WHAT IS DISTRICT ENERGY AND HOW DOES IT WORK? GORDON MONK Technology Integration Manager BC Hydro Power Smart Twitter hashtag: #ps10 AGENDA 1. 2. 3. 4. 5. The Concept - What is District Energy? The Benefits – Why Implement DE? DE’s Challenges and Barriers Clean Energy Sources Profiles of Notable DE Systems THE DISTRICT ENERGY CONCEPT THE DISTRICT ENERGY CONCEPT • A network of pipes that distribute thermal energy from supplier(s) to consumers • Network length can range from hundreds of metres to hundreds of kilometres • Number of customers can range 10 to hundred of thousands • Working “fluid” can be heated water, chilled water or steam • Consumer uses include (i) space heating (ii) DHW heating and (iii) sometimes space cooling HIGH TEMPERATURE (60o-120oC) DISTRIBUTION PIPES Prefabricated steel; external HDPE casings sandwiched layer of insulating polyurethane foam. Approximate Material Cost = $35 / ft AMBIENT TEMPERATURE (5o40oC) DISTRIBUTION PIPES • • • • Uninsulated HDPE Fewer leaks No expansion joints Cheaper and faster to install Approximate Material Cost = $4/ ft. AMBIENT TEMPERATURE SYSTEM CHARACTERISTICS/ REQUIREMENTS • Compatible with waste heat recovery from low temperature sources (Whistler Athletes’ Village, Capital Regional District, Westhills) • Compatible with large systems supplying dense developments • Require heat pumps or terminal units with large surface areas (radiant floors or ceilings) ENERGY TRANSFER STATIONS Each connected building requires: One ETS (space heat) Two ETS (space heat + DHW) Three ETS (space heat + DHW + space cool) Each ETS includes (i) HX, (ii) flow control valve and (iii) energy meter (flow + temp. differential: supply/return). HOW DOES DE SAVE ENERGY? Facilitates steady, efficient base load HOW DOES DE SAVE ENERGY? • Large, centralized thermal generators (boilers or combined heat + power units) tend to be more efficient than smaller, distributed units. • Commercial, residential and industrial buildings have differing energy demand at differing times. Aggregation flattens the load. Typical diversity factor = 0.8 • A DE system can recover waste heat from some customer and deliver it to other customers. LIMITED COOLING OPPORTUNITIES • In BC, cooling demands are relatively low. Economics are therefore challenging. • Feasible cooling from lakes, rivers or the ocean can be connected to major customers such as schools, hospitals, a dense precinct of commercial buildings, shopping centres and convention centres. • District cooling, like district heating, inherently provides community energy planning opportunities. DE SYSTEM COSTS Vary greatly according to location, density of urban form, system size, thermal energy sources, number of customers, etc. System: Capital Costs ($,000) Operating Costs ($/MW.h) Dockside Green 7,900 35 SEFC 43,200 58 BENEFITS FOR COMMUNITIES 1. Hot Swap Capability: heat-carrying network fluid provides a common denominator for multiple fuels - price spike and availability risks are minimized. 2. Future Proofing: 100-year network lifespan facilitates adoption of new technologies. 3. Waste heat recovery: economic capture from industrial, municipal and commercial sources. 4. Biomimicry: Integrated, cascading energy flows optimize community energy supply mix. BENEFITS FOR COMMUNITIES 5. GHG (NOx, SOx, CO2, PM) reductions: clean energy sources, local energy sources, economy of scale w.r.t. mitigation 6. Energy security is enhanced 7. Local job creation (construction, operation maintenance) 8. CAPEX containment: energy $ are re-invested in the local economy and community-owned systems provide public revenues BENEFITS FOR CUSTOMERS 1. Reduced fuel price volatility 2. Increased revenue generating space 3. Reduced operating, maintenance and labour costs 4. Reduced insurance rates 5. Increased reliability of service (99.98%) 6. Reduced noise & vibration BENEFITS FOR BC HYDRO 1. Electricity savings from displaced residential space heating (resistive baseboards) and DHW loads where applicable 2. Combined heat and power (CHP) generators that use renewable fuels provide clean sources of electricity 3. Reduced transmission and distribution investments CHALLENGES AND BARRIERS • High capital expenditure requirements • North American costs are relatively high due to equipment import requirements and lack of construction expertise • Out low thermal and electrical energy prices • Public finances are currently constrained due to weak economic conditions • ROI is usually insufficient to attract private equity partners • Ability to connect future loads is uncertain CHALLENGES AND BARRIERS • • • • Potential customers are often risk adverse Lack of technical expertise and technical skills Uncertainty of future clean energy supplies Lack of public awareness of DE features/ benefits • Complexity of integrated community energy planning process • Resistance to increased density in smaller communities CLUSTERED vs. DISTRIBUTED CENTRALIZED THERMAL GENERATORS Lonsdale Energy Corporation’s Mini-Plants WASTE HEAT AVAILABILITY BC Hydro generates 194 PJ in a typical year. In 2003, BC’s economy: Consumed 566 PJ of useful energy Lost 38 PJ of electrical energy (T&D losses) Lost 532 PJ of thermal energy (waste heat) BC loses as much heat as it consumes in the form of electricity and heat. NRCan estimates 22% or 116 PJ is technically recoverable. WASTE HEAT RECOVERY Industrial Waste Heat Technology: Organic Rankine Cycle. Where: Cement kilns, sawmill lumber dryers, food processing plants. Scale: Medium to large source of heat. WASTE HEAT RECOVERY Organic Rankine Cycle (ORC) Regenerator Organic ~ hydrocarbon or refrigerant with a boiling point below that of water SEWER HEAT RECOVERY Technology: Heat pumps extract heat from municipal sewer system. Where: Large sewer trunks, pump stations or outflow pipes. Scale: Small to large. Can range from home-size heatpumps extracting heat from local sewer main, to large plants at pump stations. BIOMASS - TYPES • Agricultural waste – primarily straw • Urban wood waste – sawn lumber & demolition debris, shipping pallets, pruned branches, stumps & whole trees from streets & parks • Industrial wood waste – sawdust, chips • Mountain pine beetle kill – wood pellets • Short rotation intensive culture forestry – hybrid poplars & aspens, Siberian larch,silver birch • Short rotation woody crops – intensive culture of fast growing species (alder, poplar, willow) • Herbaceous crops – switchgrass, prairie tall grass, hemp, sorghum, reed canary grass, alfalfa, bromegrass COGENERATION OR COMBINED HEAT AND POWER (CHP) • Simultaneous generation of useful heat and power from a single fuel or energy source • Optimized design meets the thermal demand of the building cluster, campus, precinct, neighborhood or community • Key advantage over separate generation of heat and electricity is higher efficiency – up to 93% SMALL-SCALE BIOMASS GASIFICATION CHP Technology: ‘cooking’ of solid wood to create synthetic biogas that is used to generate electricity Where: Wherever you can receive and store large quantities of wood, often near a heat customer Scale: Medium. Not more than 5,000 homes worth of electricity LARGE-SCALE BIOMASS CHP Technology: Generates steam that drives a turbine. Where: Wherever you can receive and store large quantities of wood, often near a heat customer. Scale: Big. Usually supply more than 30,000 homes with electricity. THERMAL STORAGE Short term technology: Insulated water tanks above ground Long term technology: Underground thermal energy storage (UTES) Natural UTES: Aquifer thermal energy storage (ATES) Artificial UTES: Gravel and water pits. Borehole thermal energy storage (BTES). Buried steel or concrete tanks. CASCADE ENERGY FLOWS Commercial District Energy Station Retail Residential (MURB or Detached) METROPOLITAN COPENHAGEN HEATING TRANSMISSION COMPANY EVER-GREEN ENERGY – ST. PAUL WHISTLER ATHLETES’ VILLAGE Ambient temperature system. Heat is recovered from treated waste water effluent using heat exchangers. Reversible distributed HPs upgrade heat to 65oC for space/ DHW inside the buildings. HPs will also extract heat in summer for discharge. Predicted overall energy consumption reduced > 50%. GHGs reduced by 96%. SOUTHEAST FALSE CREEK Central heat pumps recover thermal energy from sewage influent to waste water treatment plant. The recovered heat is distributed though the DE loops at temperatures ranging from 70oC - 90oC. ETSs transfer heat for space and DHW heating. BC HYDRO DE PROGRAM Support for eligible projects: (i) Pre-feasibility study. (ii) Feasibility study. (ii) Capital incentives. When we work together, knowledge, experience and innovation can “Lead the Way to a Sustainable Future.” THANK YOU! GORDON MONK 604.453 6547 [email protected] Twitter hashtag: #ps10