The proposed solutions are part of a wider review of the potential for renewable generation in the Scottish islands, published today by the Scottish and UK government.
The review found that the levelised cost of energy from onshore wind projects on the islands are typically £19-45/MWh (€22-€53/MWh) more expensive than those on the mainland.
However, the costs of onshore wind are similar to other forms of low carbon energy being considered, including nuclear and imported renewable energy from Ireland.
The report suggests 0.4-0.5 Renewable Obligation Certificates more for wind on Scottish islands, which could be differentiated according to the location of the island, as those to the west of the mainland need more support than those to the north east.
Alternatively, transmissions charges could be capped to £30/kW/year, the review suggested.
Trade body Scottish Renewables welcomed the report and urged the governments to decide on a solution. The cost of grid infrastructure could be reduced through funding from the European Investment Bank, it suggested.