PHYS 371 Introduction to Energy LECTURE 10 WEEK 6 • GUEST SPEAKER: “ALBERTA’S ELECTRIC GRID” • COAL, GEOTHERMAL, OCEAN, AND OTEC POWER TUESDAY, JUNE 7, 2022 WEEK 6 AT GLANCE ➢ Week 5/6-Lectures: “Module 3: Energy sources” ➢ THURSDAY: Midterm 2: June 9, 2022, at 2pm. In person, NO EXCEPTIONS. ✓ Cut out for topics: Lecture 9 inclusive. ❑ Week 6-Lecture 10: Guest Lecture – Energy in Alberta. Fuel - Coal Plants. Flows – Geothermal/Waves/OTEC. o Guest Lecture – “Alberta’s Electric Grid", by Travis Gartner, Department of Physics and Astronomy, UofC o Coal Power Plants- Fuel: Source of Power (background), Technology o Geothermal- Flow: Source of Geothermal Power (background), Geothermal Technology o Ocean Waves- Flow: Source of Power (background), Technology o OTEC - Flow: Source of Power (background), Technology ❖ 2 group discussions ❖ 2 minibreaks ❑ Week 6-Lecture 11: Space weather and Power grid o Space Weather (background). Dangers to the power grid ❖ 1 group discussions ❖ 1 minibreaks ➢ Week 7-“Module 4: Energy and our world” Alberta’s Electrical Grid June 6, 2022 About Me • MSc student in atomic and molecular physics • Silicon photonics for trace gas sensing • High resolution infrared spectroscopy of van der Waals clusters • 7 years experience in the AB utilities industry • PPA contract analysis • Real time power plant operation and financial trading Resource Base: Coal • Historically coal has been the dominant fuel source for electrical generation in Alberta • Large natural reserves of near surface subbituminous coal • Almost half of Alberta land area is some kind of coal bearing formation • Annual raw production: ~15 million tonnes Resource Base: Coal Electrical Generation by Fuel Type (2018) Highvale Mine, AB • Until 3 years ago, Alberta’s electricity generation was ~40% coal powered • Rising carbon costs and political pressure to decarbonize the grid have led to a large shift away from coal generation • Repurposing of old coal plants into natural gas plants • • • Save remediation costs Lower emissions Capitalize on another abundant resource Coal Transition in AB • Since 2018 ~2000MW of coal has transitioned to gas fired power • 12% of provincial capacity • 15% of current electrical generation capacity • Natural gas has shot up to 60% • Fossil fuels still account for ~80% of all generation Resource Base: Natural Gas • Alberta has the 25th largest proven natural gas reserve of any COUNTRY! • Alberta is the 8th largest natural gas producer of any COUNTRY! Marketable Gas Production by Province (2019) Resource Base: Natural Gas Resource: • 31 Tcf conventional • 3,424 Tcf shale Production • ~10 Bcf/d conventional • <1 Bcf/d shale Resource Base: Natural Gas • Large existing transportation infrastructure in AB • Negligible cost to transport gas in AB for electrical generation • Efficiency and emission gains over coal Efficiency and Emissions • Natural gas plants emit 50% less CO2 for equivalent energy output • Natural gas emits large amounts of CH4 • While burning coal does not release CH4, mining it does! Resource Base: Wind • Alberta’s wind resource is one of the best in Canada • Average annual wind speed of ~7m/s (if you remember this is well above the cut-in speed for a wind turbine) • Currently 2100MW of installed capacity • 12% of grid capacity • Wind is not reliable • Blows 33% of the time • Can’t form the basis of a stable grid Resource Base: Wind • Atmospheric westerlies • Chinooks • Bring the heat and the wind • Air cools as it rises over the mountains and warms adiabatically as it descends • This generates a large (relatively speaking) number of windy days in southern AB Resource Base: Solar • Alberta also has a great solar resource, particularly in southern AB • Warming air descending the mountains clears a lot of the cloud cover • ~300MW installed capacity • 2% of grid capacity • Like wind, solar is not a reliable resource to build a grid around • With daylight savings, its dark, a lot! • Perform better in low temps • Heat is a resistance in a circuit • Snow is highly reflective Competing with Fossil Fuels • As installed capacity for wind/solar/other renewables rise, cost decreases, making them more attractive • Efficiency gains for renewables are largely driven by advances in technology • More aerodynamic blade designs for wind • Materials advances in PV cells • Biomass/geothermal capture tech • Financial Incentives starting to pile up • Climate agreements • Carbon offsets Alberta’s Electricity Market • Pre-1996 – Cost of service model • Vertically integrated utility companies set rates based on their cost to generate (plus a limited profit) • Paid for capacity (the ability to produce electricity) • ENMAX, EPCOR, ATCO • How the rest of Canada operates (more or less) • Post-1996 – Energy only model (deregulation) • • • • Power contracts sold off to diversify who owned generation capacity Paid only for electricity you produce Generators free to price their generation however they want (with exceptions) Generators can take plants offline for any reason Alberta’s Energy Only Market • Managed by the Alberta Electric System Operator (AESO) on an hourly basis • Generators submit electrical supply offers to AESO in blocks up to the total capacity of their power plant • Anywhere between $0/MWh to the price cap of $999.99/MWh • Baseload generation MUST be offered in at $0/MWh • Wind/Solar must offer in entire capacity at $0/MW/h • These fuel types are price takers as they cannot ramp up/down generation • AESO dispatches generation from cheapest offer ($0/MWh) until electricity demand is exactly met by supply Dispatch order for all generators on Sept 7, 2021 Baseload Generation • Power supplied to the grid to meet minimum electricity needs • Constant reliable source of electricity • Supplied by coal, natural gas • Supplemented by wind/solar Baseload Generation: Coal • Coal plants must run at a minimum MW output to maintain safe operation • Minimum stable generation (MSG) for a 400MW coal plant is ~150-200MW • This generation block is priced at $0/MW/h so the unit can stay running • The rest of the capacity is usually priced up higher • Running at MSG reduces thermal stress from firing the boiler and ramping the turbine Baseload Generation: Gas • Combined cycle natural gas plants • Hot exhaust from gas turbine fed to a steam turbine for additional output • About 20% more efficient than a simple cycle gas plant • More complexity means more thermal stress when ramping Combined Cycle Gas Plant • MSG like a coal plant to reduce stress Baseload Generation: Renewables • Wind and solar are not dispatchable fuel types • You get what you get • Rule of thumb is that wind turbines produce usable electricity 33% of the time • No solar at night Peaking Generation • Electricity produced to match variations in demand • Not optimal (for thermal/economic reasons) for power plants to operate at maximum output • Some capacity reserved to meet peak demand • And get paid peak prices • Needs to be generated quickly • Simple cycle gas, hydro • Priced up coal (but this is still slow) Simple Cycle Gas Plant Importing/Exporting Power • Done mainly for financial reasons • Realize spread in prices between markets • Three transmission lines move power East, West, South • Must coordinate with other jurisdictions • Schedule in advance • Importing power forms part of AB baseload generation Electricity Demand in AB Lights/Heat turn on at work Industrial processes turn on Baseload generation always running Peaking plants turn on Lights/Heat on at home Peaking plants turn off Seasonal Variations in Demand Considerations for AB Market • AB is the only truly “free market” for electricity in Canada • Decades of Conservative leadership • Things that come along with deregulation (in general) • Good • • • • More accurate resource pricing (maybe) More investment (maybe) Diversity of fuel types entering the market Overall cheaper pricing over the last decade (despite volatility) • Bad • • • • Price manipulation (maybe) Insider trading (maybe) Volatile swings in price Greater stress on aging baseload generators Considerations for AB Market • Take advantage of our great renewable resource base • Subsidies needed for wind/solar • Job creation • Public engagement and education • Will need coal/gas for the foreseeable future for a stable grid (or until there is a breakthrough in storage (battery) technology) U of C Cogeneration Plant • 12MW capacity • Provides 75% of yearly campus electricity • Exhaust gases used in heat recovery to generate hot water for campus Carbon Capture in AB • Contentious (to say the least) • Conservatives (…so AB) love it • Funnels more money to entrenched energy entities • Largely funded by taxpayers • Gives a much-needed PR boost to these companies • Liberals usually don’t support it • But does it work… Shell Quest CCS Plant (AB) • How does it work (video) • https://www.shell.ca/en_ca/aboutus/projects-and-sites/quest-carboncapture-and-storage-project.html • Common reporting methods to the public, focus on the positive • “…to date, Quest has captured and stored over 6 million tonnes of CO2” • Third party analysis tells a different story • The technology is probably not ready • Does it deserve investment • R&D or otherwise CCS Technology • Carbon Capture & Sequestration • Immediate hurdles • Retrofitting old plants is very expensive • Precombustion vs post combustion efficiency gap Post Combustion CCS • Typically have high energy costs and usage • Availability of the tech is tempting • Unproven Pre Combustion CCS Minibreak This Photo by Unknown author is licensed under CC BY-NC. LECTURE 10 WEEK 6 PART 2 COAL POWER PLANTS PHYS 371 Introduction to Energy TUESDAY, JUNE 7, 2022 Different types of engines • External combustion engine • Internal combustion engine • Continuous combustion • Intermittent combustion How is an internal combustion engine different from an external combustion engine? External combustion engine • Fuel heats water outside of piston. • Were used for transportation, but too inefficient. • Still used for power plants. • Coal • Nuclear • Natural gas External combustion for power plants • Fuel (coal, natural gas, uranium, etc.) • Boiler (where the water is boiled) • Stack (CO2 leaves, or other pollutants, not for nuclear plant) • Turbine (steam pushes this around) • Generator (makes electricity) • Condenser (cools steam to repeat cycle) • Cooling tower (Waste heat to atmosphere) Steam Turbine Turbine Condenser Boiler Pump Source: http://e-learning.kku.ac.th/course/view.php?id=470&cal_m=3&cal_y=2008 Fuel runs boiler Turbine Condenser Boiler Fuel in Pump Source: http://e-learning.kku.ac.th/course/view.php?id=470&cal_m=3&cal_y=2008 Boiler heats water (Heat In) Turbine Condenser Heat in Boiler Pump Source: http://e-learning.kku.ac.th/course/view.php?id=470&cal_m=3&cal_y=2008 Hot steam pushes turbine (like a fan blade) Turbine Push Condenser Boiler Pump Source: http://e-learning.kku.ac.th/course/view.php?id=470&cal_m=3&cal_y=2008 Spinning turbine makes useful work Turbine Work out Condenser Boiler Pump Source: http://e-learning.kku.ac.th/course/view.php?id=470&cal_m=3&cal_y=2008 Coal power plant Bełchatów Power Station, Poland In 2018, it emitted 37.6 million tons of carbon dioxide, more than any other power station, with relative emissions estimated at 1.756 kg per kWh. The plant releases more carbon dioxide each year than the entirety of Switzerland https://en.wikipedia.org/wiki/Be%C5%82chat%C3%B3w_Power_Station Fuel in Heat in Push Work Out Heat out Diagram of a fossil fuel plant Energy Environment and Climate, 2nd Edition Copyright © 2012 W. W. Norton & Company Figure 5.9 52 GROUP DISCUSSIONS PHYS 371 Introduction to Energy LECTURE 10 WEEK 6 PART 3 GEOTHERMAL, OCEAN, AND OTEC POWER TUESDAY, JUNE 7, 2022 Geothermal https://energyeducation.ca/encyclopedia/Geothermal_electricity Credit: Yuri_Arcurs/iStock/Getty Images Plus https://energyeducation.ca/encyclopedia/Geothermal_electricity Reykjanes – 100MW With an installed capacity of 100MW electricity generation, it comprises two 50MW turbines that siphon steam and brine from a 290°C-320°C reservoir – one of the hottest geothermal fields in operation. It is owned and operated by HS Orka, a subsidiary of Canada-based Alterra Power. Reykjanes geothermal power station, Iceland https://www.nsenergybusiness.com/features/geothermal-energy-plants-iceland/ https://energyeducation.ca/encyclopedia/Geothermal_district_heating https://energyeducation.ca/encyclopedia/Ground_source_heat_pump https://energyeducation.ca/encyclopedia/Ground_source_heat_pump Minibreak This Photo by Unknown author is licensed under CC BY. Energy from Ocean waves https://energyeducation.ca/encyclopedia/Energy_from_ocean_waves https://energyeducation.ca/encyclopedia/Dynamic_tidal_power https://energyeducation.ca/encyclopedia/Tidal_force https://energyeducation.ca/encyclopedia/Tidal_power Articulated sections: hydraulic cylinders Fluid motion produce pressure to move the electric generator Not a heat engine! Efficiency: 80%-90% Needs 50 meters of water (10 km offshore or more) R. Henderson, “Design, Simulation, and Testing of a Novel Hydraulic Power Take-off System for the Pelamis Wave Energy Converter, “ Renewable Energy, Vol. 31, No. 2, 2006, pp. 271-283. doi:10.1016/j.renene.2005.08.021 https://actionrenewables.co.uk/n ewsevents/post.php?s=everythingyou-need-to-know-about-tidalenergy https://www.nationalgeographic. org/encyclopedia/tidal-energy/ Minibreak Ocean Thermal Energy Conversion (OTEC) GROUP DISCUSSIONS
