The Sea is one huge store of heat and could provide a large amount of our heating needs (despite what Billy Connolly and his childhood memories of sea-side holidays think). We are looking at the possibility of harnessing a tiny fraction of this heat to lower our carbon, costs and energy use.
We are currently coming to the end of about 12 months of research around something called a closed loop marine source heat pump. Plas Newydd on Anglesey sits on the edge of the Menai Straits in a spectacular position but it also has another claim in the National Trust in that it is as one of the largest oil use properties. (historically it could go through 1500ltrs of oil in a day) As part of the ‘Fit for the future strategy’ which is part of the much larger National Trust energy strategy we have been looking at what to do to both lower use and then to ‘shift’ from oil to something more sustainable.
The initial thought was to look at biomass and we worked with the Carbon Trust and Burro Happold on evaluating a biomass option for the site and yes it did look a viable option but a very expensive one and would involved a lot of construction and upheaval on the site, which is both listed and partly scheduled. Another option we have been working on is to harvest some of the heat from the sea and to heat the mansion via a set of heat-pumps. But from the research we did there seemed to be a lack of case studies to follow (unless we fancied going to Hawaii) there were some small ones on the Thames but nothing using the vast heat which is stored in the sea. We are researching something called a closed loop-system (brine is pumped through a pipe in the sea and it gathers a small amount of heat which is used via a heat pump to warm the mansion)
Another peculiarity of a heat pump is that if you want it to be efficient you need to circulate the heating water at much lower levels. 55c as opposed to 80c ish. Paul conducted some tests with the existing heating system last Dec (when it was -12c) and ran the heating for 24/7 at lower flow temp instead of the on off of a conventional system) to see if the heating system would still allow the mansion to reach its operating temps (much more detail to come on this) but it did.
what have we done so far –
We have conducted three separate dynamic heat model test how much heat do we need not what are we currently supplying via the oil
Evaluated (followed pipes) the current heating system to see how we can adapt it
The Carbon Trust funded Arup to look at how a marine source heat pump would integrate into the current system but also where we needed to improve the fabric of the mansion because of the risk of some rooms not getting warm enough (secondary glazing – we have already placed 2000m2 of insulation in the attic)
The School of Oceanography Bangor are currently surveying the sea bed, ecology, temperature, currents, geology for a potential marine collector. we need to understand what is there and would we have an impact or not
so far everything is looking favorable – a heat pump does need power but we are also working on installing a 50kw PV system in the coming weeks subject to planning permission
Much, much more to come on this and have a feeling that if we go ahead there will be an awful lot of interest. But lets finish the research before counting our chickens as it were! devils in the detail (you may have heard this quite a few times in this blog)