Design Rules for Autonomous Hybrid Energy Supply Systems for Various Types of Buildings in Central Europe

Transcription

1 RUHR-UNIVERSITY BOCHUM 1 Design Rules for Autonomous Hybrid Energy Supply Systems for Various Types of Buildings in Central Europe Dipl.-Ing. Alexander Broy, M.Sc. Izabella Vasileva, Prof. Dr.-Ing. Constantinos Sourkounis Ruhr-University Bochum, Germany 2 nd International Conference on Power Options for the Eastern Mediterranean Region 7-8 October, 2013, Nicosia, Cyprus

2 Content Aim of the investigations 2 Hybrid systems Dimensioning guideline Example: Design of two supply systems Simulation studies

3 Aim Development of an designrule for autonomous power supply systems 3 Houses and buildings far away from the grid (for example a grid connection is too expensive) Power supply based on wind- and solar power in combination with a storage system Complementary character Increased system availability

4 Hybrid systems Definition: Island grid systems, that realizes a power supply based on more than one electrical source 5 Advantages: High amount of energy Direct use of solar energy or its other forms: wind energy, biomass and hydropower Inexhaustible and everywhere available Environmentally friendly: for example prevention of CO2 emissions Enlargement of the performance of the overall system Disadvantages: Stochastic fluctuations of renewable energy supply Objective: In addition to the deterministic- also take account into the stochastic fluctuations and thereby make a suitable, careful planning of the overall system

5 Aim 6 PV - System Windmill Battery system Consumer/Load

6 Hybrid systems AC Hybrid systems 7 AC technology performed on the consumer side power distribution, as well as all other conducting lines Power flow depends on the account balance Advantages: The use of conventional AC loads Connection to the public network possible

7 Dimensioning guideline Start Determination of the daily energy consumption and the load profile of the consumer Determination of maximum power demand 8 Consumer/Load Determination of diversity factor any restrictions Determination of coverage rate by solar energy Setting up time PV-system Preparation of the annual statistics of the global radiation for the location Determination of coverage by the wind energy Determination of the permissible Discharge limit and η Batt Determination of the availability ā (coverage rate) with G dim =GA Preparation of the annual average of the static wind speed for the location Battery system calculation of battery capacity G dim =GA Specified coverage ā rate reached? G dim =GA Selection of Windmill from the mean wind speed and coverage rate Checking if the annual energy yield is the specified coverage rate Windenergyconverter Calculation of peak performance PV - system End

8 Electrical power [1000kWh/a] Dimensioning guideline Load profile and expected energy demand is the basis for the dimensioning of the generator system BDEW - representative standard load profiles: Main application in the field of energy 9 Weekdays, Seasons Static average power consumption 0,07 0,06 0,05 0,04 0,03 0,02 Sonntag Werktag Samstag 0,01 0 Time Typical power consumption behavior no longer to detect Load peaks extremely extremely flattened

9 Dimensioning for a household Daily-Energy demand: Wd,Household = 12,171 kwh 10 Peak power: Total power: Simultaneity factor: Load profile: P peak = 5, 6 kw P total = 8, 21 kw g = P peak P total = 0, 68

10 Dimensioning for a household PV system: Coverage or average availability: 60% Annual mean - irradiation: GA = 1 n n i=1 G i = 4, 46 kwh m 2 d 11 Standard Deviation: Coverage rate (average availability): δ = 1 n 1 ( n i=1 a GA, δ = 1 G i 2 n GA 2 ) = 2, 12 kwh m 2 1 2π δ GA = 81 % Dimensioning irradiation: G dim a = 60% = GA 1 δ a 1 + GA 2π 1 2 δ GA 2π = 7, 46 kwh m 2 d Optimal peak performance of the system: P pk,opt = E 0 W d G dim i η i = 1, 5 kw E0 - irradiance of standard test (STC)

11 Dimensioning for a household Wind energy converter: 12 Covering rate of the wind energy converter : 40% W d,gesamt = 4432 kwh year W Sun = 2659 kwh year W Wind = 1773 kwh year Mean windspeed (year): 4,5 m/s Type Rotordiameter AD REM 500 W 10 m rotor area 78,54 m 2 Nominal power Nominal windspeed start-up speed 524 W 8 m/s 2,0 m/s

12 Dimensioning for a household Wind energy converter: Power: P WEC = 1 2 ρ A c p v 3 (t) 13 Annual energy yield: using W WEC = ρ = 1, 225 kg/m 3 0 t P WEC t dt = 952 kwh year Annual energy ammount: WEC: W Wind = 1773 kwh year W Wind = 952 kwh kwh 2 = 1904 Jahr year

13 Dimensioning for a household Battery system: Autonomy factor: AF = 8 Tage 14 Discharge limit of the battery: 20% Battery capacity: C N = A F W d η Batt 0, 8 C N = 152, 5 kwh

14 Dimensioning for a supermarket Consumer: Bezeichnung Symbols Values Daily energy demand W d,supermarket 145, 3 kwh 15 Peak power P peak 8, 99 kw Total power P total 10, 38 kw simultaneity factor g 0, 86 The specific daily load profile of the typical supermarket

15 Dimensioning for a supermarket Description Symbol Value PV - system Dimensioning irradiation G dim 7,46 kwh m 2 Optimae Peak power P pk,opt 24 kw 16 Annual energy yield W a 32693,4 kwh Covering rate wind ā wind 40 % WEC Mean windspeed v 4,5 m s Energy demand (40%) W wind,40% kwh Jahr Wind energy converter Windspot 7500 Start-up windspeed 3,0 Annual energy yield (1 x WEK) Annual energy yield (2 x WEK) W a,wind m s kwh kwh Battery system Battery capacity (AF=10) C N 2289 kwh

16 Simulation results Energy balance of one year Building PV energy yield [kwh/year] Wind energy yield [kwh/year] Sum [kwh/year] Household 2774,5 1710,0 4484,5 17 Supermarket 31022, , ,8 Month Energy deficit / surplus [kwh/month] Household Supermarket January 3,3-326,4 February 11,1 10,6 March 25,7 261,9 April 18,7 86,6 May 2,3 7,1 June 44,3 785,6 July 44,4 731,7 August 10,5 473,3 September 2,5 19,6 October -77,3-613,9 November -42,3-632,6 December 10,3-447,9

17 Energy Energie [kwh] Energy [kwh] Simulation results (household) Household Consumer Sum Energy Generation Monat month Month month PV-system Load WEC PV-system WEC Consumer/Load Monthly energy surpluses and deficits and profiles of the monthly energy yields (Located in Alghero, Italy) and consumer values

18 Energy [kwh] Energie [kwh] Energy [kwh] Simulation results (supermarket) Supermarket Consumer Jan Feb Mrz Apr Mai Jun Jul AugSep Okt NovDez Monat month Sum Energy Generation Jan Feb Mrz Apr Mai Jun Jul AugSep Okt NovDez PV-system Monat PV-Generator Verbraucher WEK Monthly energy surpluses and deficits and profiles of the monthly energy yields (Located in Alghero, Italy) and consumer values month Load WEC

19 Conclusion 20 A Guideline to design a hybrid system for autonomous energy supply has been developed It was shown that it is possible to supply different types of buildings (according to different requirements) with renewable energy sources by using a hybrid system The load profiles and energy requirements of both building types were analyzed and set as the basis for sizing the generator side. Standard load profiles are not matching but can be used to reconcile them with the developed load profile Further work could be a detailed load management to decrease the capacity of the battery system.

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