An Important Milestone In Maintreaming Solar Electricity

Last Thursday, in Birmingham, Alabama, an important goal was reached in assuring the mainstream acceptance of solar power.

The accomplishment was the approval of new guidelines (called Acceptance Criteria or AC) by an organization called the International Code Council - Evaluation Services (ICC-ES). This document, AC 365, addresses the safety and performance of building-integrated photovoltaics (BIPV) as a roofing material.

Now, this is all very boring and technocratic. In the big picture, though, it is a huge signal that the PV industry is maturing. It is extraordinarily important that as BIPV is rolled out in ever larger amounts, that it performs the way people expect it to. If sub-par products are being installed, the inevitable failures could cripple the entire industry.

Back in the late '70s and early 80's, badly designed incentive programs resulted in a lot of poorly made solar thermal systems being installed. The subsequent failures set solar energy back 20 years. Given the current state of the world, this cannot be allowed to happen again.

Now before getting into the meat of this, a quick primer is in order here. BIPV are PV modules that are integrated into the building envelope. Thus, they must function as a building material as well as an energy conversion device. AC 365 covers BIPV that is integrated into clay and concrete tile or asphalt shingle roofs. That is, it covers the BIPV products used in most residential new construction. My favorite example (because I designed it) is PowerLight's SunTile.

This type of design is finding a favor among new home builders because the aesthetics are superb as compared to standard "rack and stack" PV systems, with the modules supported above the roof.

Despite builder's enthusiasm for the technology, it is often tempered with concern. Roof leaks are a huge liability for buiders and they seek assurance that the BIPV will be as effective a roofing material as the rest of the roof. Building departments are often even more skeptical. They require proof that these products will be safe in fires, windstorms, and hailstorms; that they won't break if someone walks on them or leak in heavy rains; and will be as durable as other roofing products.

This is where ICC-ES comes in. The International Code Council (ICC) is the semi-public body that writes what are known as model building codes - the International Building Code (IBC) being one example. Building departments then adopt these codes and they have the force of law in those jurisidications. The ICC itself is primarily made up of building code officials and the process of writing these codes is public (though not widely publicized).

ICC-ES deals with products which are not addressed by the building codes -- innovative products that, when local building officials are asked to approve, they scratch their heads. This has been the situation that BIPV installers have faced when trying to pull permits. It requires a lot of education of building officials on the issues, not least because many of the BIPV products on the market may not perform adequately as a roof. AC-365 specifically covers BIPV as a roofing material, and not electrical safety (which is already addressed by Underwriter's Laboratory requirements) or solar performance.

So when ICC-ES releases this draft criteria on January 1st, 2007, this means that there are a standard set of requirements that everyone can go by. Manufacturers can perfom testing, and if successful, obtain an Evaluation Report (ER) that proves to building officials and clients that they comply. This will significantly smooth the permitting process and facilitate the sale of these systems.

The release of this AC is the first step towards the eventual incorporation of BIPV requirements into the International Building Code. Hopefully, these requirements will be written into the 2009 IBC, which will have force of law in many jurisidictions in 2010. At that point, BIPV will be firmly established as a mainstream building material, on par with all other types of roofing.

On a more personal note, I am very happy to have been to be part of this precedant-setting process. I worked closely with ICC-ES staff in writing AC-365. While getting this acccomplished is clearly of great importance to my employer, I was also glad to see that one of our biggest competitors showed up at the meeting and spoke in support of the criteria.

Meanwhile, there are are couple of other very important regulatory issues being resolved at the moment. More on this in a future post.