‘ Standardization’ is a word that can bring cheers & jeers to an industry. The PV connector market has grown hand-in-hand with the solar PV market, by some reports as much as 40% per year since 2000. Generally considered a commodity, today there are over 38 varieties of PV connectors yet no standards exist governing interchangeability or compatibility. For almost ten years suppliers have been making PV connectors in two types of technologies and three styles (not all of which are mateable). Was standardization ever considered or is where we are today the result of an evolutionary process leading to a defacto standard? Do we find ourselves in a “Catch-22” situation that poses a challenge for our industry? Let’s start the discussion with a little history.
From 1970 to 1983, PV installations grew rapidly as a result of the ’73 oil embargo and the 1979 energy crisis which brought renewed attention to develop solar technologies. But throughout the rest of the 1980’s there was only moderate growth due to falling oil prices. The Gulf War in 1990 once again renewed interest in solar power as an alternative to oil & petroleum products. Although few tax credits or incentives existed at that time, approximately 1.2 million buildings in the United States became solar heated in the mid 1990’s and over 1 million homes had some form of solar power installed.
In 1996 the first PV connector system was introduced. Known as Type 3 connectors, the bodies were made from a thermoplastic elastomer and used a friction fit to maintain a physical connection. This product required special tools and techniques which were not considered to be field-installation friendly. So several years later, in 2002, the Type 4 PV solar plug connector system entered the market and was able to coin the phrase ‘plug and play’. This style used connector bodies made from a type of hard plastic and were designed for easy assembly & installation with no special techniques or multiple tools required. By 2007 there were 19 different Type 4 PV connectors – by 2010 there were 38 different models. (Each with its own crimping tool.)
Grid-connected solar PV continues to be the fastest growing power generation technology. Although solar currently represents less than 0.5% of global electricity generation, as renewable energy gains importance in the US electricity market many are forecasting that solar PV shipments will continue to rise at a compound annual growth rate of 50% for the next four years. And what of solar PV connectors? With this type of projected growth is now the time to address the “Catch-22” situation in our industry?
What would happen if standardization was considered and discussed? Would long lead times for PV connectors – which idle some projects and leave installers & owners wringing their hands – cease to be a problem? It is widely accepted that everyone benefits from standardization. For customers there is a single solution worldwide with lower costs and interchangeability that eliminates multiple tool & retrofit costs. For manufacturers there are economies of scale, quicker marker acceptance, improved delivery & availability. For everybody there is a broadening of the supply chain. The more people who use a standardized product the more people will want to use a similar product.
In the PV market, contact and tool standardization are by-products of connector standardization. Today manufacturers of PV connectors offer either: (a) Type 4 connectors with contacts featuring stamped & formed pins from flat metal; (b) Type 4 connectors with contacts featuring solid machined pins and MC4 mate-able housing design; and (3) Type 4 connectors with contacts featuring solid machined pins and a housing design that is not mate-able with other type 4 connectors. Due to the lack of a standard contact design, each manufacturer requires the installer to use their specific crimping tool. These tools are not inexpensive, and with the number of PV connector manufacturers in the marketplace this situation leaves installers with added cost.
PV connectors are part of a system, and how well they connect and disconnect along with the ease of assembly & installation is important to installers. Electrical standards for PV connectors have been established through the National Electric Code (NEC) and UL. However no design and/or contact standards exist. The ‘defacto’ standard has not been uniformly accepted by manufacturers. The need for compatibility and interchangeability is clear. The question is whether installers are willing to continue to accept the status quo OR do they want a single standard? A decision needs to be made about the “Catch-22” in our market and we believe that must come from the customer, the installer. Their voices need to be heard.
By: Kathryn Graber