The 1500 MW is the available resource after taking account of planning, environmental and other practical constraints on development, as well as the limitations of the electricity supply network. The figure assumes a cost limit of £0.10/kWh -- discounted at 8% over plant lifetime. Not surprisingly, given Scotland's favourable wind regime, the study found that wind energy dominated the resource with potential for up to 1100 MW of installed capacity -- nearly 75% of the practicable resource.
The study reveals that, depending on siting, up to 300 MW of new generation could be absorbed into the existing electricity system without any significant alterations to the transmission network. However, the amount of new capacity that could be connected rises to around 1500 MW if up to £45 million is spent on re-configuring the network. The study's network analysis reveals that the transmission system north of Dundee and Pitlochry is incapable of accepting new generation without being reinforced. However, utility HydroElectric says that in certain areas minor additional generation on the grid may be possible, but this would need to be determined on a case by case basis.
The report points out that any power generated by new renewables which was not exported from Scotland would displace output from existing generation. Moreover, it would be competing with the avoidable cost of generation for the Scottish electricity system which currently averages around £0.015/kWh. Therefore it concludes that the main stimulus for renewable energy projects in the short to medium term will be the Scottish Renewables Obligation (SRO).
However, the extent of the renewable resource revealed by the study contrasts sharply with the size of the forthcoming SRO. The government intends to contract for around 30-40 MW of new renewables capacity in the first round, but says that it expects to make two larger obligations later. The Scottish Office claims that the existing over capacity in electricity supply was a major factor determining the size of the SRO.