Hybrid RE Power Plants: A Global Perspective on Technology Trends (SAARC Energy Centre 16 th April 2019)

Transcription

1 Hybrid RE Power Plants: A Global Perspective on Technology Trends (SAARC Energy Centre 16 th April 2019) Unrestricted Siemens AG

2 Hybrid RE Plants Table of content Economics of hybrid RE power plants 5 Operational and design challenges 9 Solutions for combined operation of multiple RE assets 14 System level benefits of solar-wind hybrid power plants 18 Regulatory / fiscal / policy tools for hybrid RE concept 21 Case studies 23 Page 2

3 Hybrid Renewable Energy Systems Erratic energy sources like wind and solar are not dispatchable, that is, available on command of utility dispatchers Sometimes or often, the wind blows when it is cloudy, or the sun shines when the wind is calm A system that combines various energy sources is called a hybrid system Diesel generators are often used for reliable power, and wind or solar are used to decrease the fuel costs Studies of a site can indicate the optimal combination of wind, solar, and diesel (or gasoline) to provide power at the lowest overall annual cost Typical Case Study - Communities w/o access to power grid These communities will need to plan for Various forms of electricity production Storage of energy Recovery and disposal of excess heat Power management and control hardware and software Simulation and forecasting models for setting and maintaining reasonable cost of energy Page 3

4 Hybrid Renewable Energy Systems In a full hybrid system, the engine runs continuously and the wind/solar sources subsidize (add to) the available energy, saving fuel by shutting down the engine whenever possible The inverter is synchronously matched to the power frequency and voltage, providing more or less power as is available As long as the engine works and the diesel fuel lasts, system availability is high If the renewable sources are low, the fuel will be used faster (and require replenishment more often) If the engine fails and there is no storage (battery), the system will only have the varying renewable energy and might not function at all due to voltage variations Solar energy might carry the load until mid-afternoon, but the wind system would be too variable in many locations Page 4

5 Hybrid RE Plants Economics of hybrid RE power plants Page 5

6 Energy Source Cost Choices 100% $ 0% Hypothetical Cost Line 50% $ $ 50% Wind 33.3%S, 33.3%W, 33.3% F Solar $ 0%S, 100% F 0% $ 100% 50% Fuel $ 0% 100% 100%W, 0% F Assess cost of various mixes of energy, enter total costs, sketch contours to seek lowest cost region Page 6

7 Economics - Hybrid Renewable Energy Systems 1 GEV MP-C Wind Turbine = 131 T of diesel fuel saved / year 100 kwp = 44 T of diesel fuel saved/year Page 7

8 Optimizing the design for the best ROI of hybrid RE concept Page 8

9 Hybrid RE Plants Operational and design challenges Page 9

10 Operation/Design Challenges for ANY Renewable Site Typical Issues / Challenges Generation far from load -> needs transmission investment (who pays?, local resistance, etc.) (AC or DC transmission?) / PV-QV curves / Transfer Limit Analysis / Onshore-Offshore installation? Needs Wind and Solar Irradiation forecasting tool Needs extra dynamic compensation (CAPEX) narrow nominal PF-range (if any ~ old Type 1 / 2 WTGs) Harmonics Operator Challenges: Stability issues (increased Regulation needs) sudden weather change / sandstorm Reverse Power Flow (protections) Acceptable range of voltage increase after plant connection (2-3%) Negative Energy Prices (!) Market issue Renewables cannot be involved in Unit-dispatch / AGC Set DNE (do-not-exceed) limit (max output, short term forecast) Future: real-time telemetry (IEC based), auto-forecast, auto dispatch Page 10

11 Operation/Design Challenges for HYBRID Renewable Site Site dependence of renewable sources (Site survey with long term data acquisition & forecasting) Hybrid renewable energy system design (Configuration and sizing of the hybrid system components with the objectives) Supplying the power reliably under varying atmospheric conditions Minimizing the total cost of the system Maximizing the system efficiency by efficient energy flow management strategies Optimization through simulation studies under real operating conditions for a reasonable tradeoff among conflicting design objectives Economic viability (cost-benefit analysis of hybrid system for reasonable payback period) Real world application Design of power conditioning devices with maximum power point operation of energy sources Optimal energy management strategies and their testing with laboratory prototype hybrid controller Development of hardware and associated software for field-implementation Page 11

12 Other Operation / Design Challenges The location is the prime driver of the cost-analysis When the remoteness and lack of roads makes fuel-hauling or helicopter transport too costly, the wind or solar components must be increased to ensure reliable power Matching of the load times to the energy times determines the need for storage capacity Load matching for time of day limits output as well Diesel engines must be sized for highest load to carry the loads in normal operation The savings is never greater than the fuel savings Battery Storage? Batteries provide a form of storage They are required for wind and solar energy, but diesel (gasoline) generators could run to carry the load Large battery systems require some maintenance checks but usually last for many years (7-20 Adding storage means that the energy available is leveled and unnecessary engine starts are avoided Page 12

13 Risk profile of renewable energy projects Risk Level Project Development Project Construction Project operation Page 13 Energy resource assessment, site Technical location, design, technology Grid connection, offtake agreement Permitting, land acquisition Commercial Regulatory Actual site conditions, Suitability of the Equipment to local conditions (Logistics) EPC track record, Project management Regulatory change, interconnection Reliability of Equipment, suitability to local conditions (corrosion, cyclones ), Local O&M competencies Interest rates, labour costs Regulatory change

14 Hybrid RE Plants Contemporary solutions for combined operation of multiple RE assets Page 14

15 Multiple Asset Operation Wind/Diesel Wind/diesel systems work well where sunlight is limited, as above the Arctic Circle or below the Antarctic Circle Wind turbines have worked well at the South Pole Station, but diesel generators are also hard at work there Gasoline engines also can be used, but may lack the life of a heavy diesel engine Solar/Diesel Solar power has a much more stable short term output than wind power; the solar energy is less volatile than wind to use an economics term. As the insolation rises in the morning, the diesel engine might be shut down until late afternoon or when clouds reduce solar power for a certain number of minutes The controller could run the diesel engine only when the battery voltage drops below a very low set point, such as 10.5 volts and stop the diesel when the battery voltage rose to approximately 13.9 volts Tripartite Systems More complex than the wind/solar type The system balance between wind and solar is determined as in a conventional system, adjusting the costs of each to match the available energy Each of these sources offsets the need for diesel consumption, yet including some diesel capacity improves the availability and reliability of power Page 15

16 Multiple Asset Operation Power Controller System monitoring by computer allows programming of automated supervisory monitoring and determines actions to take in response. The system functions in software might include Start an engine Control battery charging Control energy load dumping for wind turbine Change loads to match available power Engage engine clutch Report alarms to a distant operator Page 16

17 Managing Intermittent energy and Variable load Samoa 550 kw wind farm (running) Kiribati 500 kwp PV plant (building) Mauritania 4.4 MW wind farm (running) PV + inverter Power instructions Voltage Frequency Current Flickers coef. Harmonics (%) Grid resilience Power instructions 1.3 MWp PV plant (building) Network analyzer Page 17

18 Hybrid RE Plants System level benefits of solar-wind hybrid power plants Page 18

19 System Based Benefits Decrease environmental pollution (Reduction of air emission) Energy saving (Reduction of air emission) Abatement of global warming (CO2 and other green house gases are not produced) Socioeconomic development (Develops employment opportunities in rural areas) Fuel supply diversity (Diversity of energy carriers and suppliers) Distributed power generation (Reduces requirement for transmission lines within the electricity grid) Managing Intermittent Energy and Variable Load Page 19

20 Market potential Extendable to a generalized solution for any kind of stand-alone site. Independent of continuous availability of the renewable source as well as grid power availability. Power converters are modular in nature For any kind of critical load in stand-alone site Telecom towers Cold storage plants Hospitals Military establishments Fuel stations Page 20

21 Hybrid RE Plants Best regulatory, fiscal and policy tools for promotion of hybrid RE concept Page 21

22 Typical Regulatory / Policy Drivers CO2 targets Sustainability Initiatives Renewable Share Increment targets Energy Efficiency Related Initiatives Energy Market Related Drivers (privatization, trading, etc.) Targets on decreasing petroleum-dependency Targets on decreasing primary fuel import Increase IPP generation model Keep generation away from consumers Environment Initiatives Smart Grid Penetration Initiatives Energy Tariff Related Regulations Job Creation Targets Poverty Alleviation Waste Reduction Targets Enhance competitiveness of agro-industries Better Financing Opportunities Page 22

23 Hybrid RE Plants Case studies Page 23

24 Case Study 1: Wind/diesel on mining site Location Kiribati Hybrid Technology Installed Capacity Hybrid Wizard controller PV: 1.3 MWp ( kwp) Diesel: 5.45 MW Peak load 3500 kw (Week) AVERAGE WIND SHARE: 30% FUEL CONSUMPTION: - 30% DIESEL SAVINGS: T /year = 1 TURBINE PAID FOR EVERY 3 MONTHS! Page 24

25 Case study 2: Ensuring Grid Stability - Hybrid PV system for remote island POSSIBLE OVERCAPACITY OF PV PRODUCTION DURING WEEK-END Hybrid Wizard: Real time management of PV and Diesel power plants Fuel savings: 596 T / year Page 25

26 Case study 3: High penetration Wind-Diesel system for island Option 1: Hybrid Wizard without Battery storage 1.37MW NO 40% Option 2: Hybrid Wizard + Battery storage for spinning reserve WIND POWER 1.92 MW YES BATTERY AVERAGE RE SHARE 70% Location Hybrid Technology Caribbean Island Hybrid Wizard controler 70% 100% m 3 /year Capex: - 35% vs Option 2 PEAK RE SHARE RE USAGE DIESEL SAVINGS 90% 100% m 3 /year Capex > Budget Installed Capacity Wind: 1.925MW PV: 114kW Diesel: 1.9 MW Battery for spinning reserve Peak load 1.3 MW PV Wind Genset Page PV Wind Genset

27 Conclusion Combinations of energy sources will provide more reliable power than any one source alone --- energy diversity Diesel, propane, or gasoline engine-generators produce power on demand, and can self-start when the power line voltage is dropping Natural gas can be piped to some areas When wind or solar energy is available, the fueled generator will shut down, saving its fuel cost Although overall costs could be higher, the power is more reliable Page 27

28 THANK YOU FOR YOUR ATTENTION! Gergo Varhegyi Head of Siemens PTI Middle East Siemens Building, Masdar City, Abu Dhabi, UAE Phone: Fax: Mobile: gergo.varhegyi@siemens.com siemens.com/power-technologies Page 28