The UK is in one of the best locations in the world for wave and tidal power generation in terms of both geography and expertise. It has a unique opportunity to establish itself as the global centre of excellence for marine renewable technologies and infrastructure, but the industry still lags behind wind power in terms of technology and investment.
Generating electricity from the UK's wave and tidal resources makes sense because marine energy is clean, efficient and predictable. It is not reliant on the vagaries of the weather, which ensures consistent power generation. The country also has numerous tidal range sites to take advantage of, including the world's second highest tidal range in the Severn Estuary.
Marine energy presents a significant economic opportunity for the UK to capitalise on; wave energy has the potential to generate £2 billion and thousands of jobs. The benefits of this growing sector can be captured through the entire supply chain; from research and development through to engineering, manufacturing, installation, operation and maintenance.
It has been touted that as the sector gradually rolls out more and more devices, marine energy could be ready for commercialisation and mass scale deployment by 2020. The recent announcement that the Crown Estate and Scottish Government have named 10 wave and tidal power installations around the Orkney Islands and Pentland Firth, with the potential to power up to 750,000 homes, is a real step forward for the UK in achieving its marine energy potential.
The Government has also recently released its draft Marine Energy Action Plan which sets out recommendations for the development of wave and tidal power in the UK and outlines the main challenges for the marine energy industry. Government departments and agencies such as Defra and the Environment Agency would be involved, and the plan suggests encouraging financial support from both public funding bodies and private investors.
However encouraging these announcements are, there are a number of hurdles to overcome if industry is to deliver large-scale deployments. These include issues of prototyping and developing the hardware cost-effectively, finding the right component suppliers, creating a safe and effective installation vessel fleet, and installing and maintaining the equipment.
One of the main requirements of the sector is the development of power generating technology that successfully and continually works in – and withstands the harsh conditions of – the marine environment. Unfortunately the marine renewable supply chain is still relatively immature; with regards to wave energy technologies, for example, there are a number of devices on the market but there is no real convergence of ideas nor any real consensus on design.
Device makers and technology providers also need access to testing facilities and hydro-dynamic expertise to ensure the effectiveness of their products in a variety of real-life conditions. Facilities such as Scotland's European Marine Energy Centre (EMEC) offers developers the opportunity to test full scale grid connected prototype devices in realistic wave and tidal conditions.
Another company that has made an active contribution in this area is QinetiQ. A number of device makers use the company's testing centres at Haslar in Portsmouth and Rosyth in Fife. These include Checkmate (maker of the Anaconda wave energy system) and Aquamarine Power (maker of the Oyster device).
The marine testing facilities at Haslar include a 270 metre long ship towing tank and a 125 metre ocean tank, the largest covered stretch of water in Europe. Haslar is also the founding ‘home’ of hydrodynamics, the science of how objects move through water and how water moves around them.
Physical prototyping of marine device designs is an essential part of the journey from drawing board to deployment at sea, and is particularly important in establishing the business case for individual ventures. While early pioneers in wave and tidal were sometimes tempted to miss out this step, the result was invariably sub-optimal performance and the need for costly recalibration, or at worst a completely written-off project.
It is becoming increasingly important for designers to physically model and test devices, as well as analyse and evaluate designs using computational flow models to calculate the likely amount of energy that a particular device will yield.
Deploying marine devices
Physical deployment is an issue that should not be underestimated, with a major stumbling block being the shortage of suitable deployment vessels for marine devices, particularly in adverse weather conditions. There are also different vessel requirements depending on the type of marine device. For wave devices, the type of deployment vessel is perhaps less of a challenge as these devices can be towed and anchored.
Tidal devices, however, are potentially massive structures that have to be secured underwater and need specific deployment vessels with heavy lift capabilities and the ability to accurately position the device once in place.
There is also the question of vessel availability. The same deployment vessels are currently being used for oil, gas and offshore wind, and are not necessarily available when marine device developers want them. In order to meet 2020 targets, the UK needs to be deploying up to 8 devices a week from 2015 onwards – this is currently unfeasible, so many more vessels need to be urgently built. A number of utility companies are already looking to invest in the sector and to commission vessels in consultation with hydrodynamic design experts in order to fill this gap.
Wave and tidal power standards
Global standards for wave and tidal power devices are being developed by the European Marine Energy Centre (EMEC).
The wave and tidal power device standards will be reviewed in May by the International Electrotechnical Commission (IEC), which sets global standards to improve industrial efficiency, safety, environmental protection and world trade.
The wave and tidal power device standards are part of a wider suite of marine energy standards developed by EMEC. They propose measures for the performance; reliability and survivability of devices; assess wave and tidal site resources; and look at key aspects such as design and manufacture, environmental appraisal and health and safety. EMEC says over 4000 copies of the wave and tidal power device standards proposal have been distributed worldwide. They are already in use in many places, and EMEC says it is collating feedback as the industry develops. John Griffith, Standards Project Director at EMEC, says: “It is vitally important that the marine energy industry develops standards that provide international credibility”.
Once deployed, there is the further challenge of maintaining and servicing the devices in what is often a remote and hostile environment. Because of the relative difficulty of replacing components offshore, anything that makes maintenance as seamless and quick as possible is to be welcomed.
Companies like QinetiQ are heavily involved in developing condition monitoring technologies, which can remotely detect issues such as fatigue cracking and lubricant contamination via advanced sensors. Being able to anticipate problems before they occur means that repairs and servicing can be more accurately planned, downtime minimised and maintenance costs controlled.
Grid and infrastructure
A marine renewable-ready UK grid system and supply chain infrastructure (including ports and skilled workforce) is also imperative for the level of deployment required to help meet 2020 targets and beyond. While there is a considerable amount of floating infrastructure designed to support the offshore oil and gas markets, this is not always available in a timely and cost-effective manner to the marine renewable market nor is it always tailored to its needs.
An environmental regulatory framework is vital for helping the marine renewable sector develop into a long-term substantial energy supply and for providing protection against the potentially adverse affects of deploying structures in the marine environment. Expertise is vital to help the supply chain deal with issues such as identifying suitable locations to deploy marine energy devices, assessing specifics such as flow limits and navigational issues, performing environmental impact scoping studies on possible locations and identifying necessary permissions and certifications required to install and use marine devices.
As well as devices, the environmental impact of the deployment vessels has to be considered. By 2020, it is likely that European legislation will require every vessel operating in European coastal waters to have substantially reduced acoustic noise to limit the effect on marine wildlife. QinetiQ for one is transferring its expertise in radiated acoustic noise measurement and reduction in the defence sector to the marine environment, and is already embarking on such procedures in vessel designs for the civil sector.
The marine energy industry represents a tremendous opportunity for the UK, not only in terms of significantly contributing to the renewables mix, but also as a focus for the creation of new jobs and new companies to service this growing industry.
However, the marine energy supply chain still remains relatively immature and requires ongoing financial and political support. It also needs access to technical expertise and consultancy, whether that means helping inventors get their ideas from the drawing board and into the water or ensuring that the deployment of marine energy devices does not result in unnecessary disruption to the surrounding environment.
In order to secure the country's national energy supply and manage the transition from a predominantly carbon-based energy model to one that is diversified across a mix of resources, the UK needs to develop strategies based on a variety of technologies. Marine energy, although less high profile than the wind power industry, needs to be treated as a vital part of this mix.
About the author:
David Elliott is a consultant in QinetiQ's maritime platforms division and member of RenewableUK (formerly BWEA)'s Marine Strategy Group. QinetiQ is an international technology company that provides services for the marine supply chain from planning and business case development to optimised deployment and ongoing monitoring.