Wind turbines in
Denmark
Intermittence and
hydraulics
Focus on the Danish
case
Jean Pierre Riou
English translation Bernard Durand
Avertissement : cette série d'articles en anglais reprend des articles du Mont Champot en français afin d'étayer une publication ultérieure.
Cet avertissement explicatif sera rapidement supprimé.
Why the development of intermittency in France will
impose additional load monitoring on its nuclear reactors, which deteriorates
their profitability and compromises their safety, without participating in the decommissioning
of any of them.
Costa Rica, Uruguay, Quebec and Norway generate more
than half of their electricity from hydro power. A good part of this energy,
stored in dams, allows them all the fantasies of production with intermittent
means such as solar or wind.
But the problems raised by the Sivens dam project
painfully remind us that this model is not universally applicable.
However there is no other mean of storing massively
electricity than using hydraulic reservoirs. This is the reason why countries
not having such an asset cannot reduce the installed power of their dispatchable
power plants by a single MW in return for the development of intermittent
resources, whatever their power.
This power of intermittent sources is likely to fall
to less than 1% of its installed power when the wind drops, as this March 12,
2018 in Denmark.
"High pressure
potatoes" can, however, fall on an entire week in Europe, while regularity
of electricity supply to the network is essential. This explains why Germany
has still not reduced its controllable fleet by 1 MW in return for 100,000intermittent MW. Similar is the case of Spain. The French are mistaking if
they believe that the closure of 3 GW of coal is due to any reason other than the economy in
electricity consumption due to the commissioning of the Georges Besse 2 plant
for the manufacturing of nuclear fuel.
The
Danish case
The case of Denmark
requires special attention since it has succeeded in 25 years in reducing
its fleet of coal-fired powerplants by 2
GW, from 10,214 MW in 1995 to 8,141 MW in 2015, in parallel with the
development of 5 GW of intermittent wind
power. And that, without having hydraulic reserves allowing to cushion the
vagaries of the wind production. The table below details this development
Deciphering
This evolution of the Danish electricity fleet can
only be understood within the Nordic network with which it is closely
connected, mainly with Sweden and Norway which supply it with almost all of its
imports, and with Germany to which it exports its surpluses, as shown in the
graph below which illustrates the development of its cross-border trade since
1990.
The red line drawn on
this graph shows the evolution of the trend of these exchanges. Denmark was a
net exporter in 1995. The exports/imports balance gradually decreased, until it
became negative from 2011, and represented up to 17% of Danish consumption in
2015.
Nordic and Baltic
hydraulics
The Nordic
electricity network, which connects Sweden, Denmark Norway, and further on,
Finland, Estonia, Latvia and Lithuania is characterized by a considerable
hydroelectricity input, with the exception of Denmark and Estonia. Hydraulic
power provided, in fact, 96.3% of Norwegian electricity consumption in 2016 and
half that of Sweden, Finland, Latvia and Lithuania. These countries are largely
using this facility to open or close their floodgates to regulate the network,
as shown by the sudden variations in Lithuanian hydraulic production, below.
All Denmark’s eggs in its neighbors' hydraulic / nuclear basket
Nuclear energy also
characterizes the electricity mix in Finland, where nuclear / hydro power
accounted for 83.4% of electricity production in 2016 (excluding cogeneration),
and in Sweden for 80.3% of production (87% of consumption).
It is in fact the
Swedish and Norwegian hydraulic reserves which allow Denmark to have power when
the wind drops. And assure him a possible outlet for its excess of wind
production, because these neighbors have no more difficulty opening floodgates
for export than closing them to absorb surpluses. Imports by Denmark are all the more important
as its wind turbines produce less, and it becomes an exporter when the power of
its wind farm exceeds, roughly speaking, 2800 MW. This is shown in the graph below,
which also illustrates the strict correlation between the amount of wind power
produced by Denmark and the amount of power it exports, or is forced to import.
Source AIE, Danemark 2017
Such behavior with such accommodating neighbors more
than makes up for its lack of hydraulic storage capacity, and avoids having to
subsidize emergency thermal power plants when wind is lacking, as Germany does.
The hinge 2005 2015
Between 1995 and 2005, 2.5 GW wind turbines were added
to the Danish electricity park almost without reducing the thermal park (minus
0.3 GW). This increase in installed capacity was, however, accompanied by a
decrease in exports, due to an increase in consumption over the same period, as
we can see in the graph below.
The horizontal red line highlights the similarity of
consumption between that of 1995 and that of 2015, which frame this study, and
without which any comparison would be biased.
It is the period 2005 2015 which is significant, since
it was then that Denmark made most of the reduction in its thermal fleet. But also,
from a net exporter, it has become an importer of 17% of its electricity needs,
while its consumption fell regularly, from 34.2 TWh in 2005, to 31.7 TWh in
2015.
Epilogue
Its electrical system gives Denmark the most expensive
electricity in Europe for households, with 0.3088 € / kWh in 2016, while its
Nordic and Baltic neighbors benefit from a kWh 2 times cheaper: 0.12 € in
Estonia, € 0.16 in Latvia, € 0.12 in Lithuania, € 0.15 in Finland, € 0.18 in
Sweden and € 0.15 in Norway.
But at least the wind industry, with 25,000 jobs in
Denmark, represented 8.5% of total exports, while the internal wind market
represented less than 1% of activity in this small country in 2011, before
China took over the market.
The other point of view
These figures were indicated in the letter sent by the
industrial sector to the Minister of the Environment at the time, to remind him
that the place of Denmark as European leader in this industry attracted the
eyes of the whole continent on Denmark's wind energy regulations, and that
plans to take into account the nuisance caused by their low-frequency noise
risked being copied by other countries.
And that it would cause considerable damage to the
Danish economy if the regulations concerning the protection of local residents
were to be tightened.
This is roughly the content of this edifying letter, a
sworn translation of which was published in a Finnish report (p 73/74 via Waybackmachine).
This letter is dated to the time when Professor H.
Møller, undisputed acoustics specialist in Denmark, fought for wind turbines very
low frequencies and infrasounds to be measured in homes and not just
calculated. It was the time when he was sacked from the University of Aalborg
where he professed. At which time this University spoke, on its own site, of
the mafia practices of this dismissal on economic pretext, and the press also denounced
these practices and paid him a vibrant tribute.
