Renewable Energy Hosting Capacity in Horizon Power Systems. November 2013

Transcription

1 in Horizon Power Systems November 2013

2 Introduction to Horizon Power WA's regional and remote electricity provider State Government-owned and commercially focused Serve 33,000 residential connections and 9,000 businesses, including major industry Responsible for the generation, procurement, distribution and retailing of electricity

3 Our Aims Meet the Quality of Supply obligations to all customers Empower our customers to make informed choices around energy management Support Renewable Energy - economically efficient manner

4 Total Load: 275MW Total RE Generation: 47MW (Wind 9MW) (Solar 1MW + 7MW) (Hydro 30MW) Total RE Hosting Capacity: 88MW (Centralised HC 40MW) (Distributed PV HC 48MW) Total distributed PV: 7MW

5 Systems with high RE: (% of peak load / % of energy): Kununurra (100% / 99%) Coral Bay (100% / 46%) Denham (92% / 45%) Hopetoun (65% / 38%) Marble Bar (76% / 34%) Nullagine (75% / 34%) Esperance (37% / 27%) Sandstone (15% / 8%) Carnarvon (13% / 7%) Mount Magnet (11% / 5%) Exmouth (8% / 4%) Broome (7% / 3%) HP NWIS (0.4% / 0.2%)

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7 Current Situation Rising levels of Renewable Energy Old, small, radial style networks Not designed for distributed generation Many systems have reached their operational limits In islanded systems, there is a limit to how much solar power we can connect: Hosting Capacity

8 Technical Assessment Process: 1. System Hosting Capacity Assessment 2. LV Network Impact Assessment

9 LV Network Impact Assessment (in Brief): TX Utilisation (total embedded generation 20% of the distribution transformer rating ref. WA DCM ) Network voltage rise and thermal limits Proposed system technical compliance (Standards, Inverter Approval status, anti islanding protection, etc). Compliance with Technical Requirements for Renewable Energy Systems (HPC- 9FJ ) Phase imbalance limits

10 System Hosting Capacity Assessment: Spinning Reserve Maximum Load Minimum Load Step Load Capability Contractual Considerations

11 Definitions: Generation Management utilises energy storage or feed in management to control the output profile of the renewable energy installation. Unmanaged Hosting Capacity (UHC) is the limit for hosting of renewable energy without Generation Management. Managed Hosting Capacity (MHC) is the hosting capacity that can be made available for systems equipped with Generation Management. Total Hosting Capacity (THC) is the sum of the Hosting Capacity (HC) and Managed Hosting Capacity (MHC). Spinning Reserve (SR) is the extra generating capacity that is available from online generators connected to the power system.

12 Generation Management Renewable Energy Smoothing Install energy storage devices that release energy back to the grid to prevent system instability Feed-in Management Allows the utility to actively constrain customer s generation output to prevent system instability

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14 What happens when a customer installs solar panels?

15 What is the impact on the system during cloud cover? We can reliably connect a certain amount of solar panels

16 What happens when more customers install solar panels? Engine 3 not running

17 What is the impact on the system during cloud cover? May cause unplanned power interruptions

18 What happens when customers use a generation management system? Engine 3 not running

19 What is the impact on the system during cloud cover? Battery gives Engine 3 time to ramp up

20 Renewable Energy Smoothing Power O0 Ramp Down Rate Too High Maximum Allowable Ramp Down Rate Oss Cloud Event Key Renewable Energy Source Output Power Inverter Output Power with Renewable Energy Smoothing Inverter Output Power without Renewable Energy Smoothing Losses Time Steady State: Inverter Output Power Renewable Energy Source Output Power - Losses

21 Preliminary Definition Total Hosting Capacity The Total Hosting Capacity (THC) is made up of the sum of the Unmanaged Hosting Capacity (UHC) for unmanaged renewable installations plus the Managed Hosting Capacity (MHC) for managed renewable installations. The Total Hosting Capacity (THC) is defined by: THC = UHC + MHC

22 Preliminary Definition Spinning Reserve The total spinning reserve is equal to the sum of the spinning reserve allocated to unmanaged and managed hosting capacity respectively, as follows: SR = SR UHC + SR MHC

23 Unmanaged Hosting Capacity Criteria The Unmanaged Hosting Capacity Criteria seeks to ensure that: The real power fluctuations of unmanaged renewable energy installations on Horizon Power s systems must not exceed the spinning reserve available on those systems. The Unmanaged Hosting Capacity (UHC) Criteria is defined by: UHC = SR UHC / f RF Where: SR HC = the spinning reserve allocation for unmanaged hosting capacity; and f RF = the Renewable Energy Fluctuation Factor.

24 Renewable Energy Fluctuation Factor The renewable energy fluctuation factor is defined by the product of the renewables system diversity factor (f DIV ) and the renewable installation output fluctuation factor (f OPF ), as follows: i.e. f RF = f DIV x f OPF System SR (kw) f SR f RF f DIV f OPF Spinning Reserve Fluctuation Factor Diversity Factor Output Reduction ARDYALOON % CARNARVON % ESPERANCE % EXMOUTH % NWIS % YALGOO %

25 f DIV x ( kw A + kw B + kw C + kw D ) (Diversity Factor) kw D f OPF x kw D (Output Fluctuation) kw C kw A kw B

26 Managed Hosting Capacity Criteria The Managed Hosting Capacity Criteria seeks to ensure that: The real power fluctuations of managed renewable energy installations on Horizon Power s systems must not exceed the spinning reserve available on those systems, taking into account the effect of generation management on the power fluctuations of managed installations. The Managed Hosting Capacity (MHC) Criteria is defined by: MHC = SR MHC / ( f RF x (t G / 12) ) Where: SR MHC = the spinning reserve allocation for managed hosting capacity; and f RF = the Renewable Energy Fluctuation Factor; and t G = the generator start time in (min).

27 Renewable Energy Smoothing Power [kw] Nominal Ramp Down Time Tn = 720 seconds (12 mins) On Rn = * On / Tn [W/s] Nominal Ramp Up Time Tn = 360 seconds (6 Minutes) NL = 100 * / Tn [%] Key Renewable Energy Source Output Power Inverter Output Power with Renewable Energy Smoothing Linearity Bounds Losses Tn Time [s] Parameters Rn := Nominal Ramp Down Rate [W/s] Tn := Nominal Ramp Down Time [s] On := Nominal Rated Inverter Output [kw] := Maximum Input Deviation [s] NL := Percentage Non-linearity [%] Ramp Down Rn = x On/Tn [W/s] Ramp Up Rp = 1000 x On/Tn [W/s]

28 Maximum Loading Criteria The Maximum Loading Criteria seeks to ensure that: The maximum capacity of installed generators on Horizon Power s systems must not be exceeded at times when dispersed renewable energy installations are operating at minimum output. The Maximum Loading Criteria is defined by: L PEAK + ( THC x f RF ) = G MAX Where: L PEAK = the system peak load; THC = the total hosting capacity; f RF = the Renewable Energy Fluctuation Factor; and G MAX = the maximum installed generator capacity.

29 Minimum Loading Criteria The Minimum Loading Criteria seeks to ensure that: The minimum loading capability of installed generators on Horizon Power s systems must not be exceeded at times of minimum day time load and high renewable installation output. The Minimum Loading Criteria is defined by: L MIN ( UHC x f DIV ) = G MIN Where: L MIN = the system minimum day time load; UHC = the hosting capacity for unmanaged installations; f DIV = the renewable system diversity factor; and G MIN = the minimum loading capability of the installed generation.

30 Halls Creek Hosting Capacity Example:

31 Halls Creek Hosting Capacity Example:

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34 RE Hosting Capacity Working Group: Review Existing Hosting Capacity Criteria & Limits Risk Based Criteria development and optimisation of spinning reserve Feed in Management Development System Smart Operations Development of Control Algorithms and Integrate Sky Camera Utility scale energy storage Customer Load Management (including PV load balance) Standalone renewable energy solutions UFLS & Proactive Load Shedding Schemes Review System audits

35 Thankyou More information available at: