During our family visit to Denmark, my wife and I took a few
days to
travel around and look at the windpower scene. Travel is expensive
but the
distances are small.
Here is a shot opf Riso from 1996.
We took public transport as far as Claus Nybroe's local town where
he met
us in his battered Lada. What a relief to find that not everyone
in
Denmark drives a brand new car!
..
We spent a great weekend with Claus
(www.windmission.dk).
It was flat calm, so the 4kW Windflower machine
behind his house was not doing much.
----
On the Sunday we visited a neighbour
who owns a 170kW Wind World turbine on his farm. On summer evenings
they
sometimes go up to the nacelle to admire the view.
This was no ordinary farmer though. He has built a 25kW direct drive pm alternator, and he has yummy software for visualisation of flux lines and heat conduction in the laminations (www.quickfield.dk). I wish I could afford it! Claus has started to import some smaller permanent magnet alternators from China, at very affordable prices. We bench tested some, and they look to be ideal for self-build enthusiasts, whose biggest problem is finding a suitable low speed generator.
Public transport is very efficient in Denmark (see www.dsb.dk),
but we
decided to hire a car for a few days so we could indulge in our
favorite
passtime of getting lost up the back roads. For two people, the
cost is
about the same as going by train/bus.. around 2DKr/km (30pence or
50c/mile). It's
worth shopping around for the best deal rather then going straight to Hertz
or suchlike.
On the road we admired the clusters of big wind machines which are
scattered across the country. I would say that it is possible
to see a
'mill' (as they call them) from most places, but I would not really
say
that they often dominate the landscape, even though they produce 10%
of the
electricity in Denmark. I am told that there are very few permissible
sites left for windpower, and that the future is offshore, but I reckon
they could easily find room for a few more turbines on land if they
really
needed to.
It was a sunny day with a good breeze. We ate some bread and spread
beside
the ancient stones at Jelling. A two bladed turbine caught
my eye and we
agreed to investigate. I must say I did not find the machine
aesthetically
attractive. The visual effect was busy and unsettling, but I
was curious.
It turned out to be another downwind household machine, and we chatted
with
the locals but failed to meet the owner. We spotted a few more
of these,
and some smaller 3-bladed versions, as we made our way on toward the
northwest coast.
Our itinary was not completely random. We arrived at the Folkecenter
for
Renewable Energy (www.folkecenter.dk),
and they made us welcome overnight
for a very modest payment. I found their little collection of
wind machines fascinating.
They even had a 900watt Whisper, running very nicely
(although its digital meter was defective, as usual). They had
one of
Claus' smallest mills, and a few household mills, and quite a few obsolete
prototypes of one sort and another. The boss, a guy called Preben
Maegaard, boasted that they had the biggest collection of small machines
anywhere (I could not get a word in to tell him about Scoraig) and
that
unlike other sites, they actually tested them there. Needless
to say I got
quite excited about this. I met their young test engineer, Lars
Christian
and had an interesting chat. He had some very high spec. equipment,
but did
not have time or funds to test anything smaller than 22kW, and most
of
their recent work was with much bigger turbines. He did tell
us how to
find the manufacturers of the downwind machines we had been seeing
- a
company called Gaia Wind Energy in Viborg. It seems they
are now the only
active manufacturers of small machines in Denmark, apart from
Calorius-Westrup, makers of an ingenious, mechanical water heating
machine, who have had very little commercial success.
The Folkecenter is a visitor centre of a sort, and also takes trainees
from
third world and eastern european countries. The idea is that
these
trainees probably have too much academic knowledge already, so they
are put
to work doing practical things. I hope they find this useful..
I am sure
the folkecenter does. They have a brand new undergound, solar
heated
training centre nearing completion. I hope they will run some
proper
courses in there. As I was leaving, Preben gave me a lecture
about how bad
the UK government is at fostering renewable energy. He is right.
The UK
policy of pushing the cost of windpower ever downwards has done little
to
promote its public acceptability, or to nurture the manufacturing base.
Preben believes fervently in subsidies for wind energy. He points
out that
all the other power producers get assistance too. Until now,
the
electricity companies have been paying about 0.60Dkr (=6pGB=10cUS)
per kWh
for wind energy (and consumers pay twice this for the power they buy),
but
there is a move afoot to force this subsidised price downwards.
While
talking, Preben photocopied and handed to me a long diatribe he had
just
written against this retrograde trend.
Misty rain obscured our view of Jutland as we progressed toward
Skagen at
the northern tip. We passed a group of 35 very handsome 600kW
Vestas
turbines, with some maintenance activity. By the time we had
threaded our
way around the access tracks, the crane was packing up - too much wind
to
replace the gearbox mounts. The engineers were friendly but absorbed.
We
were impressed by how shiny their tools and trucks were.
The blades of these big machines seem to move slowly, but in fact they
aren't wasting any time, when you consider how far they have to go.
There
is quite a difference between these slender, willowy limbs, and the
stumpy
blades of the older machines from the 1980s. In fact it is quite
alarming
how they bend back toward the tower under load. The old 55kW
machines,
which seemed so big to me in 1982, now seem like kiddie's toys, with
their
little red-tipped 'wings' tumbling around at 60rpm. These old
mills may
not be so productive but they seem more personal somehow, less haughty.
And many of them are still there, in farmyards and on little hillocks
across the land.
_-oO*Oo-_
In Skagen, Jytte achieved her ambition of standing where the skagerrack
meets the kategat (or whatever) in some pretty raw weather. The
place is a
tourist trap but very charming out of season. We managed to get
lost,
watching a long load (windmill tower) turning a corner, instead of
reading
the signs.
As usual it was well worth it and we ended up at what appeared
to have been the WindWorld factory. There was a huge machine
there with a
very swanky duck-tailed nacelle, in the back yard. How anyone
could not
want such a thing in their own back yard is quite beyond my comprehension.
Our final windpower detour on the way home was to visit Gaia in Viborg,
a
city at the exact centre of Jutland, in an area where most of the wind
industry is based. The city itself is known to have been in existence
at
least as long ago as 2495 years after the creation of the world.
Gaia had
only moved in recently, to an industrial site adjacent to a very large
Vestas tower facility. The director, Jens Wodstrup was kind enough
to give
us quite a bit of his time. He is currently building two sizes
of mill,
both downwind, and both grid-connected. The 5.5kW version has
7 m diameter
and its three blades spin at a giddy 131rpm. It costs 106,000kr
(10kUK,17k$US) installed in Denmark on a tower, but Jens recommends
the
larger 11kW machine with two blades which we had seen first of all.
This
has 13m diameter and runs at only 57 rpm, so it works much better in
low
winds. the price is double but the energy production is maybe
three times
as much. They have sold about 50 machines, mainly the larger
type.
Gaia Wind, Absalonvej 1. DK-8800 Viborg, Denmark.
The economics of these 'household mills' are pretty marginal, even with
the
good buy-back tarrifs in Denmark. Jens explained that it was
more
important to know the tax system than the engineering even. They
tax what
you sell and they tax what you buy. He plans to visit the government
minister and plead for net metering. There were several nacelles
in the
factory, and he could produce 20 per month, but sales are slow moving.
Planning permission often takes a year, by which time some customer
have
lost interest.
The blades of the smaller mill are built by Olsen the boatbuilder, and
he
makes a very tidy job, complete with wingtip brakes for overspeed control.
The larger machine uses a 13m one-piece blade from LM, with a teetering
hinge at the hub. I wondered if these ran smoothly (the one I
saw running
had rather a shake to it) but Jens pointed out that this was the most
reliable of the recent generation of household mills. The others
of that
size had suffered intractable problems with noise and suchlike, and
had
mostly been withdrawn from the market. In recent years, household
mill
installations (up to a 13m size limit) have been elligible for a 30%
grant,
which helped to promote their development while the program lasted.
I
believe the idea was to increase the amount of windpower on the grid
by
exploiting the fact that small mills are more acceptable (in contradiction
to the overall trend). It's a pity that the most succesful result
is such
a quaint object.
After this we returned to the Copenhagen area, for more family jollity.
The Dane's have an exceptional appetite for good cheer, and it is quite
normal to have a few beers in the morning. On Sunday we spotted
a familiar
face in the papers - our friend Preben. It seems that the
european union
are investigating the folkecentre for fraudulent accounting.
Just another
case of persecution against renewable energy, he claimed.