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GGR348/1408 C- Free Energy Wrap-Up Lecture

GGR348/1408 C- Free Energy Wrap-Up Lecture. Other C-Free Energy Sources. Hydro-power Geothermal Ocean Energy. Hydro power. Two kinds: reservoir and run-of-river

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GGR348/1408 C- Free Energy Wrap-Up Lecture

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  1. GGR348/1408C- Free EnergyWrap-Up Lecture

  2. Other C-Free Energy Sources • Hydro-power • Geothermal • Ocean Energy

  3. Hydro power • Two kinds: reservoir and run-of-river • Electrical power from reservoirs depends on rate of water flow x elevation difference between reservoir surface and the turbine x turbine and generator efficiencies • GHG emissions (especially methane) are associated with decomposition of organic matter that is flooded when reservoirs are created • Lifecycle GHG emissions in worst case projects (reservoirs flooding a vast area of the Amazon rainforest and with low elevation drop) can equal those from coal powerplants • Lifecycle GHG from Canadian hydro projects are very small

  4. Objections to a proposal to build a transmission line (shown in the next slide) to bring more hydropower from Quebec to New England, via New Hampshire:“Why are we allowing [Eversource – the power company] to slice our state in half for an unnecessary transmission superhighway carrying dirty power from a foreign country?”. Sierra Club spokesperson.

  5. Trends in hydro-electricity production

  6. Regional and global hydro-electricity production

  7. Hydroelectricity generation in 2014

  8. For your information, here is the breakdown of electricity generation capacity in China at the end of 2014: • Coal, 907 GW • Hydro, 300 GW • Natural gas, 135 GW • Wind, 90 GW • Solar, 28 GW • Nuclear, 21 GW Coal has remained at about 78% of total generation since at least 2004.

  9. Geothermal Energy • If you go deep enough, it gets hot enough (several hundred deg C) to generate electricity (temperature typically increase by 20 K/km) • The key question is then a matter of cost • Low temperature geothermal heat (80-120 C) could be used for many industrial processes, especially food processing • One needs at least 200-300 C to generate electricity (efficiencies are low at low temperature) • The resource is not renewable on a human time scale but could last 1000 years

  10. Ocean energy • Tidal • Wave • Thermal – use the temperature difference between warm tropical surface water and deep (1 km) cold (4 C) water to generate electricity (the idea is called OTEC – ocean thermal energy conversion, and there have been pilot projects near Hawaii). Efficiency in generating electricity would be very low (due to the small temperature differences involved)

  11. Figure 7.9 Proposed tidal-current turbines Source: www.e-tidevannsenergi.com

  12. Figure 7.11 Geographical variation in the difference in temperature between the ocean surface and ‘deep’ water (typically at a depth of 1000 m) Source: www.xenesys.com

  13. Technology Updates • Wind Energy • Solar Energy costs • Electricity transmission • Energy storage

  14. Wind Energy Advances • Better matching of rotor speed to wind conditions to maximize electricity output for a given wind speed • Increase in cut-out wind speed to up to 32 m/s, with gradual rather than sudden cut-out- this is an issue for North Sea wind farms, where high wind speeds are common • Development of floating wind farms • Specialized equipment for transporting wind turbine components to difficult sites

  15. Transporting wind turbine blades to high mountain sites in Europe

  16. The easy part …. Source (for this and subsequent slides in this set): WindBlast (Enercon Magazine), 2015-03

  17. Through narrow village roads …

  18. …and tight mountain bends

  19. to the final destination

  20. Specialized ship for the transport of components for offshore wind farms Source: WindBlast (Enercon Magazine), 2015-03

  21. Use of concrete rather than steel towers so as to permit on-site manufacturing by mobile production facilities (next to the wind farm to be built) Source: WindBlast (Enercon Magazine), 2015-02

  22. Energy Storage • Declining cost of batteries • Graphene enhanced batteries • Advanced Adiabatic compressed air energy storage (AA-CAES) in Toronto

  23. Declining cost of batteries Source: Clean Energy Canada (2015)

  24. 3-day battery storage for a house Source: http://www.greenenergyfutures.ca/episode/energy-storage-ontario-tesla-powerwall

  25. Graphene-enhanced batteries • Graphene is a sheet of C atoms in a honeycomb structure (see below) • When used in conventional battery electrodes, it increases the energy storage and reduces battery mass, both of which act to reduce the material requirements • Graphene enhancement also reduces charging times Graphene is also viewed as a possible replacement for silicon in PV modules

  26. Storing compressed air in in durable balloons under Lake Ontario, with onshore storage of heat generated during the compression processFor more information, go to

  27. Recall: Options to get relatively steady electricity output from wind with large capacity factors (70% or more) are: • To place widely dispersed windfarms in the best wind regions (which tend to be 750-3000 km from major demand centres) and oversize them by a factor of 2-3 relative to the transmission link • To use hydro-power as (in effect) temporary storage to levelize or control the combined wind+hydro power output • To use compressed air energy storage (CAES), initially with natural gas, later with gasified biomass or with storage of heat produced during compression (advanced adiabatic CAES)

  28. Figure 3.44 Oversizing Concept

  29. Increasing the transmission capacity of transmission lines • The energy that is “lost” during transmission is turned into heat, making the transmission line hot • The amount of electricity that can be transmitted through a given line is limited by the need to avoid overheating the line • The line rating or capacity is based on standard atmospheric and wind conditions • If it is colder, or the wind is stronger, the line will not heat up as much for a given power flow, so more power can be permitted • Thus, line capacities vary with the season, and this is already taken into account when planning the mix of electricity sources to use (“dispatching”) at any given time

  30. However, new systems that entail sensing the temperature of the line every 2 m and transmitting the information via a fibre optic cable that is within the electrical cables, can allow transmitting more electricity than based on standard seasonal line ratings – often by 15% and occasionally by 100%. • So … we have the nice result that when the wind is stronger and more electricity is generated by a wind farm that is oversized compared to the rating of the transmission line, the transmission capacity of the line also increases (because of the cooling effect of the stronger winds), so less electricity will be wasted or “spilled” (to use the industry jargon) Source: “The proof is in the putting”. IEEE Power and Energy Magazine, Jan/Feb 2015, pp74-84.

  31. Figure 3.44 Oversizing Concept

  32. Performance metrics: • Cost • Land area required • EROEI • Resource density and effect on cost

  33. Trend in cost of electricity from new wind in the US, 2009-2015 LCOE=levelized cost of electricity (what you have been calculating in your PSs) Divide cost in $/MWh by 10 to get cost as cents/kWh Source: Lazard’s Levelized Cost of Energy Analysis – Version 9.0 (17 Nov 2015)

  34. Trend in cost of electricity from new PV in the US, 2009-2015 Divide cost in $/MWh by 10 to get cost as cents/kWh Rooftop C&I: 10.9-19.3 cents/kWh Utility-scale: 5.8-7.0 cents/kWh Source: Lazard’s Levelized Cost of Energy Analysis – Version 9.0 (17 Nov 2015)

  35. Capital costs and LCOE in US, 2015 • Residential rooftop PV: $4100-5300/kW, 16-21 cents/kWh • C & I rooftop PV: $2600-3750/kW, 10-15 cents/kWh • Central utility PV: $1350-1750/kW, 5.3-6.9 cents/kWh • CSTP, no storage: $6500/kW • CSTP, 18 hours storage: $10,000/kW, 12 cents/kWh • Wind, onshore: $1250-1700/kW, 6.1-8.0 cents/kWh • Wind, offshore: $3000-4300/kW, 7.2-10 cents/kWh • NGCC: $1000-1300/kW, 5.5-6.0 cents/kWh • Conventional coal: $3000-8400/kW, 7.2-15 cents/kWh • Nuclear: $5400-8200/kW, 10-15 cents/kWh Source: Lazard’s Levelized Cost of Energy Analysis – Version 9.0 (17 Nov 2015), for capital costs, own calcuations for LCOE assuming 5% real interest rate, which closely match EIA (2015). Many of Lazard’s LCOEs are not plausible. Capacity factors assumed here: solar, 0.2; onshore wind, 0.25; offshore wind, 0.5; fossil, 0.65

  36. From Table 12.2: Land area required to hypothetically meet the entire 2005 world electricity demand over a period of 100 years using various electricity sources

  37. From Table 12.3: Comparison of EROEI for various electricity sources.

  38. Notes for the preceding slide: • For fossil fuels and nuclear, the EROEI is based on all the energy inputs except the fuel itself • This includes energy for mining, processing and transporting the fuel used at the power plant, and for end-of-life decommissioning of the powerplant • The low EROEI for NGCC arises because the energy required to explore, drill, build pipelines and transmit natural gas is about 25% of the energy value of the fuel used. Thus, for a plant at 54% efficiency, the EROEI is 0.54 over (0.25 x 1.0) = 2.2. To make this equivalent to the EROEI’s given for wind and solar – multiply by about 2.5.

  39. Figure 12.1aWind electricity generation potential based on winds at a height of 100m, kWh/m2yr based on total wind farm area (with a turbine spacing of 7D x 7D, where D=80 m is the rotor diameter)

  40. Figure 12.1bElectricity generation potential (kWh/m2yr) from concentrating solar thermal power assuming a collector:ground area ratio of 0.25 and 15% overall sunlight-to-electricity efficiency

  41. The following map shows the minimum of the computed cost of PV and wind electricity, assuming • annual electricity production from concentrating solar thermal power (CSTP) and wind as shown in the previous slides • capital cost for wind power of $1500, annual O&M equal to 2% of the capital cost, and 5% financing over 20 years • capital cost for CSTP of $3000/kW, annual O&M equal to 5% of the capital cost, and 5% financing over 20 years

  42. Figure 12.1c Minimum of CSTP and wind electricity cost (cents/kWh) (excluding transmission cost)

  43. C-free energy sources for transportation: • Plug-in hybrid electric vehicles - renewable electricity from the grid would cover 60-75% of the distances driven - the vehicle batteries could also serve as short-term (second to hours) energy storage when the vehicles are parked and connected to the grid • Hydrogen or biofuels for long-range driving in vehicles with high efficiency • Fully electric vehicles if optimistic battery performance and cost projections pan out • Investments in high-quality rail-based urban transit infrastructure combined with transit-supportive urban form

  44. Biomass energy • Given the priority need for land for food production, the future global potential will depend strongly on human diet (diets with high meat require much more land, thereby crowding out bioenergy crops) • The most effective use is bioenergy for combined heat and electricity (cogeneration) • Biofuels from temperate food crops (ethanol from corn or wheat, biodiesel from oily crops) make absolutely no sense. Ethanol from sugarcane is possibly justifiable, although long-term sustainability has not been proven • Biofuels from ligno-cellulosic crops might be an ecologically viable method for meeting a small portion of transportation energy demand (that which remains after reducing demand through better urban form and mass transit and through use of renewable electricity in plug-in hybrid electric vehicles)

  45. Far out Scenario

  46. A global grid? Electricity from Antarctica? Source: Chatzivasileiadis et al. (2013, Renewable Energy 57:372-383)

  47. Blue: existing HVDC lines. Red: planned Source: Chatzivasileiadis et al. (2013, Renewable Energy 57:372-383)

  48. Blue: existing HVDC lines. Red: planned Source: Chatzivasileiadis et al. (2013, Renewable Energy 57:372-383)

  49. My work involves constructing “integrated” models of the global energy system to address these questions • For various scenarios of growth in population and GDP per person in various world regions, what combinations of technical and behavioural measures can achieve the goal of eliminating fossil fuel CO2 emissions by 2100 or sooner? • More specifically, what are the tradeoffs between energy supply and demand, between energy intensity improvements in different sectors (buildings, transportation, industry, agriculture), and between actions in different world regions in achieving a given global emission reduction target? • What are the required energy and material requirements during the transition to a C-free global energy system for different scenarios concerning population, GDP/person, energy efficiency, and behavioural factors? • How sustainable would the various scenarios be?

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