Micro-Cogeneration: Is There a KW in Your Future ? Skip Hayden Renewable and Integrated Energy Systems Better Buildings by Design 2010 Burlington, February 2010 Natural Resources Ressources naturelles Canada Canada Integrated Energy Systems Objectives • Appreciate what micro-cogeneration is • Understand the range of advanced micro- cogeneration technologies now impending on the North American marketplace • Understand the potential energy, environmental and system advantages offered by micro-cogeneration • See how you may have your own kw in your future. ? ? What are you looking for ? ? ?? CCHT: Canadian Centre for Housing Technologies CCHT Research Houses • Located in Ottawa and operated by three agencies – NRCan, NRC & CMHC • Consists of two identical research houses and townhouse-type info- demo centre • Houses Design Heat Loss – > 40,000 BTU/hr • Both houses are under Simulated Occupancy Protocol Microgeneration • A notion of generation both heat and power on site to serve the thermal load <50kW th and electrical <30kW el plus the grid • May employ any combination of electrical generation and storage technologies that are on or off grid • Technologies – Stirling Engines, IC Engines, Fuel cells, microturbines, thermophotovoltaics, thermoelectrics, solar • or combinations of the above Micro-Cogen Concept Benchmark Architecture (natural gas fueled, outdoor unit, current technology) Outputs: Inputs: Intelligent Home electricity from grid Load management normal AC loads weather inputs space heating occupancy inputs Inverter / Charger AC Bus: domestic grid hot water Battery parallel space cooling DC Bus: managed AC loads radiant floor heat fuel IC engine + 3 way catalyst Variable Speed DC output pool heat Shaft driven heat pump Hydronic Interface distilled water (?) Cogeneration System Why Microgeneration? • Latest Advances in Building Technologies • Security of Power Supply • Control Over Assets • Economics • Reduce need for new power generation facilities • Reduce GHG’s Potential functions / specifications • “Occasional Stand-By Service”: – Drawn from battery storage for a couple of hours max during occasional grid interruptions – Supplies managed loads such as refrigerator, freezer, well pumps, controls, alarms etc – Availability of about 1000 hours over 10 years – Competes with the idea of buying a gasoline generator – Can recharge during night at lowest grid rates (Ontario model) • “ Peak Rate Avoidance & Emergency Service”: – Drawn from engine during daily peak electricity pricing period (Ontario model) – Supplies heating / cooling needs, domestic hot water and selected loads – Availability of 4 to 6 hours x 5 days per week resulting in 13,000 hours over 10 years – Satisfies need for independence and preserves occupant comfort during emergencies – Theoretical potential to zero out electricity bill • “Continuous Cogeneration Service” – Stirling engines and fuel cells will run longer at lower capacity with higher inherent E/Q ratios – May need electricity storage even more than the IC engine option above – Non-reciprocating systems promise longer life with lower maintenance • “Off-Grid Luxury Service” – Architecture suitable for integration of solar- PV / wind and solar- thermal – Propane or Bio-diesel capability for luxury market segment Myths, Facts and Customer Mindset… •Myths: – Grid interconnection is a must (it’s doubtful customers will invest their own money to put electricity on the grid) – High electrical efficiency is a must (E/Q ratio is more significant) – 500 $/Kw must be attained (< 10 Kw it’s irrelevant, it’s the up front incremental cost premium and monthly charges relative to other alternatives that counts – domestic cogeneration systems compete for disposable income like any other consumer purchase) •Facts: – Reliability, low maintenance, low noise and low emissions are very important • Customer Mindset: – It’s an appliance - integrated products are essential – We are surveying how Canadian customers value each function – “independence”; “comfort” ;“value” and “image” may sell Microgeneration – Technology Options • PEM and SOFC Fuel Cells • Stirling Engines • Reciprocating Engines • Thermophotovoltaics • Thermoelectric • others Proton Exchange Membrane (PEM) Fuel Cells • Modulating output • Efficiency 35-45% • Pure H2 or external reformer • Field trials around the globe Solid Oxide Fuel Cell (SOFC) • Output 1-50 kW electric • Internal reforming • Efficiency 45-50% Solid Oxide Fuel Cell Trial • Fuel cell operated for over 2 months. • Operating period covered – mid-winter conditions (outdoor temperatures for a few days in the range of –10C to –20C) – Shoulder season conditions – Spring 2005 – Summer conditions – several days with no space heating. • Fuel Cell was in good operating condition throughout the project, and on its return. • Fuel Cell demo project was successful as it met the objectives of the project. Electrical Wiring Power Generation and Load Satisfied Test House Electricity Consumption and Supplies 20-Mar-05 (Excluding Data Acqisition and Heat Dissipation) 5 19.1 Fuel Cell Electricity supplied to House 48.4 Fuel Cell Electricity Exported to Grid 4 0.6 Utility Electricity supplied to House 19.7 3 CCHT Test House Consumption 2 1 0 Power (kW) 0:00 2:00 4:00 6:00 8:00 10:00 12:00 14:00 16:00 18:00 20:00 22:00 0:00 -1 -2 -3 -4 Time Stirling Engine • External combustor • Close to mass production • Electric efficiency 10-25% • Large field trials in Europe • Seen as a replacement of heaters and boilers (& Central Generating Plant) External Combustor Cogeneration Stirling Engine • Gaseous or Liquid (bio) Fuels – AC, and DC “backbone” • Generates heat and electricity • Optimize BOP • Alternative renewable energy sources EnMax Pilot – Calgary, December 2007 • AC WhisperGen generating 1kW, propane fired • • Provided both heat and DHW to the home this winter • Integrated with radiant floor heating through a LatentoTM latent heat exchange thermal storage tank Stirling Engine MicroCogen System with Electrical Storage • Demonstrating combination system integration (forced air space heat and DHW) • Investigating performance advantage of lithium-ion vs lead-acid batteries • Exploring economics and environmental impacts using typical house electrical and thermal profiles Stirling Engine Trials • 6 kW (~20,000 BTU/hour) heat generated • 750W electrical generated; 575W useable on the grid • 115kg; 400mm x 550mm x 850mm • Startup time before core reaches 70°C ranges from 0 - 30 min, depending on setup. The shortest uses no cooling water until core is at 60°C • Shutdown time is 20-35 mins. Shortest uses fresh cooling water and dumps the heated cooling water. • Since startup and shutdown times are long, it is most efficient to run the engine continuously. Stirling Engine Efficiency IC engines • Proven technology • Integration with forced air and water based heating systems • Electrical output 1-6 kWelect • Large field trials in Japan Hybrid IC Sngle-Cylinder Engine – HE Condensing Furnace System • Generate 1kW electric & 3.25/18kW thermal power (only heat – condensing) • 50% of generated electricity was used to satisfy the house demand; the rest was exported to the grid • Operated reliably and with high efficiency at CCHT for 4 weeks • Second generation under development – modulating output and back up power + space/water heating • Extremely quiet Hybrid ICE/HE Furnace System – CCHT Results Cost of Heating System Operation Breakdown of Electrical Supply and Demand Climate Energy System From Engine 7 High Efficiency Furnace 40 30 From Grid Two Stage Furnace Locked to High House Electrical Demand Outdoor Temperature 6 30 25 ) 5 20 20 Exported El ectricity 4 10 15 3 0 Electricity (kWh/day) 10 2 -10 Average Dailiy Outdoor Temeprature (°C Temeprature Outdoor Dailiy Average Daily Heating System Cost of Operation ($/day) 5 1 -20 0 -30 0 08-Oct-05 22-Oct-05 14-Jan-06 28-Jan-06 08-Apr-06 22-Apr-06 08-Oct-05 22-Oct-05 08-Apr-06 22-Apr-06 14-Jan-06 28-Jan-06 05-Nov-05 19-Nov-05 03-Dec-05 17-Dec-05 31-Dec-05 11-Feb-06 25-Feb-06 11-Mar-06 25-Mar-06 05-Nov-05 19-Nov-05 03-Dec-05 17-Dec-05 31-Dec-05 11-Feb-06 25-Feb-06 11-Mar-06 25-Mar-06 Date and Time Date and Time IC Micro-Cogen Aisin • 6 Kw electric at 35% efficiency • 10:1 turndown • Low NOx • Outdoor installation • Very long maintenance interval Borehole Storage to Manage Excess Heat Micro-Cogen Integration Micro-cogeneration technologies to supply space and water heating requirements, along with electricity at overall efficiencies of 90% This potentially large (several million) distributed source would be a highly efficient way to reduce requirements for new large electricity generation with at least a 3-fold reduction in carbon emissions Further coupling this with cost-effective borehole storage for heat and later extraction with a heat pump could further double the emissions reduction Advanced, interactive smart controls are required to ensure optimally efficient energy generation and utilization within the residence and the grid This is an important step on the road towards net-zero housing PHEV (Plug-in Hybrid Electric Vehicle integrated with house, micro-cogen and grid Micro-cogen system charging PHEV at night Micro-cogen unit Driving green and efficiently during day PHEV feeding electricity back to grid during peak A/C demand Seasonal Storage for Excess Heat with Micro-turbine Thermophotovoltaics (TPV) & Thermoelectrics (TE) • Ceramic, heated by flame with recirculation and evne O2 enrichment (membranes), becomes a highly luminous, tuned source, emitting light and