Which is a better deal: an established, off-the-shelf type of solar panel or a cutting-edge type that delivers more power for a given area but costs more?

It turns out that’s far from a simple question, but a team of researchers at MIT and elsewhere has come up with a way to figure out the best option for a given location and type of installation. The bottom line is that for household-scale rooftop systems in relatively dry locations, the more efficient but more costly panels would be better, but for grid-scale installations or for those in wetter climates, the established, less efficient but cheaper panels are better.

The costs of solar cells continue to plummet, while the costs of installation and the associated equipment remain relatively constant. So, figuring out the tradeoffs involved in planning a new installation has gotten more complicated. But the new study provides a clear way to estimate the best technology for a given project, the authors say.

The findings are reported today in the journal Nature Energy, in a paper by MIT graduate student Sarah Sofia, associate professor of mechanical engineering Tonio Buonassisi, research scientist I. Marius Peters, and three others at MIT and at First Solar and Siva Power, solar companies in California.

The study compared two basic varieties of solar cells: standard designs that use a single type of photovoltaic material, and advanced designs that combine two different types (called tandem cells) in order to capture more of the energy in sunlight. For the tandem cells, the researchers also compared different varieties: those in which each of the two cells are connected together in series, called two-junction tandem cells, and those where each cell is separately wired, called four-junction tandem cells.

Read more at Massachusetts Institute of Technology