Only those of a certain age can now remember candle-lit nights of the 1970s, so it is not surprising that Scots are complacent about "security of supply" - the assumption that the lights will always respond to a flick of the switch.

That complacency may be set to change, at least to the extent that we may need to start thinking about importing power to keep the lights on. In a Scottish Parliament debate last week, energy minister Fergus Ewing spelled out the risk posed by the premature closure of the Longannet coal-fired power station, ostensibly because of stalled negotiations over grid connection charges. "This is very serious" he said.

"My information is that, unless there is a resolution, Scottish Power must intimate to National Grid, no later than the end of March, that Longannet will be closed. Therefore, unless the negotiations are concluded successfully, there is a great deal at stake... At one point, Scottish Power was optimistic that a deal would be reached. We are not satisfied that the assumptions that National Grid has made are prudent-in fact, many of our experts take the opposite view."

However Ewing's plea to fellow MSPs that Longannet's future was "too important to be used as a political football" seems unlikely to prevail. Some, like former Labour energy minister Brian Wilson and columnist already suspect the SNP Government themselves of taking the "gold medal for brass neck" by creating a distracting political spat with Westminster out of the long-established grid charging regime, instead of working to ensure that Longannet's Spanish owners Iberdrola, parent of Scottish Power maximised the life of the landmark power station.

Already Fife MSPs of all parties, along with the Scottish Government itself, are staking out positions of solidarity with Longannet's 260 workers whose professionalism was praised by Ewing for: "delivering electricity for this country for 42 years over 215,000 running hours [from a station designed ]to have a life of 25 years and 150,000 running hours,".

It is not hard to see "Save Longannet" crystallising into a full-blown campaign in the coming months, although any extension of the existing plant's life would only be a stay of execution. Regardless of a National Grid system that "discriminates", in the Scottish Government's view, against power stations that are furthest from the biggest markets in Southern England, and which actually pays out to those who are closest (including the three power stations that Scottish Power owns in the Home Counties), toughening European rules on emissions mean that the highly inefficient and - by modern standards - dirty Fife plant would have to close by 2020 whatever Scottish Power and National Grid's negotiations.

As well as threatening jobs in Scotland's open cast coal mining industry, the imminent loss of Longannet will take a massive chunk out of Scotland's "baseload" supply of energy (also comprising the life-limited nuclear plants of Hunterston and Torness) that underpins the intermittent renewables element - mostly onshore wind - that currently provides 45% of Scotland's energy mix. While Scottish wind power received a boost last week, from the award of 11 Department of Energy and Climate Change (DECC) 15-year "contracts for difference" to supply the grid, including the 448 megawatt Neart na Gaoithe offshore wind farm in the Firth of Forth. While industry body Scottish Renewables hailed the award, which have achieved 1GW of offshore wind in Scottish waters as "potentially kick-starting offshore wind in Scotland", it was criticised by conservation group Friends of the Earth Scotland as a "disappointing" minor addition to the stock of offshore wind generation. In any case there is no serious expectation that last week's round of awards will significantly impact the question of security of supply in the foreseeable future.

As for tidal and wave energy, prospects for that experimental sector impacting on the mix have receded even further into the future. As the Herald revealed yesterday, none of the contenders for the £10m Saltire Prize for producing a viable device now has a chance of achieving the goal by the June 2017 deadline.

According to Professor Colin McInnes, who holds the James Watt Chair at Glasgow University's School of Engineering, the hopes of a non-political, or rather science and engineering-based, energy debate in Scotland are already forlorn. He is critical of the way that the energy debate has been led by the Scottish Government, and sees the growing uncertainty about how to provide baseload and "dispatchable" (emergency top-up) power as a case of "chickens coming home to roost."

McInnes, like his Glasgow colleague Professor of Engineering Paul Younger who was quoted extensively in last week's parliamentary debate, believes that the lead time needed to construct new fossil fuel plants that will take the strain when renewable power is not available, is fast running out. The Scottish Government's emphasis on renewables targets has, he says, distracted attention from baseline needs and realities, and allowed "barking" ideas about a potentially renewables-only Scotland to gain mainstream currency.

"We need to have an energy policy that is technically well-founded, we need a balanced energy mix. Instead of what should have been a simple matter of energy economics, we have seen the debate politicised by a 2020 target to achieve the "equivalent" of all of Scotland's energy needs by renewable energy."

"Why would you want such a target? It's an arbitrary number thought up by spin doctors for a purely political purpose. It's more fitting for the 1950s Soviet Union than for a a dynamic modern economy."

"Because of these targets and the [rhetoric] about becoming the Saudi Arabia of renewables, the fact that the priorities of the three big power stations that have been powering Scotland for decades have been quietly forgotten."

"If Longannet were to go within 18 months, it's not just that we would be losing that massive output, its also the nature of it being baseload, Longannet is running 24/7, and being coal-fired it can be ramped up and down to anticipate demand

Last week's parliamentary debate on the need for a better energy strategy, led by the Scottish Conservative MSP Murdo Fraser, was welcomed by Fergus Ewing as a chance to address the "threat" to Longannet and consequently to Scottish electricity generation, though it remains to be seen how much political airtime will be allotted to seeking ways to diminish that threat, as opposed to seeking to allocate blame for allowing it to arise. The Scottish Government got its retaliation in early, writing to the Prime Minister earlier this month implicitly blaming the UK Government for presiding over the allegedly discriminatory charging regime.

In what Labour's shadow energy spokesman Tom Greatrex described as "synthetic outrage" and "a red herring" Nicola Sturgeon is clearly framing up this issue as the prime suspect in the slow-motion death of Longannet. However another likely cause is Scottish Power's failure to apply promised green modifications to the venerable plant, including a once-mooted UK Government-funded £1bn carbon capture pilot scheme, that might have allowed it to eke out a few more years of useful life.

But the blame game also applies retrospectively as well. As the Sunday Herald revealed in January 2013, it was the Coalition's own green measure, the carbon price floor tax, introduced in 2010 that is said to have scuppered Spanish-owned Scottish Power's trumpeted plans to upgrade Longannet into a model "clean" coal generator, by adding around £250m to the costs.

As business secretary Vince Cable last week emphasised, the fact that the UK has a national grid, and can always import energy from England makes the return of Heath-era candlelit evenings as firmly consigned to the 1970s past as Spangles and Chopper bikes, although Prof Paul Younger warned of "serious, serious trouble" if the National Grid was found not to have the capacity to import the required amounts of electricity.

While opposition parliamentarians, including the Green MSP Patrick Harvie, have challenged the Scottish Government's emphasis on grid charging as the root of Scotland's burgeoning energy anxiety , the Scottish Government's call for a reform of the system does have academic support.

Stuart Haszeldine, professor of carbon capture and storage at Edinburgh University believes that the current highly centralised grid regime is "bizarre" in that it results in a situation where Longannet's relatively cheap coal-fired electricity costs about £40m a year to be connected to the grid, while a similar power station producing the same energy in the south of England would actually receive a payment of £4m.

"The current grid charging regime does appear to discriminate against [power stations] getting built in Scotland". Haszeldine says. "Longannet pays to provide power to nearby Edinburgh and Glasgow but if a southern English power station was to supply those cities, they will be paid money to generate the electricity that will be shipped from the South to North".

"We don't get a clear answer as to why that is, except that it is part of a 'national balancing'. The National Grid says it has no responsibility of structuring the strategy, or the strategy of investment about where power gets generated. Clearly in Scotland we could host [new power stations] on the Longannet site and [closed-down East Lothian coal-fired power station] Cockenzie has planning permission to build one there, but Scottish Power are not actioning that."

"Despite their name, Scottish Power have no responsibility to Scotland, their job is to make money for their shareholders. If you ask the UK Government, as we do, who has responsibility over the planning and supply of energy to the benefit of the UK, they say we have given responsibility to National Grid. If you ask them, they say, no no its up to the market to decide."

Haszeldine "as a scientist" is also interested in the potential, although more in terms of the jobs opportunity in high value manufacturing than in power generation, from unconventional gas or fracking, to which Scotland's two main parties are attempting to outbid each other in their degree of opposition.

This view is shared more vehemently by Glasgow University's Colin McInnnes, who sees the auction of rhetoric - bid up again by Labour's Lewis MacDonald in the Scottish Parliament last week - as an offence to the Scottish tradition of rational scientific debate.

"We need to be more grown-up in our thinking about energy in general, and if you look at some of the misinformation that's being spread about fracking, it's quite astonishing.

"The fact is that nobody is entirely sure what the [shale gas] resources is, but we now have this blanket moratorium on finding out because there's an election coming up. We should be licensing some experimental drilling in order to get a handle on what the cost is of extraction. It's entirely sensible to find out about the scale of the resource, then you will know what you have if you need to get them out of the ground, even if not for [hydrocarbon-derived energy] then as the feedstock for petrochemicals and lots of the other things that we use in everyday life."

"We have been so used to having the luxury of reliable, cost-effective energy in Scotland we don't care about where it comes from. Now that the situation is becoming more challenging, we need to think in terms of engineering and economics, but the risk is that we in Scotland are politicising the issues to such an extent that its really detrimental to having a rational debate. I can understand that there will be objections to fracking, but they have to be based on the actual scientific evidence."

Given the fractious and divided nature of Scottish political reality, only enhanced by forthcoming elections this year and the next, the time does not seem propitious for a calm and purely technical consideration of how to ensure a stable and secure energy supply, that will encourage investment and keep the proverbial lights on. The fact that the clock is fast running down on Longannet, and the urgency of the jobs situation there will be a steady reminder that power involves hard choices as well as a twitch of the finger on a kettle switch.