Goodbye October; Inching, Leaping and Dying Back; Autumn Leaf Mould Energy Potential (Part 1 – The Idea)

As the light seeps from the grey wet scene at 3.30pm, I’m taking a pause from work on “The Reactor” to catch up with a blog post. More about this project later, but first a few of the gorgeous and varied light and cloudscapes which we’ve enjoyed this October. I really never bore of the infinite variety of this single view to the South East. No more words needed about these views.

It’s a week since I was standing in front of our ESSE wood burning stove monitoring and stirring some pans of lemon curd and crab apple jelly when I did a double take after hearing a comment by Scott Malkin, the founder and chairman of ‘Value Retail’, on BBC Radio 4.

It heightened my sense of the end-of-the-spectrum quality of life here.

His comment, in a discussion on how businesses set the prices for their goods, on the ‘Bottom Line’ programme, was that 2 out of every 3 Chinese visitors to the UK make a visit to Bicester Village. What?

For those who don’t know, there is an upmarket, big name brands, discount outdoor pedestrian shopping ‘mall’ located about an hour and a bit from London in the Oxfordshire countryside. Huge numbers of presumably mainly urban based, affluent Chinese tourists flying to Britain from the other side of the world, apparently can’t resist making a special trip out of London. To shop. And Mr. Malkin informed listeners that it’s not at all unknown for these visitors to spend tens of thousands of pounds during a single trip to this “chic shopping outlet”, one of a clutch of similar establishments around the globe.

I’m frankly relieved that I get more excited by the simple challenges of working out how to live here more efficiently and economically, particularly with regard to energy usage, than splurging in shopping malls, though we’re not averse to appropriate technology which helps us in our quest to understand how to live better, in an unconventional home.

We’ve recently had a really clever British designed and built gadget called an ‘Immersun’ fitted, which acts as both an energy monitor, and more impressively calculates when our home isn’t making use of all the electricity we’re generating through our PV panels, and automatically diverts the excess into our hot water system by powering the immersion heater – at constantly variable wattage according to just how much of a surplus there is.

As you can see, it even tells you what it’s up to. In the past such home generated electricity excesses would have made their way into the National Grid and probably been used by our nearest neighbours, though how anyone could possibly value accurately such electricity exports is quite beyond me, since we’re not provided with an electricity export meter, simply a generation meter. I’m really keen on microgeneration, and the idea that a nationally well developed network of small scale producers, would add a degree of resilience to the system as well as avoiding the huge losses of power inevitable with long distance transmission of electricity.

Since we only heat our water with an electric immersion heater anyway, this Immersun boost is extremely helpful. But it also encourages an awareness of just what power particular appliances draw upon, and how they vary, for example during the different stages of the cycle of a washing machine. I’ve mentioned in a previous post how, counter-intuitively, generating your own electricity seems to encourage greater efficiency of use. It also seems to develop incremental habit changes, for example with us the decision to switch to a lower power of kettle. Interestingly a recent ‘Which’ comparison of kettles rated them for speed of boiling, ecofriendly characteristics but strangely nowhere was the appliance wattage listed. Obviously, it takes the same amount of energy to boil a fixed volume of water regardless of how quickly it takes, but if you’re generating variable and sometimes low amounts of power, it’s sensible to choose a lower wattage model.

“Slow down, you move too fast, Gotta make the moment last”

Simon and Garfunkel maybe had it sussed all those years ago.

Having worked out recently in a particularly nerdy moment, just how much energy gets dumped down the plughole every time you lift a bath plug and the hot water, with all the energy it contains, leaves the home for good (about 2 KWH worth for a 7 inch deep bath), we now fit a simple twin wall polycarbonate cover to the bath around bath time. Not only does this reduce steam and condensation into the bathroom, but also allows this heat to gradually dissipate into the house – interestingly it takes about 36 hours with our acrylic bath for the temperature to fall from a hot bath’s initial 42 degrees C to an ambient of about 20 degrees C. This figure is actually is a bit above our normal chilly bathroom temperature.

Now if some bright spark printed a similar lightweight plastic bath cover with a His and Her’s side of perhaps life size images of well known celebrities in suitably scanty attire, and sold it from one of Mr. Malkin’s upmarket boutiques, I imagine every Chinese visitor would be booking an extra seat on the flight home to accommodate their ******** (I had the idea of calling this a BathMate, but having just checked on line, I see that this name has already been nabbed by those interesting folk at Love Honey who I first encountered just over a year ago when researching buzz pollination – Click here for link, but don’t look up BathMate. Really).

At a cost of about £10 for a suitably sized bit of polycarbonate, I’m sure anyone, even Mr. Malkin, would be impressed with the return on capital – I reckon you’d save about £55 per annum with the heat saved from, say, every other night baths, (at 30 p per bath) so a 550% annual return. Can anyone suggest a legal scheme beating this figure? I should however add that one of my blog followers has warned me against the risks of some horrible Clostridial problem from doing this, so as they used to say, don’t try this in YOUR home. I’m by nature a little more sanguine, being surrounded as we are by all manner of spores and bugs anyway in this damp climate.

Since we like our tea made from leaves, not bags, we use individual sprung tea infusers in individual cups, and having experimented, we find that leaving our blend of tea leaves to infuse for about 3 minutes, suits us both. However, the tea cools off a bit in the meantime. Fiona’s recent idea which has a huge beneficial effect was absurdly simple. Put a tea cosy over both the cups as the tea brews. Not rocket science, but in such simple ways we hobbits delight in inching towards greater economy and efficiency, and now enjoy tasty and hot tea!

Those sophisticates in the German automotive industry might call it Vorsprung durch Technik (Für Hobbits).

I’ve also just added simple secondary glazing to all the windows, doors and roof lights in our home last month by using 6 mm clear Makrolon UV single polycarbonate sheeting – this after researching secondary twin wall polycarbonate sheeting for an internal greenhouse skin and finding a company selling offcuts from larger jobs at reasonable prices. Birchwood Trading apparently mainly market these offcuts to people with pets kept in vivariums. Fortunately, most of the windows in our old hobbit house are very small, so the entire 21 openings could be fitted with such vivarium sized offcuts. So now, not unlike an upgraded vivarium, the inmates can enjoy a cosier environment and still see out with less condensation.

Total cost about £350, and of course the polycarbonate has a hugely superior thermal value to ordinary glass glazing, albeit without the vacuum or argon filled benefits of a modern sealed double glazed unit. A simple toggle system allows me to remove them for cleaning or in the unlikely event of a heatwave if more ventilation were required.

For us, commercial leaps forward like the Immersun seem to happen quite infrequently. (Maybe we should get out a bit more?) But we also reckon that the recently launched, and again British designed, G-tech Air Ram vacuum cleaner is another brainwave presumably designed by engineers going back to the drawing board and having a rethink. We’ve used Lithium Ion battery powered cameras and a lawn mower for over 30 months, so the concept of a light weight, more maneuverable appliance, with no bags and a quick recharge really appealed. We knew that Li-ion batteries now seem durable and reliable, and incredibly frugal of electricity when charging. The Air-Ram matches the advertising hype for us, and is transformational in allowing a regular speedy whizz round, with almost zero energy usage (compared to the typical 2 KW rating of most hoovers), and an ingenious swivelling handle that can get you nearly anywhere. I now enjoy doing a quick hoover whilst I’m slowly making making the tea and anyone running wood burning stoves will appreciate how tricky it is to keep on top of dust and wood fragments without regular hoovering. If you do have your own means of electricity generation, you can recharge the unit when your system is producing surplus power.

But what about the garden?

With all this inching or leaping in technology and practices, and the pervasive march of globalisation, are the real movers and shakers of the UK taking their eyes off the natural world. There’s been a flurry of reports around the likely impact of the new-to-the-UK fungus induced ash die back disease. Sifting through the data and opinions presented does make for gloomy reading, and in time it looks likely that a large percentage of the 80 million UK native ash trees will succumb. They’re a big part of the local landscape, and as most owners of wood burning stoves will confirm, ash is the best wood for heating.

But as with all diseases, there will be naturally more resistant trees amongst the majority in a newly exposed population. So is mass culling of all affected and in contact trees, or even treating trees with potent fungicidal agents as one expert proposed, a rational response? Won’t it destroy the potentially resistant individuals? This disease, caused by Chalara fraxinea, joins a growing list of new-to-the-UK tree pathogens over the last few decades –  Fireblight, Dutch elm disease, sudden oak death, and Phytophthora ramora in larch trees.

The bank to the North of our high meadow looks gorgeous in all lights or mist, with the leafless silhouettes of mainly mature ash trees.

What trees should one plant in the future to ensure a wooded landscape? It seems one has to take pot luck, given the time scales of tree growth and maturity, and what may hit us next. Two days before I wrote this post, the first confirmed case has indeed been located in a recently planted hedgerow in our county, Carmarthenshire. As I’ve often mentioned, we use recycled cardboard throughout the garden – as a degradable mulch or as a basis for compost, but are there risks of importing new diseases with this material, since I guess most of this packaging comes from trees grown on the other side of the world?

I was midway through collecting leaves to compost this year, and tidy up the garden, when I was sent the latest post by Carolyn’s Shade Garden in the USA. All our leaves are left where they fall in the borders as a brilliant natural mulch; but yards, drains and paths do have to be cleared for safety reasons. It was Carolyn’s intelligent well written blog, which got me started on blogging early last year. The simple inching forward idea for me in her most recent post, (Your Most Precious Garden Resource), clearly presented with a few well chosen images, was not just to collect the leaves as an invaluable resource, but using a lawnmower to mulch the leaves more finely with repeated passes with the collecting box left off.

I was sceptical about how well our small Bosch Li-ion lawnmower would cope with a big pile of leaves, but it managed really well and as a consequence I was able to quickly fill 2 big bags to replace the mulch/compost/leaf mould used in the garden this autumn. You obviously do need to wear good eye and face protection if you use a lawnmower in this way.

I’d already filled a couple of big bags with unchopped, or rather once chopped leaves. Since the bags were still light enough to tip over, I simply turned them out and started to mulch the leaves again with the mower. In doing this I noticed, not surprisingly, that in the centre of the bag a section of leaves was already heating up. But how hot was it? Measuring the temperature in the pile at over 20 degrees C got me thinking, and “The Reactor” concept began to form.

The plan is to construct a well insulated compost pile, to the rear of the greenhouse. And then to duct air warmed by the heat of the decomposing compost or leaf mould, but isolated from the air and gases in the compost, into the recently created inner skinned zone of greenhouse, so that temperatures can be achieved allowing reasonable crop growth through the winter months, with just the energy needed to run a 20 watt fan to shift the air. Even if this fan ran 24 hours a day, which is hopefully unlikely to be necessary, such a frugal electrical devise would only cost about 8 pence per day for the nearly 0.5 Kilowatt hours of electricity used.

There’ve been a huge number of issues to consider and research in designing and building such a system, and very little that I could find to use as a guide on-line although there was sufficient encouragement from the link here, where a water filled heat exchange method was used in the USA by Katherine Brooks to heat the soil of her growing beds in a 16 x 12 foot poly tunnel used for herb growing. Some of the points I want to consider are:

  • Trying to construct it from materials already on site where possible.
  • Trying to work out how to add and remove material or compost without having to completely dismantle the set up. Or designing it so that if dismantling proves to be the only solution as the compost material source gradually and inevitably cools, and then needs replacing with a new batch, then it can be done fairly simply and quickly.
  • Trying to have a target for the temperatures I’d like to achieve. I’m not thinking tropical, but would like them to be higher than the just-above-freezing which I managed last winter, using only the occasional candles as effective but really sooty heat sources.
  • Trying to establish just how long a compost heap is likely to give out usable heat. This in itself is like the ‘how long is a piece of string question’. So many variables affect this like ambient temperature; compost ingredient mix and in particular the ratio of carbon to nitrogen in the mix; how fine or large the constituent particles are; how moist the material is; the size of the heap; the amount of airflow into the pile; the degree of insulation; how often the heap is turned, etc. Aaaaargh!

I decided that whilst the various elements of construction were taking place I should get out the digital thermometer and take some readings from 3 of my recently set up big bags with mainly shredded leaf litter contents (as above, where the pipes allow me to take maximum temperature readings at the middle of the heap, and below), and simply covered with a bit of cardboard.

Given that these are uninsulated bags, of modest size, and the contents aren’t really high in nitrogen, getting core readings of 36 degrees C inside the thick plastic waste pipe, which will itself insulate a little from the maximum temperature present in the decomposing leaves, seemed a promising start. I’ll try to add a graph of temperature changes in a few weeks (if I ask Fiona nicely to create it for me).

I finally settled on some key elements to the design being:

  1. To heat just the inner polycarbonate protected zone volume of about 7 cubic metres – 3m x 2.2m x 1m of air, inside our 14 x 8 foot greenhouse. A separate issue has been ensuring that the nectarine and apricot trees which are planted in the greenhouse, but outside the inner zone, are sufficiently chilled to ensure flower buds form next spring, or we’ll miss out on the wonderful fruit we enjoyed for the first time this summer.
  2. To use a redundant 20 watt axial bathroom fan with a throughput of about 85 cubic metres of air per hour.
  3. Initially aim for a minimum temperature target of 15 degrees C for the inner zone.
  4. Use some old fridge racks which have sat in a shed for years waiting for just such a project to be dreamed up, as a potential base for the heap allowing the compost to be raised off the ground by a few inches.
  5. Use some surplus Celotex sheets cluttering a barn to insulate ‘The Reactor’.
  6. Get the whole thing up and running before serious frosts arrive this winter.
  7. Fortunately, we should have enough raw material to fuel the reactor until spring given the autumnal leaves, easy access to a source of cardboard, herbaceous autumnal garden waste, poultry manure from the recently acquired flock, wood chips/dust from chainsaw logging up. Oh, and plenty of pee, for additional nitrogen input.

The above image shows the inner greenhouse zone which will be the initial target for heating with autumnal leaf mould energy potential.

Will it work? More details are planned for my next post. And if it doesn’t work, well, I’ve now publicised the pseudo-technical inadequacies of my plans for all to criticise. Speak now and alert me to any major flaws in my thinking, before the disappointment of failure kicks in. (Addendum – there are a lot of subsequent posts which I’ve written now about how this idea has developed and its implementation. If you want to find the other posts quickly, then Click here).

Now, back to “The Reactor”, where the ever willing Fiona gets stuck into levelling the site.

There’s still much to enjoy, and plenty of colour in the rest of the garden as the days shorten.

From above: Sorbus sargentiana leaves, Sedum ‘Autumn Joy’, Clematis viticella ‘Polish Spirit’, lower copse with Saxifrage fortunei rubrifolia, meadow copse and ‘tweaked’ Honesty, Lunaria annua ‘alba’, seed heads.


11 thoughts on “Goodbye October; Inching, Leaping and Dying Back; Autumn Leaf Mould Energy Potential (Part 1 – The Idea)

  1. You are so nice to say such complimentary things about my blog. Knowing that readers appreciate it, keep me going when it often seems like a lot of hard work. I am so glad that you tried our leaf grinding scheme. It seems to have led to a much bigger project which I look forward to hearing more about in the future.

    • Hello Carolyn,
      Thanks for the comment. As you know, reading your comment about snowdrop thermogenesis last year led to a bigger project ( this blog!), so I’m pleased that down the road another of your posts inspired the latest idea…. I hope to have ‘The Reactor’ set up within a week or so, but it may be weeks before I can really see how succesfully it works, but as always a lot of thought and useful information is being assimilated along the way. I do agree with you about the value of the occasional encouraging word, particularly when you’re wondering what/if to write about at this time of the year. So thanks again for leaving a comment, Best wishes

  2. As always, I love your photography! We make use of our leaves for mulch and compost making, too. I have been applying last years leaf/grass compost to the perennial beds and vegetable plot. It gives me such immense satisfaction to utilize what nature has placed at my feet. You two have such a lovely place!
    Blessings ~ Wendy

    • Hello Wendy,
      Thanks for the comment. As you can tell, I also find the concept of using natural resources all around us as really satisfying, if not the always the speediest way of achieving results. I thought of you this week when we finally got round to watching the DVD of the film ‘Poetry’, since I admire your writings. I wondered if you’d seen this moving Korean film? There’s a great little scene at the introduction of the poetry class, where the tutor talks about the challenges and delight of sitting in front of a blank piece of paper wondering what you’re going to write. A bit like a blog post as well I guess,
      Best wishes

      • No, I have not seen the film…but I have written myself a note to check into it. When I write a poem I have a picture in my head or in front of me first. A picture is worth a thousand words and so I harvest some of them. In writing that last line I can see a new poem starting in my gray matter… Intense events also create a need to write. I think song writers often write this way. Thank for telling me about the film.
        Blessings to you & your family ~ Wendy

  3. Grumpy Hobbit, have you thought of using the fan from an old computer? I appreciate you have a redundant bathroom fan available, but if for some reason, that doesn’t work, you might think of visiting a recycling facility. Almost all dumped desktop PCs get dumped with the power supply and its in-built cooling fan still operating. You could easily strip out the power supply and the mains lead to the PC is generally standard (also available from the dump). The power supply is itself a transformer, generating some heat, which would add to the heat inflow into your greenhouse, but at the cost of using a little of your PV electricity. Just a thought! KTB

  4. Hello Kevin,
    Thanks for the comment. I did indeed consider an old computer fan, but reckon the extra oomph of a 20 Watt bathroom fan might give me a bit of extra leeway for extracting any heat that is generated… gloom over the last 2 days ( 2.5 degrees) was lifted today as internal temps at the top of the rector’s compost pile have reached 17.5 C, but I still need to connect an external power cable. Extreme rain forecast for here tomorrow permitting, I’ll try to upload images of all the gory recycling details of the now finished and primed reactor….
    BW, Julian

  5. What a lovely blog with such fantastic photography. We manufacture the immerSUN and are delighted to learn that you are satisfied and your immerSUN is ‘doing what is say’s on the tin’

    • Hello Jo,
      Thanks for the very kind comment. I’m delighted that you’re checking up on user comments about the IMMERSUN. It is indeed a brilliant product, and British designed and built as well.Even I’ve been able to programme it….I normally leave these jobs for Fiona! So well done to you all. Proper green jobs and product for the UK as the New Energy Bill is debated! You might be interested by the KWH electricity data which I found just after writing this post and put into my next,’Hello November…’ post. This was actually from before the Immersun arrived, but I’ll repeat the exercise in 9 months or so, and expect we’ve been able to drive our usage down even more. I’m really keen to try to get the message out that micro generation reduces energy consumption by way above what you produce, and in these austere times that alone is worth pushing.(Which of course no mega project will ever achieve). If you fancy putting a link to my blog, or quoting me on what a great product it is for anyone with a micro generation set up…… I would of course be delighted!
      Thanks again and best wishes

      • Hello Julian,

        We’re trying constantly to be aware of the customer feedback to ensure that we continue to produce a product that people are happy with and it’s very important to ‘keep in touch’ . We launched the immerSUN in August and have increased our staff members threefold, we are located in a ‘deprived are’ at the heart of the Lincolnshire Wolds where unemployment levels are high and vacancies are few and far between coupled with the extortionate cost of getting to work is restricting to say the very least. All of our team are incredibly passionate that renewable systems, (especially PV) should be integrated into building rather than using the building as a host for the system hence the immerSUN was borne. I do hope that you remain very happy with your purchase and I am sure you will see the returns quickly. If you email me your link I will endeavor to attach to our website. I would love to use your statement as a testimonial.

        Kind regards!


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