A Kipp & Zonen SMP11 pyranometer enables real-time irradiance calibration and is an essential component of the system.
CloudCAM detects clouds, predicts cloud movement and provides cloud, solar irradiance and solar power forecasts from seconds to 15 minutes. The system was originally conceived to assist stability in off-grid solar-diesel hybrid systems and has been further developed to provide irradiance and power forecasting for grid-connected PV power plants.
Off-grid application
CloudCAM with the Kipp & Zonen pyranometer has been deployed in a number of applications. One is at three remote solar-diesel hybrid micro-grids for the communities of Ti-Tree, Kalkarindji and Lake Nash in Australia’s Northern Territory. Solar power stations of around 300 kW provide up to 85% instantaneous penetration into each of the Power and Water Corporation (PWC) micro-grids.
Ramp rate control is required so that the diesel generators do not stall when clouds quickly reduce the solar power supply and the load falls on the diesels. This grid stabilization was initially provided solely by large banks of lead acid batteries. In 2015 CloudCAMs were installed at Ti-Tree and Kalkarindji, and integrated into the real-time control systems at each power station as the batteries neared the end of their useful life.
CloudCAM predicts cloud events and signals a system that ramps down the PV supply via the inverter, allowing the diesel generator to ramp up at a rate that avoids stalling and engine damage. This reduced battery usage by approximately 30% and deferred future battery capital expenditure.
This ramp rate control also increased the average energy yield of the solar power stations into the micro-grids by about 5%, through reducing the -20% losses associated with charging and discharging the batteries. Battery round-trip efficiency is -80% and reducing the amount of solar power required to charge the batteries meant more was available to be sold into the PWC micro-grids. Fulcrum3D’s in-house technicians and engineers completed the installation and integration and provide ongoing support. Their unique expertise has enhanced the project outcomes.
The initial success at Ti-Tree and Kalkarindji (approximately one-year payback through higher yield and deferred battery capex) led to a CloudCAM installation at Lake-Nash in 2016 where the same performance improvement was achieved. The three CloudCAMs have been operating continuously since installation and continue to deliver demonstrated savings:
• To the solar power station owner through deferred battery capex, reduced maintenance and increased solar yield into the micro-grid.
• To PWC through reduced diesel consumption and spinning reserve requirement.
CloudCAM near-term forecasts can be nested with satellite data to make longer-term predictions.
Why choose Kipp & Zonen?
“The Kipp & Zonen SMP11 Pyranometer was the obvious choice for our CloudCAM system” said Dr Colin Bonner, Fulcrum3D’s Technical Director “the high speed, accuracy, and quality of the SMP series meets the needs for Fulcrum3D's most demanding applications”
Go to www.fulcrum3d.com/cloudcam to find out more about CloudCAM™
