In search of “only” 1414 MW (if non-dispatchable power sources are dispatchable)

Last Thursday, a Flemish newspaper brought the story that “the lights will go out in 2020”. We heard that many times before in the past. This time the statement was made by Andries Gryffroy, who was called the “energy expert” of N-VA (Flemish political party on the center right). He rightfully questioned the “energy plan” of current Flemish Minister of Energy, which is solely based on extra solar and wind energy. Even with those extra windmills and solar panels, we will not be able to produce enough energy to meet our demand in a few years and could face power shortages by 2020. More, several old conventional plants will need to be decommissioned in the next years and the new solar panels and wind mills need backup. He gave the example that in winter only 3% of nameplate power of solar energy is produced, while we use most energy in winter.

Okay, I dig that. Solar and wind provide less energy in the winter when we need most energy. Just adding more intermittent energy sources without backup and additionally decommissioning older conventional power plants, makes a good recipe for energy shortages. Especially in winter at peak demand. Especially with our aging power plants. Our politicians are talking about energy security for years now, but in the end go for extra windmills and solar panels. Probably to meet the EU goals.

Although I agree with what was being said, there were some things that seemed rather odd. For example, it was calculated that in winter we will have a shortage of 1,414 MWh and explained that this is the equivalent of 1.5 Belgian nuclear power plants. Which doesn’t make much sense. 1,414 MWh is the electricity that 1.5 nuclear power plants will produce in one hour. My guess was he was confused between “megawatt” (power) and “megawatt hours” (energy). Or was it the journalist that brought in the confusion?

Also the calculated number was puzzling. At first glance, it seems rather unrealistic. Apparently, we would be able to decommission older gas power plants PLUS arrange backup for a doubling of our capacity of intermittent energy sources, yet only need 1.5 conventional power plant to compensate for all that!?

Luckily, the paper version of the news paper mentioned how the calculation was actually done:

In search of 1,414 MW
Energy production Capacity in winter (MW) Capacity in summer (MW)
Nuclear power plants 6,000 4,000
Other thermal plants (in 2018) 3,500 3,500
On-shore wind energy (in 2020) 600 400
Off-shore wind energy (in 2020) 1,016 710
Solar energy (in 2020) 180 1,440
Small bio gas plants and trash incinerators 1,140 1,140
Biomass plant in Langerlo or alternative 400 400
TOTAL CAPACITY 12,836 11,590
REQUIRED 14,250 12,000
SHORTAGE 1,414 410

The calculation was done in MW this time and then the statement “equivalent of” made sense.

The 180 MW probably comes from 3% of the estimates for 2020. In that case it is calculated on an estimate of 6,000 MW, which seems rather steep. We are now almost at 3,000 MW, so in that case we need to double in 3.5 years to reach that level.

The 1,016 and 600 MW for wind are probably done in a similar way. According to wind scenarios of EWEA, the highest target is 3,250 MW onshore and 1,800 MW offshore. Meaning 18% and 56% of nameplate capacity (which seems rather high to me or he starts from an even higher estimate for 2020).

I did recognize that 14,250 MW number. It is the maximum capacity that is needed to be able to provide enough electricity in a harsh winter. As also seen in the table, this required capacity is higher in winter than in summer. In winter days are shorter, it is colder, we stay more in-doors, we are less likely on vacation and so on. But this maximum is not needed over the complete day, there are two peak moments:

belgium total load 2016-01-19

There is a peak in the morning, roughly from 7 until 9 am and another peak in the evening, roughly from 5 until 8 pm. The morning peak is due to people getting up from bed, switching on the lights, the coffee machine, the toaster, then public transportation (trains, metro,…) drawing power from the power grid to get people to work, machines in the factory get switched on, and so on.

The higher and wider evening peak comes from public transportation bringing people back to their homes, people switching lights on, switching on ovens/microwaves/cooking plates and so on to prepare supper (which is the most important meal in our country), switching on the television and so on. In winter we should be able to produce 14,025 MW to accommodate this peak. If there would be a shortage, chances are that it will be in the evening peak on a working day.

The problem that I have with this calculation is that the expert seem to rely on the production of 180 MW for solar and 1,616 MW for wind energy, ignoring that there is no guarantee that the sun is shining or the wind is blowing at peak hours. Those two numbers are AVERAGES over a winter, but electricity consumption is NOT ON AVERAGE. It depends on the time of the day, the day of the week/year. The 14,025 MW is necessary to accommodate for the peaks, especially the evening peak, not over the whole day.

He seem to consider intermittent, non-dispatchable energy sources as if these were dispatchable… It is not. If there is no/little sun or wind at the peak, then it is not possible to rely on that 180 MW (solar) and 1,016 MW (wind). It will only be a fraction of that or maybe even nothing at all.

The elephant in the room is that at our latitude, days are shorter and nights are longer in winter. Last winter (December 1, 2015 → February 29, 2016), the sun rose between 07:28 and 08:45 am. In the worst case the sun starts to shine when the morning peak almost ended, in the best case just before the peak (when it is not really powerful yet and production of electricity is very low).

According to the same source, the sun had set between 16:37 and 18:23 pm during these months. In the worst case, this is well before the peak. In the best case, it is in the second half of the peak when demand is going back down. Also here, sun light will be rather faint just before setting and electricity production will be very low anyway.

When I look at the production of solar energy (data via Elia) last winter there was no solar production at the evening peak from December 1 (2015) until February 16 (2016). That means that there was only a (tiny) production in the last 14 days of that period…

When I make the sum of the production of solar electricity during the morning peak, I end up with 0.45% of nameplate capacity, not even close to that magical 3%. In the evening peak it is even worse: there was only 0.17% of the nameplate capacity in the period. That is very, very far from the average of 3%. Which is not surprising knowing that in most days in winter the sun is already gone when the evening peak arrives. The contribution of solar energy to reach the 14,250 MW will be insignificant.

Therefor this 3% average over 3 months has no meaning when it comes to calculating how much extra capacity we need to come to the required 14,250 MW. We need to look at the situation at peak, preferably the evening peak.

Wind energy (data via Elia) did much better on average (it doesn’t depend on the length of the day): there was an average of 46% of nameplate power (it was unusual windy back then), but there were lows of 0,45%. For example, the equivalent of only a 8.82 MW plant on January 19, 2016 (which coincided with zero production of solar). The absolute lowest of the winter was 4.19 MW on February 24, 2016.

Of the 1.606 MW + 180 MW that was counted on in the calculation, not much is guaranteed. If he wanted to use a number, he should use the minimum of wind and solar (8.86 MW) instead of 1,786 MW. Although it is possible that 4.19 MW could also coincide with low or absent solar energy. In theory, but less likely, maybe even nothing at all. It are intermittent, non-dispatchable energy sources.

Concluding, not only were there two different things compared (capacity of dispatchable power versus average capacity over three months of intermittent power), but also this average number is used in a time frame that is different from when maximum capacity is required (over three months versus at peak).


8 thoughts on “In search of “only” 1414 MW (if non-dispatchable power sources are dispatchable)

  1. poitsplace

    I’ve seen this same problem. For some reason the green minions and experts alike seem to view wind/solar as dispatchable power…that they can even be “base load” producers even though they have absolutely no guarantee to provide power when needed…(indeed, you can be guaranteed that most of their capability will fail at random times…and that they may even consume more power than they produce to keep the blades spinning under poor conditions so they don’t seize up.

    This is why I reached the conclusion that the ONLY way to make wind remotely “dispatchable” was to convert almost all of it straight into hydrogen…and then burn hydrogen in conventional power plants. Using that method, the output from the wind turbines is better regulated (excess going into hydrogen production) so you don’t have to very the backup power quite so much.

    Oh, and of course you’d need weeks or even months of storage capacity for the hydrogen. And I decided enormous, metal lined tunnels bored under power plant sites could be a good way to store all the hydrogen. Of course, it’s WAY more expensive and still less reliable than just switching to newer nuclear plants and burning fracked gas. But at least it would be much more reliable.


    1. trustyetverify Post author

      There are indeed many who think that wind and solar are dispatchable or at least believe that intermittency poses no issues in electricity production. Been there, done that.

      I was however a bit surprised that someone that was labeled the “energy expert” of his party wasn’t aware of this. It is one thing to see this in the public, it is another to see it in those who are deciding policies. If they don’t realize that wind and solar are non-dispatchable, then I hold my breath for the future. At this point penetration of wind and solar is not big enough to show big effects (only in rare occasions), but one cannot keep adding intermittent sources while at the same time removing backup sources. Certainly not when everybody around is doing the same.

      Not that far in the past, I also thought that hydrogen was a solution in combination with intermittent energy sources. Intermittency wouldn’t be such a big problem in such processes. I however am not really sure anymore that this is the case. Hydrogen is a very poor energy carrier and storage has to be done at extremely low temperatures, which is demanding energy to keep it in that state when not using it. I haven’t looked at it in detail, but at first glance I have my doubts.

      I guess pumped storage is currently the best way of storing intermittent energy. It is not being done because it makes intermittent energy even more expensive (and if policy makers don’t realize that intermittent energy is non-dispatchable, then they probably don’t think it is necessary anyway).


      1. poitsplace

        Yeah, I’ve noticed the problem with the “experts”. They’ve just gone through green “academic” programs that do more to indoctrinate than teach practical applications or rational thought. And the really sad thing is that these educated idiots are held up by liberals as the real energy experts while actual energy industry people are considered to be completely untrustworthy and unrealistic. It really is like the lunatics are running this insane asylum.

        As for hydrogen…Oh yeah,hydrogen is awful, especially when you just burn it. But that’s kind of my point, you’re actually better off doing that…than making some crazy, hybrid, fuel cell system, batteries, flywheels, pumped air storage, etc. My “we’re better off making hydrogen and burning it” assumes only 40% efficiency. It’s just that it’s cheaper than all other alternatives per KWH..well after pumped storage. But good luck getting the necessary petawatt of pumped storage built.


        1. trustyetverify Post author

          I wouldn’t put it that extreme, but I also think that the experts are influenced by the current meme.

          To me it was surprising because he is supposed to belong to the sane ones and at the start of his interview he said rather sensible things, like the need for backup capacity (which isn’t said often in our media). But then by making the calculation showed that he didn’t realize that we don’t take electricity on average from the grid, but in a certain pattern over the day/week/year. The required 14,250 MW is needed at peak demand, not averaged over three winter months.

          Pumped storage has indeed its limitations. There is preferably a level difference (in our country, this means possible mainly in the Southern part). It is also possible on a flat area or maybe even offshore (“energy island”), but then it will become even more expensive. The drive of politicians to build them is rather low anyway. They seem to be under the delusion that wind and solar are “replacing” conventional sources, so why the need for expensive installations that probably don’t get them closer to the EU targets. Meaning going exclusively for wind and solar without thinking about expensive backup.


        2. poitsplace

          But that’s my point. This is an “expert” with such a critically flawed understanding of the most fundamental “professional” knowledge.

          As you actually start to take ANY amount time to do the math, you start running into the pitfalls of renewables. You have to as you ask questions about the engineering. What is the actual power consumption curve like? How much flexibility is there before it’s us serving the power and not the power serving us? How much concrete and steel will it req…OMFG this is hopeless from the start!

          These “experts” are dangerously compromised by ideologically driven factors…internal and/or external.


  2. TinyCO2

    Several of the EU countries, including the EU are playing Electricity Jenga where they see how many blocks of reliable supply they can withdraw before the tower collapses. Several of them (eg the UK) are relying on importing electricity from their neighbours at times of shortage but I wonder how many times the supply counted on by one country is also counted on by another. There won’t be enough spare to go around. When towers fall they make take out neighbours in a cascade effect.


    1. trustyetverify Post author

      At this point there is still room for some jenga pieces to be removed. Germany is exporting its excess power coming from intermittent sources and its neighbors are still able to absorb it. Denmark is lucky to have Norway and Sweden as neighbors that absorb its overproduction and can provide when underperforming. Belgium only has a very tiny percentage of intermittent energy, therefor no big issues yet. But I hold my breath if I see that we and most of our neighbors are doing exactly the same: more wind and solar, while dismantling base load and backup power…



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