Worldwide PV Panel Efficiency and Energy Density Comparison

Updated with More Panels and More Recent Data as of July 27, 2010

One of the popular questions we’re always hearing is “which panels are best?” Another version of that same question: “Are PV solar panels becoming a commodity?” or “Is there that much difference between one brand or another?” We decided to assemble a couple of comparison charts. We used the  California Energy Commission (CEC) list as of July 2010 for the PTC numbers, as well as currently available manufacturers’ product data sheets for panel square footage to create a quick comparison of STC to PTC efficiency (see bold faced column) for similar monocrystalline and polycrystalline photovoltaic solar panels with similar STC DC rating (or as near as we could find) We used a 240W panels as the baseline. If a manufacturer didn’t offer a 240W panel, we looked for the closest panel to that size. The resulting chart shows Sanyo and SunPower ranked at the top (only exceeded by thin film), followed by a group of manufacturers that some might find surprising. Canadian Solar, China Sunergy, Phono Solar, CEEG, Andalay (now known as Westinghouse), Sharp and SunTech are all positioned in the top ten in efficiency of PTC (which we like to call “AC” watt rating even though the inverter is not yet “in the game”). Here is the table of popular brands, sorted with the best STC to PTC efficiency at the top and the worst at the bottom.

It’s interesting to take a second look at this same list, this time sorted in order of the PV panel energy density (highest PTC  watts per square foot -  or as we like to call it, “AC watts per square foot”). When we look at solar panels this way, SunPower stands out at the top and thin film falls to the bottom. This is no surprise, as it’s common knowledge that SunPower panels require less roof space than other panels, while thin film requires much more space. Sanyo is second on the list (also, no surprise). It is the next three panels, which round out the top five, which might raise a few eyebrows: China Sunergy, CEEG and Phono Solar. The top ten is rounded out by Sharp, Siliken, Trina, Canadian and Kyocera. WholeSolar is proud to offer six of these top ten high performance PV panels at very compelling pricing. You can follow the link to product pages elsewhere on the WholeSolar website and then leave us your name, email and zip code on the right panel of this (or any WholeSolar website) page. Here’s the same table as above, except that it is sorted in order of the highest PV panel energy density:

Of course, there are many ways to make panel comparisons. Just today Greentech Media featured an article written by Shyam Mehta titled Efficiency Leaders in Crystalline Silicon PV. It presents a different approach to amking such comparisons and argues that the gap is closing rapidly among the top panel makers.