E.ON at EMEC

The E.ON project, located off the west coast of the Orkney mainland, is a three year programme to test a P2 Pelamis machine at the European Marine Energy Centre (EMEC).

Designed and built by Pelamis and owned by E.ON, the P2 machine is the first of a second generation of Pelamis wave energy converters and the first wave machine to be sold to a utility for operation in the UK.

The machine will be operating at EMEC alongside a similar P2 machine owned by ScottishPower Renewables. The two utilities have a working agreement to maximise the learning from operating and maintaining the machines as a wave farm.

The testing or ‘work-up’ programme is structured through a series of weather states, each with progressively higher wave heights. The Pelamis machine will be tested over a defined period of time in each state before graduating to the next.  This approach allows progressive management of risk for the technology, and ability to find and handle any unexpected technical issues as they arise. See our section about 'Real Sea Testing' for more information on this approach.

The learning and experience gained from the project will be used by E.ON in the development of a 50MW wave farm located to the north of EMEC.  The project could see up to 66 Pelamis machines connected to the UK grid and was awarded an agreement for lease from The Crown Estate in 2010.

Photo: E.ON's Pelamis P2 at EMEC, April 2012

Project Updates

The E.ON P2 machine was successfully installed onsite for the first time in October 2010 and generated electricity to the national grid within a few hours of connection. In over a year of progressive testing since then, Pelamis and E.ON have celebrated the following significant achievements:

• Generation of smooth wave power

The E.ON Pelamis machine has now been tested in wave heights of up to 8m with sustained generation.

In these moderate sea conditions, the Pelamis machine has been absorbing bursts of power in excess of 2MW. These highly variable peaks have been converted into smooth 30 minute average electrical output of 270kW, roughly enough to meet the electricity needs of 550 homes¹. Electricity generation has peaked at over 400kW. As electricity generation is increasing throughout the testing process, measured conversion efficiency has consistently measured around 70% across the range of sea conditions. 

The measured performance of the Pelamis is in very good agreement with our simulations, as verified by third parties, giving us a high level of confidence in our projections for the onward economics of the technology. 

We continue to focus on fall-back control and system robustness but following completion of the first stage of our workup programme, we are progressively increasing response and power absorption. Generated powers are expected to rise substantially with future operations as we ramp up the control and power take-off systems.

• Capture Widths

Pelamis Wave Power has measured capture widths approaching 20m in small seas. The capture width of a machine is the width of wave front from which all the energy is extracted. Even though the Pelamis is only 4m wide it can capture a much greater width of wave front. The theoretical maximum capture widths of the Pelamis are much higher still and we will continue to work towards these limits through improved control of the machine response. For more information about the power capture abilities of Pelamis see 'Power Capture'.

• Installation & Removal Operations Proven

The new installation and removal systems, developed with the support of the Carbon Trust, have proven their worth with smooth and safe connection and disconnection of the machine whilst in conditions  up to 2.25m significant wave height so far. That’s pretty choppy, with individual waves above 3.5m high, and sufficient to make intervention possible year round without excessive waiting on weather, which as an enabling factor of commercial marine energy. The removal operation has also been conducted using a single vessel instead of the two that were required previously. The tests have also proven the use of the local Orkney Towage vessels, hired by the hour, to tow the machine out to the EMEC site and to hold the machine heading during the automated installation operation.

The machine has been fully installed and grid connected within 90 minutes of arriving on site, and at the end of an installation period it has been removed from site with a 12 minute operation. These times are set to reduce further as experience is gained and systems are improved.

Video above: The Pelamis P2 generating electricity from EMEC in April 2012

¹Calculation based on DECC report ‘Energy Trends’ which states that the average UK home requires 4.2MWh year.