Seven companies have been awarded leases for 10 sites in the sea around Orkney and the Pentland Firth.
Here the BBC Scotland news website profiles the developers:
The Edinburgh-based company has been developing the Oyster, a hydro-electric wave energy convertor.
Martin McAdam, chief executive officer, said: "Harnessing the power of the sea to produce clean energy will play a crucial role in our future energy security and in meeting the UK's climate change objectives.
"Deploying Oyster on a commercial scale has the potential to generate millions of pounds for the Scottish and UK economy and to create hundreds of jobs on a local and national level."
The UK division of the German-headquartered company is the second largest electricity generator in the UK and also owns its second biggest power distribution network.
MARINE CURRENT TURBINES
Bristol-based, the company installed the world's first offshore tidal turbine near Lynmouth off the coast of Devon in May 2003.
MCT plans to have its first phase of more powerful 66 SeaGen tidal turbines deployed during 2017 with the whole scheme operational by 2020.
Managing director Martin Wright said: "The Pentland Firth and Orkney waters are strategically the most important marine energy areas in Western Europe so we are delighted to have secured approval for a lease by The Crown Estate."
During 2006, it was the first company to install a tidal turbine at the European Marine Energy Centre (Emec) in Orkney.
James Ives, chief executive of the Dublin-based developer, said: "Today's development marks a major step forward for both OpenHydro and SSE Renewables and the marine renewable industry in general."
He added: "We are very excited about further developing our presence in Scotland which will build on OpenHydro's important research work that has been ongoing at the Emec since 2006."
PELAMIS WAVE POWER
Edinburgh-based, PWP developed the Pelamis Wave Energy Convertor - the world's first commercial-scale offshore wave energy machine to supply electricity to the grid.
It was also the first to be commercially used.
Chief executive officer Neels Kriek said: "The challenges associated with the ambitions which have been set today are significant, and the team at PWP are energised to embrace these challenges to the benefit of ScottishPower Renewables, our other customers and the UK low carbon economy objectives."
SCOTTISHPOWER RENEWABLES DEVELOPMENTS
Part of the ScottishPower group, which serves five million homes and businesses in the UK and western US.
Its registered office is in Glasgow.
Director Keith Anderson said: "The announcement today is another significant step forward for Scotland and its ambition to be a world leader in generating renewable electricity.
"The Pentland Firth has some of the best marine energy resources in the world and we are delighted to have secured two excellent development sites."
SSE RENEWABLES DEVELOPMENTS
A subsidiary of SSE, which supplies electricity and gas to more than nine million properties in the UK.
SSE sites - including hydro-electric schemes - generate 10.7 megawatts (MW) of electricity.
Stephen Wheeler, director of SSE Renewables, said: "We believe our commitment to marine renewables will not only deliver a significant contribution to the renewable energy mix and climate change targets, but also enhance Scotland and the UK's position as world leaders in marine energy.
"We look forward to working closely with statutory bodies, local communities and the Crown Estate to develop these sites prior to bringing forward applications."