THE sale of a batch of licences by the Scottish Government for additional offshore wind generation this week has resulted in some controversy. There are, of course, those who are delighted at the £700 million revenue raised. Others, like Tasmina Ahmed-Sheikh in these pages and Robin MacApline elsewhere doubt whether a good deal was done. I admit to sharing doubts with Tasmina and Robin, but I also tend not to cry over spilt milk and instead look for the possibilities to come.

The reality is, as all serious observers now note, that Scotland has enormous potential to generate renewable energy. Offshore wind is one of the ways in which this will be achieved. The real question to be asked in that case is how is that opportunity captured for the long-term benefit of Scotland?

A look at the economic fundamentals of offshore wind is the first thing to do. There are four fundamental elements in those economics.

READ MORE: ScotWind: Where are the 17 projects based and how much energy can they make?

First, a charge can be made for the right to exploit this opportunity. That is what has just happened, whether at the right price or not

Second, it would obviously be to Scotland’s advantage if as much of the value created in building these facilities could be located in Scotland as possible. The critics are suggesting that this is one of the weaknesses of the deals now signed: there is little requirement to use Scottish technology in what is going to be built.

Third comes the energy production stage. It will be vital that this production be both recorded in Scotland for tax purposes and be used to support Scotland’s long-term economy through the creation of employment, through the creation of exports, through the support for the Scottish currency that it will generate, and for providing the energy security that will both underpin the well-being of the people of Scotland and attract business into it for long term economic advantage. My suspicion is that the Scottish Government thinks that these upsides are worth a lot more than charging too much for licences now, but it is a trade-off and we do not know if they have got this right as yet.

Then there is the fourth element, which is the one that I am most interested in, simply because I am not seeing it discussed. This relates to the taxes owing on this production.

Some such taxes will be paid as a consequence of people being employed to build and then work on these facilities.

Other taxes will be owed on the profits earned by the companies generating this energy. A decidedly robust approach will be required to make sure that the right sums are paid when these profits are earned.

There is, however, another, much more important component to this tax take. That will be the equivalent of the Petroleum Revenue Tax paid on Scottish oil production when that oil was flowing, and when the UK Government had a sensible policy on this issue prior to the 2014 referendum.

My point is that granting a license to the seabed on which to build or tether new offshore wind generation capacity is one way in which the national resource of Scotland is paid for by these new facilities. However, it is not the seabed that actually results in power generation. It is wind that creates the energy, and those winds have not blown as yet. They will only do so in the future and what is absolutely vital is that at that time the value that is generated from these winds, which are the property of the people of Scotland and no one else, must be taxed so that Scotland gets its fair communal share from the value of the electricity to be produced, much of which will be exported given the amount that might be generated.

To achieve this Scotland will need a new tax. I call it a SWET, which stands for a Scottish Wind Energy Tax. It is this tax that could generate the most revenue for Scotland from these new wind farms.

And it is this tax which replaces Petroleum Revenue Tax in the projections of future Scottish revenue that may play such a big part in an independence debate.

If, and I recognise that I might be putting a lot of emphasis on that word, the Scottish Government is playing a canny game here of getting companies signed up to wind generation at relatively low cost to then collect large tax revenues on the basis of the Scottish wind that they use to generate profits as well as electricity after independence, then, this might be a good deal. That, though, is entirely dependent upon there being a SWET.

Debate on that tax is needed now. A lot may ride on it.