Current discussions surrounding the routing of power lines, large-scale power plants, nuclear and coal power as well as prices for heating and electricity show: decentralized power and heat generation is the way of the future. The energy of the sun and biomass are the most important resources. Thomas Bleul, Managing Partner at spanner, explains the role of wood in this ongoing change.
Wood – the energy source of the future
We believe that biomass plays a very important role in the energy supply of the future. Woodchips are a simple, readily available fuel class and available in a decentralized fashion at most locations and in sufficient quantities. This resource can therefore contribute to reaching the goals of the energy transition in a valuable manner, as it is capable of covering the primary energetic needs several times over: (cf. Study, Link)
Source: Potentials of renewable energies and their contribution to future energy supply, Dr. Joachim Nitsch, DLR, Institute for Technical Thermodynamics, System Analysis and Technical Evaluation Department. Lecture at the Environmental Symposium at the University of Konstanz: "Climate and energy in the field of tension between risk and responsibility." June of 2009
Wood becomes particularly attractive if it is not only used as a source for heat, but also power. Our Spanner Re² wood cogeneration plants can be activated or turned off in mere minutes in order to meet demands. In contrast to solar panels and wind turbines, they are not dependent on the weather or the time of year, though they can be operated in conjunction with both of these technologies in a hybrid manner in order to ensure a stable coverage of basic needs if the conditions for the other two technologies are not optimal.
Heat and power generated from wood is therefore useful in every respect. If 50 percent of the wood that is currently just being burned in Germany would be converted into heat and power using the wood carburettor technology, the heat yield would remain the same. But the annual power yield of two entire nuclear power plants would be generated as well.
Innovative technology, powerful and reliable
Spanner Re² wood cogeneration plants have been successfully competing on the market since 2009. Our patented wood carburettor technology has convinced hundreds of customers with its performance and reliability. The more than 450 units installed around the world possess a total output of more than 17 MWel and more than 40 MWth. They achieve an annual total operating time of 3,375,000 operating hours. Multiple units of the first production years have meanwhile accumulated plant operating times of more than 40,000 operating hours with an annual operation of 7,500 to 8,000 hours. This proves the great future opportunities for our technology and also serves to dispel any doubts that still exists in parts of the market and that are mainly due to the state of the technology in years past. Thanks to our experience, we are capable of assessing under which conditions the wood carburettor technology is sensible in its application and under which framework conditions it is not to be recommended. As a matter of course, we provide this know-how to all of our customers.
A clean affair
The special use of patented reformer technology in the Spanner Re² wood cogeneration plants is provided by the ultrapure, tar-free gas that is produced in the process. All emissions created by the plants are far below the required limit values of TA-Luft.
| Measuring component | Limit values of TA-Luft | Holz-Kraft Wood Cogeneration | Below limit |
| CO (mg/m3) | 650 | 37 - 47 | - 94 % |
| NOx (mg/m3) | 500 | 458 - 498 | - 4 % |
| Dust (mg/m2) | 20 | 2 | - 90 % |
| Formaldehyd (mg/m3) | 60 | 0,4 - 0,5 | - 99 % |
| Benzol* (mg/m3) | 10 | 0,5 - 2,5 | - 75 % |
Electricity generation costs
The electricity generation costs of a wood cogeneration plant are decisively influenced by the price of fuel, in this case dry woodchips, as well as the use of the generated heat.
| (in Euro-Cent per kWh) | Best case | Worst case | |
| Material costs for woodchips: 0 – 150 Euro/katro | 0 | 12,0 | |
| Maintenance costs (incl. replacement parts, motor replacement, etc.) | 2,7 | 2,7 | |
| Working costs: 10 – 40 Euro/h | 1,0 | 3,0 | |
| Other costs | 1,0 | 1,0 | |
| Financing (6,000 h per year, 3.5 %, 10 years) | 8,0 | 1,0 | |
| Total 1 | 12,7 | 28,7 | |
| Value of heat | - 8,0 | - 0 | |
| Total electricity generation costs | 4,7 | 28,7 | |
The operator can additionally decide between two different levels of automation for his plant:
Approach 1: The heavy automation of the plant and its accessories increases the initial investment while working expenses during operation are decreased. For this model, the working costs per hour are higher (see Table: Worst Case)
Approach 2: The plant is less heavily automated, accessories are acquired by the customer himself. The initial investment is lower for this model, but the working expenditures are higher, even though the working costs per hour are less (see Table: Best Case)
Decentralized electricity and heat generation and regional value creation
In all places where Diesel units are currently being used to generate power, the Spanner Re² wood cogeneration plants are also an economically viable alternative. The often complex and expensive diesel logistics can often be omitted due to the use of regionally available resources. In contrast to Diesel, which has consumption costs at 1 USD per 1 kWh, savings of up to 65 % are currently possible using wood cogeneration plants.
According to expert calculations, use of a wood cogeneration plant also allows for more money to stay within the local region as compared with a diesel unit of the same performance level (see calculation below).
Source: Calculations for Spanner Re²
Flexible output with 3 models
The Spanner Re² wood cogeneration plant can provide outputs from 10 kW to 1 MW depending on requirements.
Scalable for megawatt projects
Because of the great scalability of our plants, we are also receiving more and more large-scale projects: by installing multiple Spanner Re² wood cogeneration plants, operators can quickly and flexibly implement entire plants at a megawatt scale. Every individual wood gas reformer works autonomously from the other ones and can be turned on or off in a matter of minutes, so that individual systems can be turned on or off as required. This ensures a high degree of availability and an optimal adaptation to current consumption rates.
Perfect for power self-supply purposes
Especially in Germany, the idea of self-provided power supply becomes more and more interesting due to rising electricity costs. Our "smallest" wood cogeneration plant is an answer to this issue: the HKA 10 generates nine kW of electrical power per day in continuous operation. Energy-intensive agricultural and business enterprises can generate up to 72,000 kWh of power, valuing up to 18,500 Euros themselves. This value is calculated from the power costs savings as well as the state subsidy for self-generated and self-used power (KWKG subsidy). The heat can also be used by the owner himself or fed back into the grid.