The weather factor
Cheap, reliable, low-carbon energy has become the ultimate goal the world must strive to achieve, according to all sorts of government agencies, international organisations and perhaps hundreds of environmentalist groups. Yet as anyone who has ever worked with demanding clients knows, cheap, reliable and good (which is fast becoming a synonym for low-carbon) rarely go together.
As the joke goes in certain professional circles, a project can be done either cheaply or well. Reliability adds a whole new vector for things to go wrong if they can go wrong and they always can. And reliability, as has been stated time and again, is the biggest problem of renewable power in its wind and solar segments. Hydro can also occasionally become unreliable, when there is severe drought, but on the whole, hydropower delivers stable supply of electricity.
Criticism to the reliability of solar and wind farms has been dismissed as either the work of oil shills or something that would be solved perfectly easily with energy storage. While it is true that energy storage can help boost the reliability of power supply from solar and wind farms, just how much it can boost it remains an open question. For now, energy storage capacity available is limited to a few hours, meaning it would be good for the occasional accidental blackout. But what happens if the blackout lasts longer?
The reason most often given by renewable energy sceptics for their scepticism is that the sun doesn’t shine 24/7 and the wind doesn’t blow 24/7. Energy transition fans must be tired of hearing this truism. But that’s not all that’s problematic with wind and solar.
Two of the world’s largest offshore wind power developers, Denmark’s Ørsted and Germany RWE, recently reported weaker financial results for the first half of the year, blaming them not on the pandemic but on lower wind speeds. That’s right, the average wind speed during the first six months of the year was too low for Ørsted’s wind turbines, so electricity output fell by 4%. In all fairness, a 4% decline in output is not such a big deal… until it is when wind is one of two sources* of energy to rely on and demand is rising.
The problem was not just an offshore phenomenon, either, according to RWE. The German company reported lower average wind speeds for onshore wind farms in Northern and Central Europe as well. And if you follow electricityMap on a daily basis for a month, you might see some interesting swings in wind (and solar) output for any given country that has substantial capacity.
One of these interesting swings occurred three years ago in the UK. In July 2018, media reported how the UK’s wind power output had slumped by 40% percent due to a rare event known as wind drought, which means exactly what it says on the label. Luckily, according to the National Grid, demand was comfortably low so the problem was not dramatic. A little boost in gas generation made sure this demand was met. And the problem was forgotten.
That renewable energy is dependent on the weather is another of those truisms energy transitioners must be tired of hearing. It is understandable why: there is nothing anyone can do about the weather but follow it and make it work for them. Yet some advance planning might be in order when we’re talking about making weather-dependent energy sources the dominant ones for whole countries.
Energy storage is not a solution now — the world’s biggest battery can only supply half a million households with power for an hour and that was before it caught fire, still in construction. And it costs $84 million to built. Storage will likely continue to not be a solution in the future as well, as solar and wind capacity expands: besides money and the risk of a short circuit, battery storage also takes up a lot of space—the more storage, the more space. Added to the space already needed for solar farms and onshore wind turbines, the land issue begins to look increasingly serious and potentially costly.
The weather factor in renewable energy has been brushed aside for years even though it is central for this energy. Solar panels work because the sun shines and wind turbines work because the wind blows. What happens when either resource is unavailable for any length of time is not something headline makers like to dwell on.
Perhaps this is because currently wind and solar droughts are a non-issue. When it’s unusually cloudy or the wind is lower than necessary, there’s always natural gas to be switched on at a short notice. The weather factor will become an issue if plans to eliminate natural gas fro the energy mix materialise. It is also the reason these plans will probably never materialise.
The thing we all need to remember when it comes to energy and more specifically electricity is that supply reliability is crucial. It is even more crucial than emissions despite a flood of information arguing the opposite. The reason reliability trumps emissions is that most people would not welcome a blackout.
Blackouts are not a popular event anywhere where people have got used to regular electricity supply for generations. When this regular supply is disturbed people tend to get annoyed, some even angry. Since blackouts will be the topic of another article, I’ll drop the subject for now. Suffice to say, angry people are not every government’s dream.
The energy transition is based on a significant increase in demand for electricity. This demand for electricity is the foundation the whole transition plan sits on. And to satisfy this demand, we need a lot more generation capacity. Needless to say, for the proponents of the transition this capacity should only come from solar and wind farms. The risk of this capacity performing below targets for weather-related reasons no one can anticipate or avoid appears to be considered so small it is not worth discussing. However, if you are going to plug a whole continent into the grid, you’d better make sure this risk is not just small. You’d better mane sure it is non-existent.
*Hydrogen is not, strictly speaking, an energy source. Besides, green hydrogen involves reliance on wind and solar.