Prices for wood pellets have almost tripled since last year. Whereas in September 2021 the price was still 237 euros per ton, in September 2022 it was already 764 euros per ton - and rising. The culprit here is the increased demand for alternative fuels, especially since the prices for oil and gas have exploded since the start of the Ukraine war. Many pellet heater owners are therefore desperately looking for alternatives. Straw pellets could be a cheaper solution. But there are a few things to keep in mind!
As a by-product of the grain harvest, many millions of tons of straw are produced annually, which are mostly used as bedding pellets for e.g. horse stalls due to their absorption capacity. Since straw pellets absorb up to 400% of their dry weight in liquid, the volume of manure is also reduced.
But does it also make energy sense to use straw bedding pellets as a substitute for wood pellets for heating? If we look only at the calorific value of straw pellets, the answer is quite clear: because straw pellets have a comparatively good calorific value of 4.5kWh/kg. Wood pellets have an average calorific value of about 4.9 kWh/kg, which means that straw pellets can easily keep up with them in terms of energy.
But straw pellets can also save money: For example, one ton of straw pellets costs around 300 euros on the Internet throughout Germany, which corresponds to a price advantage of around 300 to 400 euros per ton compared with wood pellets.
However, problems can arise when burning straw, especially in older pellet stoves, due to the amount of slag produced, the higher level of dust emissions, and the increased amount of ash.
Ordinary wood pellet stoves are therefore only conditionally suitable for operation with straw pellets. However, modern pellet stoves are often designed in such a way that they can also burn straw pellets in accordance with the standards.
Anyone who wants to fill their pellet store with straw pellets for the 2022/2023 heating period should therefore first check the extent to which their own pellet stove can also burn straw pellets. Particular attention must be paid to whether the prescribed exhaust gas limits can also be met with straw pellets.