The gravitational relationship between the earth, moon and sun actuates one of the most potent sources of energy we know: tidal stream. Harnessing and commercialising its potential however has been a challenge that’s only now – literally – being fathomed. 

Orbital Marine Power Ltd, with offices in Edinburgh and Orkney, is a pioneer in the field with its unique technology under continuous engineering development, including testing of scaled systems in tank conditions and open ocean environments since the company was founded in 2002. 

Recently it brought its breakthrough 2MW SR2000 floating tidal turbine prototype programme in Orkney to a close to make way for the company’s first commercial turbine variant – the 2MW O2. 

The SR2000 was arguably the most successful full-scale tidal prototype to date says chief executive officer Andrew Scott. “A lot of great performance came out of that machine but it was a prototype and we knew from an early stage of development that there were improvements that we could make.

“These include enhancements to the system from a yield perspective. Expanding the swept area of the turbine to a 20-metre rotor diameter means an almost an 50% increase on swept area on its predecessor. That has a big effect on reducing costs of electricity for the turbine,” he adds. 

In October 2018 Orbital opened a £7 million crowd funding debenture on the London-based Abundance Investment platform to support building the O2, a 74m-long floating superstructure with two 1MW turbines at either side and a rated power output of 2MW.

The technology, he says, is unique to Orbital Marine: “Most people are familiar with the concept of an underwater wind turbine but from day one we saw a different solution, one that’s more akin to constructing and anchoring a boat with the significant cost and risk benefits that result from taking that approach.”

The first O2, which will be operational next year, is being constructed in Dundee drawing on a supply chain that spans Scotland, the UK and Europe – with bearing systems from Sweden and Germany, anchors from Wales, composite rotors from England – but  Scotland plays the leading role. 

Most of the turbine manufacture is being done by TEXO Fabrication in Dundee, with the fabrication process using steel from Liberty Steel Dalzell in Motherwell as well as utilising  many of the traditional engineering and industrial capabilities within Scotland.

It’s something Scott is proud of. “Tidal stream energy has very much been a Scottish-led endeavour and that’s logical given the industrial and engineering heritage we have here, from shipbuilding to oil and gas. it’s natural to seize the opportunity to diversify those skills into an industry with similar requirements and operations. And of course, we have a great tidal resource here too.

And, he says, there are major opportunities in the export market. “We see an ever-growing global demand for the supply of low carbon energy solutions like our own. However, turning that into a sustainable job and wealth creating industry for the UK requires investment though, chiefly in the creation of a domestic market. 

“Servicing a domestic demand will allow the supply chain to entrench capabilities here in the UK such that we export turbine equipment and services and avoid exporting companies.” 

“Strategically, the UK should be looking to be at the forefront of this decarbonising revolution that is under way and including tidal stream as part of the mix is a no brainer. It’s a win-win as far as we’re concerned.”