daltontrees

Very nicely done!

Generally yes but not absolutely. Just like supermarkets selling meat byt eh kilo and filing it with water to get the weight up, logs are less and less vaulable as their water content increases. Encouraging logs to be priced pourely by weight encourages the selling of wet or partly seasoned logs. Every bit of excess water requires some of the log's calorific energy to be used up in heating then vapourising the water into steam. The logs will still burn but won't give out teh same heat because a large part is going up the chimney as steam. Where no doubt it condenses on cooler parts of the building and creates a problem.

And it mught be wrh bearing in mind that if this 'nerd' is left to research it himself, a Google search for 'calorific value' of wood will turn up this thread. How's the customer going to feel then? I have to say that I find it disappointing that quite a few people in the industry aren't able to quote or even approximate for their customers something as basic as how much heat a fuel gives out. As has been said, if BG tried being vague, this Ofgas would shut them down. So come on, it's not hard.

Eh? The link takes me to a web page that shows that wood is CHEAPER than everything else...

Equivalent calorific value in GigaJoules is 4.6 per cube then. It's interesting to think of logs in kWh though. I have a 7kW stove, which is quite terrifying when it is going full blast. A cube of ash is going to give me 1280/7 = 183 burning hours. Which is a month at 6 hours a day. That about fits in with what I have been getting through recently, although I haven't quite been using a cube a month because a rarely have the stove on full tilt.

OK, no-one's suggesting a rate. I have checked the arithmetic for logs at £250/T three times and the rate of c.£14/GJ is right. But I had made a mistake in the gas comparison. Here is the corect figure at current supplier prices of c.£0.05/kWh Gas comparison £0.05/3.6MJ = £0.05/0.0036GJ = £13.88/GJ (weird and coincidentally same as wood price). Sorry for any confusion.

I'll have a look just now... Meantime does anyone want to suggest what a going rate for a tonne of 20% moisture would be, split and delivered?

Have I said something to offend? Not only have I answered your question and told you how I have answered it and given you the facility to tweak the answer for any situation, but I have tried to explain why a customer might genuinely want to know what the calorific value is. And I have compared it with the calorific value of gas and electricity and given you a way of showing customers how cost-effective logs are. Your instinct to try and answer your awkward customer question is sound. If I had the option to shop in two places and one of the suppliers couldn't answer my sensible questions, I would go with the other guy. Honestly, it's not hard to prove the case for logs. He's not an awkward customer, he's a customer, and the customer is always right even when he is wrong. And sometimes an awkward customer is trying you out for bigger things. Or can bad-mouth you rightly or wrongly to other potential customers. It pays to persevere. Ignore the opportunity if you like, it's your business. Challenge my figures or calculations or reasoning by all means if you want, debate is healthy and I'm not always right. Ignore me too if you want. I shan't try to help again.

I think it's reasonable to want to know. Calorific value can be expessed in kWh or in Joules. As the FC documents linked by someone earlier show, a typical oven dried wood will have a total energy of about 5MWh per oven dry tonne. That's equivalent to 5,000,000J x 60 seconds x 60 minutes = 18GJ (GigaJoules). If a tonne of oven dried (or very dry anyway) logs will cost £250, then the cost of wood energy is £250/18GJ = £13.88 per GigaJoule. Gas is about £0.05 per kWh which is £0.05 per 3.6MJ which is equal to £72 per GigaJoule. Electricity is about £180 per GigaJoule. If you're selling logs that are less than dry, the FC leaflet gives a rough way of adjusting the calorific value. Bottom line is that you can point out to customer that logs are a substantially cheaper way of heating space than gas or electricity. Remember though that stoves are only about 70% efficient. So it costs more like £20/GJ. This approach only applies to price poer weight. Densitied of dried woods vary considerably and the equivalent calculation for £ per cube is difficult. But since only comparison of £ per calorific values allows a customer to see the sense of buying logs, £ per cube is meaningless.

Excellent! Cheered me up on a rainy morning this did.

Erm... a chog is a lump of wood. Chogging is cutting wood into lumps. Done on th ground we might call it crosscutting. Gravity being what it is, it's pretty hard to chog in a tree without it going down. But if you had a crane you could in theory chog up. Snatching, now that makes no sense. And what on earth is negative rigging if it's not positively rigged?

I'm on a roll now! Pet hate for me is 'pollarding'. Originally meant coppicing above ground level to keep grazing animals away from the regrowth. The right word for reducing tree in height was 'polling'. Now pollarding is just a fancy and meaningless word for topping.

Plus cannae stand advantageous buds and auxiliary buds. The words are adventitous and axillary, but rather oddly the misused words seem appropriate for the situations.

I loath the steady degradation of words in my lifetime, you can see it happening and no-one cares except that I do because we are left temporarily without a distinction between two words meaning and permanently without a clear meaning for one or both of them. There's obvious things like 'awesome', which in my day meant filling one with awe (wonderment ). Now it means nothing. But there's the housebuilder's favourite 'home'. Used to mean an integerated household, the secure environment created by a family or group. The word for a residential building, freestanding or detached, was 'house'. Now Barratt build homes, it's not the people that move into their flimsy structures that build the home. Marketing people are the worst, they will bastardise anything to make a sale. Next up is 'impact', which I still say is a sudden, damaging, encounter. 99% of the time the right word would be (and used to be) 'effect'. But that's not dynamic enough for news stories. Yet you will still hear about the 'impact' of global warming on trees. I'll get back in my box now. My dad used to chide me decades ago for using 'brilliant' to mean anything other than 'emitting or reflecting intense light'. Whatever!

A tantalising but inconclusive article. Personally I hope the chinese are serious. Based purely on the size of China and UK, anything UK does is trivial compared to chinese policy

Definitely looks like opposite buds, ergo not Prunus or Betula. griseum seems like a good shout.

The pictures are a bit fuzzy, that porbably explains the variety of answers. It's a good idea when photographong buds with an autofocus camera to put something (even if it's just the back of your hand) right behind the bud to give the autofocus something to bounce off, otherwise it gives you the background in focus and the bud blurred like in these pictures.

Guesses are 1. Aesculus sp. 2. Betula utilis 3. Robinia pseudoacacia 4. Ulmus parvifolia or sp. 5. Tilia sp probably x euopaea

I'm not sure I'm with you there. Cassian hasn't proven anything, his article is educated and experienced speculation but it falls far short of normal standards of perr-reviewed science. I don't mean to belittle him, but the notion of two opposite direction helixes of wood on a stem is a theoretical impossibility. By this I mean that vascular tissue cannot possibly cross and yet continue to put on annual increments. The inner part of the crossing pair would be crushed and strangled, cutting off water flow upward and killing the part of the tree served by it, unless there is a mechanism to replace the flow somehow. It's quite a challenge to explain even in theory how this could be done. I have no doubt whatsoever that braided structures are stronger per unit weight than unbraided ones, and have good flexibility characteristics too. After all, I climb and lower on braided ropes almost daily. But ropes don't need to grow. Right there the usefulness of the comparison ends for me.

Leftfield theory... a small epicormic was bent into ground contact by a fallen (now gone) branch and has rooted, establishing a strong downward union. This is about the only thing I can think of to explain the nature of the bark above the 'root'.

Had to look back at the other post myself, it's not one you see everyday. As I mentioned in the other thread, I fancy getting one of these but I have been trying to get one ever since and can't.

http://arbtalk.co.uk/forum/tree-identification-pictures/69478-i-d-please-evergreen.html Lyonothamnus floribundus. Do try to keep up, please!

Now you're talking! That's a whopping 72Wh. Enough energy to light a room for 4 hours solid.

I guess the secret is to get the batteries with the highest Ah rating for the voltage. For example, the total energy stored in a 1 Ah 24V battery should be the same as a 2 Ah 12V battery. I occasionally have t take cores of tres with an auger bit. I am seriously thinking of converting one of the dud batteries on my Makita to a connection to a car battery. Not very portable but for roadside trees needing 6 300mm cores the weight isn't a problem and that much wet wood drilling will kill a Makita 14.4V 1.3 Ah battery after 3 cores.

Brace and bit is a pretty good back-up, once you put the butt of the brace on your stomach, put some weight on it and give it a few turns, you're there. Surprisingly quick and easy. Picture borrowed form Wikipedia