Wood pellets - getting what you pay for

When you take a delivery of wood pellets, your supplier tells you how much they have delivered, and charges you for it. How do you know that they have actually delivered what they say they have? If they haven't, you could be paying more than you think for your energy.

The importance of accurate weighing of blown wood pellets

You rely on the accuracy of your supplier's weighing equipment (known as a weigh-loader on a truck). But the reality is that standard on-board weighing equipment is not accurate.

There is a real risk of wood-pellet customers not getting what they pay for. So European governments and national Trading Standards bodies have put in place protections for the consumer.

Legal for Trade wood-pellet delivery trucks

Weigh-loaders can be certified by Trading Standards as Legal for Trade. This means that they have gone through rigorous tests to ensure that they give accurate readings across the range of measurements. They receive a certificate and a sticker to show that they are sufficiently accurate to be used for charging customers and to prevent any tampering with the settings.

If your supplier's weigh-loader is Legal for Trade, it should have a visible sticker containing the following components:

Legal for Trade sticker on Moba weigh-loader

  1. Green M sticker
  2. CE mark
  3. The weigh-loader's accuracy class. Class III means a minimum of 500 "verification scale intervals" (i.e. accurate steps) between zero and the maximum weight. The scale in the picture weighs up to 20,000 kg (Max1), so to meet the requirements of Class III it should be able to weigh accurately in at least 40 kg steps. This one (as for all our Legal for Trade weigh-loaders) actually measures in 20 kg steps (e1), i.e. twice as accurate as the minimum required for Class III. 
    You may see Class IIII weigh-loaders in use on wood-pellet trucks, but not on trucks that are Legal for Trade, because Class IIII only requires measurement in 100 steps between zero and the maximum, i.e. in 200 kg steps for a weigh-loader with a maximum of 20,000 kg. That would not be accurate enough for legitimate billing.
  4. The verification organisation's four-digit identification number.
  5. Tamper-proof lead seal on control box to ensure unit cannot be unofficially recalibrated.

This is not a cheap option for wood pellet suppliers, and it's not them that benefits from the accuracy of certified systems (it's you). So most of them don't have suitable equipment, and some of them may not tell you about it, on the assumption that you don't know and won't ask.

Non-Automatic Weighing Instruments regulations (NAWI)

The authorities are aware of this risk. So they introduced some time ago the Non-Automatic Weighing Instruments (NAWI) regulations. These regulations require suppliers to use suitable weighing equipment wherever they are billing customers by the weight of a delivered good, as is the case for blown deliveries of wood pellets.

Any supplier that charges their customers for quantities measured by weigh-loaders that are not Legal for Trade is breaching the regulations, and can be prevented by Trading Standards from continuing to supply without the right equipment.

If you don't know how much you will take exactly, and want the flexibility to pay for the quantity measured on delivery, you should only buy from suppliers who offer trucks with Legal for Trade weigh-loaders, both for your own practical benefit and to avoid being complicit in illicit activity by traders whose equipment is not fit for purpose.

The weigh-loaders on Forever Fuels' pressurised tankers are all certified as Legal for Trade. To our knowledge, as of early 2012, only one other pellet tanker in the country (operated by Maylite Industries) is equipped with a Legal for Trade weigh-loader.

The alternative is for your supplier to weigh quantities of pellets onto the truck using a weighbridge at the depot. They can then deliver and bill you for the quantity measured by the weighbridge. If for any reason they can't deliver the pre-weighed amount (for instance, if you over-ordered), they will have to go straight back to the weighbridge to weigh the difference. Working this way, make sure you are dealing with a reputable supplier, who will use an accurate weighbridge and not blow off pellets after weighing out or before weighing back in.

ENplus requirements: gauged weigh-loaders

The European wood-pellet accreditation scheme, ENplus, refers to Legal for Trade weigh-loaders as "gauged weigh-loaders". ENplus has a set of requirements for producers and another set of requirements for "traders" (i.e. suppliers), so you know that the pellets have been both produced properly and handled and delivered properly. One of the requirements for traders is that the trucks should be equipped with gauged weigh-loaders.

Most British suppliers can't meet this requirement, so those who can't but who nevertheless want ENplus accreditation have applied for derogation from this rule. If you want a genuine ENplus-A1 delivery like you can get on the continent, you should ensure that your supplier is both supplying pellets that have been accredited to ENplus-A1 standard, and is themselves meeting all the ENplus requirements for traders, without derogation.

Non-specific calibration and testing

Suppliers may try to tell you that their equipment has been calibrated or tested for accuracy. They may have been, but unless they have been certified Legal for Trade by a national Trading Standards body, you can't rely on the accuracy. Anyone can go for the certification, and only this certification meets the requirements of the regulations, so why, other than because they know they wouldn't pass, would they go for some other type of testing and not Legal for Trade?

If it's not Legal for Trade, the weigh-loader may not have been tested to ensure that it will remain accurate across the range of measurements and over time. It may have been able to give an accurate reading under ideal conditions at the time of the test, but not in the real world. It may give an inaccurate reading if the truck is on a gradient or if the body on a tipper has not been allowed to settle in the horizontal position for long enough before doing the reading.

Legal for Trade tippers and tankers

In fact, it is so difficult to get reliably accurate readings with tippers, and the cost of doing so sits so heavily on a machine that is being used primarily because it is cheap, that it is extremely rare to find one certified Legal for Trade. That is one reason why only tankers tend to be used for wood-pellet deliveries on the continent, where they have more experience of these issues.

The easy way to make sure you are being charged accurately

Once you know about this risk of being billed inaccurately, you have a simple defence. Ask to see the sticker on the weigh-loader. It should be clearly visible. It should carry a green square with a letter M on it, the approved qualifier's identification number and the CE mark.

Or, if you want to check at a time other than during delivery, you could ask to see the certificate for the weigh-loader. But of course you can't tell from a certificate that it relates to the equipment on the truck that does the actual delivery. So it's best to check the sticker on your supplier's truck from time to time. And then you'll know for sure whether you are being billed legitimately or not.

Don't take our word for it, see for yourself

The Trading Standards Institute provides a brief summary of the NAWI rules, with a postcode search system to find the local Trading Standards office that can advise on weights and measures issues in your area.

Nottinghamshire Trading Standards have a good page on Weighing equipment in use for trade.

Southwark Council also provide a useful summary of the weights and measures requirements for equipment used for trade.

The National Measurements Office has a page of Frequently Asked Questions on the NAWI regulations, some of which are of relevance to wood pellets.

The legislation is available in the National Archives, but isn't the easiest read, like all legislation.

You can still get hold of a very old summary produced by the Department for Trade and Industry