Until now, solar energy generation in Scotland has - with the exception of a £1.2 million 'solar meadow' installed at Edinburgh College in 2013 - been almost entirely confined to small scale domestic or community developments which have seen solar panels being installed on the rooftops and outside walls of south-facing homes, schools and even prisons.


But, over the last nine months, eight commercial projects varying in size between 1.8MW and 19MW have been granted planning permission in Aberdeenshire, Angus, Perth & Kinross and Dumfries & Galloway.


Further large scale solar projects are also being planned for Borders and Fife, which - compared with northern and western areas of Scotland - enjoy greater sunlight radiation.


In total, there are now over 100MW of large-scale solar projects in the planning stages or awaiting construction to add to the 153MW of existing solar capacity from more than 31,000 installations, mostly panels on peoples' homes. If all the planned project are built this could lead to a 66 per cent increase in solar production in Scotland over the next couple of years.


Despite the growing interest in solar energy production, Scotland, where most investment into green energy schemes has gone into onshore wind farms over the last decade, nevertheless lags behind the rest of the UK when it comes to solar.


While more than 40 per cent of electricity used in Scotland currently comes from renewable sources, solar production currently only accounts for less than 2 per cent of renewable production.


Over the course of 2014, solar energy production in the UK almost doubled from 2.8GW to nearly 5GW: enough to supply the electricity needs of more than 1.5m homes and the equivalent of one and half nuclear power stations. Even so, UK uptake of solar power is still well below the installed capacity of Germany and Denmark, which enjoy similar levels of solar irradiation.


Last month a report from Deutsche Bank concluded that, with the cost of photovoltaic panels having fallen 80 per cent over the last six years, solar energy is now on the cusp of becoming competitive compared with the cost of producing electricity from fossil fuels.


Deutsche Bank estimates that the cost of solar technology will fall by a further 40 per cent between now and 2017 when solar - ahead of other green sources of energy which remain heavily dependent on public subsidy - will be close to being able to undercut oil, coal and gas without the need for any subsidy.


Helped along with improvements in battery technology and cheaper electricity storage solar power will, says the report, become the dominant global electricity source by 2030.


According to Deutsche's analysts, today's 130GW of global solar capacity - which currently accounts for just one per cent of the global electricity market - will grow tenfold over the next 15 years. By 2050, the report says, solar will account for 30 per cent of global electricity production.


Earlier this month London-based Green Hedge Renewables announced plans for a 4MW solar farm in Fife which could provide enough renewable energy to power 1,300 homes.


Tom Selway, Green Hedge's head of community affairs, said that Fife's reputation as one of the sunniest places in Scotland had persuaded the company to invest in its first venture north of the border.


Dependent on getting planning permission and securing a grid connection, Selway says that the farm could be up and running early next year and, depending on how quickly other developments in the pipeline progress, could be one of the first commercial sized solar farms to start producing electricity in Scotland.


The growth of interest in solar power and the potential to open solar farms in Scotland led to Cambridgeshire-based Lark Energy to open an office in Edinburgh in 2013.


In October the company was granted planning application for 4.99MW solar farm at East Culkae in Dumfries & Galloway and plans to submit an application for a similar-sized farm at Causewayend, between Newton Stewart and Wigton, later this year.


Lark's managing director Jonathan Selwyn said that his company is also examining the potential of around half a dozen further sites for solar arrays in the south and east of Scotland.


"We are not yet at the stage of being able to operate without any public subsidy but we think that after three or four years of declining subsidies we will be at the point where we won't need any further support," says Selwyn.


The 4.99MW size of Lark's proposed farms is important as, from the beginning of this month, the UK government reduced the amount of subsidy payable under the so-called Renewables Obligation Order to solar plants for developments generating 5MW or more.


According to the John Forster of the Solar Trade Association Scotland, the drop in government subsidy for large scale developments means that it is unlikely that Scotland will ever see the massive solar farms that have been built in Spain, China, India, Japan and the US in recent years.


Instead the growth is likely to be in medium and small scale projects including projects like Glasgow City Council's plan to place solar panels on 400 patches of wasteland scattered across the city.


Edinburgh, meanwhile, is looking to put up arrays in disusued quarries and on pit bings or slag heaps.


Other places that have successfully seen the installation of solar cells abroad, and which could be followed in Scotland, include the otherwise unused land surrounding motorway junctions or on the sound barriers built to reduce noise pollution from major roads.


One of Forster's main priorities over the coming months, he told the Sunday Herald, will be working with the Scottish Government to create the country's first solar energy policy.


""There is a huge opportunity for solar power that has yet to be captured in Scotland and this policy will help Scotland achieve its climate-change target," Forster said.


The ambitious target, set by the Scottish Government, is for renewable energy to be able to fill the equivalent of 100 per cent of the country's electricity needs by 2020, allowing for a baseload of fossil fuel and nuclear generation to guarantee supplies on low wind or low sunlight days.


Forster said that the STA believes that solar will be able to survive without any public subsidy from 2020, when declining subsidies - which have been calculated on the assumption that the cost of panels will continue to fall - will be phased out.


The STA's Scottish branch was set up last year in response to the growth of interest in solar power in Scotland, which has seen installed capacity rise from just 2MW in 2010 to the current 153MW.


The sharp rise is mostly down to the introduction by the UK government in 2010 of the so-called feed-in tariff scheme which pays consumers and businesses to install solar panels as well as other renewable devices such as wind turbines.


The growing potential financial rewards of solar power last year led to a fight between a wind power project and a solar power company for control of a former wartime airfield at Tealing near Dundee.


The future of a £3 billion windfarm off the east coast was thrown into doubt in December when Angus councillors approved a planning application for a rival 31MW solar panel park (Scotland's largest yet), put forward by Green Cat Renewables.


Seagreen Wind Energy, a joint venture between Scottish and Southern Energy and the construction company Fluor Ltd, had previously been granted conditional approval for the development a sub-station on the site in support of their proposed 3,500MW offshore wind turbine development.


It is now expected that the competing developments will enter into negotiations to explore whether both plans can co-exist.


Stephanie Clark, policy manager of the industry body Scottish Renewables, points out that the co-existence of solar panels and onshore wind turbines can make for an optimally efficient use of resources as solar panels can be sited in the otherwise unused land between turbines.


Combining both solar and wind generation on the same site, says Clark, also smoothes out the inevitable peaks and troughs of both forms of power resource as wind turbines typically produce most of their powers in the winter and autumn while solar panels produce more electricity in the spring and summer.


If the panels are positioned sufficiently high above the ground, Clark notes, the land can also continue to be used for other agricultural purposes such as the grazing of sheep.


Clark said: "While commercial scale solar is still in its infancy in Scotland, the falling price of photovoltaic panels combined with our longer daylight hours mean that despite our notoriously dreich weather this technology is not only viable, it also has the ability to make a good contribution to our overall renewable energy mix."


Unlike the building of wind farms, which have divided communities the length and breadth of Scotland because of their potential visual impact on the landscape, solar energy projects have not, at least so far, generated any significant public opposition and most applications for planning permission for solar projects have not attracted any objections.


A study published last year found that most people in Scotland are relaxed about living close to a solar farm, with more than one-third of people saying they would be happy to live near a solar project and half of those surveyed saying they had no strong opinion about them.


Of course that might have something to do with the fact that the solar power industry in Scotland is still in its infancy and all constructed projects have so far been small and relatively unobtrusive. Whether that public support will continue once larger arrays start being built on multi-hectare sites in the coming months remains to be seen.


COLD CALLING


The launch of the so-called feed-in tariff in 2010 which provides subsidies to households and businesses created a sizeable installation industry in the UK almost overnight and this has led some installers to make unsolicited phone calls to consumers touting their services. If you are phoned with an offer that sounds too good to be true the advice from trade body Scottish Renewables is to read the fine print carefully before signing any contract and to check with Local Energy Scotland, which maintains a list of approved installers as well as providing advice on the installation of renewable energy schemes.


CASE STUDY


The fashion retailer M&Co has for the last four years been generating its own green energy to power its network of 250 stores across the UK through a subsidiary company MEG Renewables, based in Inchinnan, Renfrewshire. Although most of its projects are hydro schemes, the company has recently installed solar panels on the rooftops of two of its stores in Scotland, Forfar and Largs, as well as two stores in England, and these are now supplying around a fifth of the stores' electricity use. Business development manager Kenny Hunter says that the trial has been a success and the company is now considering installing solar panels at other M&Co stores around the UK. Unlike the company's hydro schemes, most of the power from the solar panels is used directly in the stores with any unused power sold back through the national grid.