Heating - Biomass system- District heating

Template assignment

Base case

• Small community using diesel (#2 oil) or electricity for heating in each building
• Building cluster #1: 5 residences of 200 m² each with 65% efficient oil heating, building heating load of 80 W/m²
• Building cluster #2: Community building of 3,000 m² with 70% efficient oil heating, building heating load of 70 W/m²
• Building cluster #3: 15 residences totaling 2,000 m² with electric heating, building heating load of 85 W/m²
• Building cluster #4: Community building of 5,000 m² with 65% efficient oil heating, building heating load of 70 W/m²
• Domestic hot water heating base demand of 15%
• Electricity rate is $0.09/kWh; diesel (#2 oil) rate is $0.75/L

Proposed case

• District heating network services all buildings in community
• Installation of district heating gives efficiency savings of 15% due to upgraded control systems in the new energy transfer stations
• The network is a branched system, as shown in the figure below:
  

• The buildings are connected indirectly to the network via energy transfer stations
• Planned expansion of 20%
• Supply temperature of 90ºC, return of 60ºC
  
• Central plant building will contain a 75% efficient 400 kW biomass boiler costing $140,000; and a 70% efficient 400 kW peak oil boiler costing $40,000
• A third boiler with a 400kW capacity costing $20,000 is added for backup in the central plant
• Additional building and yard for wood waste costs $150,000
• Additional operator and maintenance costs of $20,000 annually are expected
• Wood waste from nearby mill costs $20 per ton, delivered
• Customer premium income of 40% to compensate for the other costs that the existing building owners have today in owning and operating and maintaining the existing energy systems

Solution

The worked-out solution is the data file selected from within the RETScreen Project Database. The user automatically downloads the Project Database file while downloading the RETScreen software.