Cracow Clean Fossil Fuels and Energy Efficiency Program

Phase I

The first Phase of the program included testing of the low emission sources, a building energy conservation demonstration, and incentives analyses.

CHARACTERISTICS OF THE LOW EMISSION SOURCES

Low emission sources in Kraków include 100,000 home stoves, 227 traveling grate ("stoker-fired") boilers and more than 2,000 hand-fired boilers. The traveling grate boilers burn low cost, fine coal, and are the largest sources. Hand-fired boilers burn coal and/or coke depending upon the type. The source testing program was designed to obtain performance data on the most important source types to allow the relative importance of each to be weighed.

Home Stoves

The coal stove tested during this program is a traditional storage stove built of brick and covered with ornate ceramic tiles. It has been reported that there are seven million such stoves in Poland. These stoves are fired once or twice daily during Winter. Each firing period lasts about 1 1/2 hours, and during this time the stove's mass is heated. After the burning period is over, the room is heated as the masonry slowly cools.

Testing was done at the Academy of Mining and Metallurgy (AGH) in Kraków with a test stove built in place by local craftsmen. The test protocol used was based on U.S. standard methods for testing wood stoves and allowed continuous measurement of emissions and efficiency during burn cycles.

A range of fuels were tested, including coal typically used (10-20% ash, 30% volatiles) and low volatile, smokeless briquettes. The briquettes are being considered for future use and are not yet available on the fuel market. In tests with normal operating procedures, thermal efficiency of the stoves was found to be considerably higher than expected (60-70%). Emission factors for particulates were found to be very high with coal firing. With the low volatile briquettes, particulates were reduced by more than an order of magnitude. Similar results were obtained with use of low volatile coke.

The work at AGH included tests with a wide range of operating conditions. During the course of this work a new operating procedure was developed which can produce efficiency levels of 72-75% consistently.

Hand-Fired Boilers

There are two major types of hand-fired boilers in Kraków; steel boilers designed for coal firing and cast iron, designed for coke firing. Coal is considerably less expensive and produces greater levels of particulate emissions. Steel boilers generally cannot burn coke and in many cases coal/coke mixtures are used.

Efficiency for the hand-fired boilers ranges from 60-73%. As in the case of the home stoves, particulate emissions increase with increasing fuel volatiles content and wherever possible, coke or coal/coke mixtures should be substituted for coal. CO emissions are very high from the hand-fired boilers and this is not greatly affected by fuel type. CO can be reduced by careful use of overfire air, particularly during the time immediately following the addition of fresh fuel to the bed.

Stoker-Fired Boilers

Two stoker-fired boilers were tested during this program. The first is a 20 year-old hot-water boiler which provides heat to a local part of the district heating system and is rated at 11.6 MW thermal output. The second is a 40 year-old boiler which provides process steam to local factories and is rated at 2.9 MW output.

In both cases, boiler excess air is controlled manually and operators do not have instrumentation which allows excess air to be properly adjusted. The result is very low thermal efficiencies, 55-60%, particularly at low load.

These stokers are designed to use pea-size coal. The fuel actually fired has much more fines than is considered optimal. Tests showed performance can be improved significantly through a combination of improved fuel and better excess air control.

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BUILDING ENERGY CONSERVATION

During this program, a demonstration of low-cost weatherization and other conservation techniques was done on four two-story buildings in a Kraków cooperative. The four identical buildings have 66 apartments each and are connected to the district heating system.

Different combinations of energy efficiency measures were tried in each building over 2 heating seasons:

• Baseline building (no improvements)
• Regulated hydroelevator
• Regulated heat exchanger
• Thermostatic valves on radiators and chemical cleaning of pipes in the building
• Fiberglass insulation of air space under the roof
• Fiberglass insulation of air channels in the concrete slab of the basement ceiling
• Weatherization package consisting of

		- Caulking interior cracks and around door and window frames
		- Weatherstripping all doors and windows
		- Installing door sweeps and thresholds on all entry and balcony doors
		- Sealing infiltration bypasses around electrical and pipe openings in the basement
		- Suggesting to residents that they not block radiators with furniture or curtains

External polystyrene insulation applied either to all walls or to flat (no windows or balconies) walls only

The demonstration showed that the weatherization package (cost $45 US per apartment) and roof insulation (cost $37 US per apartment) were cost-effective, with simple paybacks of less than four years at current energy prices.

Some form of control was needed to reduce the amount of heat delivered to the building; otherwise the weatherization will just make it overheat. The demonstration used thermostatic valves on radiators, as well as temperature reset controls on building hydroelevators or heat exchangers. The district heat utility, MPEC, feels that comparable savings can be obtained by installing heat exchangers and air temperature-based controls in the network substation nodes, each of which serves from 5 to 25 buildings. This would lower the cost of controls to about $80 per apartment.

The building receiving the control, weatherization, and attic insulation measures reduced its seasonal heat energy consumption by over 21% (640 GJ, or almost 10 GJ per apartment). The other measures tested, external insulation and basement insulation, did reduce energy consumption, but were not cost-effective and, in the case of external insulation,were prohibitively expensive for widespread implementation.

In summary, the demonstration project identified affordable weatherization measures which could reduce heating energy by over 20% in all types of Kraków's older, un- or under-insulated buildings. The measures improved comfort, reduced energy bills, and were well received by the housing cooperative residents, cooperative management, and MPEC.

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ANALYSIS OF INCENTIVES

Recognizing a limited willingness and/or ability to pay for reduced emissions, a study was done to identify and compare incentives programs which the City might implement to promote options for the low emission sources. This was done for specific options, consistent with the five subprojects identified for the program and included:

• Replacement of hand-fired boilers in the Old-Town part of Kraków with new gas-fired boilers.
• Elimination of local boiler houses by connection to the district heating system in selected parts of the city.
• Conversion of small coal stoves to electric heating in the ºobzow part of Kraków.
• Use of smokeless briquettes in small coal stoves.

In each case, a study was done to evaluate the cost impact of conversion on the user. A twenty year cash flow analysis was prepared based on two different assumptions about energy prices over the period. In the first energy price scenario, current prices in Poland were escalated over time. In the second scenario, estimated free market prices were used to eliminate price distortions caused by current subsidy policies in Poland.

In each case, options for incentives programs were identified. Legal and institutional barriers to the implementation of incentives programs were studied. In cases where financial incentives were considered (direct conversion assistance, heat cost subsidies, tax relief) the level of incentive was set to eliminate cost burdens to the users.

With current price trends of energy carriers and the operating and capital costs, conversion of heating systems imposes high cost burdens on users. The City will need to implement some type of incentives program for almost all those who change their heating system. In the case of direct financial assistance, it will be necessary to change some legal regulations so that such assistance can be given to individuals. Currently, prices of gas and electric heat are considered low in Poland. If conversions are delayed and future prices come in line with Western European (free market) prices, the subsidy levels required will increase significantly.

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