The gas crisis in Europe is getting worse: during the last 2 years we have witnessed a huge increase in gas price, even 8 times bigger than price of 2020.
The effect of all these events have made gas a very expensive source of heating for the end user, and many people are in search of a new alternative of cheaper fuels for heating.
One popular alternative which attracts more and more users is biomass, a renewable resource with much lower cost compared to gas.
What is biomass?
Biomass is any organic material that can be used as an energy source. It includes a wide variety of fuels, such as: wood, pellet, briquettes, agriculture residues, energy crops.
As an energy resource, it is unlimited, recyclable and environmental-friendly. As a fuel it has significant advantages-practically no sulphur content and a very low ash content in comparison with common fossil fuels.

What are the different types of biomass fuels?
Pellet is a material100% natural. It is mainly made of wood essence. Pellets are produced by extruding wood residues. Their typical shape is cylindrical. Thanks to the natural substances of wood which are eliberated during pressing, they take a solid form with no need of chemical additives.
Pellets can also be obtained from other agricultural residues (husks, leaves, hay, etc). This type of pellet is named agropellet.
Fuel type | Calorific power kWh/kg | Maximum humidity % | Ash content % |
Pellet | 4,8-5,2 | <10 | <1 |
Agropellet | 4,0-4,2 | <15 | 5-7 |
Carbon | 5,2 | <15 | 4-8 |
Lignite | 1,6-3,8 | <20 | <10 |
Cereals | 4,2 | <20 | 0,6 |
Fruit husks | 4,2 | <20 | <4 |
Wood chips | 4,3 | <20 | <4 |
Wood | 4,0-4,3 | <20 | <4 |
Wood briquettes | 5,2 | <20 | <4 |
Why choose biomass?
It is a renewable fuel
Biomass is the only fuel whose carbon dioxide (CO2) environmental balance is zero, meaning that the plant during its lifecycle absorbs through photosynthesis process the same amount of carbon dioxide as it emits during combustion. This means that the total impact of biomass combustion is neutral.
It can be fed and burnt in an automatic way
In contrast with wood, pellet or other granulated fuels can be fed and burnt in an automatic way. The fuel is stocked in a big capacity silo which offers autonomy 3 to 5 days. The advantage of using biomass fuel is that it can be automatically fed, offering the end user more comfort. Additionally, ignition, combustion and extinguishing of the boiler are all made automatically.
It is economical
Biomass or pellet can be purchased during the summer months at a much lower price, and stocked for the winter season. They are not subject to state taxes like oil, and it does not have secondary distribution expenses like gas. The purchasing price is the final price.
What is the fuel consumption and the annual economy?
The necessary fuel quantity is different for every house, depending on insulation, heating distribution system, external and internal temperatures. However, the hourly fuel consumption can be calculated theoretically by the following formula:

Where: C– fuel consumption in kg/h, P – boiler power in kW, η – boiler efficiency in %, Hu fuel calorific power in kWh/kg.
For example, for a house of 200 m2 with a 40kW boiler, efficiency 91% and fuel with calorific power 5,0 kWh/kg (pellet – see table above), the hourly consumption will be C = 40 / (0,91 * 5) = 8,8 kg/h.
In order to evaluate what this calculation represents in annual fuel consumption and economy, the easier way is to report to a previous known consumption of known fuel (gas or wood). By taking into calculation all the above mentioned parameters (calorific power, efficiency, humidity), we can make the following conversion:
1 kg wood = 0,7 kg pellet = 0,85 kg agropellet
1 m3 natural gas = 2,1 kg pellet = 2,5 kg agropellet
Example 1: A house that had a previous consumption of 10 tons wood fuel within a winter season, will need 7 tons of pellets or 8,5 tons of agropellets.
Example 2: A house that had a previous consumption of 2.000 m3 of natural gas, will need 4,2 tons of pellets or 5 tons of agropellets.
More info about Thermostahl biomass products: https://thermostahl.ro/en/biomass-boilers/