Renewable Energy: Essential terms terms and and concepts for citizens and a dvocates advocates

Transcription

1 Renewable Energy: Essential terms and concepts for citizens and advocates Courtesy of NASA

2 Contact Information Pete Shoemaker Pacific Energy Center 851 Howard St. San Francisco, CA (415)

3 The Big Picture Courtesy of NASA

4 Courtesy of NASA The sun is the only input.

5 Fossil fuels are millions of years of stored sun energy.

6 Which allows our lifestyle to expand to this.

7 Peak Oil But the Age of Oil is temporary.

8 Renewable Energy And we ll need a lot of different sources to replace it.

9 Conclusion Fossil fuels are an extremely dense, very portable form of concentrated energy. They are impossible to replace directly. Key #1 to the transition to renewable energy is DIVERSITY.

10 Types of renewable energy 1. Hydroelectric 2. Tidal 3. Geothermal 4. Biomass 5. Wind 6. Solar (electric, thermal)

11 Hydroelectric: large scale Uses water flowing over a generator to spin a wheel and create electricity. Very green. Courtesy of DOE/NREL Problems: Ecological disruption, fish & wildlife

12 Tidal Great potential, since water carries tremendous power. Problems: Harsh conditions. Environmental disruption. Source: cbc.ca

13 Geothermal: large scale Uses the heat of the earth to create steam and turn a generator. No emissions, produces 24/7. Courtesy of DOE/NREL Problems: Site specific. Good sites are usually away from population.

14 Geothermal: small scale Also called Ground Source Heat Pump. Uses the stable temperature of the earth for heating and cooling Problems: Site location. Expensive up-front.

15 Biomass Sun energy Stored in plants as they grow Still there when they re harvested Can be extracted and used

16 Biomass: Biodiesel Made from cooking or other household oil. Use it in cars just like gasoline.

17 Biomass: Ethanol (grass) or algae Doesn t use food. Much better than corn ethanol.

18 Biomass: Methane Turns cow dung into fuel. Very cost-effective for appropriate sites. Keeps methane out of the air.

19 Wind Abundant Can be low-cost Fast-growing Problems: Courtesy of DOE/NREL Site-specific Large up-front cost Environmental issues Intermittent production

20 Windmills: Two different types Defined by axis of blade rotation: Horizontal axis (HAWT) Vertical axis (VAWT)

21 Windmills: Swept area Potential output is directly related to the input of wind energy: the amount of area swept by the windmill

22 HAWT: Larger is usually better Horizontal axis: area = πr² R Doubling the blade length increases the area 4x.

23 Power in the Wind Wind power is a VOLUME-based equation V = x³ x x x 10 mph (10 x 10 x 10 = 1000) 5 mph (5 x 5 x 5 = 125) Doubling the wind speed increases the potential wind power 8x.

24 Light energy Photovoltaic (PV) Solar: Different Types Electricity produced directly from light Heat energy Concentrated t Solar Power (CSP) Electricity produced by steam Solar Water Heating (Solar Thermal) Heat produced in water, can be also used for space heating All courtesy of DOE/NREL

25 Conclusion Fossil fuels are dirty but predictable in their output. Renewables are clean but multi-faceted and variable. Key #2 to the transition to renewables is INTEGRATION.

26 Keys to Transition to Renewables 1. Diversity 2. Integration

27 Wind Array Variability 2007 CAISO (California Independent System Operator) report on Integration of Renewable Resources

28 PV Array Variability Jay Apt and Aimee Curtright': "The Spectrum of Power from Utility-Scale Wind Farms and Solar Photovoltaic Arrays."

29 The Electric Grid Electricity can be transported at the speed of light, therefore any point can be said to be connected to all others. This network is called the GRID and is nation-wide. Source: onearth.org Source: NREL

30 The Electric Grid There are three main components of the grid: Generation: Creating electricity. Transmission: Moving it in bulk from generators to distribution ib ti centers. Distribution: Bringing it from centers (sub-stations) to individual homes and businesses.

31 The Electric Grid Source: PG&E

32 The Electric Grid Step up Above 50,000 V (69 kv up to 765 kv) Transmission Sub-station 10,000 V (10 kv) Generation 120V 240V Distribution Step down 12000V(12kV) 12, V Home Step down Business Source: NR

33 Grid Terms Supply side Demand side Generation Usage (load)

34 Grid Terms Baseload: Minimum amount of power that is always needed d Seasonal load: Increase in demand in specific times of the year. Peak load: Maximum amount needed. Capacity: Total power that the system can provide.

35 Grid Terms Baseload PG&E 2006 Annual Usage

36 Grid Terms Seasonal load PG&E 2006 Annual Usage

37 Grid Terms Peak load PG&E 2006 Annual Usage

38 Highest demand occurs on only a few hours in the year The top 50 Hours represent 0.6% of the total hours in a year MWs Load Duration Curve Time

39 Grid Terms Capacity PG&E 2006 Annual Usage

40 Grid Terms Unused Capacity PG&E 2006 Annual Usage

41 Grid Terms Spread out the demand and you can lower the capacity need. PG&E 2006 Annual Usage

42 Grid Terms Demand Management or Demand-side Management Load-shifting How do you get people to use less power during peak times and more during off-peak?

43 Demand Management Strategies 1. Reduce overall load. -- Energy efficiency, conservation 2. Inform people so they can cooperate voluntarily. -- Publicity, it Flex Your Power alerts 3. Create the ability to remotely turn off certain appliances. -- Smart AC, smart meters, etc. 4. Charge more for peak usage. -- Time-of-Use rates, Peak-Time pricing and others.

44 Grid Integration Challenges Source: onearth.org

45 Grid Integration Challenges 1. How do you ensure a constant baseload? 2. How can you handle daily variability? 3. How can you predict output and budget appropriately? 4. What storage devices are available and practical? -- The more storage, the more load shifting possible.

46 Grid Integration Challenges 1. How do you pay people for renewable energy? 2. How MUCH do you pay people for renewable energy? 3. Should you pay differently for different types of renewables?

47 Methods of Payment Two fundamentally different concepts: Net Metering Serves es the onsite load FIRST, then interacts with the utility grid. One meter Feed-in Tariff Does not serve the onsite load and ONLY interacts with the utility grid. Two meters

48 Net Metering Meter Customer side Utility side

49 Net Metering Generation: 3 kwh Surplus: 2 kwh Load: 1 kwh Customer side Meter Cash credit: $.60 2 $(going rate) Utility side

50 Net Metering Generation: 1 kwh Surplus: 0 kwh Load: 1 kwh Meter Cash credit: $.00 Customer side Utility side

51 Net Metering Generation: 0 kwh Need: 1 kwh Load: 1 kwh Customer side Meter Cash debit: $.09 1 $(going rate) Utility side

52 Net Metering kwh/mo Average monthly usage PV system production 750 Roll over May SUMMER October WINTER April

53 Net Metering kwh/mo Average monthly usage PV system production 750 The surplus covers the shortfall, and your yearly bill is minimal May SUMMER October WINTER April

54 Net Metering kwh/mo Average monthly usage PV system production 750 PV system produces less than your yearly usage. 500 You pay this amount 250 May SUMMER October WINTER April

55 Net Metering kwh/mo Average monthly usage PV system production 750 PV system produces more than your yearly usage. 500 You are paid a different rate for this amount TBD. 250 May SUMMER October WINTER April

56 Net Metering PV system production Inverter data Meter Customer side Utility side

57 Feed-in Tariff Generation track Feed-in (credit) Meter Usage (debit) Meter Usage track

58 Net Metering Meter Customer side Utility side

59 Comparison Net Metering 1. One meter 2. One yearly payment (check), net amount 3. Often not easy to determine PV production 4. Payback can vary depending on your tier usage Feed-in Tariff 1. Two meters 2. One monthly check, one monthly bill 3. Easy to determine PV production 4. Payback usually much more predictable

60 Rate Structures Net Metering: Tiered rate the more you use, the more you pay. PG&E E-1 Residential Rate 6/1/10 kwh Cents per Less than 101% - 131% - 201% - Over 300% 100% 130% 200% 300% Percentage of baseline allocation

61 Rate Structures Feed-in Tariff: Fixed rate over time, possibly adjusting for inflation. 20-year Feed-in Tariff 25 Cen nts paid per kwh Years

62 Rate Structures Can have a mixture of both In PG&E territory: Systems from 1 kw to 1 mw (1,000 W to 1,000,000 W) are under Net Metering Systems above 1 mw are on Feed-in Tariffs

63 Feed-in Tariffs: How much to pay? Should it be higher than non-renewables? Should it be fixed or according to some kind of profitability index? Should you pay different amounts for different renewables?

64 Grid Parity When the price per kwh of electricity from a renewable source is equal to the current average grid price. PV example: System net cost: $20,000, lifetime maintenance $4,000. Expected to generate average of 5,000 kwh per year for 30 years, total of 150,000 kwh. $24,000 / 150,000 = $.16 per kwh Current PG&E average age price = $.16 per kwh = Grid Parity

65 Renewable Energy Credits Called RECs or green tags The green attribute of the power Connected to carbon offset accounting Central feature of a system to move money from polluters to non-polluters.

66 Carbon Offsets Making activity carbon neutral Funding projects that remove as much carbon as you generate Additional social & business image value

67 Keys to Transition to Renewables 1. Diversity 2. Integration 3. Economics

68 Environmental Impact Large PV array in the desert. Manufacture & Materials Transmission i Construction Generation & Maintenance

69 Keys to Transition to Renewables 1. Diversity 2. Integration 3. Economics 4. Environmental impact

70 Keys to Transition to Renewables 1. Diversity -- Need a wide variety, fit technology to site 2. Integration -- Ensure baseload, reduce variability 3. Economics -- Good incentives, fair to all ratepayers 4. Environmental impact -- All aspects of project

71 Smart Grid Source: EPRI Intelligrid Architecture Source: NPR

72 Courtesy of NASA