Category: Utility Scale Generation
A continuing trend in the solar PV industry is continual cost reduction with electrical design studies being the first items typically to be considered due to their mis-understood purpose. This approach is short-sighted as design uncertainty dramatically increases the risk of other costs and future problems when eliminated. Based on the 1-10-100 principle, performing key studies upfront proves far more cost effective than later remediation.
In contrast, when improperly selected due to circumspection, studies can increase the electrical design cost up to 50%.
Stantec, has identified when and which electrical studies are necessary for utility scale solar farms; thereby reducing this soft cost without compromising the design and safety of a facility.
This poster presentation shall explain the role of each study in simple terms and provide a table matrix explaining when a study is indispensable or simply optional.
Electrical studies contain sophisticated modeling, calculations and simulations to properly size the equipment and prevent oversizing while ensuring personal safety and analyze the behavior of the plant under various transient and dynamic conditions and fault scenarios.
Necessary Studies: Load Flow Analysis, Short Circuit Analysis; Concept of Protection or Protection Philosophy.
Optional, but highly recommended studies (per project basis): AC & DC Cable Ampacity; Protection and Coordination; AC & DC Arc Flash Hazard Analysis; System Grounding; Temporary Over Voltage (TOV) and Effectively Grounded; Power Quality Analysis (Harmonics); Reactive Power Support and Voltage Control (RSVC); Insulation Coordination Study and Analysis; Transient Recovery Voltage (TRV); Lightning Protection; System Power and Energy Loss Study and Analysis; Voltage Drop Calculations.
As a case study, Stantec shall present the 12MWAC / 19.8MWDC Pendleton Solar Farm which is connected at 27.6kV in Ontario. The owner of the Pendleton Solar Farm requested that the site be fully analyzed prior to being designed and constructed. Studies were submitted as a stamped formal report. If the solar farm had been designed with the minimum necessary studies, the design cost would have reduced considerably.
Solar project developers are scrutinizing every cent in order to win increasingly more competitive power purchase agreements; therefore, it is important to scrutinize the level of design effort as well.
To be cost effective while still mitigating risks, studies should be evaluated on significance vs design requirements.
Daniel Kraemer– Project Manager, Controls & Solar Ontario, Stantec Consulting Ltd.