Tidal devices - performance review

Following the Scottish Renewables Marine Energy conference in Inverness, a couple of interesting performance metrics emerged.

Atlantis recently announced that the MeyGen project had generated 700 MWhr during August, apparently from 2 AndritzHydroHammerfest (AHH) turbines.  We thought it might be interesting to extract an average capacity factor from these figures.

2 turbines at 1.5 MW - 3 MW installed capacity.

Number of hours in August: 31 * 24 = 744

Total potential output = 744 hours * 3 MW = 2.232 GWhr

Actual output: 700 MWhr

Capacity factor: 0.7/2.232 = 31.4%

This may be a slight over-estimate, as the third AHH turbine may have made a minor contribution late in the month following its re-installation, but even with that proviso, these are not bad figures for a full month (i.e. neaps and springs).

ScotRenewables made a similar claim - that its 2.0 MW SR2000 had generated 116 MWh over week.  This equates to a capacity factor of 116/(24*2*7) = 34.5%, and we understand that this period was intermediate between spring and neap tide.

As runtimes extend and reliability improves, we hope to see these numbers go up too.

Revisiting the Marine Current Turbines capacity factor

Some while ago, in this blog post we calculated an apparent capacity factor for Marine Current Turbine's SeaGen in Strangford Narrows of 38%.

We've been rooting around in OFGEM's ROC database to see if there's further information available on SeaGen's performance.

Looking at the ROC register, which reports the number of MWh generated for ROC-accredited projects, it seems that the SeaGen achieved monthly average capacity factors of up to 58% in its best years.

This analysis is based on SeaGen having a capacity of 1.2 MW and is consistent with another blog analysis we did of the capacity factor of the technology.



This analysis begs some other questions though - what went wrong in 2011?  and has the technology been abandoned since 2014? It also seems that the capacity factor was pretty variable, pointing to a lack of reliability - fair enough in a prototype technology.

We'll be using this approach  to look at other technologies too, in the upcoming Redfield review of tidal technologies and its companion volume - Redfield review of wave technologies.  Contact us for details: info(at)redfieldconsulting.co.uk

More interesting marine recruitment

Interesting to see that Atlantis Resources is beefing up its management team too, with the hiring of Jim Forbes as Chairman of the UK business.

Details here.

So just like Aquamarine, there's a real strengthening of management teams going on in the space right now, and a real commercial focus on the new hires.