A short holiday in Margate

Travelling by train is energy efficient. 

My beloved and I recently came back from a few days holiday in Margate. I was yearning for a few days by the sea – this is a good way to have a reasonably sustainable holiday without air travel. On this occasion we travelled by train. It is easy for us: Cambridge to Kings Cross then St. Pancras to Margate. We carry our minimal luggage in back-packs. 

We stayed at the Premier Inn which is just next door to the railway station so easily walkable even with luggage. I cannot find anything on the Premier Inn website about sustainability other than pledging to reduce water consumption by 20% per guest by 2030. Reducing water use is good, and often saves water heating energy too, though the flow restrictors on taps can be annoying – it took rather longer to fill the kettle than at home. The same applied to the bath which turned out to be a very good thing as I had trouble with the plumbing and had to ring for help to get the bath taps to turn off! If not for the low flow taps we might have had a flood. The shower was fine. I don’t need a monsoon to get washed properly. A/C can be a major energy hog too but in this place there was none. The weather was not very warm anyway. 

Low flow taps rarely save water. 

The annoying thing about the low flow taps solution for water saving is that quite a lot of time it makes no difference to the amount of water you use, only the time it takes to get it out of the tap. Filling the bath takes an amount of water depending on the shape and size of the bath and how deep you want it. A bigger bath or low flow taps means it takes longer to fill. The amount of water you need to put in the kettle depends on the number of cups of tea/coffee you are making. Again, low flow taps means you take longer to get the required amount of water.

In many hotels the kitchens are a major hot-spot for GHG emissions. I have no idea about this particular hotel but I do know from other research I have done that boiling water can be a major hot spot for energy use. For example, steaming eggs is usually more energy efficient than boiling because you only need to heat a small amount of water – enough to generate steam for the required amount of cooking time. (This reminds me I now have an egg steamer at home and I should measure how much energy it uses.) Also, I gather many hotels and restaurants keep a pot of water boiling all the time for things like coddled eggs. This saves time for the staff and customers because you don’t have to heat the water from ambient temperature for each order but it wastes energy because you lose steam constantly. 

The beaches were remarkably clean.

There was very little litter on the beach, possibly because the weather did not encourage al fresco eating but maybe not. There were plenty of tidying opportunities by putting recyclable things into bins and there was plenty of messaging advising us to do so. Sometimes the messaging looked like graffiti. I liked this busy bee, set into a cliff face (presumably blocking up the entrance to a cave or tunnel.)

 

This thing that looks like a bathing machine is actually a sauna, possibly recycled from a horse box. Out of picture on the right there is a sign that says ‘Welcome to your community sauna. Volunteer powered, Wood Fuelled and Free to Use.’ Next time we go there I think I will take my swimming costume – whatever the weather. 

Bathing machine = sauna.

There was also a tidal pool nearby which you could use for cooling off. There were several of these along the coast. We even saw people swimming in them although the air temperature was only 11-15°C. I dread to think what the sea temperature was like.

One more energy-related thing – wherever we walked on the coast path we could see wind turbines on the horizon. My pictures were not good enough to show you but the turbines were definitely there and turning.. Turbines are easy to see on the coast because there are no buildings floating in the water cutting off the view. (Next time I buy binoculars I will see if I can find an adapter for taking a photo. Or possibly a tripod so I can hold the binoculars steady and take the photo by hand. The turbine blades were always turning. The North Sea is a very good source of clean power. Thank goodness the current government is including them in their growth plans. 

Finally, I was very taken with this hat (or whatever it is). This was exhibited in the Turner Contemporary museum and I think it was part of a competition for young people, possibly making use of found objects. There is a sign that suggests the age category was 11-15 years. Perhaps a budding fashion designer?

If ever you are in the area I also recommend a visit to the Shell Grotto and to the Margate Caves. 

Shell grotto

Margate Caves.

What does flushable mean?

Most of us know (I hope) that we should only put the 3 'P's down the loo (pee, paper and poo). However, sewer blockages prove that we often ignore this advice [1]. So what does it mean when an item is labelled as flushable? I found a protocol for testing this [2] which is a bit long in the tooth (2008) but I doubt it has changed hugely since then.

This post is not really about energy at all, rather plastic and how to avoid it blocking up our sewers. I have experienced a sewer system clogged with wet wipes and believe me it was smelly. I did not actually have to get into the pipe to clear it; I just viewed it from the ground level but the sewage worker did get in, wearing rubber waders. I did not envy him. This particular blockage mainly consisted of wet wipes which are a common cause of blockages as they contain plastic and are not fully biodegradable. These did not come from us but from a neighbour; we have a shared drain.

lnspiration from Ocean and the Regen Festival on Parker’s Piece

Inspiration from Ocean (2025), and the Regen Festival on Parker’s Piece.

I recently went to the see the film Ocean (Not Oceans, part of Blue Planet, though both feature David Attenborough.) This is the second time I have seen it and it was definitely worth watching again. The film is horrific in places but also beautiful. The horrific bits include the trawling for fish and shellfish and consequent devastation of the sea floor vegetation and (separately) the turtle tangled up in ghost fishing gear. Did you know that trawling is still allowed in most marine protection areas? Hopefully not for much longer, however.  Also in this blog post I describe my reaction to snorkelling over a coral reef, some advice on avoiding microplastics and the book: ‘A Dairy Story’ about adapting a dairy farm to avoid separating calves from their mothers. 

The most beautiful bits of the film were undoubtedly the kelp forests, and I also loved the footage of huge orcas (or something like - we could only see part of the head) delicately picking up and eating sea urchins. This is akin to watching donkeys eat stinging nettles. 

Offshore wind vs. fishing and Marine Net Gain.

Offshore wind farms have environmental and social impacts. Birds can be killed by the turbine blades (though far more are killed in other ways each year [8]). Fishermen have to stay away from wind farms for fear of snagging their nets on the turbine support structures [9]. So overall, are they a good thing or a bad thing? Under current legislation, developments requiring planning permission need to show an expectation of 10% increase in biodiversity. This rule is called Biodiversity Net Gain (BNG); marine Net Gain (MNG) is the same thing for marine developments such as wind farms. It is not yet mandatory in legislation. The  consultation on it concluded in 2022 with this response: 'Further work is required on the MNG assessment framework to define how this can be established, as well as close working with approaches to strategic compensation for offshore wind development. The government will work with stakeholders to clarify further the distinction between the policy areas as delivery mechanisms are established.'

Options for a green funeral (revisited)

Earlier this week I went to a funeral at Barton Glebe Burial Ground . It is a beautiful place and when I die I would like to be buried there, if anywhere. Cremation is still the most common burial method in the UK but Woodland burials are gaining ground.

I have posted on this subject once before [1] but it was back in 2012 . Most cremations use natural gas to burn the body, ensuring a high temperature and complete combustion. However this also generates carbon emissions. Recently I have heard of electric powered crematoria [2] and even hydrogen to replace natural gas [3] though not many places have these facilities. The electrical option may mean upgrading electricity supply and the hydrogen option has potential safely issues and difficult supply logistics. However either approach vastly reduces greenhouse gas emissions. Other options for the future include resomation (also called water cremation) or composting. However composting is not currently legal in the UK and resomation is not widely available. (Co-op Funeral Care does offer it).

Recycling fibre composites used in wind turbine blades

The volume of wind turbine blades to be recycled over the next few decades is phenomenal : some sources estimates range up to 800,000 tonnes per year (globally) in 2050 [1]. Sending all this to landfill would be a challenge as well as a huge waste. Unfortunately the blades are usually made of carbon fibre composite which makes recycling difficult. However, it is possible and if it is possible for wind turbine blades it should be possible for other uses of fibre composites such as aircraft wings, body parts for cars and so on.

Fibre composites materials, typically glass fibre or carbon fibre, are valuable for their high strength to weight ratio and resilience to fatigue. These valuable properties come from the strength of the fibres and the bond between the fibres and the surrounding material which is typically a polymer. The difficulty with recycling fibre composites is in separating out the fibres without losing strength. 

Wind turbine blades are usually made of carbon fibre because it is more stiff than glass fibre although it is more expensive. Fatigue resilience is also particularly important because wind turbine blades are subjected to cycling loads as the vanes rotate. These cycles can cause cracking and carbon fibre is more resilient than glass in this respect. However even carbon fibre blades do not last forever – typically 20 to 25 years - and then they must be either be sent to landfill or recycled. (It is also possible to repurpose the blades. There are some examples of blades used for bike shelters and in playgrounds on the BBC website here but these do not generate electricity.) Since the blades are very large and carbon fibre costs 18 times as much as glass fibre (per tonne: $23,600 vs. $1300 (Table 1 and 2 from [2]), material recycling is much preferred. 

To recycle the fibres they first have to be separated from the surrounding material. The main techniques used to do this are:

Mechanical – this means chopping the material into small pieces and sorting them. This is the least costly of the three methods compared here [2]. However, the fibres become short which effectively loses strength. This method is analogous to recycling paper by chopping it into small pieces and separating the fibre from the rest of the pulp. Typically the paper (cellulose) fibres become unusably short after 4-5 cycles. (https://recycled-papers.co.uk/green-matters/lifecycle-of-recycled-paper). For carbon fibre, particularly where high strength is needed, it is not possible to separate usable fibres with this method. Hence the final strength (and value) of the resultant material is zero. [1]. 

Chemical – this means dissolving the polymer matrix surrounding the fibres and is called solvolysis. This method is the most expensive [2] but effective, especially with carbon fibre (100% yield cf. 56% yield for glass fibre [2]). Given that carbon fibre is also more expensive than glass fibre this method is the most cost effective approach giving the highest net value [2] Fig 2).

Pyrolysis or other combustion including microwave assisted pyrolysis (MAP). Burning off the polymer without damaging the fibres is easier with glass fibre because this is more heat tolerant. 

Overall, the best recycling option to retain strength (least loss) is chemical recycling of carbon fibre as shown in this chart. The losses are calculated as 1- (fibre yield x retained relative strength of fibres) and expressed as a percentage.

 

Data from [2] tables 1 and 2 (converting from strength retained (yield * relative strength retained) to strength lost). For carbon fibre, loss is 100% from mechanical recycling because no usable fibres can be recovered. Chemical recycling works well for carbon fibre because 100% of fibre can be recovered at 100% of the original strength. This is the most cost effective recycling method.

Summary

Carbon fibre composites are used for many applications, including wind turbine blades, where high strength, stiffness and fatigue resistance are needed. Increasing use of renewable energy from wind is expected to generate large volumes of carbon fibre waste from retired wind turbine blades. Ideally this would be recycled. 

Carbon fibre is very expensive compared to glass fibre which favours recycling even where this is relatively expensive. For recycling, it is critical to separate the fibre from the surrounding polymer matrix without losing strength. The most cost effective way to do this is to use solvolysis - dissolving away the polymer leaving the fibres behind. Other methods are cheaper but lose value by losing or damaging the fibres.

[1] Liu and Barlow (2017) Wind turbine blade waste in 2050 in Waste Management https://doi.org/10.1016/j.wasman.2017.02.007

[2] Liu, Meng and Barlow (2022) Wind turbine blade end-of-life options: An economic comparison in Resources, Conservation & Recycling https://doi.org/10.1016/j.resconrec.2022.106202

Pause due to head injury

I have not for posted a while, mainly because I have been seriously ill in hospital and have undergone 5.5 hours of brain surgery.  As a result my cognitive faculties are definitely below par especially my memory. This is inconvenient to say the least. I also have a poor sense of time.  I hope I will get back to normal soon. I have been recommended to maintain a normal routine as far as possible. This is easier said than done. A zoom meeting can be a struggle  (where has the chat gone?) I guess usability testing on these apps does not include use by people with head injuries. They are still a good test for cognitive function.