The solar industry has grown up based on panels.

Solar is installed on a building's roof, laid down on special panels that need a host of government approvals before they're hooked to a utility's grid – at whatever price the utility wants to pay for the excess electricity.

But it doesn't have to be that way. Solar energy can be integrated with the building materials. It can be part of the design of the roofing system or the walls. It can be a design element.

If you want to put Dow PowerHouse shingles on your roof, instead of old-style black ones, do you need an approval process? If they don't look any different from other shingles, and if your local deed covenant doesn't specify shingle color, why should you? Just install them and go.

And what about that panel frame? SCHOTT Solar and BASF are now showing a plastic pan that integrates all aspects of a solar system's installation in one easy-to-install unit. If the design becomes a standard, it's yet-another step in the “shingle-ization” of solar roofing.

What about walls? QSOLAR's Kristal panels come in six designer colors. They are rigid enough not to need frames, they can go on walls as well as roofs, and (most important) they're designed this way to reduce cost and increase durability – not just to look pretty.

By printing a photovoltaic coating onto steel, as Tata Steel demonstrates, you transform solar technology from something that must be installed as a panel, on only the sunniest roofs, into something that can become a basic design element in new buildings and, in time, a do-it-yourself project on even the shadiest homes.

The efficiency of a solar cell, the percentage of solar radiation shining on it that can be turned into electricity, is just one measure of a product's marketability. Cost matters, installation matters, and increasingly design matters.

We have not yet reached the tipping point here, but I predict we will. If your business model is based on installing an expensive, high efficiency solar panel on someone's roof, on getting government and utility buy-in for that project, your glory days may be about to pass you by.