After oil

13.02.08 12:04 Filed in: The Prague Post
Project looks to drop carbon emissions with hydrogen-powered buses

Two Temelín-size nuclear reactors — that’s what would be needed to power all the road transportation in the Czech Republic, according to the Nuclear Research Institute in ?ež, near Prague.
The institute is the country’s leading proponent of using hydrogen to fuel the cars of the next generation. Nuclear energy remains the most promising means of generating hydrogen, according to Lud?k Janík, a scientist at the institute.
It would take a daring government to approve such an expansion, Janík said. In the meantime, the institute is leading a consortium of companies determined to prove the viability of hydrogen as a fuel by putting the first hydrogen-powered bus on Czech roads.
Hydrogen buses are quiet and clean, and instead of noxious exhaust fumes, they emit pure water. As early as next year, the people of Neratovice, a small town situated next to a chemical plant in central Bohemia, will get to enjoy the benefits of near-silent, emissions-free public transport, the institute says.
Hydrogen, along with electric cars, has long been positioned as one potential fuel source for the future, with advocates touting the benefits of a “hydrogen economy” that eliminates the need for fossil fuels. As oil hovers around record prices and concerns about global warming grow, the need to develop alternatives fuel sources has been cast into sharp relief.
“When we take into account crude oil availability around the globe, especially with regards to the political stability in respective countries and the ecological aspects of its use, it’s almost certain that we will need to change [our choice of fuel source] sooner or later,” Janík said.
Rather than joining an up-and-running project like the European Union’s CUTE (Clean Urban Transport for Europe), which already has hydrogen buses on the roads in London, Berlin, Hamburg and Iceland, the institute decided to cut its own path.
“We decided to develop a more advanced bus — with the goal of optimizing energy flows and minimizing H2 consumption,” Janík said. “And we wanted to engage as many Czech companies as possible.”
The project has gone at a breakneck pace, moving from research to the construction phase in less than a year. Most of the thanks for that goes to the institute’s partners, namely Škoda Electric and Germany’s Proton Motor, Janík said. After the bus is finished, it will be certified for Czech roads and, if there are no major obstacles, it should be running by spring next year.

Chemical batteries
As important as fuel is to vehicles, the heart of the hydrogen bus is the hybrid fuel cell system on its roof. The system combines a fuel cell with super capacitors as electric storage.
“Particularly for applications with high-peak loads, like urban stop-and-go traffic, strong economic benefits are possible,” said Joachim Kroemer, head of sales at Proton Motor Fuel Cell near Munich, Germany.
This has two main advantages, Kroemer said. First-generation hydrogen buses, which don’t have electrical storage, require more than 200 kilowatts of fuel cell capacity. The institute’s project requires fuel cells with less than 50 kilowatts of storage, reducing investment costs.
In addition, thanks to electric storage, the bus can recover breaking energy and reuse it during acceleration, much like hybrid electric cars.
“This allows a reduction of fuel consumption by more than 30 percent in typical urban cycles, drastically reducing operational costs,” Kroemer said.
Although internal combustion engines powered by hydrogen share some of the benefits of much more expensive fuel cells, they produce more noise, are less efficient and not completely emission-free. By burning hydrogen in much the same way traditional cars guzzle gasoline, the engines release nitrogen oxide, a powerful greenhouse gas.
Although hydrogen emits no carbon monoxide or particle emissions, its production has drawn criticism. It makes sense to think of hydrogen more as a battery than an energy source, and where the energy put in this battery originates matters greatly.
“It is important to produce hydrogen in a way that does not burden the environment with harmful emissions,” Janík said. “Using renewable or nuclear power is the preferred way.”
The institute is working on new ways of splitting water to produce hydrogen. Its main focus is on Generation IV nuclear reactors, which operate at higher temperatures (up to 1,000 degrees Celsius) than current light-water reactors. These higher temperatures could make hydrogen production much more economical.
Even with today’s less-than-perfect technologies, one kilogram of hydrogen can be purchased for 3.70 euros ($5.4/(95 K?) and used to travel 100 kilometers (62 miles).
The Neratovice buses will be buying their hydrogen from the country’s first gas station to include a hydrogen pump, which will start operation at the end of November or earlier, said Zbyn?k Brada, a project manager at Linda Gas. In addition to the buses, the filling station will be open for other vehicles.
“I am sure that car manufacturers will make use of the station to present their hydrogen vehicles in Prague,” Brada said.
Experiences in Germany show that local inhabitants are not afraid, but rather proud of their local hydrogen station, Brada said. More than 100 hydrogen filling stations are already in operation across the world.
“There is no risk involved in pumping hydrogen as long as basic security precautions are heeded,” he said.