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Microinverter
CURRENT PV SOLAR SYSTEMS
  • underperforming systems
  • safety danger fighting fires
  • complex installation design
  • output data through expensive 3rd party monitoring solutions
ACCURATE’S “SMART” SYSTEM
  • only fully commercial solution
  • output boost reduces capital spend 20% higher IRR, NPV, less Payback time
  • simplified installation design
  • panel specific data to reduce O&M costs
PROBLEMS
  • Fastest growth anticipated in the industrial and utility sectors
  • Upfront capital costs for solar installations are still prohibitive; payback in 12-20 years
  • Current system architectures have the following drawbacks:
    • Shading can reduce output 40%
    • Soiling can reduce output 5-20%
    • Mismatch between panels reduces output 15%
    • Central inverter optimization reduces performance to the weakest panel
    • Smaller more expensive inverters required for installation variations
  • Fire prevention and normal maintenance of solar arrays is currently hazardous with live panels
  • Centralized monitoring (if it exists) gives only gross AC output at the meter
SOLUTIONS
  • ACCURATE is only solution for the commercial sector – multiple 100KW systems
  • Payback reduced typically by 2 years
  • ACCURATEdynamically optimizes each panel’s output - allowing a major reduction in total system cost by reducing panel count
    • Project IRR boost (typically 1%)
    • Levelized Cost of Electricity 3¢/KWh closer to grid parity
  • ACCURATE’s inverter efficiency is greater than the closest competitor
  • ACCURATE reduces design complexity allowing for multiple orientations, panel types & partial shading
  • Panels can be individually shutdown during fire emergencies or routine maintenance
  • Panel level data is available on the web: revenue grade metering; theft and maintenance alerts; and warranty compliance available




SMART 3kW String Inverters (Patented Technology)


Depending on the size of the array, there is an option to include a string inverter on each twelve panel 3kW string to convert the 500 VDC to 240 Volts AC split phase, 208 VAC 3-phase, or any other required AC voltage. A string inverter with each twelve panel string starts the DC to AC conversion at the earliest stage which reduces the IR loss on power delivered to the electrical grid, as well as simplifying the wiring to the grid. Also having, as an example ten 3 kW string inverters on the roof instead of one 30 kW Inverter on the ground protects from having the entire system shut down in case the 30 kW Inverter fails. The 3kW String Inverter is specially designed to operate with the SMART DC Boost 12-Pack Device to maximize harvest of the solar string. Using optimization supplied from the SMART DC Boost 12- Pack Device, the inverter has a reduced parts count and complexity. This distributed approach is beneficial to both devices. A reduction in stress placed on components help to extend the life and reliability of the system. A quick bullet of features is outlined as follows:

The 3kW String Inverter
  • A number of small inverters (typically 3kW) are connected to a string (10-12 modules), feeding directly into the grid.
  • Yield gain of 1-2% from the pairing of the SMART DC Boost Modules and reduced complexity it offers as well as the elimination of string to string interactions which magnify the impact of permanent and temporary mismatch.
  • Simplified magnetics due to High Order Harmonic Elimination Algorithms
  • Dry Film capacitors from military design
  • Reasonable conversion efficiencies now approaching 96%.
  • More efficient single operating point design
  • More durable from reduced strain on key components
  • Scalability makes the same inverter theoretically applicable to systems of all sizes and facilitates system design and installation. This can be extended to allow systems to be progressively enlarged (of particular interest for commercial rooftop installations).
  • A larger number of monitoring points makes diagnosis of issues (ground faults, soiling etc.) easier and limits the impact of inverter fault or failure.

All designs draw on experience gained from many years working in the aerospace/military fields. The component selection process takes into account extreme temperature and operating conditions seen in solar array installations. The electronic circuits are designed to operate at full power over the operating temperature range of the solar panels in which they are attached. Each design undergoes review to reduce part count and operational befits to extend the life and reliability of the system as a whole. Typical warranties for power electronics are much less than the warranties of the solar panels in today's market. These designs will change that extending operating life and reliability to match those of the solar panels. By having a large installation done in small blocks, if a problem does occur then only a small block of it goes down. The rest of the system will produce power.

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