Neighbourhood Energy in Vancouver Sewage Heat Recovery within a city-wide strategy

Transcription

1 Neighbourhood Energy in Vancouver Sewage Heat Recovery within a city-wide strategy IDEA Annual Conference, June 4, 2013 Kieran McConnell, NEU Systems Engineer SLIDE 1

2 1) The role of Neighbourhood Energy in Vancouver Greenest City ) Sewage Heat Recovery in Southeast False Creek 3) Bridging to a Citywide Strategy SLIDE 2

3 Reaching our 2020 GHG Goal: Neighbourhood Energy s Role GCAP goal: 33% carbon reduction by 2020 (reduce 1,110,000 tons CO 2 / year) 3

4 Regional Context North Vancouver: Lonsdale Energy Corp (est. 2005) UBC: modernization of campus system and biomass conversion underway SFU: UniverCity implementation in progress Richmond: West Cambie system commissioned Surrey: City Centre system implementation in progress 4

5 Neighbourhood Energy Systems in Vancouver 5

6 Southeast False Creek Neighbourhood Energy Utility (NEU) 6

7 False Creek Energy Centre The False Creek Energy Centre: Centralized thermal energy (hot water) production facility, integrated with a new municipal sewage pump station. Sewage heat recovery is the primary base-load energy source and supplies 70% of the annual energy demand. Natural gas boilers used for backup and peaking heat.

8 Key System Data Medium Temperature Hot Water System 3.0 MW Sewer Heat Recovery Unit ( SHR ) 16 MW Natural Gas peaking boilers (4/4/8) DPS Summer Winter Supply 65 C 95 C Return 55 C 55 C The SHR Heat Pump Modular design Will be upsized in ~2018 Self cleaning Serviced locally Customer Base Today Buildout Floor Area Served 320,000m2 600,000m 2 SHR Capacity 3MW ~8MW Annual Usage Ratio 80% 70% GHG Reduction ~70% ~60% SLIDE 8

9 Sewage Heat Recovery 101. SLIDE 9

10 Key Components Sewage The system requires lps at all times Sewage Screening 2mm vertical rotating travelling screen Four-Way flow reversing valves to scour evaporators every 2 hours Hot Water Flow from 20-45lps Return temperature limited to 60 C Heat Pump Supplied by Trane Canada, designed and built by Tecsir Two centrifugal compressors, chosen for turndown and operating range Variable hot water flow and discharge temperature SLIDE 10

11 System Performance Overview The system performance is measured by Reliability Turndown Capability Thermal Capacity and efficiency SLIDE 11

12 System Performance Reliability The major variable in an SHR system is the incoming sewage. Solids, grease and fibers Screening Flow Reversal Quarterly de-fouling Rapid temperature changes 2011 Sewer Separation Program Significant improvement Winter Sewage Average Temperature 15 C 18 C Rain Event Temperature 9-12 C 15 C Heat Pump Shutdowns ~35 ~5 SLIDE 12

13 System Performance Reliability The major variable in an SHR system is the incoming sewage. Rapid temperature dips cause heat pump shutdown Typically occur in November and December Average ambient Temp is <5 C Average precipitation 170mm per month 2011 Sewer Separation Program to divert storm flow Significant improvement Winter Sewage Average Temperature 15 C 18 C Rain Event Temperature 9-12 C 15 C Heat Pump Shutdowns ~35 ~5 SLIDE 13

14 System Performance Heat Pump Configuration The Heat Pump can be configured daily to optimize performance Single Series Parallel Thermal Output kw kw kW Maximum Outlet 70 C 82 C 70 C Usage Summer - Baseload The system was designed to provide 82 C water. In practice, there are very few scenarios where this makes sense. More efficient to run in Parallel mode and trim the system temp with a boiler Turndown is achieved by running a single unit 700kW (23% of 3.0MW) Below that, unit become unstable as return temps rise SLIDE 14

15 System Performance Capacity The system is exceeding design capacity by a significant margin. The primary reason is warmer than expected sewage temperatures Design Actual Winter Sewage Temp C C Summer Sewage Temp. 18 C C System Capacity 2.7 MW 3.0 MW The result is an increase of seasonal usage from 67% to 70% Additional heat pumps will be optimized for the increased sewage temperature SLIDE 15

16 System Performance Seasonal Performance Coefficient of Performance Optimal at full load and 65 C ~3.4 Reduced at 50% load and 65 C ~2.9 Reduced at full load and 80 C ~2.9 Seasonal Average CoP Capacity System peak far exceeds baseload Summer conditions -> shutdown? SLIDE 16

17 Neighbourhood Energy Goals - Vancouver By 2020: 95,000 tonnes + 25,000 tonnes = 120,000 tonnes Convert existing steam heat systems to low carbon energy sources (such as Central Heat and Hospitals) SLIDE 17 17

18 Neighbourhood Energy Goals - Vancouver By 2020: 95,000 tonnes + 25,000 tonnes = 120,000 tonnes New and expanded systems (Southeast False Creek, Northeast False Creek, River District and other major development areas) SLIDE 18 18

19 Summary Neighbourhood Energy is needed to achieve rapid GHG reductions Opportunities: Convert existing steam heat systems to low carbon energy (biggest opportunity for GHG reductions) Establish new systems to serve large, high density areas undergoing rapid development Expand established systems to serve existing buildings Low density areas of the city are not a high priority for Neighbourhood Energy Site specific solutions can be utilized Need tailored approach for each area to facilitate systems and address development industry concerns SLIDE 19

20 Identifying Target Areas Energy study has mapped areas of the city with high potential for Neighbourhood Energy systems: Existing steam heat systems Large development sites and corridors where rapid, high density development will occur Areas of the City with existing buildings that could be connected to Neighbourhood Energy SLIDE 20

21 Strategy Target Areas Downtown Central Broadway Cambie Corridor SLIDE 21

22 Need for a Tailored Approach Existing systems in Vancouver have different types of ownership (private, public sector and municipal), and regulation BCUC (private) and City Council (municipal SEFC) Some target areas are not served by existing systems, requiring compatible connection policy. Business case for development of new systems varies with density, scale, types of land use and pace of development SLIDE 22

23 Enabling City Policy Tools Energy Centre Guidelines: policy that guides evaluation for new low carbon facilities Utility Regulatory and Contractual tools: used to control utility access to CoV streets and infrastructure. Cost Competitiveness Measures: may include adjustments to property tax policy for utilities, access to senior gov t grants, capital funding etc. Connection policy tools: examples include zoning policy, SLIDE 23 and service area bylaws

24 Vancouver Neighbourhood Energy Opportunities SLIDE 24