We waste green energy… new research project

taken from a slide by Jan Spriet of the Dwr Uisce project of the work at Penrhyn Castle

Tomorrow and the BBC are filming at Penrhyn Castle on a project we have been working on for well over a year now. The project in outline is simple one which is to harvest heat from the waste water for re use. There was a Biomass project in the Lake District which got me thinking about this. At this campsite we heat up about 10,000 litres of hot water in a large tank which is all used in the popular sites showers in the morning. This very warm water is then flushed down the drain and goes to the sewage treatment plant. What a waste! But this is the same for almost every house, hotel and business in the world. No matter what generates the hot water and how green it is, a wasted KW is a waste KW. The questions for a research project is around how can we harvest this waste heat from showers, sewage, dish washing, clothes washing and so on in an economical and practical way.

The National Trust have been looking at this very question and teamed up via the Dwr Uisce project with Trinity College in Dublin and Bangor University here in N Wales to investigate. Can we harvest energy from our waste water? Penrhyn Castle generates all of its heat from a biomass district heating system. 25% of its electrical needs are met by the on site solar PV system. The biomass and generated electric are used to make hot water for the flats, offices, catering and toilets. All of the waste water from these systems go down the hill to the septic tank. The researchers have been spending the last year monitoring where this heat is, how much and where would be best to harvest this heat. Based on the Lake District campsite experience I had a theory about the septic tanks but we soon realised because of the distance from the castle that most of the heat was lost by the time it reached the tank. Following lots of monitoring the best place at Penrhyn  is under the kitchen in the cellar as the water here has the highest temp and volume of hot waste water and therefore use. (the water is up to 60c when leaving the sterilisers and dishwashers) the next question is how and what impact will this harvesting have eg on grease management in the wastewater (eg will is settle in the pipe before the grease trap?)

The Universities have come up with three different approaches. Copper pipe in pipe harvesting. The hot water going into the kitchen is next to the waste water leaving the kitchen and thus could exchange heat (theoretical 26% efficient) or pushing the waste water through a buffer tank which is theoretically 36% efficient or a combination of both. The research is also looking at putting this harvested waste water then through a heat pump to gain even more heat. The systems are still being bench tested in Dublin at the moment but also looking at the grease impact to see if it settles earlier in the pipe inside the castle thus blocking the waste pipe. This factor is currently being bench tested. The equipment will be installed in the coming months to test real world use vs theoretical estimates. There are a few off the shelf large systems which are ideal for new large-scale sites that we could use today but nothing at this scale and also retrofit in such a sensitive building

Another of Jan Spriet’s slides on one of the theoretical make-up of the Penrhyn Castle heat recovery system

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New renewable energy technology under our feet and falling from the air. Using a very old concept

Image copied from The Times article on the application of Teng on PV

I was asked by the BBC to review a new concept in renewable energy generation. That of something called Triboelectric Nanogenerator or ‘Teng’ for short. I am often offered new tech’ which will make us all super rich or make so much energy we won’t know what to do with it and in the end its re packaged stuff or snake oil. But from my side Teng looks like a new approach using a well-known phenomenon (tribo is from the greek word for friction) . that of static electricity generated through pressure/ fiction. The initial article in The Times newspaper I read reviews the technology and quotes a Prof Zen Wen who is looking at a multi use approach for this generation from clothing to mobile phone charging. One such idea is to coat the thousands of hectares of PV we have in the UK with the transparent teng films to produce electricity from rainfall. The pressure from the rain makes an electron travel from one material to the other thus creating a circuit. From initial work the research group now claim to have created over 100,000 time more electricity per unit than the first trials and up to 300w per m2 which if true is more electricity than commercial PV. This approach seems to have been made for the part of Wales I live in with its rain and shine! whilst I’m at it with future tech why not then coat the underside of the PV panel with a thermoelectric metal (the those fans on stoves) to again generate electricity when the sun is hot. I will now stop as I’m getting ahead of myself. durability will be key as well as efficiency.

I hope this tech continues to develop as I can so much use for pressure generated electricity. Footpaths, roads, tyres,  in the sea from waves, wind pressure…

The uses are many even the possibility of powering your devices from your effort, This is a concept for teng shoes


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Spoilt fror choice or not knowing which horse to back… energy conundrum?

My PV this February. Not producing electricity on a sunny day when I needed it the most in a cold house. There are some weaknesses in renewable energy systems and we need to build more capacity  than we use  at peak to get over these weaknesses. see further on!

Tomorrow I will be a panelist in the Institute of Welsh Affairs event in Bangor University debating ‘Whats the best future energy mix of energy for North Wales and its people’ I’m there representing distributed and community energy. For me the case of localised energy is a simple one of local decision-making, accountability and benefit retention. For example in terms of the £20 billion going into the new nuclear power plant on Anglesey the control is really with the foreign banks and or Westminster in what they will offer to said banks. For many of the community energy schemes I have been involved in the decision is local first and then government bodies second in terms of consents and support. The Welsh Government have set their stall out in terms of declaring that every new energy scheme must have an element of local ownership (not sure a £20 billion nuclear power station counts… oh yes forgot as this is outside WG powers and decisions is from Westminster. back to accountability, decision-making and who does it?) but they have set a very laudable ambition of 1 GW of generation will be in local ownership (lots of definitions need clarifying here but they are consulting on ‘local’)

The model we have wont work if we want a 100% renewable energy as we have a very centralised grid system and a decentralised environmental resource (can be windy or not, night-time and so on, wind on far side of the country… we’d be fine if we could move the cities to the resource but. ha)

We have a mixed grid but also not much spare capacity in the UK. The interconnections can also be flat-out for much of this time of year and all its takes if for one of the main power stations to trip over and the frequency goes and system failure can cascade off and then we get into black starts (Have a look at Wikipedia). ‘we’re all doomed Mr Mannering!’

I saw an excellent presentation by John Gowdy of Regen on what would be needed to meet our current UK electricity need of about 50GW ish load from renewable sources and simply put we need about 80GW of renewable energy generation capacity because of the load factor of renewables. The question I always ask is do we have enough power on a cloudy, dry, still February  (day or month) when demand is at peak but renewable energy is not? (This 50GW is currently  free from Electrical Vehicles, more computing server capacity, possible air conditioning growth based on climate change, more houses…) I am a 100% believer in renewable energy but we need to look at the way we pay for, distribute and store energy if we want to reach this future (and will we pay for it?) simple question. If we put the estimated combined £50 billion budget of Hinkley and Wylfa Newydd into energy efficiency in order that we use much less electricity than the Nuclear could generate (don’t know) I wonder what the economics would be? But we live with a market economy where we pay for products and not for the energy we don’t use. (I won’t go into demand side management for now) Current energy storage will be fine for a few hours but not for a few days. We use storage as a sort of top up at the moment and not as a big gap filler (we don’t have a enough storage and by quite a margin) then we get into interconnections with other countries and the whole thing gets even more complicated (won’t mention Brexit)

It’s going to be an interesting debate tomorrow. We don’t have a choice in terms of a low carbon future but the ‘how’ is up in the air at the moment. Back to my title question in terms of ‘which horse to back?’ If we have the money…all of them, then we will be guaranteed to win. but also we need to look at a business model which values the energy we don’t use in order to get some serious investment in there.

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The National Trust’s research ambitions. Knowing more, to look after what we all care for better

The National Trust research strategy. Sabine on the front cover who has been quietly researching and monitoring the impact of our land management practices at Hafod y Llan for over a decade now

Yesterday and it was Manchester. I attended one of the three workshops the National Trust is holding on its journey to setting itself up as an accredited Independent Research Organisation but also developing on its new research strategy into a research and delivery plan. The NT is famed for its research but usually this is based on various criteria such as local need, national programme, personal interest or often as a host for others as we hold a huge array of resources from land to people to built structures, libraries, archaeology but also as a willing partner to help others to help ourselves. The NT is joining all of this together through its staregy

The workshop was good in getting me to think of the wider meaning of research and not just peer-reviewed papers in an esteemed journal but for me everything from evaluating turbines for durability through to the sustainability of paints right down to the whole life analysis of a disposable coffee cup! Research at its root is simply ‘finding’ things out

The word research is derived from the Middle French “recherche“, which means “to go about seeking”, the term itself being derived from the Old French term “recerchier” a compound word from “re-” + “cerchier”, or “sercher”, meaning ‘search’.

In my world I have quite a few ‘research projects of the go and these include

  • Developing on using Water Pumps as hydro turbines with Trinity College Dublin
  • (PhD) Climate change modeling on National Trust sites in Wales with Bangor University
  • (PhD) Community energy contributions the Wales Future Generations Act (Bangor University )
  • (PhD) Heat harvesting for re-use from waste water at a National Trust property
  • Monitoring and performance approaches to NT renewable energy systems

…and the list goes on! But overall its to add value, establish clarity or look at new approaches to the day job. It will be interesting to see how we the  Nation Trust focuses its lens on the huge range of research possibilities based on the vast amount of work we have to do day-to-day looking after things, explaining, engaging, making things relevant, learning from the past to help the future and all that

For example every time we build a hydro we have to do a huge amount of research to make sure the system is appropriate for the site. This is the Hafod y Porth hydro near Snowdon. We found that the system is actually on the site of the old hydro (archaeological research). This is was one of the first totally prefabricated weir systems installed (technical research). Research, research, research!

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Kerb stones, mud, manure = fantastic pizza!

The clay earth oven is now complete and making fantastic pizza

Forgot to do this blog this summer. I set myself a goal to build and earth oven in the back garden. I have been thinking about it for a while and when they found the remains of the oldest in the UK under where we were going to build the National Trust Penrhyn Castle biomass system it sort of sealed it.

The base is made of free recycled concrete kerb stones thanks to Gwynedd Council (they were re doing a cycle path near the house and I  asked if I could have them). the void in the base is filled with broken kerb and broken bricks topped off with 6″ of sand. A base of thermal bricks I found and then the oven was built over 10 days in three layers of mud, gravel, sand, straw and two types of manure!

The raw ingredients of an earth oven. Cow manure has a binding enzyme in it and horse manure has small grasses in it for the final coat.I’m also blessed in having horrible soil for gardening but fantastic of earth oven. Very, very heavy clay

Thanks to ‘Building with Cob’ book for leading me through the method and the measurements. Getting the door aperture right in relation to the internal void is key. (the door has to be 61% of the height of the inside of the dome) building a ‘former’ out of sand and then covering in wet news paper for the first layer to take with no straw (thermal layer)

sand former with newspaper cover. This paper stops the clay binding with the sand and makes digging the sand out of the dome easier once completed. I should have used second-hand ones from a storage heaters as they are thicker

You can see the first thermal layer with a part built second layer ‘insulation’ with the straw in it

you can see the stratification of exiting smoke and the intake lower layer with fresh air entering nicely in this image

Its was a good few days of work (The earth, sand and straw was mixed with a tarpaulin). The whole thing was more or less free except for the thermometer  and some borrowed bits (£3.50 for the thermometer). What I’d do differently next time?More straw in the final finishing layer to stop the surface cracks.

Here is the essential tool for most of the work. (manure as well)

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…and which log stove did i choose?

Quick update on the log stove I went for! Both the Morso Owl and the Jones family are happy. 6.25kw seems the perfect heat loss for my old house. I have a vent through my 1.1m thick wall to make the stove and building regs happy

Firstly thanks to all those who suggested makes and types from my previous blog . In the end I went for a Morso Owl. There are several reasons why. The main one being the shape of my square, deep inglenook with the flue right at the back meant that I needed a back flue system and a deep rather than a shallow and wide stove. My heart was initially set on the Burley Fireball as it is the most efficient log stove in the world. But with a top flue only on a tall shallow stove meant that I had no room to put bends in to push the stove out to get the heat in the room rather than warm up the inglenook which would have been lovely by the time I went to bed (Part J building regs had a part to play here as well)

having been an official buyer of many  stoves from Ebay for years this time i went for a new stove with a 10 year warranty and parts are really cheap. I now have for the first time something called a rolling flame which indicated my stove is correctly sized and happy. An efficient stove is one which is driven hard, burns cleaner with less residue

I also splashed out on an Ecofan 810. Stove top thermoelectric fan (heat turned into electricity to power the fan. starts working at 65C up to 350C) the fan system  gets heat out of the fireplace earlier and into my room. I did some academic research into TEG’s as its abbreviated into and  it seems to work. (my limited hair is moved when I put logs in…which to me means warm air is being pushed out more than through heat convection and radiation)

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That’s a pretty power-house! Re visit to the hydro projects in the Lake District. Quality!

Hayeswater Powerhouse. I dare you to tell me this does not fit into its landscape. Stunning site. Thanks to an additional donation the project has also already repaired over 500m of Lakeland wall around the powerhouse and helped safeguard / repaired the scheduled ancient monument below the powerhouse (old lead mine workings with a huge water wheel pit which again Storm Desmond took a chunk out of )

Give credit where credit’s due. The National Trust in Wales are known as ground breakers within the NT for doing environmental work especially renewable energy but the Lake District… and it pains me to say this, do build really tidy hydro power houses! (Wales do good work but the stone work on the Lake District systems is stunning…being an aficionado of good stone work!) I’m not a fan of pastiche but when something is well build and the skill shines through then the stone and roof work on the NT built hydros in the Lakes are a joy to the eye

The innovative twin hydrolite turbines in Hayswater .
Never been done before with Hydrolites. (generated 1.1GWh in the last 12 months) The hydro has not missed a beat and is an example to others

Hause Gill hydro power house near the village. Again this is stunning stonework

The chilli intake over 200m above Hayeswater on the entrance to the old reservoir and next to the reservoir access track. Mr Garry Sharples modeling the latest in weir design

I was up North again today in the snow…the stingy on the face type. To revisit the hydros I saw well over a year ago which were then cutting the turf. Hayeswater and Hause Gill. The former is a 250kw twin hydrolite turbine system and the later a 100kw Gilkes pelton system. I was there early on during site selection and did a little bit of support in the very early days.  Both built-in sensitive locations within typical Lake District valleys and by god do they fit into their landscapes. Garry and John should be very proud of these projects. Hayswater was built-in the teeth of storm Desmond which had a good go at destroying the National Park and the hydro was delayed for quite a while as the main contractor was helping dig out the village of Glenridding at the bottom of the valley (the village have re named one of the bars to thank the contractor of the Hayeswater hydro contractor who came through flood and high water  from the hydro site to help when the village were most in need. Beckside Bar as its now called) I know the NT have a reputation for high quality but in the Lakes our efforts in site selection and design were and are actively supported by the Friends of the Lakes


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