Non Nuclear Technology: Renewables

Transcription

1 WNU-SI in Canada 1 Non Nuclear Technology: Renewables July 9, 2008 Toshiya NANAHARA Central Research Institute of Electric Power Industry (CRIEPI), Tokyo, Japan

2 Future Options for Energy to Cope with CO 2 Problems Except for Nuclear 2 Cleaner fossil fuels and their efficient use, Renewable energy, Energy efficiency in buildings, appliances, transport and industry, Carbon capture and storage, etc.

3 3 Renewables for Electricity Production Hydro: small-scale hydro, Solar: photovoltaic, etc. Wind: wind turbines High Growth Geothermal: conventional and innovative Biomass: wood chip, biogas, residue, etc. Ocean: wave, tide, etc. etc.

4 4 Outline of Presentation [Main target] Photovoltaic and wind power [Outline] 1. Technology outline and recent trend 2. Advantages and disadvantages 3. Characteristics from the viewpoints of electricity grid

5 5 Photovoltaics Generation (PV) Solar Irradiation Solar Cells DC Inverter Single crystal Multicrystal Amorphous Tradeoff between cost and efficiency AC System Interconnection Type Stand-Alone Type

6 6 Photovoltaic Generation Solar Cells: Single crystal Type Installed in 1995 [Photo] By courtesy of Dr. Nakaoka

7 7 Wind Energy Converter (WEC) Wind Wind Turbine Gear, etc. Generator, etc. Electric Output Mechanical Equipment Electrical Equipment Fully understanding wind power requires various backgrounds.

8 Wind Farm 8 21MW = 750kW x 28 Otonnrui Wind Farm (Horonobe, Hokkaido) [Photo] By courtesy of Horonobe Town

9 9 Site Suited for Wind Farms Availability of wide land, Access to a good road, Easy access to transmission (or distribution) lines, Not-included in natural park, High wind speed. etc.

10 PV Capacity in the World 10 3,000 2,500 PV capacity World Total Netherlands Australia Others Capacity (MW) 2,000 1,500 1,000 USA ,596MW Japan Germany Year [Data source] NEDO HP

11 WEC Capacity in the World 11 50,000 Capacity (MW) 45,000 40,000 35,000 30,000 25,000 20,000 15,000 10,000 5,000 Wind Power World Total UK Italy China Denmark India Others 2007 (Start) 74GW Spain Germany USA Year [Data source] NEDO HP WindPower Monthly HP

12 PV & WEC Capacity in Japan 12 Installed CapacityiMW j 5, 000 4, 000 3, 000 2, 000 1, 000 FAc t ua l s FPr oj ect i on( METI (Target case) Installed CapacityiMW j 60, , , 000 [Source] METI committee' s report, NEDO Home Page, et c. 30, 000 Phot ovol t ai c FAc t ua l s Wind FPr Power oj ect i on( METI (Max. Efforts case) Photovoltaic Wind Power 0 20, Fi scal [Source] Year METI commi t tee' s report, 10, 000 NEDO Home Page, et c Fi scal Year

13 13 Key Issues In the Presentation Advantages and disadvantages Comparing renewables with the other energy sources could be a highly controversial issue. Renewables viewed from electricity grid The other aspects of renewables: distributed generation / intermittent generation.

14 14 Outline of Presentation 1. Technology outline and recent trend 2. Advantages and disadvantages 3. Characteristics from the viewpoints of electricity grid of photovoltaic and wind power generation. 4. Closing remark

15 15 Advantages of Renewables Non-exhaustive carbon-free energy source. Generally speaking, they are: Supposedly environmentfriendly energy, More easily accepted by public, Technology improvement in recent years, etc.

16 16 Disadvantages of Renewables Generally speaking, They have low power density; Their capacity factor is mostly not so high. Thus, they are mostly expensive than conventional energy. Their output is unstable; They sometimes needs provision for environmental impacts. etc.

17 Emission of Power Sources g-co 2 /kwh CO 2 equivalent Fuel Equipment, Operation ex Considered Process for Coal Thermal Mining Transportation Electricity Production Ash disposal 17 Emission by 1 kwh Electricity Coal Thermal Oil Thermal LNG Thermal LNG CC Photovoltaic Wind Power Nuclear Geothermal Small hydro Power Source

18 18

19 Renewable Energy Capacity Factor 19 Required area (order) Capacity factor Photovoltaic 10-2 kw/m 2 11% (Japan) Wind Power 10-3 kw/m % Biomas Power 10-4 kw/m 2 Depending on fuel availability Therma 10 0 kw/m 2 90%

20 Production Cost of Renewables 20 Production cost(\/kwh) Photovoltaic Wind Power With Capacity Value Thermals Cost of renewables is decreasing. However, the following measures are generally introduced due to their high cost: Institutional measure: feed-in-tariff, renewable portfolio standard, etc. Subsidy for installation, etc. [Data source] New Energy Subcommittee of the Advisory Committee for Energy

21 PV system cost (10 4 yen/kw) Installation BOS Solar cell [Data source] NEF HP

22 ŽžX Ü Ü^ J Ž ž P ú Žž 22 Ouput power - do Í(pu) (pu) Ouput power - do Í(pu) (pu)

23 23 Pros and Cons of Photovoltaics [Advantages] Applicable to various places (residence, etc.), Low maintenance requirement, Small environmental impact : noise, etc., Familiar to many people, etc. [Disadvantages] Low energy density: solar insolation:1kw/m 2, Low capacity factor: about 12%, Intermittent output: dependence of on weather, Not economically viable, etc.

24 24 Pros and Cons of Wind Power [Advantages] Relatively low cost in renewables, Larger capacity factor than PV s at a windy site, etc. [Disadvantages] Challenges in harnessing wind, Low energy density, Intermittent large output fluctuation due to weather, Environmental impacts noise, scenery, etc. Windy area not densely resided area weak grid, etc.

25 25 Challenges in Harnessing Wind Turbulence is inevitable. Its power is proportional to third power of its velocity. Wind turbines are used under severe natural conditions: eg, gust, lightning, typhoon. Difficulty in adjusting a turbine to a specific wind conditions, Reliability of a wind turbine, Requirement of maintenance works, etc.

26 26 Closing Remark (pt.2) Renewables, as a matter of course, have their inherent pros and cons. How do you assess them in comparison with the other energy sources? Most renewables take advantage of interconnecting to a power system. This causes another important aspects of renewables discussed later.

27 27 Outline of Presentation 1. Technology outline and recent trend 2. Advantages and disadvantages 3. Characteristics from the viewpoints of electricity grid of photovoltaic and wind power generation. 4. Closing remark

28 Action Plan of IEA to respond to 28 the Request of G8 Summit Cleaner fossil fuels Renewable energy:.. A dedicated international group of experts. will speed development of common technical and policy approaches to integrating intermittent renewable energy into electricity grids. Energy efficiency in buildings, appliances, transport and industry Carbon capture and storage

29 29 Challenges in Connecting Renewables Distributed generators interconnected to weak grid; e.g. PVs to lowvoltage distribution lines (100/200V) Intermittency of output power with difficulties in accurate output forecasting. Transmission Distribution

30 30 Intermittency of Renewables Outputs of PV and wind turbines contains large fluctuations difficult to predict. Their output could be very low in case of peak demand. In a power system, supply have to match demand at all times.

31 31 Trend in Impacts of Wind Power penetration Area of impacts Major Impacts small Local (Distribution) Power quality: eg,voltage Subtransmission Load flow: congestion large System-wide (Transmission) System security, Supply-demandbalance

32 Local Impacts #1: Voltage Fluctuations V 95 V 107V 95 V

33 33 Local Impacts #2: Malfunction of Relay Change in fault current at a substation Malfunction of protective relay Fault current 100A Fault w/o DGs Fault current 80A Fault current 10A w/ DGs

34 34 Local Impacts #3: Islanding ƒxƒcƒbƒ` z dü Ï dš DGs may continue their operation after a circuit breaker opens. It will hinder system restoration and, in the worst case, the fault cannot be removed.

35 35 Penetration that Could Cause the Problems Expected technical problems Voltage fluctuation due to reverse power flow Faults can cause -- Increase of short circuit capacity -- Malfunction of a protective relay operation -- islanding Penetration of DGs problems occur [Note] More than 5 to 20% More than 40% More than 20% More than 20 to 30% [Note] Penetration rate: ratio to distribution line capacity. They are sample values obtained for the worst case through experimental and simulation studies.

36 System Impacts #1: Intermittency 36 Their large scale integration requires more flexibility (eg, reserve) in a power system. How the flexibility is improved or maintained in a future power system? Capacity value* of PVs and WECs: not so high (controversial issue) Needs for back-up power * Capacity value: an index that shows how the power source is reliable when it is needed.

37 Sample Output of WECs 37 1 Dec./2004 Site T4 T4 n _@2000 N12ŒŽ Output (pu) ½ Ïo Í(pu) [Source] NEDO report, NEDO- NP-0012 Output (pu) ú 0.5 ½ Ïo Í(pu) Output of a WEC Dec./2004 S n _ Ìo Í N12Œ Ž Smoothing ú Total Output of 30 WECs

38 Example of Japan 38

39 System Impacts #2: Trip Due to Volt. Sag 39 [Source] Juan F. Alonso-Llorente, Integration of wind Generation within the Power System - Experiences from Spain, Eolica Mediterranean, Rome, September, 2005.

40 Impacts and Their Countermeasures 40 Quant. Major Impacts Countermeasures small large Power quality: eg,voltage Load flow: congestion System security Supply-demandbalance Variable speed machine FACTS (eg, SVC) Output curtailment System reinforcement Fault-ride-through capability Output forecast Electric storage Demand response Hydrogen

41 41

42 42 Closing Remark (pt.3) Integration of renewables to a power system presents a technological challenge. New generation technologies including renewables tend to be not so flexible as conventional ones. Are there any measures to improve the flexibility of the future generation mix?

43 43 Outline of Presentation 1. Outline and recent trend 2. Advantages and disadvantages 3. Characteristics from the viewpoints of electricity grid of photovoltaic and wind power generation. 4. Closing remark

44 44 Closing Remark: a Personal View Almost all energy technologies will be needed to resolve the future energy problems. Renewables would be surely one of the promising candidates. What is your scope on the future energy system with nuclear, renewables and other energy sources? System-wide scope would become more important in the future. For example, in assessing the new energy such as renewables, due attention should be paid to power delivery, end-use, etc. aspects.

45 45 Thank you very much for your attention.

46 46 Future Options and Time Span Short term Medium term (CO 2 Problem) Long term (Depletion of resources) Efficient use of energy Renewable energy Cleaner fossil fuel Carbon capture and storage

47 Renewables: Difference among Countries 47 Electlic energy mix (Denmark) Renewables Biomas Electlic energy mix (Sweden) Wind Municipal Waste Biomas Wind Denmark 2000 Renew -ables Hydro Sweden 2000 Thermal / Nuclear Thermals [Data source] IEA, Renewables Information 2002

48 Production Cost of Renewables 48 Production cost(\/kwh) Photovoltaic Wind Power With Capacity Value Thermals Cost of renewables is decreasing. However, the following measures are generally introduced due to their high cost: Institutional measure: renewable portfolio standard, feed-in-tariff, etc. Subsidy for installation, etc. [Data source] New Energy Subcommittee of the Advisory Committee for Energy

49 Sample Impacts of WEC on Voltage 49 Substation Wind Power WP WP WP Distribution line 10km Point A 600 [Wind power] 6800 Voltage at point A kw) 200 (V) min min.

50 50

51 51

52 52

53 Wind Power Capacity in the World 25,000 20,000 Start 2001 Start ,000 10,000 5,000 0 Data source WindPower Monthly HP 53 Capacity (MW) Germany USA Spain India Denmark China Italy UK Portugal Netherlands France Canada Japan Others

54 54 Capitalcost for residentialpv system s of 3kW10 4 \ Production cost\/kwh [Data source] NEDO HP

55 Distributed Generators (DGs): 55 Tentative Definition by CIGRE Not centrally planned (by the utility), Not centrally dispatched, Normally smaller than MW, Usually connected to a distribution system. DGs: uncontrollable small generators at the places not previously expected