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Wood chip drying

Wood Chips Drying

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To us high-quality of the product and of the drying process is very important at the same time.

Sustainability is fundamental to our work and defined for us with the best combination from ecologically + economically + socially!

For an excellent drying result and a healthy environment!

“With my solar drying plant for wood chips (144m² solararea) from CONA I’m able to dry about 2600 bulk cubic metres wood chips a year. It allows me to offer wood chips of high quality to my customers from my own forest.”

Michael Berger

"Only on the saw the saw work did not calculate itself any more, but now by the revaluation of the waste material by a solar drying plant I can continue my saw work again positively."

Saw mill Weingartner

Advantages of drying wood chips with solar

The use of solar-air collectors in drying process has several advantages:

The medium air is suitable for drying process and there is no need of an additional heat exchanger. Because of this it there is no risk of freezing, evaporating and leaking.

CONA has developed solar-air collectors, which have very efficient absorber technology. A peak power of more than 700W/m2 can be reached!

Furthermore the air is transported through isolated airshafts to the damp wood chips to avoid loss of power.

Little air intake
Because of heating up the air in a closed system the relative humidity is increasing and more water can be transported. For that reason less cubic metre of air are necessary for the drying process.

Patented technology
CONA’s solar-air collectors are patented and have been awarded with several prizes. Also the sloping grating is patented.

Saving solar energy from summer for winter
Because of solar drying of wood chips the net energy is increasing. 

Preserving and refining harvest
Farmers and foresters can preserve their harvest in a high quality with the help of solar energy.

Climate protection
For protecting climate it’s necessary to use CO2 neutral energy. Drying wood chips with the help of solar energy means linking two sources of green energy. With drying damp wood chips farmers and foresters can refine their harvest and reach a higher energy output.

With the help of CONA drying facilities biomass like bushes, wood from deciduous trees, foliage, twigs and rind can now be used as high quality bio-energy.

Floor types

Sloping floor

CONA has developed a patented sloping grating, which facilitates processing the wood chips (watch video).

The sloping grating is made of special panels with gill perforation to optimize the air stream through the damp wood chips. Furthermore blocking of the gill perforation/air holes is avoided. Because of the huge surface of the panels the wood chips are dried well and only little pressure is built up. For that reason the system is very energy efficient (about 0,3 – 0,5€ electricity costs per bulk cubic metre wood chips).

Because of the patented sloping gratings the dry wood chips can be removed easily from the drying chamber.
patented grating with gill perforation from CONA

Flat floor

Practicable level rust for drying.

CONA also offers a practicable level rust alternatively to the patented sloping ground.

This is suitable especially for different drying goods and a universal application.

Panels with openings which go down so that the material can not fall into but the air can flow out. Even the small parts of the wood chips can not cover the holes.

The generous, whole-flat ventilation causes a very low pressure construction and also enables with high aerial achievement to use very sparing ventilating fans and to use a little electric energy.

With usual agricultural tractors the loading and unloading by the drying property can be mastered without problems.

The level rust is a little more expensive on account of the more stable implementation than the sloping ground variation.


Our measurements have shown following results:

40m2 drying plant:

  • 8000 – 1000 BCM wood chips per season
  • drying wood chips from 60 – 40% water content to a water content of 10 – 20%
  • 150 to 200 kWh more energy output per BCM
  • only 1500 to 3000 kWh energy input

100m2 drying plant:

  • about 2000 BCM wood chips per season
  • drying wood chips from 60 – 40% water content to a water content of 10 – 20%
  • 150 to 200 kWh more energy output per BCM
  • 300.000 – 400.000 kWh yearly performance
  • only 4000 – 6000 kWh energy input

400m2 drying plant:

  • about 8000 BCM wood chips per season
  • drying wood chips from 60 – 40% water content to a water content of 10 – 20%
  • 150 to 200 kWh more energy output per BCM
  • 1.200.000 – 1.600.000 kWh yearly performance
  • only 16 000 – 24 000 kWh energy input

Payback period of the investment 5 – 8 years (depending on support payments)For prices and dimensions please contact us.


Frequently asked questions about our solar wood chips drying plants

The duration of the drying process depends on 3 important factors:

dimension of the drying plant and solar collectors
weather and sunny days
water content of wood chips at the beginning
Our experience shows that under good weather conditions during summer time the drying process takes about 1 – 2 weeks and 3 – 6 weeks in spring and autumn.

The solar collector is integrated into the roof. It’s best to place the collectors on the southern side but it can be also placed slightly western. One drying chamber needs to be 5,5 – 6m long and width depends on the needed capacity. A drying chamber that bears a capacity of 60 bulk cubic metres needs a width of 7,5m.

The main part of the needed energy is produced by solar radiation. The ventilators need about 2 – 4 kWh/BCM.

The drying process takes place in 10 – 20 charges per year. So there is a need of a separate storehouse for the dry wood chips.

The wood chips are distributed evenly on the sloping grating and less pressure is built. So it is possible to use very energy saving ventilators. It’s also easier processing the wood chips on the grating.

After planning the drying plant together with our customer the installation can be done in a few days depending on the roof.

It is possible to do a lot of things under your own auspices. The gratings can be installed totally on your own. But installing the collectors should be done under investigation of our employees to guarantee a smooth running of the drying plant.

The sloping gratings can also be used with other sources of energy and in combination with solar energy and another one.

Do you plan to get a solar drying plant?

We’d love to discuss your project and its requirements – contact us now to see if we can provide the best solution for your needs!

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