Absence of wind and presence of frost on the blades, snow which covers the solar panels for several days: periods of extreme cold are not ideal for the exploitation of renewable energy sources. And our witness is right: we do not talk about it, or little. It was therefore time to give the floor to the usual experts.
The stakes linked to energy, whether in terms of consumption (heating, travel, manufacturing, etc.) or production (end of nuclear power, efficiency of renewable energies, etc.), are enormous. We are in a paradoxical situation: as it develops, the world has growing energy needs (think of the billions of people in China and India whose lifestyles have changed significantly in recent decades) but, at the same time, there is a awareness of the need to reduce our “carbon footprint” (to put it simply: the pollution generated by our way of life).
In the middle of all this, there are the citizens, you and us, inundated by militant slogans, by shock statements, by sometimes contradictory opinions, in particular with regard to the production of electricity. And then there is Josiane, who would like to “complete and real information“, and who reproaches us, rightly, for talking about it only in one direction.
“You are always very quick to announce the performance of the wind turbines on a windy day and to relay the information transmitted by Ecolo or the promoters. To give (to your audience) complete and relevant information, you should also communicate this: wind and solar produce zero when it is very cold, while citizens and businesses use a lot of electricity! We don’t talk about it … “, she wrote to us via the orange button Alert us.
Do snow and cold really have an impact on the production of renewable energies such as wind and photovoltaics? We’re going to talk about it.
Reminder: where does electricity come from in Belgium?
Renewable energies have been developing, in Belgium as elsewhere in the world, for many years. But their output is not yet sufficient to cover all needs.
In 2019, in Belgium, renewable energy represented 22,7% of the total electricity produced in our country. In details:
Biomass (recovery of biodegradable waste) 4.4%
Photovoltaic panels 4.2%
Waste burned 2.6%
We therefore remain very dependent on nuclear power plants (46,6%) and gas (27,5%).
The figures vary from one period to another of the year (sunshine, wind, etc.), and depending on the availability of nuclear reactors (there are 7 in Belgium, spread over 2 plants, and some must be shut down for maintenance, work, etc.). Example: in august 2020, 3 reactors were shut down and 2 were operating at half power. Therefore, what is called the “energy mix” was as follows:
- 42.5% fossil fuel and other (mainly gas)
- 35.5% nuclear energy
- 9.5% wind power
- 8.5% solar energy
- 4% other renewable energies
Overall, Belgium is currently self-sufficient. That is to say, it does not need to ask for electricity from its European neighbors to cover its own needs. At the same time, it can give it from time to time, that is to say ‘export’, especially when its 7 reactors are operating at full capacity, as is currently the case.
What happens during a great cold?
CONSUMPTION> When it is very cold, as is the case this week, it is above all on the consumption side that all eyes are on. “Households consume more electricity“, explains Jean Blavier, spokesperson for Elia, the manager of the electricity transmission network in Belgium. Even if gas and diesel boilers are popular in Belgium, there are increased needs in electricity because there is electric radiators, electric water heaters, and more and more heat pumps. “The consumption peaks amount to 13 GW (gigawatts) during the day, whereas it is rather 12 GW in normal winter period. The increase is estimated at around 6% “ during a period of extreme cold as we know it, with temperatures going down to -10 degrees during the day.
Less wind therefore less wind
PRODUCTION > At the level of electricity production, there are also changes. Starting with wind power. “There is generally a phenomenon of icing, therefore of ice which is put on the blades of wind turbines, which causes a decrease in their production if there is wind. In addition, the cold wave that we are currently experiencing is accompanied by another climatic phenomenon: there is very little wind. There is hardly any wind in February“, explains Damien Ernst, professor at the University of Liège, specialist in questions of production and management of electricity.
A phenomenon oficing put into perspective by Johanna d’Hernoncourt, expert in wind energy issues within APERe, the Association for the Promotion of Renewable Energies. “The production of the wind farm depends mainly on the wind. Indeed, in this period of great cold, there is not so much wind, but that is not specific to the winter character, there are other periods during which there is less wind.“, she explains.
“Afterwards, there are indeed phenomena of frost and ice on the blades. When there is humidity in the air and it is very cold, there may be condensation on the blades, and the formation of ice blocks. These blocks can break off, for example with a ray of sunlight, and if the wind turbine is spinning, they can be thrown a certain distance depending on the speed of rotation. possibly cause damage if there is infrastructure at the foot of the wind turbine, or people who can walk underneath. Depending on the risk that was previously identified during the building permit, the study of environmental impact mentions certain rules to be followed.It may be required to install a de-icing system on the blades: the machine detects overweight, stops and a little heating will melt the block, which will fall to the ground and not will not be projected. This is essentially the case for wind turbines in zonings industrial “.
But the impact on electricity production “is completely negligible, there is no impact because precisely, during periods of extreme cold, there is in any case little or no wind, so the loss of production is not visible , given that even without frost, the wind turbine would still not have produced electricity“.
Solar panels: 3 reasons for lower productivity in winter
Regarding solar panels, the snow covering them theoretically prevents them from generating electricity. But the situation is not as simple as it seems. Even without snow, solar shows a very low average yield in winter. There are three reasons for this: “Shorter days, an often cloudy sky (so on the contrary, a beautiful winter day can produce electricity), and the inclination of the sun on the panels“, states Alexis Vander Putten, who heads Energreen, one of the leaders in photovoltaic installations in Wallonia and Brussels.
The cold has no influence on the decrease in the production of solar panels
However, “the cold has no influence on the decrease in production, on the contrary, when the panels are too hot, there may even be yield losses“because they are getting to safety.”In addition, the snow, if it does not cling to the panels, will even improve their efficiency because the sun will reflect on them.“, thus producing more ‘light’.
On the other hand, and it is logical, if the snow covers the panels, “this affects production significantly (there is a drop in voltage). The inverters may also display warning messages: waiting for DC conditions, which means that the voltage for starting the inverter has not yet been reached“With the amount of snow that fell his last days overnight,”it is clear that the panels are covered with snow and therefore that production is generally at a standstill“, admits our interlocutor.
It is in these moments that we realize the importance of having a diversified energy park.
On February 10, gas and nuclear provided 92% of electricity
The production of renewable energy from wind turbines and photovoltaic panels is affected by a period of snow and extreme cold.
In normal times, nuclear and gas represent around 75% of the electricity produced in Belgium (which poses a lot of questions when political leaders announce, every 5 years, that the nuclear phase-out will take place in 5 years …) . During the period of extreme cold and snow last week, dependence on ‘old’ energies increased: according to figures available on the Elia site, in the middle of the day on February 10, 53% of the electricity produced in Belgium came from nuclear power and 39% from gas, i.e. … 92% in total. Wind power shows a sad 5.3%, while solar was included in the figure ‘other’ which tops out at… 1.5%. “It is in these moments that we realize the importance of having a diversified energy park, with currently our 7 nuclear reactors operating at full capacity.“, explains the spokesperson for Engie, a historical electricity supplier in Belgium, which operates the country’s two power stations, in Doel and Tihange.
Convinced private players will invest massively, especially in offshore wind power
And when there will be no more nuclear?
However, the Ecolo party remains positive on the nuclear phase-out planned for 2025. “In 2020, renewable energies had a boom: they increased their production by 31%. Over the full year, they represented 18.6% of the electricity mix“, explained Samuel Cogalty, federal deputy. According to him,”the share of nuclear power is reduced from year to year, its availability is not constant and as we cannot easily shut down a reactor, sometimes we have to shut down the wind turbines and solar power because there are too many electricity produced, which is absurd“. Since then, “phasing out nuclear power in 2025 is obvious, especially since, regardless of the very heated political debate, the majority of reactors are at the end of their life and Engie has planned to stop their operation“.
And to make up for this deficit? “Private players are already convinced and will invest heavily, especially in offshore wind (therefore in the ‘Belgian’ North Sea), while interconnections will multiply in Europe. Belgium has just signed an agreement with Denmark, and will run an undersea cable to share the electricity of the two countries if needed“, concludes the Ecolo deputy, who admits however that the increase in the use of gas will be necessary at first.