For those who think of wind turbines as an unwelcome modern addition to the landscape, I thought it would be a good idea to share a few paragraphs from an interesting account of their history I've just found, and reproduce some of the drawings from it.
Wind powered factories:
the history (and future) of industrial windmills
More than 900 years ago, medieval Europe became the first large civilization not to be run by human muscle power. Thousands and thousands of windmills and waterwheels, backed up by animal power, transformed industry and society radically. It was an industrial revolution entirely powered by renewable energy – something that we can (and do) only dream of today. Wind and water powered mills were in essence the first real factories in human history.
The amount of windmills in early medieval times remains unknown, because the few inventories that could be studied do not distinguish between water and wind powered mills. For instance, we know that there were between 10,000 and 12,000 mills in the UK in 1300, but we do not know how many of them were wind powered (it must have been a minority). All we have are data on individual windmills, which start to appear at the end of the 1200s. Only in the 1700s and 1800s, when windmill technology really caught on, more accurate inventories appear.
In 1750, there were 6,000 to 8,000 windmills in the Netherlands, in 1850 there were 9,000 of them. For comparison, this is almost 5 times as much as there are wind turbines in the Netherlands today (1,974 turbines as of September 2009). In the UK there were 5,000 to 10,000 windmills in 1820. France had 8,700 windmills (and 37,000 watermills) in 1847.
Germany had 18,242 windmills in 1895 (compared to around 18,000 wind turbines today) and Finland had 20,000 windmills in 1900. Portugal, Spain, several Mediterranean islands and many Eastern European and Scandinavian countries had many windmills, too. The total amount of wind powered mills in Europe was estimated to be around 200,000 (at its peak), compared to some 500,000 waterwheels. Windmills were built in the countryside and in cities, and even on the walls of castles and fortifications in order to catch more wind.
So the number of windmills in the past was far greater than the number of wind turbines proposed now. Perhaps the most dense concentration of windmills was in Zaanstat, just north of Amsterdam. The following account, contemporary map and painting by Laurens Oomhein in 1756 are from Canon van de Zaanstreek.
In 1729, a new tax register for wind lease was set up, in which 635 mills were recorded: 245 sawmills, 160 oil mills, 61 hulling mills, 38 paper mills and many other mills, which all produced what could be manufactured with millstones and pistils. The mill and shipbuilding industries started all sorts of ancillary businesses such as huge mill factories, forges, rope-makers, compass makers, while the thriving whaling contributed much to the prosperity of the region. All this in turn led to an even stronger growth of the population.
To put things into a modern perspective, the largest windfarm in Wales, Gwynt y Môr, will have only 160 turbines. And even the huge Rhiannon windfarm proposed just north of Ynys Môn is likely to have between 145 and 440 turbines, depending on how big they are.
The only real difference (apart from wind turbines looking rather more elegant, although that is a matter of opinion, of course) is that modern wind turbines produce electricity rather than direct mechanical power ... but they do produce rather a lot of it. At 2.2GW, and even allowing for a pessimistic capacity factor of 25%, the Rhiannon windfarm alone (which is only the first of three windfarms in the zone) will produce more electricity in an average year than Wylfa A did.
Installed capacity ... 980 MW
Capacity factor ... 56% (ref)
Average production = 0.98 GW x 24 hours x 365 days x 56% = 4,807 GWh/yr
Installed capacity ... 2.2 GW
Capacity factor ... 25%
Average production = 2.2 GW x 24 hours x 365 days x 25% = 4,818 GWh/yr
Capacity factor ... 35%
Average production = 2.2 GW x 24 hours x 365 days x 35% = 6,745 GWh/yr