The New Mexico Solar Tour: Part 2 - PV Panel Performance: Show Me The Data

DETL PV array at Sandia Lab
DETL PV array at Sandia Lab

This is Part 2 of a two-part series on solar in New Mexico and independent testing of photovoltaic equipment. As a follow-up to my recent post The New Mexico Solar Tour: Part 1 - Panel Degradation Cannot Lie, So Plan Smart it is important that I point out that many of these visibly degraded modules are still producing power though at a lower output than its original rated value.

Shattered, delaminated, or otherwise physically damaged modules will not produce power any longer, but many degraded modules will. Best of show, of course, are the Arco and Solarex modules. If you ever see these panels anywhere being given away or sold on the cheap grab them up! They are worth their weight in gold for any off-grid application you can imagine and are nearly bulletproof.

Day two of my tour brought me north to Albuquerque, where I toured the inverter test facilities and PV microgrid at Sandia National Laboratories' Distributed Energy Technologies Lab. DETL supports distributed energy resource development through carefully controlled testing in their flexible microgrid setup. DETL is an extension of the inverter test facility that supports the DOE's Photovoltaic Program. Earlier in DETL's career, they tested solar thermal equipment here but have since retired those facilities.

DETL's microgrid capabilities include almost 100kW of PV from several manufacturers, a natural gas microturbine, a fuel cell, and diesel generator. Reseacrhers and analysts can configure these resources into many different microgrids in order to test inverter capabilities, load balancing, maximum power point tracking, grid interconnection reliability, and much more. Other testing equipment that I looked at included a state-of-the-art load simulator which via software could reproduce reasonably accurate conditions of operation for a variety of solar PV arrays in a number of operating conditions (i.e. weather, edge-of-cloud effects, grid disconnect, load imbalances, etc).

Unfortunately, facilities like the SWRES I visited previously and Sandia's DETL are precious few, relatively unknown, and sometimes don't even release their data to the public since they are under contract with the manufacturer to provide the testing and data privately like in the case of Sandia's DETL. One of the biggest problems that plagues the long-term viability of our industry is the lack of a trusted, well-known, and definitive third-party Consumer Reports of Solar Products. Unfortunately, it takes years- 5, 10, or even 15 - for field results to come in from actual live use tests of solar equipment, especially photovoltaic modules. This poses a major problem to all members of the resulting value chain.

Consumers often have very little data aside from those provided by the manufacturer's marketing literature or data sheets by which to make their decisions about investing in a product that should boast a very long power performance guarantee. Into order for the solar industry to continue to stand behind large commercial installations up to the multi-megawatt utility-scale, we need more third-party verified field testing on inverters, panels, and other balance of system equipment to help us make informed choices in our designs and implementations.