Tag Archives: water power

Saints and Sea Power in the Tidal Waters of the Irish Sea

By Alexander Portch

In 2008 the Bristol-based renewable energy developer, Marine Current Turbines[1] (MTC), installed the world’s first grid-connected tidal stream turbine in the waters of Strangford Lough on the eastern coast of Northern Ireland. Known as SeaGen S and capable of generating up to 1.2 GW of electricity from the kinetic energy of the Lough’s fast-flowing tidal currents, the device represented a significant step forward in the development of commercially-viable tidal power technologies. The recent near-collapse of MCT following the decision of Siemens, their owners, to sever their connection with the wave and tidal energy industry, served, however, as a reminder of just how much still needs to be achieved before tidal stream and tidal range devices start to receive the same level of investment and support as that enjoyed by other, more prolific renewable energy initiatives like wind and solar[2].

Nonetheless, SeaGen remains in situ, its blades rotating in unison with the twice daily rise and fall of the tide and, thanks to a 24 hour monitoring system, continuing to generate power with minimal adverse impacts on nearby marine fauna[3]. Furthermore, with the recent announcement that Atlantis, another wave and tidal energy company, is to throw MCT a lifeline, the future of tidal power in the Lough would appear to be secure[4]. A rare tale of success, which stands in stark contrast to the on-going saga of failed enterprises in the Severn Estuary.

Interest in the potential inherent in the tidal cycle of Strangford, and other similar environments around the coast of the British Isles, is, however, nothing new, with the achievements of the SeaGen device reflecting similar trends dating back more than a thousand years. In 1999 excavations at the site of Nendrum Monastery on Magee Island, the largest such landmass in Strangford Lough, resulted in the re-interpretation of linear wall structures in the waters to the east of the monastic complex as mill dams, rather than fish weirs as had hitherto been believed. Over subsequent seasons of fieldwork, the well-preserved remains of three successive phases of milling activity were revealed, with dendrochronological dating providing confirmation that this was the site of the earliest example of a tide mill in the world[5].

The first mill was shown to have been constructed between AD 619 and AD 621 and comprised a large dam, 110m in length, which served to impound water within a triangular millpond, 6,500 m2. The pond would fill at high tide and be retained as the tide receded outside the embankment, thereby providing a source of motive power to drive a horizontal waterwheel as it was released back into the Lough. This wheel would have been located in a wheelhouse positioned at the southern corner of the millpond. In the late 7th or early 8th century the first mill fell out of use and was replaced by a second complex of features on the same spot. The most marked change was a reduction in the size of the mill pond, with a new dam forming a smaller, rectangular area of impounded water adjacent to the shore. This was then largely destroyed by the final imposition of a third mill, again in the same location and dating to the end of the 8th century AD. Alongside a wealth of stone and waterlogged wooden artefacts, including a variety of stone slabs marked with crosses, the excavations yielded the almost intact upper millstone from this later development.

Remains Tidal Mill Pond

The surviving remnants of the mill pond embankments now lie largely submerged beneath seaweed and vegetation spreading from the shoreline. In the centre is the long, straight wall associated with the second and third mills, demarcating the boundary of a narrow millpond adjacent to the shore, whilst in the distance to the left is the embankment for the first millpond. Photo: Alexander Portch

Within the remarkably extensive literature on the history and archaeology of tide mills and early water mills, Nendrum has since become an icon of this site-type. Further fieldwork in Ireland is increasingly revealing just how commonplace such structures were in the early medieval period but, at present at least, Nendrum would appear to be where it all began. With my own interest in the recent and much deeper history of the interactions between humans and the non-human process of the tidal cycle, Nendrum has long been a source of some fascination and it was thus with great anticipation that I finally arrived there on a bleak and blustery day in late April. Despite the unseasonal weather conditions and the overcast leaden skies, the atmosphere of the place was tangible and it was a thrill to see the still imposing remnants of the mill pond walls in person. Thankfully a respite from the cold was provided by a superb, if somewhat modest, visitor centre which included a balanced array of written information, artefacts excavated from the site itself, interpretative reconstruction illustrations, a model of the site and an engaging, if rather dated, television documentary (great for someone nostalgic for the 90s, but otherwise in need of updating!).

Model medieval monastery

The fascinating and highly detailed interpretative model of Nendrum located in the centre of the monastery’s visitor centre. It pre-dates the discovery of the tide mills but provides a good insight into what the site may have been like a millennium and a half ago. Photo: Alexander Portch

In many respects this is the real antecedent of the ill-fated Severn Barrage. Whilst recent proponents of tidal range technology frequently tout it as an advanced technology of the future, a means by which to harness an apparently un-tapped source of endless and predictable energy, and an alternative to “old-fashioned” or “out-dated” forms of electricity generation like coal and nuclear, in reality it is nothing of the sorts. Its origins lie in the ingenuity and hard work of people living centuries earlier driven both by their need to extract power from whatever sources were available and their devotion to a power somewhat more intangible. Their lives seem almost impossible to comprehend in the fast-paced, digital age in which we now live, being bound up with cycles of day and night, ebb and flood that have long since been rendered obsolete through modern innovations. Nonetheless, with the recent proposals for a tidal lagoon near Swansea Bay only one step away from receiving government consent[6], it may soon come to pass that the tidal cycle regains some of its former importance as a source of power and sustenance at the heart of our own society.

N.B. For those interested in reading in far greater detail about the excavations at the Nendrum tide mills, a comprehensive archaeological monograph is available: T. McErlean, T. & N. Crothers, Harnessing the Tides: The Early Medieval Tide Mills at Nendrum Monastery, Strangford Lough (London: The Stationery Office, 2007).

 

Notes

[1] http://www.marineturbines.com/

[2] http://www.theengineer.co.uk/news/-siemens-hunts-for-buyer-to-take-on-marine-current-turbines/1019559.article

[3] Keenan, G., et al. “SeaGen Environmental Monitoring Programme Final Report.” Royal Haskoning: Edinburgh, UK, January (2011).

[4] http://www.imeche.org/news/engineering/atlantis-buys-marine-current-turbines-29041502

[5] McErlean, T.C. et al, ‘The Sequence of Early Christian Period Horizontal Tide Mills at Nendrum Monastery: An Interim Statement,’ Historical Archaeology, 41:3 (2007), 63 – 75.

[6] http://www.tidallagoonswanseabay.com/

 

A visit to the South Western Electrical Historical Society

By Kayt Button

The changes brought about by the introduction of electricity over the past hundred and fifty years or so or have totally transformed our everyday lives. From the homes we live in, appliances we use, our systems of communication, and types and methods of working.

Housing of the South Western Electrical Historical Society

Housing of the South Western Electrical Historical Society in an electricity sub-station (Photo: Kayt Button)

After a series of scientific discoveries from the late 1700’s through the first part of the 1800’s supplying electricity commercially began as an entrepreneurial venture for the scientifically forward thinking. Investing in electricity generation through steam engines or other power sources and profit on their investments by charging local people for electric lighting, and later, supply of electrical power. In my quest to find out as much about the early history of electricity from the 1850’s onwards, I came across the South Western Electrical Historical Society. After some communication with Peter Lamb, the society secretary, I visited the museum.

Exposition space

Exposition space of the the South Western Electrical Historical Society (Photo: Kayt Button)

The museum is located in an unused part of an electricity substation, courtesy of Western Power Distribution. The museum contains an exhibition room, where artefacts are displayed, a meeting room, two archive rooms and an office. The exhibition room contains may artefacts described as “What your Grandparents Used”. The room is crammed full of all types of appliances and equipment and although I could have spent a good few hours just browsing and taking in the written information, I wanted to look at the archive material.

I had already read a great write up on the early days of power in the south west, by Peter Lamb and after seeing how much written material there was at the society, alongside the wealth of knowledge of the people there I was thrilled. There are already a large number of individual town histories researched and recorded for the South West of England, as well as the supporting documentation for them. Alongside this I discovered Garke’s Manuals of electricity which document everything that occurred in the electrical industry at the time. With adverts and sponsorship, it is a series of books I am looking forward to investigating further alongside the many other documents and maps available at the museum.

Finding a group of such knowledge people has been a real pleasure, and not just because of a very delicious lasagne pub lunch! I am looking to work further with everyone at the museum to use the South West of England as a case study looking at the changes to electrical power over the past century and a half. Their website address is www.swehs.co.uk to find out more about them.

Co-production of knowledge: shaping the research framework of the Derwent Valley Mills UNESCO World Heritage Site

By Carry van Lieshout and Georgina Endfield

The Silk Mill Museum

The Silk Mill Museum. Source: Wikipedia

 

The Derwent Valley Mills UNESCO World Heritage site stretches along the river Derwent in Derbyshire, and incorporates the early industrial mills of this area. These include the Silk Mill in Derby, were John Lombe introduced water-powered silk spinning, as well as Richard Arkwright’s mills at Cromford, considered the birthplace of the factory system that allowed water-powered continuous production. Arkwright’s technology as well as his model of worker’s settlements were copied along the course of the river and beyond, as the mechanisation of cotton production spread out over the world. Because of the central role many of these mills played in the Industrial Revolution, a 15 mile stretch of the Derwent Valley was designated as a UNESCO World Heritage site in 2001. The site is managed by the Derwent Valley Mills Partnership, which also produces books and educational material about the mills and the valley’s wider significance.

The Derwent Valley Mills Partnership is currently planning its new research framework, funded by English Heritage, and has organised 4 workshops to develop research objectives on a series of broad themes. The author’s of this blog post, Georgina and Carry attended the first one of these workshops on March 17. While preliminary meetings had identified a range of topics or questions that have either received little attention or could benefit from more analysis, these topics needed to be brought together into narratives in order to form a coherent research strategy. This strategy will essentially be a synthesis of current views of research priorities and will be useful for future projects or funding applications. While most of the broad themes were not specifically sough related, our input is allowing us to shape their research strategy by contributing cutting edge views from the field of environmental history and by offering power and water as potential narratives to study this area.

The workshop was held at the Silk Mill in Derby. This mill had originally been constructed by George Sorocold and became the first mill in England to use water power to mass-produce silk. The Silk Mill is currently being reinvented as a venue for co-production, creativity and knowledge exchange, based on the principles of the Enlightenment, and its combination of large open spaces, river views and interesting nooks and crannies make it an inspiring venue for a meeting.  Fuelled by regular biscuit breaks and a lunch trip to a very pleasant local deli, we participated in a broad ranging set of discussions with our focus group.

Flip chart

Our focus group at work. Photo: Carry van Lieshout

The group was a mix of academics from a variety of universities and disciplines, local historians, representatives of diverse museums, conservation societies and researchers from the other mills. We split into groups to tackle the 3 themes of the day: Changing Interpretations of the Derwent Valley, Industry and Trade before the Factory System, and the Enlightenment. The format was that each group would come up with 3 Research Objectives for each theme, each of which would combine several of the research topics. The projected outcome at the end of the series of workshops will be a Research Agenda and Strategy for the Derwent Valley Mills Heritage Site in book and web form. An earlier example of such a research strategy document for East Midlands Heritage, which this process was based on, has been successful in identifying viable projects and guiding funding applications. The wealth of untapped resources and narratives that could be studied in the context of the Derwent makes us hopeful that this series of workshop will do the same!