Prince Edward Island has been one of the most active Canadian provinces in bioenergy and district energy. Three small district heating plants were constructed in Charlottetown in the 1981–85 period under the auspices of the PEI Energy Corporation, a provincial crown corporation. The first plant burned municipal solid waste to provide steam heat to the Queen Elizabeth Hospital. The second plant burned woodchips to provide energy – both steam and hot-water heat – to nearby provincial government buildings and later to other larger private buildings in the downtown area. The third system was based at the University of Prince Edward Island. Both woodchip-fired systems were expanded in the early 1990s to heat more non-government buildings.

Description
Financial resources / Economic Benefits
Results
Environmental Benefits
Biomass Fuel Supply
Customer Satisfaction
Potential District Energy Market in Canada
Contact


Description

In 1995, Trigen Energy Canada Inc. purchased all three systems and established Trigen-PEI. The new company set about constructing one large, district energy system. It connected the three separate systems together and consolidated heat generation at the Energy from Waste Plant on the Charlottetown waterfront.

As well, the company installed a new heat-recovery boiler for the garbage combustion system and added a high-efficiency biomass plant to burn sawmill waste. State-of-the-art emissions controls were also installed at that time. A 1.2-MW Ewing Power Systems’ backpressure turbine generates electricity to operate the plant; any surplus is exported to the grid. The expanded district energy system became fully operational in 1998.

This new district energy plant still provides steam to the nearby hospital. It also delivers hot water to a 15-km hot-water heat distribution system that runs throughout the core area of the city. The plant serves over 60 customers and heats 84 buildings, including all the provincial buildings, the university, the technical college, two shopping malls and many other apartment and commercial buildings in the centre of Charlottetown.

The Charlottetown District Energy System also provides energy for cooling to two major customers. Steam that provides district energy to the Queen Elizabeth Hospital is used to air-condition the hospital through the use of steam absorption chillers. The University of Prince Edward Island, meanwhile, employs hot water from the district energy system for cooling by means of hot-water absorption chillers.


Financial resources / Economic Benefits

The customers of the Charlottetown District Energy System do not pay to be hooked up to the system. The utility bears the costs. Trigen-PEI contractual agreements have two tariffs – a Demand Charge for the cost of the district energy system and hookup, which is tied to the Consumer Price Index, and an Energy Charge, which relates to the quantity of energy used. The Energy Charge tracks the price of oil. Most customers find that their energy costs are about 10 percent less than the cost of heating oil. (Natural gas is not available on Prince Edward Island.) Customers are also insulated from dramatic, short-term swings in the price of oil.

Other economic benefits of the Charlottetown District Energy System include the following:
• Less capital tied up in individual building heating systems and heating-oil inventories;
• Elimination of heating system maintenance and replacement costs for customers;
• Greater local self-sufficiency. The Charlottetown District Energy System burns some 66 000 tonnes of Price Edward Island waste materials to displace 17 million litres of imported light heating oil;
• Increased local employment from constructing and maintaining the district energy system. The provincial government estimates that for every dollar spent on biomass fuel, 70 cents stays in the local economy; and
• Increased profitability of the company that supplies the sawmill waste. (A former liability is now an asset.)

Results

Environmental Benefits

Like other biomass-fired district energy systems, the one at Charlottetown offers many environmental benefits, including the following:
• Reduced CO2, SOx and NOx emissions;
• Reduced spillage and leakage of heating oils from individual building systems;
• Improved environmental air quality. For example, with only two stacks at the Trigen-PEI plant, there are fewer point sources for pollution than there were with individual building heating plants. The Trigen stacks are equipped with the latest pollution control equipment, including air scrubbers and multi-cyclones and filters for removing particulates;
• Reduction of municipal waste landfill and related environmental impacts. Burning municipal waste reduces the landfill area required by roughly 90 percent;
• Elimination of landfill of sawmill waste and potential soil and water contamination; and
• A significant contribution to Canada’s commitment to reduce GHGs.


Biomass Fuel Supply

The Charlottetown District Energy System is fuelled by a combination of municipal solid waste (45 percent) and sawmill residue (45 percent), with only 10 percent generated by oil. Each year, the plant burns up to 33 000 tonnes of municipal waste that is collected from Charlottetown and its surrounding communities. Oil-fired boilers at the district energy plant and at the University of Prince Edward Island and the Prince Edward Home provide energy backup and peaking capacity during the coldest weather.

The system burns an equal quantity of sawmill residue that is supplied by Georgetown Timber, a large stud-wood mill on the east end of Prince Edward Island. The residue is delivered to the plant in large 45-foot, self-unloading (walking floor) vans. Before the new Trigen plant was constructed in 1997, most of the sawdust, bark and shavings were dumped in a huge pile behind the mill, which posed serious environmental concerns.

The Trigen biomass plant is now burning hog fuel, a combination of mainly bark and sawdust. (The mill bags the shavings and sells them for bedding.) Included in the fuel mix is old sawmill waste from previous years. The sawmill hopes to clear up this residue in two years.

The combined municipal waste and sawmill residue displace roughly 17 million litres of heating oil per year.

Customer Satisfaction

The customers of the Charlottetown District Energy System are generally supportive of the utility. One of the first private sector customers was the Charlottetown Hotel, which was connected to the pilot district heating system in 1987. Manager Gary Craswell said, “The District Energy System works great for us. We have had few technical problems.” The hotel has even considered removing its old oil boilers and re-using the space in the basement. “The cost of removing them is the only reason that they are still there,” he said.

Another customer is the Charlottetown Area Development Corporation (CADC), which owns two large downtown properties that were connected to the district energy system in 1999.

First, the Harbourside Project consists of a large block of office and apartment buildings. The manager of properties for the corporation, Wade Arsenault, is positive about the benefits of district energy systems. “I think that it is a wonderful system,” he said. “The CADC needed to replace six separate boilers and carry out other upgrades to the heating system. Trigen-PEI came in and installed their heat transfer station and did the other system upgrades at no cost to us. That saved us roughly $350,000 in capital expenses, and our heating costs are now about the same or have perhaps gone down slightly compared with the cost of heating oil. So we are very pleased with district heating.”

The second CADC facility connected to the district energy system is Founders’ Hall. This former Canadian National Railway Company workshop in Charlottetown is being transformed into a museum and exhibition centre. “That also turned out well for us,” said Mr. Arsenault. In this case, the corporation subsidized the hookup to the district energy system because the building was too far off the line to be economical for Trigen-PEI. “With district heating, we save on furnace maintenance costs,” he said. “But the main plus is that we did not have to construct a boiler room, so we have an extra 100 square feet of building space that we can rent out.”

Other Islanders have commented on the compact nature of the building heat transfer stations. Pat MacInnis, a teacher at Charlottetown Rural High School, said, “The efficiency of the heat transfer station is tremendous. All you have is a little box, and it heats the entire school.”

Potential District Energy Market in Canada

It is well known that Canadians are among the highest per capita energy users in the world. While we have some regional variations, we depend heavily on fossil fuels to meet our heating and electricity needs. Canada is also a heavily forested nation, accounting for 10 percent of the world’s forest. According to 1996 figures, the economies of about 340 Canadian communities depend directly on forestry. In addition, over 200 Aboriginal communities are located in the boreal and sub-boreal forests, surrounded by significant forest resources.

In communities where timber and pulpwood are processed, numerous opportunities exist for using the waste industrial heat in district energy systems to heat large buildings and even residential homes that are reasonably close to the source of heat. Revelstoke and Masset, British Columbia, are two communities studying this option.

While the wood processing industries use much of the waste wood that they generate, surplus volumes of wood waste are in or near many communities across the country. Charlottetown, Prince Edward Island; Oujé-Bougoumou, Quebec; and Grassy Narrows, Ontario, have been able to use surplus wood waste from nearby sawmills to generate heat for district energy systems. These three communities are models for Canada.

For the many remote Aboriginal communities across the country, bioenergy-fired mini-district heating systems present opportunities to sustainably manage their forests. Other important socio-economic benefits include creating long-term jobs in the communities and reducing their dependence on expensive, imported oil.

Today about 60 district energy systems operate in Canada. Three of the systems are fired mainly with biomass, principally wood waste and municipal solid waste. Most of the other district energy systems are fired with natural gas or oil. Some involve cogeneration of both electricity and district energy.

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