it blows, other times it doesn’t, and predicting its behavior beyond a few hours is difficult. As a result, wind farms (clusters of turbines) typically have two power metrics: one for capacity, and another for capacity factor.

For example, a wind farm may have 200 turbines, each rated at 1.5 megawatts. This gives the farm a total capacity of 300 megawatts (200 x 1.5). However, how much electricity it actually produces depends on various factors. If you average the power output of all turbines over a year and divide that by the total maximum capacity, you arrive at the capacity factor.

For instance, if the above wind farm operates at 30% capacity, it would generate an average of 100 megawatts continuously. But this doesn’t mean 100 megawatts are guaranteed—on some days, it could be 300, and on others, it might only be 30. This issue not only requires more turbines than the capacity figures might suggest (since media usually highlights capacity, not capacity factors), but there's another challenge we'll cover next.

How Does the Power Grid Operate?

"Electricity generation and consumption must be balanced across the entire grid, because energy is consumed almost immediately after it is produced. A large failure in one part of the grid - unless quickly compensated for - can cause current to re-route itself to flow from the remaining generators to consumers over transmission lines of insufficient capacity, causing further failures. One downside to a widely connected grid is thus the possibility of cascading failure and widespread power outage." (source)

This means that if the wind stops blowing and a wind farm stops producing electricity, some other source of electricity has to pick up the slack.

This problem can be mitigated if you have lots of wind farms spread over a large geographical area, so that when the wind doesn't blow somewhere, chances are that it blows somewhere else. This helps, but doesn't completely solve the problem. Remember that the grid has to balance supply and demand at all times, so if bad luck has it that there's no or little wind over most of your wind farms on the same day, you still have a problem. So what should we do?

What's the Future of Wind Power?

But what can we do to help increase the quantity of clean, renewable energy being produce by the wind everywhere?

The first step is to enhance transmission. Many regions have an excess of wind energy but can't sell it to other areas that would be eager to buy it due to lack of interconnection. There are also places where new wind farms could be established, but they aren't because there are no transmission lines. A more efficient distribution system would allow us to balance deficits in one area by tapping into surpluses in another.

Another solution for allowing the power grid to accommodate more wind energy is to shape demand, which means influencing how much electricity consumers and industries use. This can be done with smart grid technology, such as smart meters that adjust electricity pricing in real-time (when prices go up, demand goes down, and when prices go down, demand increases), and by coordinating with energy-intensive industries to schedule operations in ways that optimize available power.

The third approach is increasing storage capacity. At the moment, most energy must be used immediately as it's produced, with only a small portion stored for later use (like in hydropower reservoirs). If we could store more energy, we could tap into those reserves when wind power isn’t available. The main challenge is making storage affordable, which might require breakthroughs in battery or supercapacitor technology.

Lastly, the most feasible solution appears to be diversification. While wind power is the least expensive form of renewable energy at present, it should be combined with other sources to better address the intermittency issue. Solar power (both photovoltaic and thermal), deep geothermal, wave power, hydro power (when managed properly), biomass, and more—all of these are necessary, along with a significant push for energy efficiency and conservation (it’s usually cheaper to save a watt than to produce a new one).