At least around 3000 kilometres. Here’s why:
The BRE gives a carbon intensity of 0.025kgCO2/kWh for biomass. This includes an allowance for planting, harvesting, processing, and delivery to point of use. See the 2001 emissions report and the 2003 update.
But we need to vary the emissions figure based on distance travelled. The European Environment Agency gives a figure of just over 0.12 kgCO2 per tonne per kilometre for road transport, quoted here. Even more pessimistic, the Royal Commission on Environmental Pollution says 0.18 – 0.27 kgCO2 per tonne per kilometre (see table 4.4).
Maybe not surprisingly I couldn’t find good figures for emissions associated with pellet manufacture. So taking worst case figures, we can start with the BRE carbon intensity (0.025kgCO2/kWh) and add CO2for every km travelled, ignoring the fact that some transport is already built into the BRE figure.
Assuming an energy density for pellets of 4670 kWh per tonne and using the worst case figure from the RCEP, you need to haul pellets about 2900km to the point of use before you get near emissions equal to mains gas (0.192kgCO2/kWh). In reality, the distance is likely to be even greater for these reasons:
- The fuel you are replacing may have a higher carbon intensity than mains gas (e.g. oil, delivered gas, etc)
- I used the upper end of the estimates from emissions from transport. A lower figure may be more realistic.
- I ignored the fact that the BRE estimate of emissions from biomass already includes transport and treated the figure as planting and processing only.
carbon limited 
I looked at this some time ago for one of the competitions we did with Fraser Brown McKenna.
Now of course I dont recall which figures I used, but the results suggested that for every 200km the pellets are transported, you get a 5% reduction to the potential carbon savings from the pellets. That sounds similar to your results.
I think I used the numbers for transport from the environmental commision report on biomass. Anyway, 2000km is a long way by road, and this would be a dumb way to transport pellets over any distance. So the question then is, what are the impacts for various delivery scenarios – ie, say from Canada by ship, where does it sail from and to, and how many transfer points are there to ge the fuel where it is needed at the local level.
Alot of work has been done on the energy balance of biofuel, both ethanol and diesel, and I think someone needs to complete the same for pellets. The former bristish biogen good quality pellet standard should include an agreed standard for transport fuel. Certainly down here in the southwest, it makes either wood log or chip boilers, where both fuels are easier to source much more attractive.
N/.
Good point that it’s likely to be a mix of transport types. I was looking for a soundbite because when you tell traditionalists that you’re transporting pellets any sort of distance they say things like “well you might as well not use biomass then.” For a detailed comparison of energy for pellet manufacture and transport vs coal, check out this report
its interesting that we try to be as thorough as possible when making decisions, look at the numbers, make a concientious objective decision based on as many facts as we can collate before we make recommendations. But the detractors, well, they can use hearsay and conjecture to evoke an emotive response.
So, I wholeheartedly agree that sometimes we need to distill all the facts, numbers and percentages etc, the stuff that makes most people nod-off, into a nice simple emotive soundbite.
I appreciate that it is necessary to respond to a negative view point, just disappointed and frsutrated that invariably this ends up being on their terms of sound-bites, the lowest common denominator of any discussion.
This has a parallel in the current distrust of micro-wind. Anyone worth their salt should have pointed out to clients that in all likelihood the performance would be poor. There is nothin wrong with the technology, just the application in many instances has been akin to mis-selling. this has done us all a major dis-service.
Some of these things take thought or research (like siting microwind) which is why selling micro turbines at B&Q is a non-starter. And especially with small wind there are manufacturers who make pretty extravagant claims just to flog turbines. It’s helping no one.
ok, here’s another question then, as I dont have a copy of the royal commission report.
SAP 2005 uses standard CO2 density for wood fuel of 0.025kg/kWh. I have small farm estate/residential client that wants to swap to biomass from their current LPG. They currently spend nearly £3.5k a year on LPG, with resultant emissions in the region of 15,000Kg from 65,000kwh or fuel.
The proposal is to source wood locally, probably within 10-15 miles, and most definitely thinnings from managed woodland and not additional planting and chip on site. There seems to be no data out there to review the standard 0.025 figure. This project is not about building regs, so I am free to go off-reserve with the statistics if I can justify the values and context. Unfortunately, I cant find anything to use. Any thoughts?
You could make some assumptions about chipping and transport and calculate the carbon intensity from scratch. Why not start at zero emissions for the wood itself and work out the fuel consumption for the chipper, fuel for trucks, and (if appropriate) energy for drying? It’d be very interesting to see what figure came out.
Another interesting point is that the 0.025 carbon intensity figure from SAP applies to chips and pellets, even though pellets are much more energy intensive to manufacture. In the case of pellets, I bet doing the emissions calculations would be tricky but here you seem to have a situation where the whole manufacturing process is a tidy little parcel right there on the doorstep.
You know what, when I have an idle moment, I’ll give it a go!
Also, did you read the BSJ article on low water volume rads? Interesting to see that CIBSE has a new heat loss calculation method including mean radiant temperatures. Any experience of the implications of this. Again, another thing for that elusive R&D time.
[…] to transport biomass more than 20 miles.” Holy smokes, where does this fact come from? I took a stab at the numbers and came up with a figure of 3000km (1900 miles) by truck before you lose the carbon benefit. […]
Is anyone know if I want to move the wood pellet from under storage to container,what machine that I can use?is there any specific vacuum or pump that I can use for move it without break the shape?
Please help me for any information.
I am looking the vacuum/pump that have capacity max.20Ton/6hours.
I really appreciate any info.