Denmark produced a record 39.1% of its electricity from wind in 2014

http://phys.org/news/2015-01-denmark-champions-power.html
"...
Denmark champions wind power, sets record

Denmark has had a record year for wind power production. Denmark got 39.1 percent of its overall electricity from wind in 2014. That figure is according to the country's Climate and Energy Ministry.

In fact, said EurActiv.com, that figure "makes the country the world's leading nation in wind-based power usage." In January 2014 alone, power from wind made up 61.4 percent of electricity consumption. By contrast, wind energy contributed to just 18.8 percent of the overall electricity production in Denmark in 2004. Denmark also has become a leading wind power manufacturer. Companies such as Vestas and Siemens Wind Power are based there, said ThinkProgress. Around nine out of every 10 offshore turbines installed globally are made in Denmark.
Denmark's goal for 2020 is getting 50 percent of its power from renewables. What is more, Denmark has a long-term goal of being fossil fuel-free by 2050, said ThinkProgress. Denmark's Climate and Energy Minister Rasmus Helveg Petersen said, "We still plan to put up more wind turbines," according to EurActiv.com, a site for EU news. Considering how countries such as Scotland, England, and Denmark are building out their offshore wind farms, this record year for Denmark strengthens Europe as a whole as a leader in the wind power industry.

The Local, nonetheless, put the record year in wider perspective. While wind power accounted for nearly 40 percent of Denmark's electricity in 2014, wind only covers about five percent of the nation's total energy use. They noted that, according to the Danish Energy Association, electricity only makes up one-tenth of Denmark's total energy usage; fossil fuels such as oil, coal and natural gas still account for about three-fourths of Denmark's total energy use.

Denmark has long been a pioneer in wind power. Reflecting on its earlier days, Vestas recalled a time when "Keen to avoid ridicule from customers and suppliers," Vestas carried out initial wind turbine experiments in secret. The first prototype looked like a giant egg whisk, before Vestas developed its three-blade turbine introduced in 1979. Now, Vestas is reported to have installed wind turbines in 73 countries around the world.

Petersen, meanwhile, said that the government has set aside 60 million kroner toward a heat pump trial program meant to encourage Danish power plants to embrace the more climate-friendly, but currently more costly, solution, according to The Local.

To date, said the official website of Denmark, also called Denmark, "Danish companies have installed more than 90 per cent of the world's offshore wind turbines." With a constant aim of bringing down the cost of energy, Denmark expects to remain a dominant player in the offshore wind turbine market.
..."

With some significant blemishes (like why isn't the UK doing something like this? ), it certainly isn't all good news but, still, not bad.

France has been getting the majority of its power from clean sources for decades now. Norway too. Denmark is flat and windy, so wind power works reasonably well there but isn't much of a solution elsewhere. Also, you need something to fall back upon if there is no wind.

Originally posted by KazetNagorra
so wind power works reasonably well there but isn't much of a solution elsewhere.

Not true! The UK happens to be one of the best places if not the best place in the whole of Europe for wind energy!
See, for example:

http://www.renewableuk.com/en/renewable-energy/wind-energy/
"...
The UK is the windiest country in Europe and could power itself several times over using wind
..."

And

http://www.britishwindenergy.co.uk/
"...The UK has 40% of the wind energy in Europe making the country a prime target for wind energy generation ...
..."

Also, you need something to fall back upon if there is no wind.

There are already a combination of solutions to that which could be developed if only there was the political will to make it happen. The 3 main potential solutions, which would probably be used combined together, are:

1, combine wind with several other types of renewables (plus possibly with some nuclear if cost effective )

2, use a supergrid to transport electricity efficiently over vast distances from where it is currently windy to where it isn't.

3, if 1 and 2 above is not quite enough alone, use off-the-grid storage. This is the most expensive solution out of these 3 options which is why it should generally be done for only when and where 1 and 2 doesn't quite cover it and, even then, only for that part that isn't covered by 1 and 2. But, still, its doable.

The combination of the above 3 main solutions can be combined with several other lesser partial solutions I know of and to all add up to a complete solution that doesn't require fossil fuels as backup.

If wind farms were scaled for world power consumption rates, what effects are seen on the winds themselves? Entropy generation is > 0 for all real process operating between thermal reservoirs. Edit: with the sun providing the energy to create the temperature differential I suppose entropy generation would be a non issue. However, the global climate depends on the winds and the thermal energy transferred by them. If we rob the winds of their kinetic energy we are losing the mode of heat transfer between the thermal reservoirs.

Originally posted by joe shmo
If wind farms were scaled for world power consumption rates, what effects are seen on the winds themselves? Entropy generation is > 0 for all real process operating between thermal reservoirs. Edit: with the sun providing the energy to create the temperature differential I suppose entropy generation would be a non issue. However, the global climate depen ...[text shortened]... of their kinetic energy we are losing the mode of heat transfer between the thermal reservoirs.

There has been some actual concern and research on this very issue.
Already wind farms have been shown to have a subtle effect on the local climate because of their wind-shadow effect where they reduce the momentum of the wind far down wind but, perhaps surprisingly to some, far up wind as well.

I do not know exactly what the best climate models would say would happen to the Earths climate as a whole if we got all our energy we currently consume from wind turbines alone. But I have heard of some predicted serious effects according to some models; the main one being significant drops in the amount of rain water falling in some parts of the world. But the current models generally indicate we are nowhere near overdoing it to that extent yet so, at least for now, it should be safe enough to keep increasing our use of wind turbines.

Denmark has a population of 5.65E06 people, compared with around 64.1 megapeople in the UK (figures from Wikipedia). So without wanting to diminish their achievement, replicating it in the UK, Germany or France is a lot harder. At this precise moment the UK is generating 19.25% of its electricity from wind [1], obviously that figure depends on the weather and that's the problem. We still generate most of our electricity from Coal (27.19% at this exact moment) and Gas (9.96%.), but the backbone is actually nuclear (27.64%.). The reason for this is that for climate change mitigation purposes coal is restricted in running time and tends therefore to be used in winter, Gas is easy to get online so it's used for peak demand (it's midnight right now so that is why it's only 10% - at midday it will be higher). Wind depends on if it's windy, which is a problem with all renewables except tidal power. What doesn't enter into these figures is solar power - and not just because it is night time, but also because it's microgenerated and doesn't enter the figures straightforwardly. Nuclear power stations are run flat out all the time - see the link below.

We have an energy crisis looming and basically need more power stations. Frankly I think that there is a limit to how much more we can extract from renewables and need some more nuclear plants, but, as the regulars here know, I'm sceptical about PWRs and, on safety grounds, would prefer to see modernised AGR designs.

[1] http://www.gridwatch.templar.co.uk - This is quite a cool website.

Originally posted by humy
There has been some actual concern and research on this very issue.
Already wind farms have been shown to have a subtle effect on the local climate because of their wind-shadow effect where they reduce the momentum of the wind far down wind but, perhaps surprisingly to some, far up wind as well.

I do not know exactly what the best climate models would say ...[text shortened]... yet so, at least for now, it should be safe enough to keep increasing our use of wind turbines.

If continuity holds for the wind streams, than any restrictive element in the stream reduces the flow for the entire stream.

Anyway...nothing is free and/or without consequence. It would be kind of ironic if we created a chaotic climate because we didn't have all the information...Oh...wait...no it wouldn't. It would just be par for the course.

'The road to hell is paved with good intentions'

Originally posted by DeepThought
Denmark has a population of 5.65E06 people, compared with around 64.1 megapeople in the UK (figures from Wikipedia). So without wanting to diminish their achievement, replicating it in the UK, Germany or France is a lot harder. At this precise moment the UK is generating 19.25% of its electricity from wind [1], obviously that figure depends on the weat ...[text shortened]... odernised AGR designs.

[1] http://www.gridwatch.templar.co.uk - This is quite a cool website.

Frankly I think that there is a limit to how much more we can extract from renewables

But we are nowhere near that limit yet! -at least not for solar energy. Do you see every rooftop of every house completely covered with solar panels? I once calculated (don't still have my notes on that calculation ) that, with 24-hour energy storage (which admittedly is currently a rather pricey option but cost will go down with time and further development ) , if every rooftop of every house was covered with solar panels that were 25% energy efficient, that would provide more than all the required domestic electric power for most typical houses (given both typical roof area and typical household energy consumption ) on most days (except in mid-winter at about UK latitude. But it tends to be windier in UK winter thus can compensate on most days with wind power ) even on days when it is cloudy and therefore the light striking the solar panel is indirect and of low intensity providing they are designed to maintain that 25% energy efficiency with such dim light which is at the very least is theoretically possible. The calculation looks even better when you throw in energy-saving features in the electrical appliances and in the home itself such as super-insulation to reduce winter heating costs etc.

Note that I have nothing against nuclear power in principle and acknowledge that it definitely can be made to work with a perfectly acceptably level of safety and thus could be reasonably used to supplement renewable energy.

Originally posted by DeepThought
Frankly I think that there is a limit to how much more we can extract from renewables ....

Why?

I'm sceptical about PWRs and, on safety grounds, would prefer to see modernised AGR designs.
The cost of developing new nuclear designs in anywhere other than China outweighs the cost of renewables.

Originally posted by humy
Note that I have nothing against nuclear power in principle and acknowledge that it definitely can be made to work with a perfectly acceptably level of safety and thus could be reasonably used to supplement renewable energy.

But it is not necessary. Biogas is a perfectly viable renewable alternative for dealing with on demand requirements.

Let's see what Denmark is and does:

Denmark is a small country. 5.5 million inhabitants 43,000 km2.
They have no rivers to produce hydroelectric power, they have no nuclear plants, they have no coal deposits, but they have some petrol natural gas from the North Sea.

So in order to be self-sustained in energy they have to use wind power. And they do it well. A good part of their consumption comes from wind.

Let's say that would relay on wind to 100%, would that be good? No, because a calm day in winter, they will freeze quite good, and the industry will stop. So too much wind percentage is not good, however good for the environment.

So they have to rely on fossil energy. Not so good because of the CO2 emission.

And, as they are connected to the European grid, they import electrical energy. This energy comes from coal which is emitting CO2, and hydro energy which is good, and nuclear which the population doesn't like much.

(Denmark has also a local production of geo energy and solar energy, despite their northly position. But this production is not connected to the grid.)

The most important number is not how much CO2 a country emits as a country, but their emission per capita.
Denmark emits 8.3 kt CO2 per person to be compared with Germany 9.1, United Kingdom 7.9, Greece 7,8, Europe in large 7,4. So Denmark is doing well, but not extraordinary well.
Let's compare with China 6.1 kt CO2 emission per capita which is better than Denmark. And USA 17.6 kt CO2 emission per capita who is the really bad guy in class.

So in all, Denmark is good, but isn't very good. Other rich big countries could do a lot more for the environment.