According to my Googlings, these buses should emit 70% less GHG▸ and 'virtually no' PM10s▸ . Not to be sniffed at, I'd say. Wonder how the total cost of ownership compares?
The part of the grant aimed at the buses rather than the refuelling plant equates to a little over £27,000 per vehicle. I suppose this is how much more than a standard diesel bus that these cost. An
article on the Bristol 24/7 website gives a manufacturing cost of £295,000, compared to £675,000 for the electric buses used on the UWE to Temple Meads route.
Before I pour scorn on some of the hyperbole, I will say that I fully support anything within reasonable cost that could help to clear up the air in Bristol, and the world beyond it. As Red Squirrel has pointed out, greenhouse gases are greatly reduced (with a caveat), and small particles of soot are absent. So far as I can tell, much less nitrogen dioxide (NO
2) is produced by a gas powered engine than by a diesel, because it operates at a lower pressure, so does not initiate the reaction between atmospheric nitrogen and oxygen that has suddenly made diesel engines so unpopular. These buses will certainly emit less unwanted rubbish than even the cleanest diesel. 110 cleaner vehicles in Bristol won't clear the air overnight, but it's a start. The refuelling station will also be open to third parties, which might encourage local delivery firms to invest in the technology.
The caveat is that the engine produces carbon dioxide and water vapour, both greenhouse gases. They are, however, much weaker in effect than the methane the were produced from, were it to be introduced into the atmosphere, as is the case whenever organic waste is buried in landfill.
Now for the hyperbole. Another more cynical headline could be "Government gives First Bus a bung of nearly £5 million to run MetroBust". South Gloucestershire may have signed the letter asking for the cash, but they won't any of the assets. I assume this misleading spin is to avoid the potential embarrassment caused by government giving public money to private companies. I'm not bothered by that when it is for the greater good, but there are some who would be.
To read the various news articles at face value, you would be forgiven for thinking that First will be taking hourly deliveries of food waste, and shovelling it into a giant machine, producing a special gas that is quite different from normal natural gas. Not so - biomethane is chemically identical to the fossil fuel version. First's refuelling plant will be connected to the gas national grid in much the same way as mu=y gas boiler is. The biomethane will be produced elsewhere, possibly in Avonmouth by someone such as
New Earth Solutions, although I am not sure if they are still going. Viridor are currently building a
much bigger plant in Avonmouth. The gas from such plants is "bought" by First, then pumped into the national gas supply. First then turn on the tap and draw an equal amount from the same national supply, making this an accounting device, because the plant would be producing gas anyway. Again, I have no issue with the process, which solves more than one problem. Waste is used rather than buried, energy is produced, and greenhouse gases fall. It's the somewhat dishonest gloss put on the story that I object to. On the plus side, if we get too many gas buses to be able to fuel them all from biogas, we will be able to use the methane producedd by hydraulic fracturing of deep rocks.
An analogy. Some years ago, a French bottler of naturally sparkling water was found to have been removing the carbon dioxide from the spring water before transporting it to its distant bottling plant. Its explanation was that it expelled the gas into the atmosphere to make the water easier to transport to much closer to its customers. It then removed the same gas from the air and injected it back into the water - voila! It didn't go down well.
So I welcome the introduction of gas-powered buses, but would like to see more honesty. GHG and PM10 are now listed in the Abbeviations and Acronyms page.
