- Introduction
The community depends on a diesel power generation plant for all its electricity needs. The NTPC power plant produces 1,941,049 kWh of power at an efficiency of 3.45 kWh/litre consuming 562,295 litres of diesel fuel at a cost of $421,721 (2000/01). Total P-50 heating oil sales were $695,212, for 703,901 litres in 2000/01. All fuel is imported into the community either by barge from Hay River, NT, originating from Edmonton, Alberta or by winter road. The opportunity to install a residual heat recovery system to the existing generation plant owned by NTPC is not feasible due to the location of the plant in proximity to the commercial district.
Key Market Issues
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Energy costs are 3-5X more than in southern Canada
- Transporting fuel has environmental implications
- Expansion of tank farms cost money
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Imported fossil fuels, requires 17% of the total GNWT revenues.
Community GHG emissions totals:
- 1.921 kt of direct emissions; and
- 1.810 kt of indirect emissions from power generation;
- A total of 3.73 kt of GHG’s emissions.
Community Needs
- Find solutions to deal with oversize & inefficient boiler, furnaces.
- Provide stability to future energy costs.
- Stop using diesel generated electricity for water heating
- Provide job creation & training opportunities
- Provide heat energy in emergencies
Community Sustainability Indicators
- Energy consumption is increasing
- Cost of energy is reflected in the cost of goods
- Is the community utilizating existing energy sources efficiently?
- How can renewable energy be incorporated into the community’s energy mix?
- Specific Objectives
Short Term:
- Identify measures which are cost effective, sustainable and meet the community’s energy needs and priorities.
- Co-operate and collaborate with local, territorial, & federal government agencies, public organizations, business, and industry to implement energy retrofits and efficiency improvement projects that would benefit buildings connecting to the DEN; and
- Avoid unreasonable burden or disadvantages for the community; and
- Promote an improved quality of life for the people living in Tulita.
Long Term:
- Promote energy efficiency as an investment activity conducted as part of multi-year program targeting multiple benefits for the community.
- Develop a strategic approach to energy efficiency with measures selected to provide a fair return on investment and other quantifiable benefits; and
- Actively pursuit of regulatory, legislative reform and market innovations needed to achieve strategic objectives.
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Utilize innovated financing techniques such as carbon offset credits, government programs for emission reductions.
- Goals
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Direct control over emissions from the hamlet operations regarding the use of heating oil.
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Direct influence over emissions from the commercial and institutional sources which may not be operated directly by the hamlet.
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Indirect control and influence over emissions which may result from activities such as power generation by the utility company.
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Extended influence over activities such as using low grade heat source for space & water heating.
- Ongoing Challenges
- Energy subsidies.
- Lack of technical feasibility & maintenance skills within the community.
- Proof of economic feasibility and the requirement to finance the capital costs.
- The NWT energy strategy has conflicting objectives (e.g., energy subsidies).
- Agencies and crown corporations involved in the; supply, delivery of energy policies and the maintenance physical infrastructure have limited the technical options available.
- Description of District Heating & Residual Heat Recovery Technology
- Types of Heat Recovery Systems
There are two basic approaches to distribution of residual heat through a district heating system. The supply can be interruptible or uninterruptible. The most common system in the NWT is an interruptible system.
Interruptible Systems (Residual Heat Recovery for diesel electric systems)
An interruptible or supplementary system supplies thermal energy into the buildings boiler system whenever surplus thermal energy is available from the electrical generation process. The building boiler system operates whenever building thermal demand exceeds energy available for the district energy system. Quite often with this type of system, the peak heating demand does not coincide with the peak electrical demand and will only supply part of the customers’ thermal energy requirements. There may be special situation where the residual heat alone is sufficient to supply 100% of a buildings thermal requirement, but it would be recommended practice for the building owner to maintain the boiler system.
Uninterruptible Systems (DEN)
A system is considered uninterruptible if supply of the design heating load of the customer building is guaranteed to the extent that the cogeneration plant is producing (same guaranteed as the electrical supply). An uninterruptible heating system using residual heat normally requires one or two small peaking boilers, allowing the system design load to be served regardless of thermal demand on the plant. Usually two small boilers would be considered to insure that the thermal demand could still be met during an outage of one of the boilers. This type of system does allow the building owner to remove the boilers, or plan the building without boilers if they so desire.
- Building Connections
There are two main options for connection of the customer building to the system. These options apply to both interruptible and uninterruptible systems.
Direct Connect (interruptible)
The building heating system is connected as a branch of the distribution system. No heat exchanger is used between the distribution system and the building heating system. The building may still have individual outdoor reset capabilities, and in some instances may operate without primary circuit pumping, which would be provided by the distribution system pumps. This is the most economical connection, as no additional heat exchanger is required except for domestic hot water, if supplied. The major disadvantage of a direct connection is the sharing of the transport medium between the building system and the distribution system.
Indirect Connection (uninterruptible)
The building heating system is isolated from the distribution system by a heat exchanger usually located in the customer building mechanical room. This type of connection is more costly than a direct connection, and has a loss of quality associated since energy is exchanged between two transport media via the building heat exchanger. This type of system allows for more control flexibility while eliminating concerns arising from sharing of glycol between the building and the distribution system.
In most cases an indirect connection is recommended, as it eliminates concerns with shared glycol, allows for more control flexibility and eliminates problems arising with maintenance, leak repair and glycol replacement.
- Energy Rates
The main factors in the charges for thermal energy are capital, maintenance & fuel cost. Usually the customer desires to see an immediate benefit to connecting to the system, even when a capital contribution is not required. In northern communities, the commercial/industrial buildings have small unattended automatic boiler systems; therefore benefits such as reduced operating manpower costs are not readily available. This results in an energy rate for customers being limited by the avoided cost of heating oil.
Cost Factor
The cost factor ties the cost of heat supplied by the thermal heat system to the price of fuel in the community. It is the percentage of avoided cost the customer can expect to pay for thermal energy delivered by the heating system. This demand charge is based on the cost of the system and size of the connected load and in most cases is less than 100%. The cost factor can exceed 100% in an uninterruptible system where the benefits to the customer would be far greater than simply fuel,
Fuel Cost
The fuel cost is the actual price per litre of heating fuel in the community, and is adjusted on predetermined schedule, normally annually at the time the heating oil prices are set by Petroleum Products Division of the GNWT.
Net Heat Content of Fuel
This is the lower heating value or lower calorific value of the fuel available in the community. This can be determined from the supplier data sheet for the fuel.
- Distribution System
Piping distribution system: consists of a hot water distribution network with supply and return pipelines in a closed circuit. Each building is connected to the network via a customer heat transfer station that regulates and measures the energy taken from the distribution system. Each building is directly connected to the distribution system.
Heat Transfer Stations
The buildings' hot water system is connected to the district heating system via a heat transfer station located in the mechanical room. Each heat transfer station consists of a prefabricated heat exchanger unit for hot water heating. The heat transfer station is provided with the necessary control equipment as well as all the internal piping. The heat transfer station is designed for ease of connection to the buildings' internal heating and hot water system.
Figure #1
- Benefit Statement
- Direct cost savings
- A district energy network system allows energy to be sold to the customer at a rate which is less that the customer’s cost of equivalent heating fuel, incurring a direct saving in the building’s annual operating costs.
- A significant reduction in the operation of the customer’s boiler system, may realize a saving in boiler maintenance and replacement costs.
- Once capital costs of the system have been recovered, energy charges to other customer can be reduced, allowing greater saving to building operators.
- There is often direct benefit to POL realized in reduced fuel storage requirements for the community tank farm.
- The CHP unit thermal demand is calculated to be maximized through load management, to guarantee demand for thermal energy by the customers.
- Long term community infrastructure cost savings
- Increased activity due to construction hiring of local forces.
- All of the savings realized, and in some cases a portion of the energy revenue form the system, remain within the region rather than being spent outside the NWT on fuel re-supply.
- Environmental concerns
- Production of GHG emissions and other pollutants is directly related to the amount of fossil fuel consumed by the community.
- Reduction of transportation and handling hazard, especially when fuel is trucked into the community.
- Reduction of transportation and handling hazard, of fuel being trucked within the community.
- Reduction in lubrication oil.
Safety concerns
- Emergency and standby power.
- Heat & energy security during power outages or catastrophic failure of the main power plant.
- Study Scope
A study was requested to confirm the opportunities of utilizing geothermal energy supply to supplement a gas fired combined heat & power (CHP) plant to supply a district energy network (DEN) to distribute thermal energy to a number of commercial and residential buildings at the incorporated hamlet of Tulita, NT. The scope of the study included:
- Review existing reports that have been produced to date that relate to the potential for CHP and district heating in the NWT.
- Short list buildings to be connected to the system.
- Develop estimates of peak thermal demand and monthly energy requirements.
- Size and develop a concept for the CHP plant/DHS system to supply heat to the customers based on fuel consumption. Due consideration will given to equipment performance, regulatory constraints, geographical location, local social- economic conditions, and energy costs; and
- Inject the waste heat into the future district heating system supplying the hotel, staff & senior housing, community administration centre, daycare and hamlet garage.
- Explore the use low grade geothermal heat energy for space & water heating
- Determine the capital and operating costs for the CHP plant & DHS. All cost estimates provided will have an accuracy of +/-20%.
- Energy Demands
- Building Loads
The district heating system has to be designed to provide enough capacity to deliver each building’s peak thermal needs during peak periods. If the system is under-designed, it would be unable to meet the peak load requirements. If the system is over designed then the capital costs to deliver the heating and electricity is too high and could affect the economics of the entire project.
Table 1 – Peak Heating Load and Energy
- Load Diversification Factor
A district energy system will have a lower thermal peak than the sum of the individual buildings’ thermal peaks. This is mainly due to the individual buildings reaching their respective thermal peaks at different times during the day. This factor is known as load diversification. The mix of buildings contained within a district energy system allows for this factor in sizing the production plant and distribution system. It is estimated that the diversification factor for this system will be 0.9. Therefore the total heat load is 1947 MWh
- Production Plant
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Central Energy Plant Development Concept
The plant concept would be to install the containerized CHP unit, switch gear, controls, and constant & variable speed pumps to pump hot water through the distribution system and ultimately to every commercial & public building in the community.
Table – 2 Production Plant Capital Costs
- Geothermal Energy (phase 2)
All land on earth can successfully harness geothermal energy using heat pumps that can be:
- Used for space heating/cooling and water heating
- Work by concentrating naturally existing heat
- Acts as a heat source in winter and a heat sink in summer
Photo #2
- System Capacity
Based on the proposed configuration of the completed system (phases 1 – 3) of geothermal heat, heat pump, micro turbine, and storage tanks, can provide 5865 GJ of thermal energy. This system capacity is based on the concept of expansion by adding another micro turbine and increasing the thermal storage. The limiting factor of the district energy network would be the piping, as only so much thermal capacity can be delivered through the pipe. During the next stage of the project development, detailed sizing will have to be performed to ensure that the future expansion of community is considered.
- Distribution Network
General
A preliminary distribution piping concept was developed including routing, sizing and material selection that will provide district heating services to the target buildings in each zone (see below). The total length of pipe of the system has not been determined yet, but the phase 1 estimated at 150 meters and the pipe size varies from 32 mm (1.25”) to 100 mm (4”).
Distribution Network Pipe Routing & Sizing
There are 3 zones which contain most of the community’s institutional, commercial, and educational buildings. Each phase of the project will connect each one of these zones to make up the entire district heating system.
Zone 1 (Phase 1)
- The Tulita hotel, staff & senior housing, daycare, hamlet garage, hamlet administration building, northern store.
Zone 2 (Phase 2)
- The district heating system would extend from the hotel site to the school, recreation center and swimming pool.
Zone 3 (Phase 3)
- The new school, RCMP station, community offices, and church
Distributed Piping System
The proposed distribution piping system is based on the production plant site being located at Tulita hotel. The route, production plant site, pipe diameter, and buildings are shown on the map in Appendix A. The route has been selected to serve the load using the minimum length of distribution pipe. The distribution pipe sizes are based on ΔT of 35º C (102º F) with a maximum flow velocity of 1.5 m/s.
The distribution sizing for the selected route has been governed by the following four key factors:
- The heated water supply and return temperature differential, referred to as ΔT (delta T)
- Maximum allowable velocity
- Distribution network pressure at the design load conditions
- Differential pressure requirements
The results of the preliminary analysis determined that the maximum heating pipe size will 100 mm (4”) diameter and the minimum size will be 32 mm (1.25”). The main pipe out the production plant is 100 mm and the service lines to each building are assumed to vary between 32 mm & 64 mm.
Distribution Piping Material
The material for the heating distribution system is designed to European standard 37.0, DIN 2458 (EN253 Standard) thin walled steel pipe, insulated with PUR insulation, and steel outside protective jacket.
Distribution System Capital Costs
The distribution system costs (distribution system with building connections to outside of building wall) for the fully developed system are estimated as described below. The pipe material makes up 45% of the total distribution system cost. It is assumed that the system will be above ground.
Table – 2 Distribution Pipe Cost
The estimate includes project & construction management, engineering, and commissioning, contractor’s overhead and profit, GST, and 10% owner’s contingency.
- Energy Transfer Stations
General
Enterra has preliminary interface costs (energy transfer stations and interconnection piping) for the system.
Building Connections - Heating
The energy transfer stations (ETS) will be designed so each building is indirectly connected to the main distribution system. Indirect connection means that the buildings’ secondary system are not hydraulically connected to the district heating, the systems are separated by heat exchanger in every building. The ETS is designed to receive 90º C (200º F) hot water from the distribution system during peak periods and return 65º C (138º F) at operation pressure not higher than 625 kPa (90 psi). To achieve this, the building’s internal heating system should be capable of utilizing 82º C (180º F) supply from the ETS and returning a maximum of 65º C (138º F) during peak operating conditions.
ETS Capital Costs
The building interface costs (ETS and interconnection piping) for the hot water (HW) and domestic hot water (DHW) systems are estimated as follows:
TABLE 3 – Heating ETS Cost
The costs listed above include project management, engineering, GST on material and 15% contingency. The ETS and interconnection points should be located at above ground or crawlspace level. Therefore the cost estimates allows for 10 meters of pipe on each side of the heat exchanger (primary and secondary piping).
Figure #3 – Representation of an Energy Transfer Station
- FEASIBILITY STUDY ASSESSMENT
- Capital Cost Summary
The total system cost is for a complete installed system including owner’s contingency, engineering, project management and GST. The level of accuracy of the cost estimates in +/- 20%, on a total project basis. The estimated costs for the total cogeneration based district heating system are shown in Table 4.
Table 4 – System Capital Cost Summary
- Customers’ Costs using Conventional Heating
There are three separate components of each building owner’s cost for heating are;
- Fuel
- Operation and Maintenance
- Capital – equipment replacement at end of design life.
Fuel Rate
The average cost of fuel oil in Tulita is currently in the $0.87 per liter. Based on the 2001/2002 fuel usage this represents a cost of $68,051 per year for the fourteen target buildings.
Operation and Maintenance
Fuel oil requires equipment, labour and regular maintenance to transform itself into hot water to provide domestic hot water and space heating. Each existing building heat plant requires labour for regular maintenance, fuel delivery and eventual boiler replacement. Based on the type of heating plants in the eight targeted buildings $6,885 per year should be spent on operation and maintenance.
Capital
From a financial perspective all of the existing heating plants have an effective life span and, over time all the heating plants will have to be replaced. The new staff housing and community administration building will require boilers. Enterra has estimated that the cost to install these boiler plants will be $115,000. The annual cost is when you assume the cost of capital is 8% and the new boiler plant should last 20 years. Therefore the cost of new boiler plants on an annual basis is $1,850 per year.
Table 5 – Building Costs
- Pro Forma Revenue and Expense
Assumptions, key results and pro forma revenues and expenses will be shown after the engineering study is complete.
The heat revenue is based on a heat price of $103/MWh. This is the price for energy the district heating system would require to generate a return on 100% equity of 8 %. The return on equity could increase if the following assumptions:
- Increased extraction of geothermal heat; and
- Expand the DEN system to supply/connect all new commercial & government buildings in the community; and
- The sale of electricity to the community hotel and staff housing.
The building connection costs should be eligible for grants through the Natural Resources Canada (NRCan) programs:
- Energy Innovators Initiative – 25% for Renewable Energy Installations up to a max. Of 80K per application or a max. of 250K per organization
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Municipal Building Retrofit Program - Sustainable Knowledge Network
- Commercial Building Incentive Program (CBIP)
- Discussion
The district energy network in general set their rates so they can be competitive with each building owners full cost to produce domestic hot water and space heating for themselves. In the case of the Tulita district heat rate would normally be set at a level slightly lower than $117 per MWh. The cost of the thermal energy would be $103 per MWh or about 87.25% of each building owners cost to produce hot water and space heat themselves. The projected annual cost for thermal energy from the district energy network would be $222,892 in 2003. These same building owners project spending $248,000 in 2003 for heating fuel. However the greatest saving would be for the building owner’s with electric hot water heaters.
- Project Implementation
Since the results of this preliminary feasibility study are positive, it is recommended that a business case should be developed for this initiative. The business case should include the following:
- Obtaining price quotations for all major equipment and confirm cost to install distribution pipe in more detail.
- Confirm fuel supply
- Review feasibility of converting existing oil fired building to hot water
- Understanding in detail all regulatory requirements for installation.
- Develop an implementation schedule, along with key dates and milestones for critical tasks.
- Defining the corporate entity that would lead the development of the project and its final implementation.
- Confirm the financial feasibility of the project based on a locally ownership structure.
- Initiating further contact with the targeted customers, and securing letters of commitment to support project financing.
- Improve the financial model as more information is obtained
- Mapping of existing electrical infrastructure, fuel storage facilities.
- Implement a comprehensive community energy planning program.
The Business Case will Demonstrate
- The use of geoexchange systems to provide heat energy.
- The value of district heat system for rural communities.
- The ability of DEN to be a platform for future Low impact renewable energy (LIRE) systems.
Provide Deliverables/Measurable Outcomes
- To promote federal, territorial, and local municipal building to connect to district energy; and
- Develop regulations for the MUSH sector to connect to district energy.
- Significant reductions in fuel use and GHG emissions.
- Act as a model for deployment elsewhere in Canada, and;
- Training Opportunities for young adults.
Time Line 2004 - 05
July
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Submit feasibility study to (RWED),FCM/GMF,TEAM
August
- Design and engineering
- Pipe route layout confirmed
- Site production well for geothermal energy
September
- Order CHP unit
- Order energy transfer stations
- Order distribution pipe
October
- Material Package for staff housing arrives
- All equipment and material arrives in Tulita
November
- Maintenance on existing heating plants/systems in all targeted buildings
- Site CHP unit
January
- Install energy transfer stations in all targeted buildings
February
- Install energy transfer stations in all targeted buildings
March
- Final survey for distribution system
April
- Start install of heat distribution system
May
- Install distribution system
June
System Certification
Once the district energy network is completed and commissioned the system will be, registered with the Environmental Choice Program Certification Program.
Table 6 - Replication Potential for CHP/DEN
Table 7 - Potential GHG Reduction Potential for Tulita
Table 8 - Potential GHG Reduction Potential for NWT
Communication Strategy
The Tulita Yamoria Community Secretariat will provide all project proponents, partners and funding agencies with a press kit containing pictures, news releases, PSA’s, video, and radio announcements. Communications will be directed as follows:
- Direct meetings with target communities and on-site demos with interested organizations.
- Promotions in local and territorial magazines/newspapers.
- Awareness promotions with clients who install smart meters at their faculties.
- Incentive packages for the users that hook up to the DEN system.
Government Involvement
Without government assistance at this stage, it is expected that development of CHP & Distributed Energy Networks (DEN) for off gird northern communities would be significantly delayed. The opportunity to produce major GHG emission reduction and supplying the infrastructure for renewable energy systems would be missed.
VCR, FCM, PCP Memberships
Enterra Environmental Corporation will become a member of the Voluntary Challenge Registry (VCR). The community of Tulita is a member of the Federation of Canadian Municipalities – Partners in Climate Change.
Consultations
See attached letters of support.
Public Policy Issues
It is an important public responsibility to maintain the integrity of the power grid. Given that electricity generation is a regulated public utility in the NWT, there are a number of policy issues raised by small producer/consumer (PC) microgen facilities like this MT CHP project. Some of them are:
- Compliance with operational standards for power safety, quality and reliability for any customer who wants to interconnect to the macrogrid.
- Standby charges are often charged to customers by utility companies to maintain their uninterruptible power right to return to the macrogrid at short notice. (i.e. the charge is for the option and to offset the cost of maintaining ready generation, transmission and distribution assets).
- “Stranded Assets” which refers to the problem of obsolete or “uneconomic” generation, transmission or distribution assets trapped on a regulated utility company’s balance sheet through the rate regulation process.
- Greenhouse Gas (GHG) Credits for reducing harmful emissions from any self-generation project. These are features of the Kyoto Protocol - yet to be fully understood - but which were recently ratified by our Parliament.
Many represent important philosophical points of view with practical advantages and disadvantages to any MT CHP installation. However they are beyond the scope of this proposal to debate at this point in time.
Conclusions
A DEN system confronts the challenges of integrating distributed, renewable & non-renewable generation with customer loads and the utility grid. Common sense is to put power production closer to where it is used and in a way that improves the systems reliability, creates opportunities for renewable energy and provides customers value.
Relevant Materials Produced by Enterra Environmental Corporation
- Distributed Energy Networks for Remote Communities - May 2003
- Yellowknife CHP Installation Pilot Project – April 2003
- Introduction to MT/CHP systems – March 2002
Statement of Qualifications (attached file)
- Benchmarking
Performance can vary from the benchmarks, depending on impact variables (or influencing factors). Considered in the project proposal include the following:
- Location - Benchmark data are expressed by geographic region. Location can affect energy performance because different regions may use different sources of energy or have different rates for energy costs.
- Climate - Each location has heating and cooling degree-days. They reflect the total number of degrees for equivalent days in a given period for which heating and/or cooling are needed to achieve standard indoor conditions at a specified location. They provide a basis for comparing different climatic regions in terms of energy use per heating and/or cooling degree-days. Heating degree-day (HDD) measures the amount of heating energy required during the heating season; it is measured by the difference between the base temperature of 18oC and the mean temperature for the day.
Following is the formula used to normalize for HDD:
- En = Ea 3 [0.3 + 0.7 (HDD30/HDDa)]
Where,
- En = normalized annual consumption for a year
- Ea = actual annual consumption for a year
- HDD30 = 30-year annual average heating
- degree-days (based on 18oC)
- HDD = actual annual average heating degree-days (based on 18ºC)
Another useful type of benchmarking that can be undertaken is comparison with the requirements of the Model National Energy Code for Buildings (MNECB) and the Commercial Building Incentive Program (CBIP).
- Calculating Greenhouse Gas Emissions
Standard conversion and emission factors are available from the fuel suppliers or other reference sources, including VCR Inc.'s Registration Guide 1999.
To calculate GHG emissions, using the following formulas:
Fossil Fuels:
eCO2 = CO2 + CH4 + N2O
Where,
CO2 = Fuel Consumption 3 EF
CH4 = Fuel Consumption 3 EF for CH4 3 GWP for CH4
N2>O = Fuel Consumption 3 EF for N2O 3 GWP for N2O
Electricity (Indirect Emissions):
eCO2 = CO2 + CH4 + N2O
Where,
CO2 = Electricity Consumption 3 EF
CH4 = Electricity Consumption 3 EF for CH4 3 GWP for CH4 N2O = Electricity Consumption 3 EF for N2O 3 GWP for N2O
And where,
EF = Emissions Factor for the individual energy source. You can obtain these factors from VCR Inc. or the OEE.
GWP = Global Warming Potential Factor, the relative global warming potential of different GHGs (compared to CO2). GWP values are available from VCR Inc.
Total CO2 Emissions:
eCO2 = eCO2 from Fossil Fuels + eCO2 from Electricity
Budget
Table 1
This report has been prepared by Enterra Environmental Corporation. No representation or warranty, either expressed or implied, is provided in relation to the accuracy, completeness or reliability of the information contained herein. This report should not be regarded by recipients as a substitute for the exercise of their own judgment. Any opinions expressed in this report are subject to change without notice and Enterra Environmental Corporation is under no obligation to update or keep current the information contained herein. Enterra Environmental Corporation may have or have had business relationships with companies mentioned in this report. This report may not be reproduced or redistributed, in whole or in part without written permission of Enterra Environmental Corporation and Enterra Environmental Corporation accepts no liability whatsoever for the actions of third parties in this respect.
Alaska Energy Authority’s (AEA’s) Alternative Energy and Energy Efficiency section currently manages or funds 47 projects totalling $63.9 million in the areas of hydroelectric, wind, biomass, transmission and distribution, geothermal, solar, diesel generation, and end use efficiency. The primary objective of the program is to lower the cost of power and heat to communities while maintaining system safety and reliability. Projects seek to increase efficiency of existing diesel power production and end use as well to develop alternatives to diesel-based energy technology.
Extensive building envelope upgrades are required on all buildings to be connected to DEN system.
Tulita community administrative offices, garage, hotel, senior & staff housing, daycare.
UTES, or underground thermal energy storage, is a subsurface application of seasonal thermal energy storage (STES). The system uses ground water and natural or artificial geological media for storage of supplied energy over seasonal periods. When rock/soil is the energy storage medium through boreholes or ducts places into the ground, the systems are referred to as borehole or duct thermal energy storage (DTES). In a DTES there is a continuous, sealed, underground pipe or loop, used to contain an energy transfer fluid to and from a heat exchanger.
Microturbine, passive solar & geoexchange systems.
Microturbine, PV/BIPV (solar), wind, and hydro electric systems.
Space heating demand for the commercial & institutional sectors for 2001/02 is estimated at 248,600 litres
Water heating for the commercial & institutional sectors for 2001/02 requires 12% (229,032 kWh) of the total power demand.
2 – 30 ton Heat pumps removes, concentrates, and transports heat from the geothermal or thermal energy storage source.
70 kW℮ & 140 kWt micro turbine to increase the heat content of the water and powers the heat pumps.
Solarwall™ passive air collectors.
Moves heated medium (water) through pipes connected to the building energy transfer station and provides space and water heat.
Tulita energy costs are electricity $0.79 kWh; and heating oil $0.87 litre
NWT 2003 Budget $931 million – Total projected deficit $214 million
The Government of Canada has launched the Pilot Emission Removals, Reductions and Learning (PERRL) Initiative.
i.e., no boiler capital, maintenance or replacement costs, no fuel system capital or maintenance cost, no fuel spill risk or fuel fire risk, no primary pumping costs, no costs associated with control systems for boiler, fuel system.
$0.87 per litre in Tulita, 2004
Buildings owned by the Two Rivers Development Group Ltd.
Estimated heating demand.
The red denotes new construction
The building will retrofit to accommodate self government administration staff.
Photo: Two 36 ton geothermal heat pumps (www.eere.energy.gov)
See appendix for distribution piping – full build out heating
Commercial customers only, due to a complicated system of subsidies & rebates the true cost of fuel are not passed on to seniors or residential customers.
For Phase 1 building only (hotel, administrative offices, seniors & staff housing, hamlet garage)
The system would be connected to all the commercial & public buildings in Tulita
The estimated cost for heating with electrical heat for all of the targeted buildings is $174,064.
Letter of Intent accepted July 6, 2004
The public administrative sector in Yellowknife uses 58,000,000 litre/per annum.
The Giant Mine site has 235,000 tonne of arsenic waste stored in chambers below the surface. The plan will require the pumping and circulating of water to be treated and the freezing of ground water surrounding the storage chambers. Both operations are both sources of low grade thermal energy.