Do you know how much energy and ash content there is in your wood pellets?

As with all new technology that comes into your home, to begin with everyone is happy to help with the ‘jobs’ associated with it, whether emptying the dishwasher or putting the iPad on charge at night.  However, the novelty soon wears off and the job can become a chore, particularly when you forget…

Your wood pellet boiler is no different; have you become aware that the job of filling it up with pellets and emptying the ash draw has arrived on your to do list? Have you also begun to question how often you are needing to do it?

How often you fill up with pellet and the amount of ash that comes out of your boiler will be directly proportional to the amount of heat you need and the fuel you burn, which is obvious to a certain extent.  But the not so obvious factor is the quality and specification of the pellets that you are burning, in particular look out for the ash content and calorific value (CV).

The ENPlus A1 standard is the now the dominant Europe-wide accreditation for premium quality wood pellets and sets minimum standards for both these variables.

The reason this is important is twofold:

First, ENPlus A1 sets a standard of <0.7% allowable ash per Kg of pellets burnt.  In practice, this means that a typical household will generate around 35Kg of ash per annum (if you use pellets for heating and hot water and burn around 5 tonnes per annum).

The size of the ash drawer of course varies between boiler models but typically they carry about 5Kg of ash, meaning that you’ll be emptying the ash about every 6-8 weeks, more often in the winter.

Woodlets pellets have an average ash content of 0.2%, meaning with the same boiler you’ll only need empty the ash twice a year. Ask your pellet supplier what the actual ash content of their pellets is, they should have a lab test to prove it.

Second, the calorific value (CV) of your pellets should be at least 4,600 Kilowatt Hours (KWh) per tonne (according to ENPlus).  It’s impossible to tell the CV value of pellets just by looking at them and the first you’ll know that you’ve been short changed by your supplier is that your pellet tank will be running out sooner than expected and the ash can will be filling up fast.

That’s why Woodlets are guaranteed to deliver at least 4,600KWh/t and is normally in the range 4,700-4,750KWh/t.

We’ve had a lot of sales enquiries over the last 6 months where potential customers have told us we’re too expensive and have gone off to buy cheaper pellets elsewhere.  Most have come back.  Why?  Because we deliver more KWh per £ than many of our competitors and therefore the best value proposition.

The numbers are easy – if we consider our retail price at £272/t (note: per tonne not per pallet – another pricing trick to be wary of), that equates to 5.8p/KWh (at 4,700KWh/t).  We’ve had a number of customers this past winter that have paid the equivalent of £240/t but measured actual heat values (via heat meters on the output) as little as 3,800KWh/t – a whopping 20% difference meaning they actually paid 6.3p/KWh.

Check for both of these variables, ask for the ENPlus lab tests if necessary – it will pay you to do so!

Ash

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