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, and the readings cannot be materially affected by the conditions nor by the operator. They receive a certificate and a sticker to show that they are sufficiently accurate and dependable 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:
- Green M sticker
- CE mark
- 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.
- The verification organisation's four-digit identification number.
- Tamper-proof lead seal on the control box to ensure the unit cannot be unofficially recalibrated.
This is not a cheap option for wood pellet suppliers, and it is not them that benefits from the accuracy of certified systems (it is 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.
The legal alternative to Legal for Trade onboard weighing 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 on-board weighing systems
The European wood pellet accreditation scheme, ENplus, refers to Legal for Trade weigh-loaders as "gauged on-board weighing systems". 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 of the international ENplus rules for traders is that the trucks should be equipped with gauged on-board weighing systems.
Most British suppliers can't meet this requirement. They initially asked for a derogation from the European rules. The European Pellet Council (EPC) agreed to a temporary derogation for a limited period of three years, in order to encourage the uptake of the scheme. The EPC intended that British suppliers would use this period to equip themselves properly, but most British suppliers preferred not to spend the money and instead used the time to lobby for an extension of the derogation.
They achieved their objective in the negotiations over version 3 of the ENplus Handbook (the current version as of late 2016). In order to avoid conflict between countries that wanted higher standards (such as Germany) and countries that wanted lower standards (such as the UK), the EPC agreed to allow national variations on the standard international ENplus rules. The UK took advantage of this to water down the standards required of delivery vehicles, to the point that almost anything goes.
We have set out on another page a comparison of all the ways in which the UK has exempted itself from the international rules, in order to save cost for suppliers at the expense of their customers. For weigh-loaders, the text that is present in the international rules and absent from the UK rules is:
Vehicles for Part Load Deliveries to end-users must be equipped with a gauged on-board weighing system.
"Gauged on-board weighing systems" is the ENplus way of referring to Legal-for-Trade weigh-loaders. The UK suppliers knew it, or they would have been happy to include this wording in the UK version of the ENplus Handbook. Instead, they dropped it for the vague admonition that:
Where Part Load Deliveries of bulk pellets are made to end-users, appropriate measures shall be implemented and/or appropriate equipment shall be used in order to guarantee that the weight of the delivered pellets is determined in an accurate way.
This allows British suppliers the option of specifying in their procedures a theoretically-acceptable alternative to Legal-for-Trade weighing, without any hope of detection or enforcement if the procedures are not followed.
If you want a genuine ENplus A1 delivery like you can get on the continent, you should ensure that your supplier is (a) supplying pellets that have been accredited to ENplus A1 standard, and (b) is following the international ENplus rules for traders. Forever Fuels is one of the few British suppliers that operates to the international ENplus standard.
Non-specific calibration and testing
Suppliers may try to tell you that their equipment has been calibrated or tested for accuracy, and that this is functionally-equivalent to Legal for Trade. It isn't. They may have been calibrated, but unless they have been certified Legal for Trade by a national Trading Standards body, you cannot 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 is not Legal for Trade, the weigh-loader may not have been tested to ensure that it will remain accurate across the full range of measurements, over time, regardless of conditions and impervious to the manner of operation. 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 is at the wrong angle or has not been allowed to settle in the horizontal position for long enough before doing the reading.
The weight reading on a tipper can be out by more than a tonne if it is not taken properly. A sharp operator could follow the correct procedures to achieve an accurate reading during calibration, and then take an inaccurate reading during deliveries, either accidentally because they are in a hurry, or deliberately in order to charge for an inaccurate weight. This is why it is difficult for tipper-blowers to achieve Legal for Trade certification.
Calibration simply means that the truck was capable of giving an accurate reading at the time of calibration. It does not provide any guarantee that the reading will remain accurate and that the reading cannot be affected by conditions and by the operator.
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 is best to check the sticker on your supplier's truck from time to time. Then you will 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