Topic started per Sail Van Nostrand. At the LIPA Contractor's meeting on 12/13/2010, LIPA and LISEIA representatives discussed the shade analysis necessary for 2011 applications. This requires further discussion and review. Issues discussed included:
1. LISEIA/LIPA draft for processing of applications:
a. How shade analysis is physically done onsite per array.
b. How reports are to be generated using third party industry software.
c. Shade analysis spreadsheet.
d. 80% and 105% rules affected by shade. 80% rule check will be against whole system, not individual array segments.
e. How this is sent to LIPA with the application.
f. LIPA Solar Clean Power Estimator. How use of this tool as is and with future modifications may allow for accurate kWh estimates in conjuction with shade analysis tools and procedures per LIPA. Tool currently needs to be upgraded to include missing inverters, panels and for larger systems to be able to accept the accurate total number of panels. It does not currently take into account exact azimuth, only nearest bearing such as ESE; so the combination of pitch and having to pick an inexact azimuth could lead some systems to fail the 105% or 80% checks when combined with shading effects when it might have otherwise passed.
2. Questions about shade analysis.
a. New construction. Ideas discussed for how to do analysis prior to construction, tree clearing, etc.
b. How to indicate when certain trees are to be removed by customer, so that when LIPA does an inspection contractor is not unduly penalized for trees that were to be removed which customer did not remove. Other shading obstructions as well.
c. Concerns about methodology.
Including checking shade at four corners of a larger array is or from the center of a small array is our current starting point and may work well for most systems. However that may not accurately take into account the way that the strings are arranged for a particular system design and layout. It also may not accurately work for certain solar technologies including micro inverters, those with maximum power point tracking devices, some thin film and devices and solutions. Transient shade issues, etc.
James Peck