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8. THERMAL ENERGY (USE OF COLD ENERGY) UPDATE ÉNERGIE THERMIQUE (UTILISATION DE L’ÉNERGIE FROIDE)
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Committee recommendations AS AMENDED
That Council:
1. Direct staff to expand the Energy Reduction Program to include a strategy that would encourage landowners to pursue thermal energy as an option for future developments when the land is adjacent to an existing or future snow dump facility ; and,
2. Direct staff to include as one of the factors considered as part of their snow dump siting process, the possibility of siting new snow disposal facilities adjacent to or in close proximity to properties that could be used for cooling in the future.
Recommandations modifÉes DU Comité
Que le Conseil :
1. demande au personnel d’élargir le Programme de réduction de la consommation d'énergie afin d’inclure une stratégie visant à encourager les propriétaires fonciers à envisager l'utilisation de l'énergie thermique pour les futurs aménagements lorsque les terrains se trouvent à proximité d'une installation actuelle ou à venir de décharge à neige.
2. D’enjoindre le personnel d’inclure en tant que facteur examiné dans le cadre du processus de sélection de l’emplacement d’une décharge à neige, la possibilité de sélectionner l’emplacement de nouvelles décharges à neige en fonction de leur contiguïté ou proximité à des propriétés qui pourraient être utiliser à des fins de refroidissement à l’avenir.
Documentation
1. Deputy City Manager's report City Operations dated 11 May 2010 (ACS2010-COS-PWS-0003).
2. Extract of Draft Minutes, 11 May 2010.
Report to/Rapport au:
Planning and Environment Committee
Comité de l'urbanisme et de l'environnement
and Council / et au Conseil
11 May 2010 / le 11 mai 2010
Steve Kanellakos, Deputy City Manager/Directeur municipal adjoint,
City Operations/Opérations municipales
Contact/Personne resource:
John Manconi, General Manager/directeur général, Public Works/ Travaux publics
613-580-2424, extension 2110, John.Manconi@ottawa.ca
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Ref N°: ACS2010-COS-PWS-0003 |
SUBJECT: |
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OBJET : |
REPORT RECOMMENDATIONS
That the Planning and Environment Committee recommend Council:
1. Direct staff to discontinue use of thermal energy for any facilities in the current City of Ottawa inventory due to cost and operational constraints; and,
2. Direct staff to expand the Energy Reduction Program to include a strategy that would encourage landowners to pursue thermal energy as an option for future developments when the land is adjacent to an existing snow dump facility.
RECOMMANDATIONS DU RAPPORT
Que le Comité de l’urbanisme et de l’environnement recommande au Conseil :
1. de demander au personnel d’interrompre l’utilisation d’énergie thermique dans toutes les installations faisant partie de l’inventaire actuel de la Ville d’Ottawa en raison des coûts et des restrictions opérationnelles;
2. de demander au personnel d’élargir le Programme de réduction de la consommation d'énergie afin d’inclure une stratégie visant à encourager les propriétaires fonciers à envisager l'utilisation de l'énergie thermique pour les aménagements lorsque les terrains se trouvent à proximité d'une installation actuelle de décharge à neige.
BACKGROUND
The use of stored snow and ice as a means of providing space cooling has been used for centuries in various parts of the world. The technology consists of collecting and storing snow and ice during colder months, protecting it during warmer months and harvesting it for cooling purposes when required. The widespread use of thermal energy has declined with the advent of new more complex, space saving, mechanical cooling systems. These mechanical systems depend heavily on electrical energy and as more responsible energy management practices are emerging, these systems are being re-evaluated.
On 12 November 2008 the following motion was brought forward: That Council direct staff to, in conjunction with Hydro Ottawa/Energy Ottawa, explore the concept of thermal energy storage using "cold energy" from snow and/or ice to determine if thermal energy storage in combination with, or instead of, traditional energy could be used in some buildings, resulting in reduced operating costs for the municipality.
The initial update was brought forward in April 2009 by the Infrastructure Service Department. The report committed the working group to further investigate the feasibility of adapting cold energy in a City-owned facility and to report back to Council in early 2010. As part of the corporate realignment, the mandate for Energy Management now resides with the Public Works Department. The current update is based on the research of the Building and Technical Support Unit within the Public Works Department.
DISCUSSION
Cold Energy: Global Snapshot
The prototype for the City’s research is based on a doctoral thesis by Kjell Skogsberg at Lulea University of Technology in Northern Sweden. An application of the thesis was installed in Sundsvall, Sweden at a large county hospital. The project involved collecting 3.6 metres of snow within a 140 metre by 60 metre asphalt pit. A 0.3 meter thickness of woodchips was placed over the stored snow to act as insulation. The participants took the cold water from the thawing of the snow, pumped it several hundred metres into new equipment that was installed to cool air instead of the existing refrigeration system. After solving several problems, they reported that 93 per cent of the summer cooling was accomplished by using the cold energy from the snow pile.
Japan has also recently undertaken several cold energy initiatives including the Glass Pyramid in Saporro which stores snow in a warehouse and uses the melted snow to cool the Pyramid for four months from June to September. In addition, Japan is expected to implement a new initiative in spring 2010 using cold energy to cool the Hokkaido airport. The airport system will use a 100 x 200 metre mound of snow that is approximately 15 metres high. The snow will be made onsite using the collected ploughed snow from the runways and tarmacs.
This project is expected to reduce current energy consumption by up to 30 percent for both domestic and international terminal buildings.
Cold Energy: North American Snapshot
The use of cold energy technology in North America is in its infancy and there are limited resources available to advance its development. Local resource, Professor Fred Michel, Director of Environmental Science at Carleton University, has provided some direction to the City in moving forward with a feasibility analysis for the application of cold energy in a City-owned facility.
Energy Management
Energy management is a critical aspect of sustainable living. Energy management includes maintaining quality control on utility accounts and reducing the use of utilities without affecting the programs they support. The City has over 1900 utility accounts that must be reviewed regularly to make sure the lowest cost is being obtained. New technologies are being generated every year and it is the role of energy management to utilize the best of these technologies in new building design and incorporating them into existing designs where possible.
There are many undeniable benefits to Cold Energy Technology. One highly recognized benefit is that snow and ice are renewable sources of energy and their use in a cooling capacity would result in significantly lower greenhouse gas emissions than conventional cooling methods. Unfortunately, with an emerging technology there are many costs and risks associated with implementation in its early stages.
As part of the City of Ottawa’s Environmental Strategy, the City has committed to reduce greenhouse gasses and in particular reduce energy consumption in three main sectors: buildings, transportation and waste. The Energy Reduction Management Unit has been instrumental in increasing the energy efficiency of existing and newly constructed buildings. The Program has delivered a number of innovative initiatives with proven success in the areas of financial savings and environmental benefits. In order to be successful, the Energy Reduction Program has a mandate to deliver a return on investment of 5 years.
Since the Program began in 2004, the City has invested over $7,000,000 with a
reduction in energy costs of almost $5,000,000.
Examples of the innovative technologies and strategies that have made huge differences in energy consumption include:
· T5HO fluorescent fixtures
· Pool blankets at municipal pools
· Radiant floor heating
· Water reduction strategies
· Installation of high efficiency furnaces and water heaters
T5HO fixtures use less energy than conventional High Intensity Discharge lamps. Recently, T5HO lamps have been installed in various Arenas and in one of the Municipal works garages where they replaced the standard Metal Halide bulbs. The new T5HO lamps provided a higher degree of colour rendering, increased the uniformity of the lighting and reduced the electricity consumption and the cost by half. To date, 26 arena pads have been retrofitted which, will result in just under $2,000,000 in reduced energy costs or, a simple payback of five (5) years. In addition, this will result in a total savings of 2.3 MWh which equates to a reduction of 660 tonnes eC02. For a full list of Energy Reduction initiatives completed in 2009 please refer to Document 1.
Pool Blankets have the potential to dramatically reduce the amount of pool water that evaporates. This in turn significantly reduces the heat load of the pool. It will also reduce the requirement for ventilation and dehumidification. When the pool covers are in use, the humidity level on the deck quickly drops which, increases the comfort level of patrons and staff working in the area. Reducing the humidity level in the pool area may also reduce potential problems caused by the humidity and increase the life expectancy of the pool envelope.
The use of radiant floor heating is being implemented in most new construction projects for buildings under 100 square meters. This process uses very efficient condensing furnaces and special tubing to heat the floors of the buildings. High efficiency furnaces and water heaters are replacing outdated low efficiency models and/or oil-fired furnaces. In many facilities special equipment is being installed to recover energy from air that has been exhausted. All of these initiatives combine to provide major reductions in energy costs and environmental impacts.
ANALYSIS
Site Selection
In order to realize a favourable return on investment, the selected City facility would have to have the highest electrical load. The largest building in the City’s inventory is the 100 Constellation Crescent Complex where the average annual electricity consumption for cooling purposes is approximately 500,000 kWh with an associated annual cost of $50,000. Assuming a cost-effective cooling system could be implemented and 80% savings could be realized, there is a potential to save $40,000 in annual electrical costs. This represents about 400,000 kWh and 130 tonnes of C02.
Obstacles to
Adapting Cold Energy in a City Facility
Recent infrastructure developments have changed the face of the Constellation Complex by reducing parking areas and adding several new buildings in the proposed future development of the site. This has made the use of a large snow pile challenging to locate within a reasonable distance from the building.
To achieve a 93 per cent cooling rate at the Constellation facility, the snow pile for cold energy harvesting would need to be 12.7 metres high. To effectively store and protect the snow and ice for future harvesting, a storage facility would need to be constructed with adequate insulation on the surrounding walls and ceiling. The cost of constructing such a facility is estimated to be between $1,500,000 and $2,000.000. Assuming $40,000 dollars in savings could be achieved as stated above, the high construction costs would off-set the savings by yielding a minimum return on investment of 38 years.
The cost is further complicated by the lack of proximity to a snow disposal facility and lack of availability for snow storage in the Constellation parking lot. This would require a very complex piping system that would likely have to cross the new roadways being designed for the area. The cost of the piping and insulation could easily run from $600 to $1000 per metre. Overall, this could result in an additional cost of approximately $150,000.
The possibility of locating a future snow disposal facility in closer proximity to the Constellation facility is a major challenge in an urban environment considering many residents may not be supportive of the proposal in particular, the late night activities that are associated with its operation. In addition, urban land costs are very high relative to rural and even some suburban areas.
Understanding that the Energy Reduction Program’s mandate is to provide a five-year return on investment for all projects, it is evident that the use of thermal energy technology is not feasible from a cost perspective at this time.
Site Comparison
The original doctoral thesis was written in
Sundsvall, Sweden which is located 62°31'41"N or the latitudinal
equivalent of Iqaluit, Nunavut, which is 2100 km North of Ottawa. Consequently,
the cooling season in this northern location is much shorter than Ottawa’s with
latitude of 45° 24'. This has an effect on the amount of snow required to produce
the same effect as well as the amount of snow that would be available for
harvesting. The Sundsvall building is the local county hospital set in a rural
area with over four times the floor area of 100 Constellation.
Cooling Degree-Days or “CDD”, is a measure of how much (in degrees), and for how long (in days), outside air temperature was higher than a specific base temperature. Cooling degree-days are used for calculations relating to the energy consumption required to cool buildings. Over the past ten years, the average Ottawa summer had 270 CDDs. The summers varied from a low of 165 CDD in 2000 to a high of 397 in 2005. Ottawa has been experiencing hotter than normal summers over the past decade and cooling systems must be designed to accommodate this reality.
Data for an airport near Sundsvall indicates an average of 50 CDDs over the past three years. Typically, Ottawa has to cool between five and six times the amount that is required in Sundsvall, Sweden to provide the same amount of cooling. This indicates that a much greater quantity of snow is required to be harvested and stored. It is important to note that because of the higher amount of CDDs, the rate at which a snow pile would melt would be substantially faster.
The Constellation facility is equipped with an interval meter that records consumption data on 5-minute intervals throughout every day. The data is available for review and is attached as Document 2. The average annual cost to cool the Constellation Complex is $50,000 and there are 2,500 employees working within the facility. Assuming an average of 100- cooling days per year it is evident that the cost per employee per day for cooling is $0.20.
The cost of electricity in Canada is 50 per cent less expensive than Sweden’s electrical costs. In Ontario, the cost of electricity is even lower than the Canadian average. Any savings in power would have much less effect on the budget than in Sweden. The cost of electricity in Sweden is among the highest in the world, where the cost of electricity in Ontario is among the lowest in the world. While electricity costs are volatile, the Energy Reduction Program must use current and trend data as the basis of its analysis.
A notable
difference between the Sundsvall facility and the Constellation facility is the
land-type. The Sundsvall facility is located in a rural area with ample space
for snow storage. Building and testing the prototype had little impact on
adjacent residents whereas any modifications to the Constellation Complex, or
another urban site, would have a high-impact on adjacent residents. An example
of this is the woodchip method that the Sundsvall facility employed as
insulation for the store snow. A stack of approximately 0.3 metres was placed
on top of the snow pile to act as insulation. When winds blew, the chips were
blown onto adjoining areas. An issue like this would have major repercussions
in an urban environment. In addition to this, the snow that collected within
the urban environment is not clean.
Opportunities
A major benefit of the “cold energy” feasibility analysis is the realization of other potential opportunities with respect to the use of thermal energy. The technology is not applicable to City facilities at this time however; staff recognize the opportunity to share insights into this technology with developers and/or researchers. The City could evaluate the possibility of pursuing partnerships with developers and landowners adjacent to City snow disposal facilities in order to promote the use of the City’s stored snow for thermal energy in future developments. In addition, the City should continue to make its snow disposal facilities available for the purpose of research and where possible, provide input and support to research groups.
There are several thermal energy systems currently on the market that use off-peak hydro rates to produce ice that can then be used to cool buildings during the day. This technology is readily available and would fit into time-of-use electricity rates. These systems are more economical to install and have the potential to achieve the same benefit as the large snow storage building at a substantially lower cost. The costs of these systems are higher than traditional systems and currently efficiencies are only realized in areas with very high cooling needs and where there is a high variance between night-time and day-time electricity rates. Typically, these systems are installed in the Southern United States such as in Arizona. The Energy Management unit will continue to monitor these technologies as part of future Energy Reduction strategies.
CONCLUSIONS
While there are many recognizable
benefits to the application of cold energy technology, analyzing the City’s
cooling needs, cooling costs and existing infrastructure demonstrates that the
technology is not feasible at this time.
The major obstacles to applying cold energy technology within a City facility include:
· 100 Constellation has the highest "cooling load" of all City facilities and therefore, the system would need to be applied to Constellation in order to achieve efficiencies;
· Lack of space for snow storage makes the technology unworkable at the Constellation Complex;
· Temperature difference between Sweden and Ottawa has an impact on cooling requirements and snow collection and storage;
· The existing low cost of electrical energy in Ontario makes the use of the snow cooling technology uneconomical;
· Retrofit costs to connect the Cooling System to Constellation would need a large capital investment, which would extend the return on investment for cost savings beyond the point of recommendation;
· The idea of linking snow disposal facilities (SDF) to buildings so we can take advantage of the cooling system might work in theory but we do not have SDF’s located in urban areas (land costs) and we do not have any City building construction plans that could be developed in conjunction with SDF’s; and,
· It is not best practice to base investment plans on a ten year estimate for what electricity costs may be. If major increases are projected to justify the use of the cooling technology and the prices fluctuate from projections there is a high risk of losing money on the venture.
It is recommended that both staff and financial resources focus on quick-win energy management strategies with returns on investment that are in line with the Energy Reduction Program’s mandate. In 2009 alone, the Energy Management Unit’s accomplishments have achieved $457,000 savings, 4,600,000 kWh reductions in consumption and reduction of 1,440 tonnes of greenhouse gas emissions.
RURAL IMPLICATIONS
N/A
CONSULTATION
The Action Plan contained in the April 2009 Thermal Energy Report ACS2009-ICS-INF-0001 outlined partnerships and consultations for going forward with the feasibility analysis. The plan was adapted to the realities of the research through the process as it became evident early on that the proposal had little technical opportunity in an urban City facility. The full status of The Action Plan can be found in Document 3.
Energy Ottawa was engaged early on in the research process and again at the end of the process to review the report findings. Energy Ottawa agrees with the group's conclusions that “cold energy” is not economically feasible within a City facility.
Carleton University was circulated Public Works draft findings which formulated this report. Carleton had many comments and objections to the findings of the report. Staff have attempted to address their concerns, but have not been successful.
COMMENTS BY THE WARD COUNCILLOR(S) – Councillor Deans
The City should become a leader in finding alternative energy sources. The present provincial subsidization of energy should not be considered a constant and the City must continue to look at green energy sources. This report of the feasibility of using cold energy is based on the worst case scenario by using environmental data which has the consequence of artificially inflating the projected cost of construction of a facility and the return on investment projections. I request that the City add the cold energy proposal to their current energy strategy that is being developed in conjunction with IBM and consider its promotion using alternative locations (i.e., Strandherd and Conroy snow disposal facilities) going alone or in partnership with the private sector.
LEGAL/RISK MANAGEMENT IMPLICATIONS
There are no legal/risk management impediments to implementing the recommendations in this Report.
CITY STRATEGIC PLAN
The City of Ottawa’s Energy Investment Strategy under the Corporate Utility Policy mandates the Energy Reduction Program to achieve a return on investment of 20% or, 5-year simple payback.
FINANCIAL IMPLICATIONS
There are no financial implications in implementing the recommendations contained within this Report.
SUPPORTING DOCUMENTATION
Document 1- Energy Reduction Initiatives Completed in 2009
Document 2- Constellation Data Electrical load
Document 3- Action Plan Status Update
DISPOSITION
The Public Works Branch, in consultation with appropriate Branches/Departments/ external agencies, will action any direction received from the considerations within this report.
DOCUMENT 1
Energy Reduction Program 2009 Measure List
|
No |
Facility |
Measure |
Cost |
Annual Savings |
Payback |
|
1 |
2009 Program |
Audit/Engineering |
$100,000 |
$ |
- |
|
2 |
Community Centres II (3) |
Upgraded to T8 |
$15,945 |
$5,261 |
3.0 |
|
3 |
Rideau Client Services |
Upgraded to T8 |
$10,377 |
$2,542 |
4.1 |
|
4 |
Swansea Garage |
Water Upgrade |
$12,766 |
2,738 |
4.7 |
|
5 |
Walter Baker |
Stand Control Heating |
$25,108 |
$4,845 |
5.2 |
|
6 |
Group 1-6 Rinks |
T5 Pad Lighting |
$255,085 |
$47,322 |
5.4 |
|
7 |
1480 Heron Road |
Upgrade to T8 |
$48,494 |
$10,614 |
4.6 |
|
8 |
Group 2- 11 Rinks |
T5 Pad lighting |
$433,844 |
$80,195 |
5.4 |
|
9 |
Main Library |
VFDs on AHUs |
$39, 998 |
$16,859 |
2.4 |
|
10 |
Alfred Taylor Rec. Centre |
Boiler Replacement (oil) |
$47,868 |
$9,881 |
4.8 |
|
11 |
Walgreen |
Toilets |
$2,154 |
$424 |
5.1 |
|
12 |
Lakeside Gardens |
Toilets & Urinals |
$10,142 |
$3,483 |
3.0 |
|
14 |
Brian Kilrea |
Lighting Upgrade |
$4,451 |
$910 |
4.9 |
|
15 |
1655 Maple Grove |
Lighting Upgrade |
$10,431 |
$3,483 |
3.0 |
|
16 |
Power Savings Blitz |
Lighting Small Buildings Group 1 |
$21, 198 |
$13, 587 |
1.6 |
|
17 |
Power Saving Blitz |
Lighting Small Buildings Group 2 |
$13, 936 |
$8,855 |
1.6 |
|
18 |
Power Savings Blitz |
Lighting Small Buildings Group 3 |
$14,762 |
$8,264 |
1.8 |
|
19 |
Ray Friel |
Lighting Upgrade |
$30,463 |
$7,810 |
3.9 |
|
20 |
St. Laurent |
Pool Blankets |
$43,424 |
$9,008 |
4.8 |
|
21 |
PInecrest Bus Garage |
Lighting Upgrade |
$189,244 |
$44,660 |
4.2 |
|
22 |
Carleton Lodge |
Variable Speed Drives |
$24,593 |
$5,187 |
4.7 |
|
23 |
Carleton Lodge |
Humidifier |
$26,650 |
$5,713 |
4.7 |
|
24 |
Blackburn Hamlet |
Unit Heater Control |
$1,573 |
$435 |
3.6 |
|
25 |
Blackburn Hamlet |
Heat Reclaim |
$31,378 |
$4,654 |
6.8 |
|
26 |
Nepean Sportsplex |
Squash Courts T5 Upgrade |
$17,714 |
$4,780 |
3.7 |
|
27 |
Walter Baker |
DHW elec-gas |
$61,129 |
$7,355 |
8.9 |
|
28 |
Swansea Garage |
T5 Lighting |
$183,207 |
$40,693 |
4.5 |
|
29 |
Nepean Sportsplex |
Stand Heating Control |
$19,868 |
$4,269 |
4.7 |
|
30 |
Lenard Depot (Cumberland) |
Upgrade to T8 |
$1,356 |
$535 |
2.5 |
|
31 |
Cyrville Works Yard |
Lighting Phase 2 |
$17,475 |
$3,770 |
4.6 |
|
32 |
Carp Memorial Hall |
Furnace Replacement (oil) |
$15,784 |
$3,268 |
4.8 |
|
33 |
Carleton Lodge |
Upgrade to T8 |
$19,731 |
$5,071 |
3.9 |
|
34 |
Agincourt Field House |
Furnace Replacement (oil) |
$15,369 |
$3,452 |
4.5 |
|
35 |
Power Savings Blitz |
Lighting Small Buildings Group 4 |
$13,988 |
$7,533 |
1.9 |
|
36 |
Vernon Community Centre |
Furnace Replacement (elec to gas) |
$ 31,960 |
$6,398 |
5.0 |
|
37 |
Vernon Library |
Convert from Propane to gas |
$2,595 |
$1,515 |
1.7 |
|
|
Totals |
|
$2,168,912 |
$457,194 |
4.7
|
DOCUMENT 2
Constellation Electrical Load Data 2005-2008
DOCUMENT 3
Action Plan from Thermal Energy Report ACS2009-ICS-INF-001: April 2009
Snow Storage and Management (Carleton University and City
of Ottawa Public Works)
Carleton University and Public
Works collaborated on the technical aspects of snow dynamics. Carleton
University’s focus was on establishing the conditions of snow when it is piled
and stored. The City granted Carleton University access to one of its snow
disposal facilities to accommodate the research. Carleton University’s support
was centred on the scientific aspects of the technology.
Cold energy Capture and Transfer Technology - (City of Ottawa Design & Construction)
Standard methodologies currently exist for capture and transfer technologies so no further research was required.
Melt Water Treatment Standards and Technology (Carleton University & City of Ottawa Public Works)
Melt water treatment was not reviewed because it was readily apparent in the dissertations issued for the doctorate that the use of 'melt water' was inappropriate for an urban environment and that it was a serious issue for those involved. The water was contaminated from particles trapped in the snow, stained from the wood chips, polluted from bird's droppings and had was very odorous. The use of melt water as a transfer medium was abandoned in favour of using a circulating solution of glycol water which would not need to be treated and which would not produce fouling of the heat exchanger. The high cost for this treatment was allowed for in the estimate of costs
Competitive installation and operating costs - (Energy Ottawa)
Competitive installations were not pursued because of the inherent high costs for building in an urban environment and the fact that there is no space available at the Constellation/Ben Franklin/Centrepointe Town Centre area. Energy Ottawa did not have the capacity for evaluation building construction costs and deferred to Public Works based on the Branch’s building experience. Cost estimate were based on standard yardsticks established from current building practices. Operating costs and efficiency losses were taken as 20% of potential savings.