The 1,000 solar panels will adorn the football-sized roof of the Paul VI audience hall, one of the top energy guzzlers in the sovereign city state. The solar system will be able to provide all the heating, cooling, and lighting needs of the entire building year-round, and any extra electricity generated will be fed back into the Vatican’s grid.

Pier Carlo Cuscianna, head of the Vatican’s department of technical services and mastermind of the project, was inspired by the calls of Pope Benedict XVI and Pope John Paul II to treat the planet with respect and their warnings that global warming will effect the world’s poorest and most vulnerable people.

This isn’t the first time the Vatican has shown leadership on clean energy. In 1999, the entire lighting system of St. Peter’s Basilica was refurbished with energy-efficient lighting, which cut its energy consumption by about 40 percent.

Although Vatican City is not a signatory of the Kyoto Protocol, the Catholic News Service reports that this solar project marks “a major move” to reduce its carbon-footprint and move away from its dependence on Italy’s power grid.

CathNews
Catholic News Service

The silicon portion is still the most expensive portion of the photovoltaic (PV) solar panel, however. So a new solar panel that uses 88% less PV material than traditional panels could help cut the cost of going solar.

"Silicon solar cells are the most expensive part of today's solar panels. Heliotube substitutes much of the costly photovoltaic material with inexpensive optics to focus the equivalent light onto small solar cells."

The new Heliotube panels introduced by Practical Instruments use sun-tracking reflective troughs to concentrate sunlight onto the PV material. Large scale solar concentrators have been developed for industrial and commercial power generation uses, but the Heliotube panels are sized to fit in standard solar panel arrays (60" x 42"), so they can be installed like typical solar cells.

There is more hardware associated with these panels (in order to do the solar tracking) and a small amount of power is lost to operate the solar tracking. Because there are moving parts, these panels will necessarily be more susceptible to breakdown than typical flat panels. But with cost and material savings, these panels could help make it more affordable for small installations to go solar.

via: cocolico and treehugger