Great things can come from rebuilding after a disaster. Rebuilding downtown Chicago after the 1871 fire started the era of high-rise construction. The great urban spaces of Boston, San Francisco, and even Beaupre’s hometown of Portsmouth, New Hampshire, arose from fires and earthquakes. They ushered in innovations like brick construction and firewalls to keep blazes from spreading, new sanitation systems, parks and squares.

So if sustainability was the only consideration in re-developing the damaged parts of New Orleans, then it would be hard to argue the pro-redevelopment position. There are, however, cultural, moral and social justice issues that weigh in redevelopment decisions. The hardest hit sections of the city were largely low income. Is it morally acceptable for governments to withhold reconstruction aid in those areas because the long-term prospects are uncertain? Flooding destroyed several government low-income housing developments. Is the government morally obligated to rebuild them? Can private lenders be compelled to approve mortgages for new homes in flood-damaged areas when Katrina showed how vulnerable they can be?

The reality is that owing to political and social factors, the damaged Lower Ninth Ward, Lakeview and New Orleans East sections of the city will most likely be at least partly rebuilt through a combination of public and private aid. So it might as well be done sustainably, but under a broader definition of sustainability than has been applied so far. Sustainable construction usually means energy efficiency, non-toxic materials, recovered materials, etc. In the New Orleans context, sustainable also means surviving the next natural disaster. The architect Frank Lloyd Wright created new construction techniques when he designed the Imperial Hotel in Tokyo because earthquakes were a constant threat. It survived a devastating earthquake in 1923 because Wright designed it with:

• a reflecting pool that provided a source of water for fire-fighting, saving the building from the post-earthquake firestorm; 
• cantilevered floors and balconies that provided extra support for the floors; 
• seismic separation joints, located about every 20 meters along the building; 
• tapered walls, thicker on lower floors, increasing their strength; and
• suspended piping and wiring, instead of being encased in concrete, as well as smooth curves, making them more resistant to fracture.

The engineers and architects who rebuild New Orleans have to apply that kind of thinking to the city’s realities. Maybe New Orleanians will ride out the next flood in homes that can float on the floodwaters, then settle back into their foundations when the waters recede. Who knows. The point is that sustainability, in this case, must also include survivability.

I love renewable energy stories. We know that if we can reduce our reliance on fossil fuels, we can reduce global warming, our utility bills and, one hopes, our military presence in the Middle East.

To cool a home in the summer months, switch the direction of the heat flow, and the same system can extract heat from the air, thereby cooling it.

More stats from the Geothermal Heat Pump Consortium, the non-profit trade association for the GHP industry:

Hydrogen fuel cells are to renewable energy what the paperless office is to business: a good idea that never seems to take off. The difference is that hydrogen cells, in all likelihood, will take off in the not-too-distant future. Investors have put a boatload of cash into fuel cell development, the underlying science is sound, and society is more open to environmentally friendly energy sources than it ever has been.

Even when they hit the market in earnest, however, I’m skeptical that hydrogen cells will revolutionize the motor vehicle industry, as hyped. Hybrid gas/electric technology is years ahead of hydrogen cells in the automotive market, and auto companies are making huge strides in hybrid technology. Just last week at the Frankfurt Auto Show, Volkswagen unveiled a two-passenger concept car that gets 240 miles per gallon. Hydrogen fuel cell makers, by comparison, don’t even have production models on the road yet.

There might be room in the automotive industry for more than one power plant architecture, but there’s a better play for hydrogen cells – powering large buildings. There are two reasons. The first is that hydrogen cells generate heat as well as electricity. In small-scale applications like cars and homes, that heat is most likely wasted. Commercial buildings are large enough to support cogeneration systems that can capture the heat from hydrogen cells and use it either for heating or to turn steam turbines for generating more electricity.

Hydrogen cells might be the greenest technology for powering vehicles, but history has proven time after time that incumbent technologies are hard to beat if they’re cost effective and do a good, if not great job. Look at Ethernet versus ATM (asynchronous transfer mode) in networking. ATM was faster and could support more services, but Ethernet was capable, inexpensive and well established by the time ATM came along. Ethernet remained the dominant local area networking protocol, but ATM found its niche in wide-area networking. Hydrogen fuel cells are looking at a similar situation. Hybrid vehicle technology is here and now and it yields good fuel economy at a reasonable environmental cost. That’s a moving target that hydrogen fuel cells can’t hit. Better to focus on a market where their adaptability makes them the technology to beat.