ADVANTAGES OF CENTRALIZED BIOGAS PLANTS
WHY WASTE BIOGAS PLANTS OFFER MAJOR BENEFITS FOR POLAND
Randy Michael Mott
President, Central and Eastern Europe renewable Energy Solutions (CEERES) Sp. z o.o.
There is a fundamental misunderstanding of biogas projects in Poland,
not only among the public, but also in the Government. Public officials
frequently speak of “agricultural biogas” and point to the large number of
plants in Germany as a model for Poland. For many reasons, this model has not
been working in Poland. This situation may improve with changes in the law. But
what is often lost in the discussion is the role of waste co-digestion in the
biogas and waste management sector. Pioneered in Denmark, central anaerobic
digestions plants have been the most successful development in the biogas sector.
Professor Jerzy Buzek, former Polish Prime Minister, President of the European
Parliament and its previous rapporteur on the development of energy technology
in the European Union, has described the Danish approach and technology as a
model for Poland's development. Our company has been planning more than twenty of
these facilities in Poland, now waiting for changes in the law to be finalized.
Centralized co-digestion plants rely upon the waste material from the
surrounding area, including not only manure, but slaughterhouse waste, sewage
sludge, household food wastes, and various food processing wastes. In Denmark,
they are chiefly owned by farmer cooperatives, since they process and store the
manure from farms and provide an improved fertilizer material in return. These plants are usually located
close enough to towns to provide biogas heat for district heating as well as
electricity and fertilizer. Because of their relative proximity to towns, they
have been developed to achieve very high levels of environmental protection and
odor control. CEERES has toured Danish plants with several local Polish
officials on multiple occasions and they are invariably favorably surprised by
the lack of odor and clean operations. These same plants can be built in
Poland, incorporating the two decades of improvements made in Denmark along
with operational training of Polish staff.
How can Poland benefit from this type of biogas plant? How especially
can the communities themselves benefit?
The centralized co-digestion plants generally are from 1 to 2 MW in
capacity. The average German farm biogas plant is 350 kW. The larger size
involves a different approach to the design and different equipment,
particularly for sanitation and environmental protection. The sterilization
of potentially harmful waste substrates is done at the facility before material
can go to the digesters. The process involves a series of special structures
and equipment to eliminate the exposure of waste material to the outside air.
All air collected within the enclosed system is processed in the odor filters,
including the latest design that is self-enclosed and uses chemical processes
to destroy all odors, circulating the process water back into the mixing tanks
going to the digesters. By 2007 with the changes in odor control, the Danish Environmental
Protection Agency found no substantial odor problems at these facilities, which
must meet tough odor standards.
To incorporate all of the state-of-the-art health and environmental
controls and still be profitable, the centralized AD plant (CAD) should be at
least 1 MW in capacity. CEERES and the biogas association are working to increase the size of plant supported to 2 MW. Smaller biogas
plants on farms do not handle the more difficult wastes and usually do not have
the environmental protections systems required for CAD plants. CAD plants
normally do not rely on crops for their energy output, using waste materials
with high methane values instead. This dramatically improves their economic
viability as shown below. Reduction of substrate costs by using waste and full utilization of the heat substantially change the economics, in addition to the benefits of the larger scale (>1 MW).
Purchase of substrates (feedstock for biogas) actually pushes the cost
of producing energy above the levels that are covered by the Polish electricity
reimbursement scheme (current or proposed). Use of waste substrates allows a more
economic operation that is feasible in Poland with lower subsidies compared to
Germany and Austria. Biogas plants of
this type are absolutely crucial for Poland to meet the mandatory renewable
energy goals of the European Union by 2020. But they also offer many more tangible
benefits to the country and the local communities.
Below: digestate being transferred to storage near its point of use on local farms
CAD plants offer many benefits to Poland that do not occur with
farm-based biogas plants. Using waste feedstocks, CAD plants offer the
highest environmental and health treatment for troublesome wastes. This is one
reason why they are endorsed by Greenpeace, Sierra Club, Friends of the Earth
and other environmental organizations. Treatment of household food wastes,
slaughterhouse wastes, and sewage sludge is done with state-of-art technology.
For waste producers, including local communities, this offers the best
treatment option with no fees or nominal fees much lower than alternative
methods. Farm plants are not designed to handle these materials and especially
lack the environmental and health facilities to do so in compliance with all EU
requirements and best management practices.
CAD plants can provide low cost heat to district heating to replace
coal-fired, polluting capacity, normally for at least 7-9 months a year. CEERES
offers this heat at dramatically lower prices than coal-fired plants. Farms plants, by definition, are normally too
geographically isolated and small to provide this benefit.
Many of the waste materials processed in the CAD plant now are used in
Poland as animal feed or fertilizer without sanitation. A few years ago, the
European Commission found many Polish waste producers were not complying with
the EU regulation calling for sanitation of many types of these wastes before their
reuse. The new EU Parliament measure allows for more feed use, but does not
remove the sanitation requirement. The cost of sanitation on top of the cost of
transport normally exceeds the protein value of the material as a feed for
animals. So the CAD plant replaces unhealthy and dangerous handling of
biological waste with a process that kills pathogens before their reuse in the
food chain. Farm plants cannot provide this function since they lack the
facilities to do so and they utilize a different design. A high level of
operator training for full-time specialists is also essential and not practical
for farm-based plants. The need for diligence on this issue is demonstrated by
the tragic e. coli contamination case in Germany earlier this year.
A CAD plant also creates serious emission reductions by displacing waste
going to landfills, direct land application and other routes that cause
greenhouse gas emissions. A 1 MW CAD
plant destroys 116,000 tons of CO2 equivalents a year by using the methane as a
fuel. This remains one of the most cost-effective methods to reduce greenhouse
gases (GHGs). Farm biogas plants use
very little feedstock (manure and crops) that reduce GHGs.
Photograph: A
specially-designed truck entering the waste reception building at a
Danish CAD plant. All waste transfer occurs inside the enclosed building, where
the air filter sucks the building air into the odor filter. Each truck is also
washed off before leaving the building.
By increased nutrient uptake in crops, the CAD plant’s digestate reduces
the excess nutrients in agricultural runoff, the largest remaining water
pollution source in Poland. Many local communities where we are planning these
facilities identify coal-fired air pollution and agricultural runoff as their
leading air and water pollution problems. A small farm plant can help reduce
nutrient runoff in a more limited scale, but does nothing to change coal
emissions.
In its electrical output, the CAD plant can provide electricity
to local industry as attractive prices. But when peak usage is not mirrored by
night demand, it can offer the electricity to local cities for street lighting
at reduced prices. So citizens benefit by lower heating bills, lower water
bills for waste treatment, and even sometimes lower municipal energy bills.
None of these benefits occur from a farm-based, smaller biogas plant. The Polish law requiring sales to the grid would have to be revised to allow these benefits.
In the area of employment and community development, while a
sophisticated CAD plant is highly automated and employs few people, it does
improve the local infrastructure for other large employers. The food and beverage industry is one of
Poland’s major growth sectors. Most all of these plants produce organic wastes,
which now must look for waste management options outside of landfilling and
increasingly away from direct use by local farmers as a feed or fertilizer
without treatment. A community with a CAD plant can offer no-cost or low-cost
waste facilities to a new investor who will build a facility that produces
thousands of tons of organic waste a year. Future siting of such food and
beverage plants by major investors will undoubtedly add the availability of
local organic waste management facilities to their decision-making on finding
the right location.
So as Poland considers changes to the new Renewable Energy Law, the Government should
look beyond the simple idea of imitating German farm biogas plants.
Scandinavian-style central AD plants offer many more advantages, far less
environmental issues, and a proven method to reach renewable energy goals in
both electricity and heating.
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