In UK there is leakage out of low pressure gas pipelines. These were built pre 1960 and around 0.5% of the methane leaks out. The grid is progressivly being replaced with new plastic pipes. However, the leakage is not related to throughput. So adding CNG vehicles does not increase the leakage.

In practice, CNG stations are usually fed from higher pressure grids that are newer, steel, do not leak at all....so what this study is saying is that there should be investment in replacing leaking pipelines in the domestic heating market. No argument with that, but this has nothing to do with CNG for vehicles which reduces CO2 with NO increase in leaks of methane.

Frankly, the argument that we should not substitute expensive oil and dirty coal with cheap and abundant natural gas that burns far more clean because we can’t prevent massive leakage of natural gas to the atmosphere is one of the most idiotic arguments I have ever head on this topic. Such leakage is fully controllable and it can be prevented at fairly low costs.

Leakage of methane from farting cows and other animals including humans is a much more serious problem because there is no easy or inexpensive ways to contain it.

BTW, I note that this study dealt only with fuel switching using CNG. What about LNG? LNG is more likely to be used in those larger vehicles that use diesels because they'd get greater range.

Is it too much to ask that the National Academy of Sciences exercise some minimal level of screening?

How convenient Harvey?

Any question of plug-in viability and you suggest big oil conspiracy.

Here, the culprit in question is, essentially, a usable fuel. Why not just harness that fuel? Would methanol fuel cell hybrids really be so bad?

Yes, instead, nat gas powered power plants and plug-ins would be more efficient, but if the auto industry isn't building them and consumers don't want to buy them, how much is your greater efficiency-potential worth in the real world?

This isn't communist America. Maybe it should be, but unless you can pass that via the ballot, consumers are much more willing to embrace CNG vehicles than plug-in ones until there is a major battery breakthrough that makes plug-ins equivalent to guzzlers -- in EVERY way.

I'm sorry, but it really bothers me how utopian dreams, despite a plethora of evidence, are consistently an argument against rational energy policy. Plug-ins have become the modern day fuel cell.

Solution: fix the leaks. This means better regulation of the owners of gas production and transmission lines. You may recall that PG&E recently blew up a whole neighborhood south of San Francisco because of lax inspection of its gas line network. CH4 is becoming the major US energy source for the early 21st century. So be it--let the producers produce and the transporters transport, but lets keep them honest. Everyone needs to play by the rules, and the referees need to have sufficient clout to keep the players honest.

GTL would turn natural gas into liquid fuels as close to the well head as possible. The liquid fuels can be transported and stored just like refined product and blended to reduce oil imports.

Im interrested to buy a natural gas conversion kit for my 2005 4 cylinders ice car. The kit is added to the car and the gasoline tank is kept intact so the car become a hybrid fuel nat gas plus gasoline so it is just a way to choose the cheapest fuel and gasoline price will lower if there is direct competition between them. Actually big oil with the help of goverments and actual car manufacturers have avoided clean abondant cheap nat gas to promote high gasoline price and the money that is given to saudi-arabia for petrol imports is deposited secretly in swiss banks accounts in the name of exxon and friends. That's why they import petrol it's because the money is transferred directly in secret internationnal bank accounts tax free. They are not interrested in keeping the money in official taxed contries like usa or canada, they prefer swiss banks via saudi-arabia.

this is kind of a no-brainer. We know that the greenhouse gas benefits of taking coal offline are greater. So it depends on your priority: ending US dependence on foreign petroleum (then you want natural gas vehicles), or lowering GHG (then you want natural gas to replace coal).

The latter is much easier and could be deployed much more rapidly. The former goal might be achieved more readily through upgrading to more efficient drive technologies (downsizing and electrification).

Thanks Roger, that answers my question about Hythane, but as I recall there's still a problem with the energy content of a volume of H2 when compared to methane as it flows through a pipeline. And whereas NG is stored energy that can be pumped out of the ground H2 requires energy more to release it from some chemical feedstock than we'd get back from using it. What are the trade-offs here?

@ai vin,
H2 should be made from excess solar, wind and nuclear energy and not from chemical feedstocks in order to be environmental sustainable. Gradually upgrading the NG pipeline to where it can also support H2, or building dedicated H2 pipeline. H2 can be stored in used-up oil or gas well as well as used up salt mine. There is no problem with the lower energy content of a volume of H2, since with higher efficiency of fuel cells and with better home insulation and multi-zone HVAC, we will use less of it. H2 forces us to be more energ efficient. Necessity is mother of invention!

<<"What are the trade-offs here?"

H2 is the most efficient synthetic chemical fuel derived from the energy of renewable energy and nuclear energy. As a chemical fuel, it can be used to store excess renewable energy produced in the springs and falls for use in winters. To combat global warming, we must be serious about going toward renewable energy and nuclear energy and wean off from fossil fuels completely. H2 will enable us to do that. Cost is more relevant than efficiency. H2 as energy storage is not as efficient as battery electricity, but for seasonal energy storage, the cost of battery electricity is prohibitive.

Fundamental laws of physics expose the weakness of a H2 economy. Energy cannot be created, it can only be converted from one state to another, and some energy is always lost during the conversion, H2 is an artificial energy carrier, and can never compete with its own energy source, either natural gas or electricity, in a sustainable future.

By creating a link between the power generation and transport sectors, natural gas-fired electricity generation in combination with PHEVs, will be one of the pathways that are both highly efficient and sustainable.