Use wood pellets or wood chips as an energy source?

Today I would like to pursue the question of the advantages and disadvantages of the two most important forms of wood energy and speculate whether the togetherness of wood chips and wood pellets will persist in the medium term or whether one variant will prevail over the other. I was inspired to write this article by a report by Dittmar Koop and Andy Ridder in the February issue of the magazine “neue energie”.

What is special about wood as an energy source is that it can be obtained in various forms. Wood pellets, wood chips or wood briquettes give the end user a wide choice and freedom on the one hand, but at the same time demand a well thought-out decision.

In terms of energy content, price and the necessary preparation steps during production, pellets and wood chips are the two extremes within the trio. Therefore I have compiled a list in which the most important advantages and disadvantages of these two forms of energy are compared.

List of advantages and disadvantages of pellets and wood chips

pellets

  • higher energy content than wood chips (approx. 15% larger)
  • better CO2 balance and lower transport costs because less water and more compact energy are moved (pellets: 2% water content, wood chips: 20 - 30%)
  • more homogeneous quality, which enables better planning security (see also Article on the seal of quality for wood pellets)
  • higher price per thermal kilowatt hour (see graphic at the beginning of the article)
  • closer coupling and dependency on the electricity price available, since more finishing steps are necessary for the production

Wood chips

  • can be made from raw wood without many preparation steps
  • have lower manufacturing costs
  • need a larger storage space
  • show greater quality differences

You can read about current developments in the bio-heating market in Germany in this article .

The following film shows the uncomplicated way of producing wood chips. The production of wood chips directly in the forest is not uncontroversial due to the high weight of the chipper and the associated soil compaction.

Long live the diversity of bioenergy sources

I do not think that pellets or wood chips will completely replace the other candidates, since the fields of application are quite different and the regional and temporal framework conditions have a major impact on the profitability calculation of the heat supply. For a user with large wood stocks in the neighborhood or good storage options, the existing price advantages will rather lead to an investment in wood chips. In a smaller city apartment, this calculation will tend to turn the other way.

The greater the thermal energy required (over 100 kW), the more the transport costs for the energy sources become apparent in the total cost calculation. With the increasing demand for heat from a consumer, pellets are therefore becoming increasingly attractive.

In the medium term, the comparison between wood energy and other bioenergy sources, such as biogas or biomethane, should also be more decisive. And of course the competition between bioenergy and fossil fuels is still an important issue that should be considered when installing a new heating system.

At this point a link to an informative page about pellets that I came across during my research.

What is your opinion on pellets and wood chips and which variant do you like better?

1 comment on “Use wood pellets or wood chips as an energy source?”

  1. Hello Mr. Kirchner, the CO2 balance of the pelett's came across me a little bit with your article, although they restrict it to the transport routes, the statement better CO2 balance remains with the reader. You only mention the elaborate manufacturing steps involved in the production of pelets in terms of costs, but here too the carbon footprint comes into play. If the pellet production takes place in a meaningful combination with, for example, a sawmill, where the required fine shavings are obtained as a by-product and if waste heat from an existing process, e.g. power plant, is used for drying, then the production of pelets is sensible. With the increasing demand for pelets, however, I see the danger that additional, energy-intensive processes will be necessary both for the manufacture of the shavings and for drying, so that the CO2 and environmental balance will be significantly more negative.
    Here, as with all things, you should think about where the materials that you buy and use come from and think about whether it makes sense to use them. Otherwise, pelets can also become an unclean source of energy.

Post a comment

Your e-mail address will not be published.

This website uses Akismet to reduce spam. Learn more about how your comment data is processed.

Deutsch English
X