Scotland currently has 2.3GW of installed wind capacity. The target of generating 50% of electricity from renewables by 2020 - once dismissed as unachievable - is now expected to be met, largely thanks to the growth in onshore wind. So optimistic is Alex Salmond, the leader of Scotland's devolved government, that he told a conference in September the country would soon run on renewable electricity alone.
"I am confident that by 2025 we will produce at least 100% of our electricity needs from renewables alone and, together with other sources, it will enable us to become a net exporter of clean, green energy," he said.
However, further progress will depend on a high number of smaller sites as bigger, less constrained sites have already been developed. There are 83 wind farms in Scotland, and sites of six to seven turbines are now expected to become the norm, according to industry body Scottish Renewables.
"Onshore wind is not slowing down, we are just moving to smaller areas," says Rosie Vetter, Scottish Renewables planning policy manager.
Karen Hamilton, partner at law firm Brodies, has researched the length of time taken for wind farms to go through the planning process during the past three years. Wind farms under 20MW, which are permitted by local authorities, were taking no longer than government-permitted schemes of over 50MW, she found.
This is despite changes to the Scottish appeals system brought in last year. Wind developments under 20MW should be approved by planning officers, rather than a committee of local politicians.
If a wind farm is rejected, the developer can appeal, but it will go through a local review board at the council, rather than the government. Councils can draw up rules to determine when an application will be heard by an officer or a committee - for example, if more than five people object to it. In effect, most small schemes are still being decided by committee, Hamilton says.
This makes meeting the higher targets a challenge, Hamilton says: "The concern is that it is becoming ever more difficult to take smaller steps towards the target."
Scottish Renewables, however, is more optimistic. A study carried out by consultants GL Garrad Hassan, which was published just before the Scottish Government increased its target, found that even with the most pessimistic scenario of growth in renewables and an increasing demand for electricity, Scotland can easily meet and pass its 50% target.
To meet the new 80% target, Scotland needs 16GW of renewables power. There is 3.5GW of wind in the planning system, with a further 3GW consented and 420MW more in construction. Another 3.7GW is expected to be developed offshore.
But this excludes non-commercial wind farms, applications for which have soared since the introduction of the UK's feed-in tariff in April. More than 270 micro-turbines have been installed since the scheme began.
Another study, for Friends of the Earth and WWF, which is due to be published this month, has even higher expectations for renewables, with onshore wind growing at 360MW a year to 2020, even with a relatively pessimistic view that just 26% of projects would gain planning consent, compared with the average actual rate of 66%.
Meanwhile, Scottish Renewables has teamed up with conservation bodies the Royal Society for the Protection of Birds, WWF, Friends of the Earth and the Scottish Wildlife Trust to agree good practice principles for wind farms on peatlands.
Peatland is valuable for carbon storage and water management, and also provides habitat for wildlife. Wind developers have been criticised for damaging peatland, an allegation denied by Vetter.
Wind developers are not actually keen to build on peat, as it is expensive, she explains. It is hard to avoid it altogether as there is so much peatland in Scotland, but such development is regulated and any environmental impact has to be mitigated.
"The agreement is just to highlight that we can build on peat as long as it is done in the right way," Vetter says.