Venice: Boats and Biofuels

Venice is an amazing place to visit. With its gorgeous buildings and canals, and the crazy neighborhood street design, it’s one of the most fascinating urban places I’ve ever explored.

Obviously, I’m not the only person who feels like that: it’s also probably the most touristy place I’ve ever been. HUGE cruise ships dock every day in Venice, leaving thousands of people to explore the city. Happily, though, outside of some of the key places, it’s actually pretty easy to get away from the big crowds and explore.

It’s hard to not see Venice as a deeply vulnerable place, though. It basically sits at sea level,

about 6 feet below where it used to be when people decided to build a city in the Adriatic Sea. As sea levels have risen, though, Venice now often actually finds itself below sea level when the acqua alta (high water) inundates the city during the winter high tides. The frequency of the inundation has increased over time, causing damage both to Venice’s tourist economy and, more importantly, to its infrastructure.

To address the immediate problem, government officials have decided to build huge gates along the edge of the Venetian lagoon that would presumably keep rising sea levels at bay during acqua alta events. The gates would go up during high tides and then go down when the high waters subside. Environmentalists and scientists worry that the gates will interfere with other natural processes of the lagoon, including flushing of treated sewage out of the lagoon, but it looks like construction of the gates is underway.

Speaking of sewage, Venice has a longer term strategy to address the primary cause of rising sea levels: emissions of greenhouse gases from fossil fuels. Two years ago, Venice announced plans to build a plant that would create biofuels using algae that feed on sewage. The biofuels would then be used to produce electricity and as a fuel source for motor vehicles. In many ways, creation of fuels seems like an ideal strategy for Venice, since the vast majority of motor vehicles are boats. While gondolas readily spring to mind when one thinks of boats in Venice,

motor boats are much more common in providing public transportation,

deliveries,

construction,

emergency medical services,

and, of course, gelato conveyance.

Boat engines, though, are notoriously dirty. They discharge fuels directly into the water and they emit a lot of air pollution. Plus, the extraction, refining, and transport of petroleum used in the boats contribute significant amounts of pollution. If boats in Venice were to switch to locally produced biofuels, they would reduce the petroleum-based emissions and emit fewer pollutants overall.

Venice’s algae-based biofuel plan has particular promise because it relies on sewage for fertilizer. Some lifecycle analyses initially concluded that algae biofuels grown with petroleum-based fertilizers might be worse emitters of greenhouse gases than even corn ethanol. Algae grown in sewage, in contrast, does not need additional fertilizers and it even helps with sewage processing. With the number of tourists who visit Venice every year, Venice seems to have an endless supply of fertilizer. I hope it will succeed in using it to create a more sustainable and locally produced fuel.

[All photos by Mark Riskedahl]

Pedestrian Culture and Infrastructure in Europe’s Cities

I’ve been in Trento, Italy, for the past week and a half teaching at the University of Trento. Like many other European cities I’ve visited, Trento has closed a large part of the city center to cars and motorbikes and created an extensive pedestrian (and bike) area. The other cities I’ve visited this trip – Bilbao, San Sebastian, Pamplona, Granada, Sevilla, and Barcelona in Spain, and Verona and Trento in Italy – all have at least some pedestrian areas. They’re all slightly different from each other, but each of them impressed me with their size and, perhaps more importantly, their extensive use by both tourists and local residents.

In Bilbao, the oldest part of the town has pedestrian-only areas filled with stores and pintxo (tapas) bars. The scene on a Friday night was amazing: people spilled out of the bars into the streets, where they stood and sat eating and drinking (and, alas, smoking). Street after street had people crowding about outside the bars.

Beyond the old town, Bilbao city planners have made sure that pedestrians can easily navigate the city: two of the bridges crossing the Rio Nervion are only for pedestrians and bicyclists, and the other bridges have dedicated pedestrian-only sidewalks or sections.

This amazing bridge, the Zubizuri, combines Bilbao’s commitment to design and pedestrianism.





In Sevilla, the old town has one of the more extensive pedestrian-only areas I’ve seen. It includes the oldest part of the city – which seems to attract tourists in particular – and a slightly newer part (but it’s still old), which filled with the city’s residents at the end of the day.

Verona is a much smaller city than Sevilla, and it at first seemed like the people crowding the pedestrian areas were all tourists. But at mid-day, that impression changed. Almost all of the shops close from 1-4 in the afternoon, and, just like that, the Italians crowding the streets disappeared. Only we tourists remained. But the change in population made it clear that local residents like their pedestrian areas as much as the tourists do. The shopkeepers must, too, because I saw many, many people walking around with their newly purchased goods from the stores in the pedestrian-only areas. I have to think that pedestrian access to these stores makes it more likely that people will drop into a shop, buy something, and continue along their car-free way.

This should lead me to Trento, my temporary home in Italy. But, because I’m here longer and have grown to love this place, I’ll dedicate a separate post to Trento.

In the meantime, I’ll note that in the United States, various cities have begun to toy with creating pedestrian-only areas. Manhattan made headlines when it actually closed some streets to cars and created new pedestrian-only areas. Portland, Oregon, contemplated a proposal to create some car-free areas downtown, but store owners protested and the city backed away from its plan. How I wish more U.S. cities would embrace the European concept of pedestrian-only areas. They bring so much life and activity to areas, and, I presume, more income to store owners lucky enough to have thousands of pedestrians strolling by.

Distributed Generation

During my conversation with the Director of Enterprise within the Navarran Department of Innovation, Enterprise, and Employment, she mentioned distributed generation as the next phase of Spain’s renewable energy investment. Distributed generation is the production of electricity at or near the site of consumption. Homeowners that get part of their electricity from their own solar panels are distributed generators, for example.

Thomas Edison’s first electricity generation station – the Pearl Street Station in Manhattan – was revolutionary because it provided the first system through which electricity could be distributed from a single power station to other nearby places. Over time, many other localized electricity systems sprung up in cities around the world, but they all produced power for a relatively small area because they could only transmit electricity within a mile or so. After a while, larger companies figured out how to send electricity much farther – over tens and then hundreds of miles. Once these companies had the ability to send electricity over long distances, they also had the ability to build much larger power plants that could produce electricity for less money. One by one, these large companies picked off the smaller neighborhood stations.

In our modern world, the continued reliance on large plants and long-distance transmission presents challenges for integrating renewable energy into the electricity system. Most cites get electricity from large (baseload) plants that operate 24-7. The electricity transmission system requires almost absolute balance between power supply and power usage, and baseload plants help achieve that need. Renewables are difficult to manage, because wind and solar, the dominant sources, are available only when the wind blows or the sun shines. If the power becomes unavailable, supply and demand no longer match, and the entire electricity system can short out. Until scientists develop better ways to store large amounts of electricity, large-scale renewable sources face serious practical hurdles.

But distributed generation provides a way to offset some of these challenges. It involves the production of less power from any given source, but also provides fewer challenges for electricity storage. If the source includes even a small battery, it can operate at night by relying on battery power. For example, this irrigation pump house is powered by solar energy.


I loved this use of distributed generation-

Solar energy powers the lights for this bike path at night. Each light has a solar collector and a battery to store the energy. When the sun sets, the battery kicks in and provides the light. The next day, the sun recharges the battery. There’s no reason why we can’t do smaller distributed generation projects like this in cities around the world. The more we invest in distributed generation, the more we offset the need for increased baseload energy and the more time scientists will have to develop larger scale storage technologies.

Solar Spain

A couple of weeks ago, I interviewed one of the directors of an agency of the government of Navarra, a Spanish province. Navarra produced more than 80% of its electricity from renewable energy sources in 2009. Navarra is in the northern part of Spain, and produces most of its energy from wind. But the south of Spain also produces a lot of wind energy. Many of the wind farms in Spain are located in olive groves (there are a LOT of olive orchards in southern Spain). I love the way these turbines rise above the olive trees here.

As big as the turbines are, they leave plenty of room for the olive trees to grow. I imagine that the owners of the olive orchards appreciate the extra income they earn from leasing their lands for the wind turbines.

Perhaps more striking than the wind turbines were the large numbers of solar installations I saw in southern Spain. Many farms had large photovoltaic arrays sitting in part of the fields.

Photovoltaic sheets are probably the most common type of solar energy people think of when they think of solar energy. They produce electricity directly from the sun and have a number of important uses. For example, the sheets can be used as roofing tiles and are very useful for small-scale electricity production. But photovoltaic sheets are quite expensive and not ideal for large-scale electricity production. However, other types of solar systems are.

In fact, Spain recently made headlines by building the world’s largest concentrated solar power generator, called PS10.

I prefer to think of it as a power-generating Barad-dur, but in a good way

Spain has also invested in parabolic trough solar power installations-

Both types of solar stations use solar energy to boil water, which produces steam, which turns turbines that generate electricity. These concentrated systems act quite similarly to coal or nuclear stations, in that they ultimately boil water to produce electricity. The main difference, of course, is that the solar stations rely on the sun for the heating source and, compared to coal, don’t emit millions of tons of carbon dioxide and thousands of pounds of other harmful pollutants every year. A lot of people continue to insist that renewable energy cannot produce large amounts of electricity, but these systems demonstrate otherwise.

Other parts of the world are investing in solar energy, of course, but I was quite impressed with the wide degree of acceptance the Spanish people have shown overall to investment in renewables. No one I spoke to in Spain challenged the legitimacy of these investments. While some of them identified hurdles to reliance on renewables (most notably, renewable energy sources often produce electricity intermittently, which is a problem with the current systems available for electricity storage), no one suggested that Spain should abandon its efforts to develop renewable energy. I’m sure this is partly because Spain has no other energy resources available domestically, but I also think it’s partly due to the broader belief that Spain will benefit in the long term from the investments it makes in renewable energy now.