With the Scottish Parliament elections just four months away, Scottish Renewables launched its manifesto today.

It is an ambitious and wide ranging document covering the aspirations and goals of renewable policy as well as many detailed policy initiatives. It sets a target that 50% of energy consumed in Scotland in 2030 should be from renewable sources.

Perhaps though the most important aspect of the manifesto is that it sets out a vision to 2030. The industry has been operating on the basis of the 2020 targets for the past decade, but in infrastructure terms, 2020 is almost upon us.

And perhaps the second most important aspect is that it sets a combined target for electricity, heat and transport. In the past decade the industry has focused on electricity production - heat and transport have never quite received the policy push that electricity has with the Renewables Obligation and CfD.

It is worth noting that this is a renewables not low carbon target, which is of course in line with current Scottish Government policy. As existing nuclear power stations in Scotland are closed in the coming years, this policy divergence with Westminster is only likely to become more acute.

There are many policy objectives. I'll keep this short and pick out just a few.

The manifesto tasks the Scottish Government to "[create] the conditions for Scottish onshore wind to be the lowest cost anywhere in the EU15". The challenge is how to develop zero subsidy wind farms. It will mean developing only the windiest sites, the vast majority of which will be in Scotland. However, a windy site on its own will not be sufficient for wind farms to compete with gas generation located in England. Wind turbines will need to become taller and bigger - on the continent turbines of more than 150 metres in height are not uncommon while in Scotland 126 metres has become a de facto maximum. There is, however, no legal or policy limit on turbine heights - the challenge for the Scottish Government is to create a policy environment where wind farms with taller turbines can be effectively assessed within the planning system.

Scottish Renewables also calls on the Scottish Government to keep pressure on DECC to persuade it to allow onshore wind and solar to participate in CfD auctions on the basis of "subsidy free contracts". The availability of a CfD contract, even on a zero subsidy basis, is a valuable instrument for a project developer - without such a contract, the task of securing project finance from the funding community will be challenging to say the least, and project finance is, of course, the lifeblood of independent developers. Funders rely on the CfD contract to mitigate market price risk as well as political risk, i.e. the risk that government policy changes affecting the price of electricity.

If the UK Government wants to continue to support competition in generation, the continued availability of a CfD, even on a zero subsidy basis, will be essential. If the industry can 'win' that argument, the next one is what exactly does zero subsidy mean? There are many possible permutations. The current electricity price? The forward price curve? The forward price curve averaged over 15 years? A carbon cost adjusted price? The price required to support gas fired projects? The list is endless.

The latter does not sound like a zero subsidy, more the minimum subsidy required to secure the investment needed for new plant. Yet Amber Rudd, Secretary of State for Energy and Climate Change, acknowledged just this in her major policy speech in November: "No form of power generation, not even gas-fired power stations, can be built without government intervention". So an argument can be made that a contract based on the support available to gas fired projects is not a subsidy, or at least not a subsidy relative to the market.

Scottish Renewables' manifesto also calls for a new regulatory and incentive framework for district heating and a policy that would require developers to consider the feasibility of installing CHP systems for all new developments in Scotland. CHP schemes in Scotland have often been installed with the backing of the public sector or housing associations. For example, a CHP scheme was a cornerstone element in the regeneration of Dalmarnock, which hosted the athletes' village for the Commonwealth Games. For the public sector, CHP schemes don't just reduce the carbon intensity of energy use, they also help to reduce fuel poverty and the public sector therefore has been willing to back them.

However, if CHP is to make an effective contribution to reduction of the carbon intensity of energy use in Scotland, CHP schemes will need to be installed more widely, and that can only happen if they are installed in privately-funded as well as publicly-supported developments. And that can only happen if appropriate planning, incentive and regulatory policies are developed.