Residents of the Shetland Isles may not have realised that they were helping to make history recently when they switched on their appliances and made tea. However, the Bluemull Sound tidal array became the first tidal power array to deliver electricity directly to the grid on a commercial basis, supplying dozens of properties on the Shetland Isles.

The Tidal Array, which was installed by green energy developers Nova Innovation, who are based in Edinburgh, has been flagged as a turning point for tidal power.

The project has also demonstrated that the technology is viable. Earlier in March, it proved this with a single energy-generating turbine, but the installation of an additional grid-connected turbine has proved the value of the technology on a commercial scale.

The industry had previously viewed tidal power on a commercial scale as the Holy Grail of renewable energy, thanks mainly to the tide's ability to be completely predictable, unlike other sources such as solar and wind.

The new array has already gone through complete testing and has been approved for grid linking thanks to work carried out by Orkney's European Marine Energy Centre.

Shetland isn't connected to the UK's national grid, but it does have its own electricity grid. This is the first time that any tidal energy project has been linked to a distribution network. The development also means that Scotland is now well positioned to drive forward huge marine energy benefits and be at the forefront of that industry. Estimates suggest that this type of renewable energy source could be worth up to £120 billion if fully harnessed.

The country also has the biggest proportion of European tidal resources, with Pentland Firth, Orkney, the Western Isles and the Shetland seas all being focal points for development.