FORENERGY – A SOLUTION FOR THE FUTURE ENERGY NEEDS
Dr. Arto Timperi, Manager, Dr. Sylvain Martin, Project Coordinator Timberjack Energy Technology
PO Box 474, FIN-33101, Tampere Finland
The demand of energy is constantly increasing and new alternative energy sources are sought to meet the strict growth and
environmental demands. Biomass is an alternative viewed as having the greatest potential. Timberjack is actively working on
equipment and solutions to create a complete chain for the production of forest bio fuel. The R&D results have been recently
demonstrated by the worlds biggest biomass fuelled power plant Alholmens Kraft in Pietarsaari Finland. The biomass
production systems are further investigated and demonstrated for the different European conditions. The tests have been
carried out in Germany, Italy, France and Spain.
1. NORDIC COUNTRIES LEAD THE
DEVELOPMENT OF FOREST BIOFUELS
This paper deals with the use of forest biomass means the
exploitation of forest residual – branches, tops and other
wood parts left on the site after harvesting. Timberjack
has together with its partners developed a unique forest
fuel production system that is demonstrated at several
power plants in Finland. This technology is further
researched and developed under EU funded project
FORENERGY having partners from Austria (ARCS),
Italy (IRL), France (AFOCEL & CEMAGREF), UK
(SHOTTON) and Finland (UPM-Kymmene and
Timberjack). The aim is to demonstrate this new forest Figure 1. The transportation problem of biomass.
fuel production technology for the other areas and
conditions in Europe. Collecting the forest residuals in a new compressed way
enables a cost-effective material handling (Fig 2.). Also
Large power companies within the forest industry are the power plant can be optimised to be efficient and clean
interested in using forest residual along with other raw when it is designed for wood material entirely. These are
materials for energy, such as bark, peat and fossil fuel. the key elements for competitive wood energy
The increased use of forest residual for energy production production.
requires, however, that the production, deliveries and
quality of forest residuals are secured. In addition, the
operations need to be financially viable and profitable.
Today an impressive part of the total energy supply in
Finland and Sweden (>25%) comes from the renewable
energy sources. The forest industry, pulp mills and saw
mills have played an important role in developing
efficient utilization of biomass, such as bark, wood waste
and other by-products from the industrial process.
2. FOREST ENERGY SYSTEM
The production of bio fuel is expensive because the
material is usually scattered over the site area. Also the
energy content of biomass is lower than the fossil fuels
are having. Figure 2. Forest energy chain.
The main problem with the transportation is the low When the basic research for the new type of forest residue
density (Fig 1.). For that reason also the transportation production technology was conducted. It became evident
cost is very significant. that the process of energy generation calls for
understanding and development of the whole energy
The development work of Timberjack has been two chain, as well as the subsequent piloting. Only when
folded; to improve the economy of the collection work in mastering these it is possible to demonstrate the total
the forest and to improve the transportation economy. economy, applicability and environmental friendliness of
the renewable energy system.
The common development factors have been the
automation in the forest and the increase of compression Forest residuals for energy production are mainly
ratio of the biomass material for transportation. obtained from regeneration harvesting sites and young
tree stands as well as from the first thinning. The
objective is to gather the residuals from the forests as
easily and efficiently as possible, while leaving the
necessary nutrients in the forest.
Most probably, there will be alternative ways of securing
the raw-material resources. The branches can be either
collected, chipped in the forest and transported to a power
plant, or they can be bundled in the forest, transported to
the power plant where they are then crushed or chipped
with more powerful equipment and cheaper energy.
Timberjack has taken an active role in charting the use of
biomass and designing the necessary machines and
equipment for gathering, transporting and
exploiting of biomass. Timberjack is not working
on this alone, but in a close cooperation with the
leading companies in the field. The solutions cover the
entire chain needed for effective use of biomass.
3. SILVICULTURAL METHODS FOR YOUNG
Silvicultural measures such as thinning and cleaning
generate biomass, which can be used when producing
energy. This renewable and clean energy raw material is
also generated when cleaning the roadsides and power
lines. Modern technology allows this valuable biomass to
be used in energy production effectively and Figure 3. Carrier TJ-770 and the multifunction felling
economically and in an environmentally friendly way head TJ-720.
Timberjack is developing a new mechanized method for 4. LOGGING RESIDUALS
restoring too dense and young forests. The basis of this
method is the multifunctioning, accumulative harvester At regeneration forest sites 35-45% of residual biomass is
head 720, which collects the cleared trees quickly and generated for every solid cubic meter of industrial wood
effectively. The individual stems are cut with a knife. The produced. Forest residual is a clean energy source that
harvester head collects automatically 1 to 10 trees at a can be utilized effectively and productively with the new
time. This bundle of trees is then stacked in suitable bundling technology. The collection of residuals enables
place. The ideal base machine is a small harvester the forests to be regenerated immediately after the
designed for thinning (Fig 3. Timberjack 770/720). harvesting and the forests can be used for recreation.
It is possible to switch between the energy head and a In the bundling method, the forest residual, or slash, left
normal harvester head for the production of pulpwood as behind by a harvester, is collected and fed into the
well as with an exchangeable harvester head for the bundler, which produces compact slash logs. Typically
collection of energy wood. This increases the availability slash logs are around 3 meters in length and about 60-80
of the machine and improves the profitability of the cm in diameter. Each bundle contains about 1 MWh of
machine investment. The productivity of this method is energy when combusted. A felling area of one hectare in
significantly higher than the traditional manual methods size yields about 70 – 140 bundles (Fig. 4.).
are. Nowadays, at least in Scandinavia, it is not possible
to find the labour to work for this kind of thinning After being bundled, the slash logs are transported from
operation. the forest to the roadside with standard forwarders. Slash
logs can be stored temporarily in the forest or they can be
The Forenergy project has been testing this transported directly to the power plant by truck. The slash
felling/collection method so far in Finland, Sweden, logs are usually crushed at the power plant or terminal
Germany, Italy and France. The results have been very inventory, which enables the use of very effective and
promising. Since the tests were started several machines economical crushing or chipping method (Fig. 5-8).
have entered into the commercial operation. The tests will
be further on conducted in the different conditions over The bundling system makes the storing of bundles clean
the Europe. and easy. Because the compact bundles do not start
decomposing immediately, it is possible to store those for
the peak periods in energy production. The bundles can
be stored either in the forest or at power plant, and the
bundles can be easily dried in stacks. Moreover, the
bundles are available for use throughout the year.
In the Forenergy project the bundling technology has 5. POWER PLANT SYSTEMS
been tested so far in Germany, France and Spain (Fig. 6.).
The tests have shown that the method works well with the A very modern biomass power plant has started its
hardwood too. commercial operation in Pietarsaari, Finland. This
Alholms Kraft Biopower Plant is the world’s largest
Normally the old power plants are optimised for fossil CHP district heating plant fuelled by biomass with the
fuel types. This limits effectiveness and causes more power of 550th MW. Timberjack’s machines are
emissions because of the less efficient combustion when involved in the fuel supply of the plant and the
biomass is used in this kind of power plants. However, experiences gathered will also be used in developing the
when the power plant is designed entirely for wood fuel machines for other plants. The plant is using more than
the fuel handling can be optimised for the bundles. This 300.000 bundles annually (Fig. 7, 8 and 10.).
saves energy and reduces investment and maintenance
costs. The performance of the collection system is measured
and every single truck load of bundles is measured by
weight, number of bundles and the cost. The database is
continuously improving its coverage and accuracy.
In Finland there are also several other power plants using
the bundles. The newest plant is JAVO in Jämsänkoski
having the thermal power of 185th MW.
The fuel system of JAVO is designed very flexible to take
bundles, stems and stumps. The plant has been in
commercial operation since May 2002 (Fig. 9).
It is estimated that by using the bundles, the
Figure 4. Timberjack Bundler 1490D. transportation distance can be increased to > 200 km and
even longer when railways are used. This makes the
bundle technology very competitive against the use of
fossil fuels (Fig. 10.).
Figure 7. On-road transportation of bundles.
Figure 5. Bundles transportation in the forest.
Figure 8. Alholmen crushing station (550th MW).
Figure 6. Bundles in France; fresh and old material.
 A. Timperi, Timberjack News 1/2000, 2/2000,
1/2001, 2/2001, 3/2001, 1/2002 and 2/2002
 A. Timperi, Nordic-Japan Environmental Conference
2000, Nagano City, 14-15.11.2000
 A.Timperi, New Technologies for the Collection
of Wood Residuals from Forests, Danbio 25-
 S. Martin, Racolta del legno per energia: Lavori in
Corso, Biella Conference, 28 Settembre 2001
Figure 9. JAVO fuel feed in.
Figure 10. The worlds first bundle train.
Timberjack has played an active role in developing the
mechanized felling system for young forests and bundling
system because we believe that enables the large-scale
utilization of forest energy – both commercially and
according to the principles of sustainable development in
an environmental friendly way. These methods will lift
the production of the renewable forest bio energy into a
new higher level that is fascinating, economical and
environmentally sound. The technology has been proven
by several commercial projects.