High Performance Power Electronics Systems for PV Solar Applications

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Join us for a free webinar that explains the benefits of an advanced inverter technology and specifically how it is capable of harvesting more energy from PV solar power generation systems. Providing insight into the factors that affect electrical yield, such as insolation and illumination (the effect of shading), and the inverter design and operating parameters that affect yield, the presentation points to “best practice” approaches that can improve electrical – and financial - yield by as much as 30%.

In addition, the importance of evaluating issues such as TCO (total cost of ownership), LCOE (Levelized Cost of Energy) and Efficacy vs. Efficiency are explained in the context of solar system performance and grid parity.

Published in: Technology, Business

High Performance Power Electronics Systems for PV Solar Applications

  1. 1. High Performance Power Electronics Systems for PV Solar Applications David Reifsnyder VP, U.S. Operations Hybridyne Power Electronics HyperWatt™ Inverter Setting a New Standard in Technology OverviewHigh Efficiency Power Conversion for the Achievement of Grid Parity December 15, 2011
  2. 2. Hybridyne Power Electronics (HPE) What we do… Source of Collection Technology Inverter Systems Usable Electricity Insolation (Power Electronics)  HPE specializes in the design and delivery of ultra-high-efficiency power electronics for the Photovoltaic (PV) Solar Industry2
  3. 3. Inverter Technology Background  Perception - No benefit in attempting to harvest energy from solar arrays during periods of low insolation  Virtually all inverters convert a fraction of the available energy  Modern power electronics allows us to get much further down into the solar array’s power curve  Origin of HPE’s “Double Conversion” approach  HyperWatt™ high-yield Inverter technology can now increase yield of solar power generation systems by 30% or more3
  4. 4. HPE Focus – “Efficacy” Advancement Toward Grid Parity  Industry Target is Meeting and Exceeding Grid Parity  Efficacy is a measure of how much energy is converted, Efficiency is a measure of how well energy is converted  Efficacy of existing technology is the single greatest limiting factor; this has a direct impact on: – Cost competitiveness – Viability of sites & location/distance of viable sites from grid  Challenge – Harvest energy during low-light (early day, late day, cloudy day) conditions4
  5. 5. What factors affect Solar PV Yield?  Insolation – A measure of the Sun Hours - determined by geography and atmospheric conditions – Represents the theoretical maximum yield in kilowatts per square meter  Baseline – Varies by location, best yield is in the “sun-belt” – No array gathers 100% of the sun’s energy or is producing during 100% of the day – Typical system yield starts mid-morning and ends late afternoon  Tilt Angle of Panels – Varies by latitude, sunlight strikes panels more directly at the proper “tilt angle”  Choice of Panels – PV panels have a significant impact on yield Approx. 10º - Southwest U.S. Approx. 45º - Toronto, Ontario – Nameplate output (Watts) varies by manufacturer; the cheapest panel is not the best – Panel life varies and yield decay measured in % per year is a major factor in long term revenue performance5
  6. 6. Let’s look at Yield in depth…  INSOLATION: The amount available at a given latitude is dependent on: – The angle of the sun’s rays as they meet the ground – The sun’s height in the sky  The typical insolation curve approaches a normal distribution, as you see below:  As the sun rises in the Daily Yield . morning, increasing in its Insolation intensity until it reaches a maximum at noon and then diminishes until darkness predominates in the evening  Actually, the sun’s brightness doesn’t change during the day – In the morning and evening the ray path is an oblique angle and the light must pass through a thicker layer of atmosphere – The light is scattered (reflected and refracted) and the intensity measured at the ground is less6
  7. 7. Let’s look at Yield in depth…  ILLUMINATION: On a typical day in our hypothetical example, let’s assume: – Some clouds roll in during the morning – It clears for a couple of hours around noon, and – Partial cloud cover returns for a period in the afternoon  While the sun is still just Daily Yield . Insolation as bright above the clouds, the amount of Illumination light reaching the ground is decreased during the cloudy periods  We now see how the effective Illumination is differentiated, and generally less than, the Insolation potential  The “raw” yield from the PV panels will follow the Illumination curve as long as the temperature doesn’t get too hot… We’ll assume that it’s a cool day7
  8. 8. Let’s look at Yield in depth…  A TYPICAL INVERTER – “turns on” when the sun’s light is sufficiently bright to cause the PV panel string to generate the inverter’s minimum voltage (usually 300 VDC on a 600 VDC max inverter) – Check any 3-phase inverter’s specs – you’ll find that the minimum VDC rating is ~300 volts  Let’s look more closely: – Point #1 is the time in the Daily Yield . Insolation morning when the inverter Illumination senses sufficient voltage to turn on Panels + Inverter – Point #5 is the time in the afternoon when panel out-put has dropped to the point where the inverter turns off – Note the sharp cut-in / cut-out of the yield at points 1&5  As we examine further, 1 2 3 4 5 – At Point #4 the clouds partially obscure the sun, panel output decreases, but the inverter is still working – But notice Point #2, the clouds are thick enough to cause panel output to drop below 300 volts causing the inverter to turn off – for an hour or so, there is no output from the inverter and also no revenue8 – Finally the clouds clear at Point #3, the inverter switches on and power is generated again
  9. 9. Let’s look at Yield in depth…  An ENHANCED INVERTER, has a lower voltage threshold and starts yielding (converting) power from the panels (DC source) to the grid earlier – With the same illumination reaching the ground as in the example using the typical inverter the picture is now quite different  Now we notice: The Enhanced Inverter turns Insolation – Daily Yield . on earlier at Point #1 and Illumination stays on longer, turning off at Point #5 Panels + "Enhanced Inverter" – At Point #2 when the clouds Panels + Inverter roll in, the illumination is de- creased but the voltage pro- duced by the panels is within the wider voltage range of the enhanced inverter; it does not turn off.  As illumination increases: 1 2 3 4 5 – At Point #3 both inverters are producing more and more electricity – During the afternoon, throughout the 2 hours or so of cloud cover at Point #4 both inverters are producing power but the Enhanced Inverter has higher Efficiency – notice that it produces even more electricity9  In summary, inverters with high (300 VDC) thresholds ignore 30% of yield annually!
  10. 10. What factor affects Solar PV yield? and offers the Greatest opportunity for improvement!  Answer: The Conversion-Inversion Process Conventional Inverter Typical Operating Efficiency – Traditional focus has been on Creation of output  Solar: silicon wafer, low-cost substrates 100%  Maximizing the nameplate (watt) rating of the solar 90% 80% panel 70% Efficiency – “Power electronics” has historically been a 60% (%) 50% second-level consideration 40% 30% – Typical Inverters are compared based on their 20% 10% efficiency across their operating range, often 0% showing data for only 20% of that range 0 100 200 300 400 500 600 700 Voltage (DC, input)  Most products target 95% efficiency, +/- a few percent  The “best” product may offer a 3-5% advantage Conventional Inverter  Support a maximum capacity factor of 13-14% – What about the “Range” itself?  Most inverters in North America “wake up” when the DC input voltage reaches 300 volts and continue operating up to an input voltage of 600 volts – That means that they IGNORE any voltage level less than 300 volts – As you might suspect, conventional inverters ignore a considerable amount of energy!10
  11. 11. What factor affects Solar PV yield? and offers the Greatest opportunity for improvement!  HPE HyperWatt™ Inverter Comparison of HyperWatt™ Inverter Operating Efficiency vs. Conventional Inverter Typical Operating Efficiency – Extends the Range – in fact, it 100% 90% almost DOUBLES the range! 80% 70% Efficiency 60% – Begins working at 90 volts and (%) 50% 40% continues up to 600 volts 30% 20% 10% – A HyperWatt™ Inverter converts 0% 0 100 200 300 400 500 600 700 more of the DC voltage that PV Voltage (DC, input) panels produce to maximize yield HyperWatt Inverter Conventional Inverter – Increases Electrical Yield by 30% on average – Delivers a 17-19% Capacity Factor11
  12. 12. Hybridyne Delivers Increased Yield “Utilizing the Shoulders of the Energy Curve”  Advanced Technology! – HyperWatt™ Inverters utilize a double DC-DC Conversion front end to enable 90 VDC wake-up  Is active at lower light levels, effective more days / year  Turns on earlier in the day, turns off later HyperWatt™ Inverter Conventional Inverter Cloud (Maximum Yield) Cover  In low light conditions, the HyperWatt™ inverter is “ON”, producing electricity Area between the two power curves represents while the conventional inverter is “OFF” additional electricity from the HyperWatt™ Inverter – Patented and patent-pending power electronics technology12
  13. 13. Factors to Consider when Evaluating Inverters  Electrical Yield (kWh / kW)  Inverter Lifespan & Warranty  Modularity  Indoor vs. Outdoor Installation  Condensation inside the cabinet  High and Low ambient temperature  PM (benefits and results of ignoring)  Isolation Transformer13
  14. 14. HyperWatt™ Inverter Product Features & Benefits  Widest DC Input Voltage Range available in a grid-tied inverter  Manufactured in ISO 9001 certified manufacturing facility  HyperWatt’s High MTBF (200,000 hours) supports 20 year warranties standard on single phase (6kW and 12kW products) and at very attractive prices on 3 phase products  HyperWatt’s “rapid-replacement” modules (works-in-a-drawer) support a Low MTTR (Mean Time to Repair) where downtime means lost revenue  Competing inverters often do not include output transformers – a precision matched transformer in a HyperWatt™ inverter  Integrated heating and harsh environment enclosure optional  Performance Monitoring is built in – string monitoring available too14
  15. 15. Inverter Comparison Tool Yield Improvement Calculator and LCOE/ROI Evaluation Tool PROJECTED HPE HyperWatt TM YIELD IMPROVEMENT & ROI Enter Enter Enter Enter Hours/ Capacity kW / Inverter kWh / year PPA/FIT/SREC Revenue/ Unit Inverter (incl. Solar Park Size (kW) Park Revenue Ext. Inverter kWh / kW year Factor Nameplate Produced $ / kWh Inverter transformer) CapEx 10,000 Annual CapEx HPE HyperWatt Inverter 1,626.00 19.00% 500 813,000 $ 406,500 $ 475,000 20 $ 8,130,000 $ 9,500,000 8,760 $ 0.50 Number of Inverters Conventional Inverter 1,204.50 13.75% 500 602,250 $ 301,125 $ 175,000 20 $ 6,022,500 $ 3,500,000 Est. Difference in CapEx per Inverter $ 300,000 Difference in CapEx (Ext.) $ 6,000,000 Improvement in Yield 421.50 210,750 $ 105,375 $ 2,107,500 Enter Increase in available power (Theoretical) 35.0% ROI (years) 2.85 Array (w/ Conv Inv) $/W $ 4.50 Enter Time Period for Revenue Calc. (years) 20 LCOE (HPE) $/kWh $ 0.0712 Period (years) 20 Gross Rev Increase per Inverter LCOE (Conv Array) $/kWh $ 0.1868 $ 2,107,500 Increase in Revenue $ 42,150,000 Less CapEx differential HPE LCOE as % of Conv 38.10% $ 300,000 Increase in CapEx $ 6,000,000 Net Rev Increase per HPE Inverter $ 1,807,500 Net Incr in Park Revenue $ 36,150,000 CONSERVATIVE HPE HyperWatt TM YIELD IMPROVEMENT & ROI Hours/ Capacity kW / Inverter kWh / year PPA/FIT/SREC Revenue/ Unit Inverter (incl. Solar Park Size (kW) Park Revenue Ext. Inverter kWh / kW year Factor Nameplate Produced $ / kWh Inverter transformer) CapEx 10,000 Annual CapEx HPE HyperWatt Inverter 1,505.84 17.19% 500 752,922 $ 376,461 $ 475,000 20 $ 7,529,220 $ 9,500,000 8,760 $ 0.50 Number of Inverters Conventional Inverter 1,204.50 13.75% 500 602,250 $ 301,125 $ 175,000 20 $ 6,022,500 $ 3,500,000 Est. Difference in CapEx per Inverter $ 300,000 Difference in CapEx (Ext.) $ 6,000,000 Improvement in Yield 301.34 150,672 $ 75,336 $ 1,506,720 Increase in available power (Conservative) 25.0% ROI (years) 3.98 Array (w/ Conv Inv) $/W $ 4.50 Time Period for Revenue Calc. (years) 20 LCOE (HPE) $/kWh $ 0.0996 Period (years) 20 Gross Rev Increase per Inverter LCOE (Conv Array) $/kWh $ 0.1868 $ 1,506,720 Increase in Revenue $ 30,134,400 Less CapEx differential HPE LCOE as % of Conv 53.29% $ 300,000 Increase in CapEx $ 6,000,000 Net Rev Increase per HPE Inverter $ 1,206,720 Net Incr in Park Revenue $ 24,134,40015 * For comparison: Conventional Inverter DC Input Voltage Minimum = 300 VDC, Hyperwatt Inverter DC Input Voltage Minimum = 90 VDC Copyright Hybridyne Power Electronics, Inc. © 2011
  16. 16. Conventional Inverter Conventional Inverter one-line See See Note 4 Note 3 DC Disconnect See Note 1 To HV Grid See AC Note 2 Disconnect DC Surge Protection AC Surge Ground Fault Protection Protection Control Notes: 1. Diode provides reverse protection. Data Monitoring Options: 2. Integrated AC contactor as Anti-islanding - RS 485 Modbus protection prevents back-feeding inverter - Web monitoring generated power to the grid. - Revenue grade kWh metering - Consult for details 3. Fused Array DC Switchger simplifies array wiring. 4. Fused Sub-array combiner.16
  17. 17. HyperWatt™ Inverter What’s inside the box… HPE HyperWatt™ Inverter “conceptual” one-line (Double Conversion) 250kW DC Surge protection, disc AC onnects, and Grid Connection From PV Array, combiners, 60 kW fused protection, transie DC nt surge DC protection, ground fault protection, etc. Control Control  Items in yellow are HPE innovations; the balance of systems preceding and following are fairly standard, though HPE insists on components of the highest quality and efficiency17
  18. 18. HyperWatt™ Inverter Application Market Coverage by Sector & Product Series Modular Modular Non-Modular Single Phase Three Phase Three Phase Custom Parallel XLS Systems Utility 500 > 500 kW XLS installations 250 >1 MW XLS XLS XLS XLS Commercial 48 96 120 144 XLS XLS installations 12 24 20 kW–1 MW Residential installations XLS XLS 6 12 0-20 kW18
  19. 19. AC Power Out Communications DC Power In XLS-48 Architecture  Modular Architecture makes repair plug and Power play (low MTTR) Module 1  Each Power Module is Power rated at 12 kW AC Module 2  Accommodates 120%+ Power over-paneling Module 3  XLS-48 Inverter consists of (4) 12 kW Power Module 4 modules  Output Transformer matched to inverter Output output located in base Transformer of panel19 Front View Side View
  20. 20. Solar Power System Monitoring  HPE Monitoring System Specifications – Standard Architecture Supports 4 Inverters (expandable) – Sample Rate: 1 second (data server storage not limited) – Data Collected: Generated kWh, Power kW, Inverter Status, Solar Irradiance, Air Temp. – 48 Analog Channels – supports solar module current monitoring Input / Output Voltage HyperWatt™ Output Frequency PV Inverter RS232/Ethernet Output Power Energy Alarms Solar Data Monitor Sensor USB/Ethernet & Logger Temperature Internet Sensor USB/Ethernet Current Computer20 Sensor USB/Ethernet Web Browser Access to Data
  21. 21. Summary  HyperWatt™ Inverters Deliver Increased Yield from PV Solar Arrays: – Sites currently economic become “super-economic”  30% more energy = 30% more revenue!  Translates to profit increased by > 30% – Compared to conventional inverters:  Yield the same energy from fewer panels or…  More energy from same number of panels – Advantages:  Improved Project IRR21  More attractive to investors, owners, and lenders
  22. 22. For more information, Please contact: David Reifsnyder, Vice President Mendham, New Jersey (U.S.) Office Tel. 973-543-5500 Email: David.Reifsnyder@HybridynePowerElectronics.com Thomas Cleland, President Toronto, Ontario (HQ/Canada) Office Tel. 866-230-3918 Email: Thomas.Cleland@HybridynePowerElectronics.com22

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