Friday, 5 October 2007

Reducing oil consumption

Here are my thoughts on reducing our use of oil while we still have some left to play with!

New Scientist (4 July 2007, "Biorefineries: curing our addiction to oil") reports that over 70% of the oil we extract is used for transport fuel. Most of the remainder is burned for energy (and this without including natural gas, another fossil carbon) or used for roads, lubricants and waxes. Just 3.4% is used in the petrochemical industry, to synthesise all the materials we depend on in our everyday lives - e.g., plastics, cosmetics, paints and medicines. Wouldn't it make sense to cut down the 90-odd percent that is used for energy and save the oil for petrochemical manufacture? If we were to do this ahead of "peak oil" then the feedstocks that we need for the synthetic chemical industries could last for centuries.

It is comparatively easy to switch electricity generation over to renewables, including woodchip and pellet technologies used for industrial "cogeneration" or combined heat and power (CHP). Slough Trading Estate has been doing this for several years so your UK Mars Bars are made using sustainable energy. This type of biofuel makes sense and does not compete for agricultural resources with food supply. The biggest problem will be scaling up the supply of woody fuel - perhaps an argument for restoring some of Britain's native woodland cover that was displaced by farming?

It is much harder to make the switch to renewables for the transport fuel we all depend on because few other materials have the energy density of petrol or diesel. Plug-in hybrids could help, if recharged from renewable electricity, but hybrid cars today are really no more than green window-dressing to enhance the reputations of the world's largest car manufacturers, while they continue to flog Chelsea tractors, SUVs, pickups and luxury limos.

Whether it's ethanol from sugar cane ('gasohol' in Brazil) or biodiesel from oilseed crops, production of biofuels for transport displaces food production (witness the soaring price of bread). More importantly, to meet the current transport fuel demands of the developed world, biofuel would have to supplant food production entirely - and then some more!

There is an overwhelming need is to change the way we use transport - both personal and freight. That's a very tall order but nothing else comes close to providing a sustainable solution.

Energy efficiency, both domestic and industrial, offers huge prizes but is barely beginning to be tapped here in England because energy is still far too cheap. There is loads of advice available on improving our domestic energy and I will post the best links I can find to help with this. Retailers and manufacturers have much scope to cut their energy consumption but the economics will need to change before they pay more than lipservice to these opportunities. Massive hikes in the price of oil and gas would drive energy efficiency but this is not going to win elections anywhere in the world and so seems unlikely to happen before we reach peak oil.

Solar thermal power is already highly efficient - vacuum collector tubes can capture over 90% of the solar energy reaching them. Rooftops around the world should be covered in them already but - outside of Germany - they are not.

Solar electricity generation, in contrast, uses only up to 15% of the incident energy. There is plenty of room yet for technological innovation, both the physics of solar energy capture and the manufacturing processes used to produce photovoltaic panels in large quantities and at low cost.

Even nuclear fission is ultimately unsustainable because the uranium reserves are limited and the environmental and human costs of uranium mining are very high. If we could tame nuclear fusion as an energy source we would really be getting somewhere!

Light bulbs

The first thing that seems to spring to mind when you mention carbon is changing your lightbulbs. That's good because it's easy and, once you've done it, it takes no further effort.

A lot of people though, including Tesco's Sir Terry Leahy, have pointed out that we can't just BAN high-energy lights because they are not suited to all situations, a lot of current light fittings won't use them, etc. How far is that true?

Energy-efficient bulbs for the standard bayonet (BC) or screw (ES) fitting are now sold for under a pound in supermarkets, department stores and the like. They are longer than their equivalent high-energy bulbs, however, so they might not fit your existing lampshade or luminaire. In that case, you need to get hold of the tiny little energy-saving bulbs that are now available from online retailers - I've listed some below - for even the small bayonet (SBC) and screw (SES) fittings. They work really well. Yesterday, I replaced a 40 watt tungsten "golfball" bulb, 95mm-long, with an energy-saving equivalent that is 5mm shorter and 35 watts lighter.

Unfortunately, these non-standard energy-saving bulbs cost £4 - £8 each which is a big barrier to replacing all the tungsten bulbs in your home.

Halogen downlighters and spots are the very epitome of modern lighting. Bright and affordable, they claim higher efficiency than regular tungsten filament bulbs. In practice, they are highly directional so that many more bulbs are needed to light a room than with traditional bulbs.

Just before I started to think about energy efficiency, I fitted 12 mains-powered halogen bulbs in a long, narrow utility room at home. I think this stupid deployment of 600 watts was the first thing that made me feel guilty about my household energy consumption. Fortunately, I discovered Megamann 7 watt compact fluorescent spots and spent a hundred quid reducing this figure to 84 watts.

Sad to say, these are only available for 240v lights so I don't think we can do anything practical yet to replace all those 12 volt halogens our homes are filled with.

I have just tried out some 1 watt LED replacements for the little 10 watt halogen bulbs with two metal legs coming out of them (called G4 capsules). They were £5 a piece, very fragile (I broke two), difficult to fit and produced negligible illumination with a ghastly mains flicker.

Furthermore, the power consumption of the transformer supplying 12 volt DC to the 1 watt LED was still 15 watts, so the real saving was 50% rather than the 90% I had hoped for.

My next stop was the lounge and dining room, with a grand total of 17 matching wall and floor lights, each using 40 watts. The Omicron replacements, at 5 watts each, have cost me £140 but they are saving 600 watts between them.

My latest discovery is energy-saving striplights, to replace those long filament bulbs built into bathroom mirrors, furniture and under kitchen cabinets. The 221mm bulb uses 5 watts rather than the 30 watt incandescent bulb: the 284mm one uses 7 watts in place of 60 watts.

How about Tesco start piling them high and selling them cheap so that we can all switch more of our lights over to energy-efficient bulbs?

In the meantime, please check out these online retailers and buy all the energy-saving bulbs you need, and can afford, to replace your high-energy incandescent lamps. I have been happiest with BLT Direct because their prices are fair, they deliver quickly and they handle returns very efficiently.

First things first

Welcome to the "Cut Your Carbon" blog. I haven't written one of these before and apologise if the style or content fail to live up to your expectations.

I am a life scientist who down-shifted from an industrial science career a couple of years ago and now work part-time on a project to generate commercial funding for really great causes in the developing world. My work on renewable energy has drawn me into the sustainable living arena and I have begun to form my views on what we can do as individuals to mitigate the impending tragedies of climate change and peak oil.

I will attempt to set out these views here and invite your responses. I will be more grateful for constructive comments than suggestions that I am mad, dangerous or likely to die soon.