theTechnophile

I’ve been reading about the future of the fuel cell car and this got me thinking about the whole topic of energy for mobile devices, including large ones like cars.

I started by ignoring the energy cost associated with manufacturing the different devices. This is clearly insane if your trying to properly assess the environmental merits of a particular technology. The whole life cycle cost must be included for a full environmental impact analysis, but since I’m mainly interested in the local effects of energy consumption I feel justified in letting myself off this time.

How’s the energy stored?

Not too may options here at the current time, if you want a reliable source of energy.

1. Electrically using a battery or similar device.
2. Chemically in some sort of fuel, probably liquid or gaseous.

Now right here we have the first problem: The electrical energy stored in the battery had to be generated somehow, with the original source probably a chemical fuel as well. Wind, solar and tidal power are also possible sources.

But what about turning it into electricity?

Each of these technologies has it’s own particular impact on the environment; the old adage of there being no free lunches certainly holds true here! Power stations, whether traditional and alternative, will fall a long way short of 100% conversion efficiency. However, generation on a large scale is often more efficient than that on the scale required by individual devices. This is the basis of the idea of centralisation which gave the UK, and other countries, a national power grid.

The grid is a big problem.

Unfortunately, most of the efficiency gained by centralised generation is promptly lost during the transmission of this electricity to where it is needed. Some estimates put the UK grid losses at 10% of total power generated and the more remote the power station, the bigger the problem; bad news for the off-shore wind-farm!

We could convert the energy into liquid or gaseous chemicals for transportation, negating the grid losses, but this action is also very inefficient. This is essentially where the hydrogen or methanol for fuel cells would have to be produced, converting fossil or nuclear fuels into another type of chemical fuel source.

So it’s just a question of where we burn the fuel.

Do we burn it remotely and move the energy, in either electrical or chemical form, or just move the original fuel and burn it locally?

If your generating power from nuclear fuels it’s a bit of a no brainer. Currently the only safe way to use this fuel is remotely, but the energy released could be used to bring the hydrogen economy to life. Manufacturing hydrogen from water requires a great deal of energy and few other sources would make this economically or environmentally viable. The alternative of creating hydrogen from fossil fuels lacks credibility: Why waste energy doing it?

The answer is to provide a fuel that when burnt releases less harmful pollution locally, but without fully addressing environmental issues on a global scale. This brings me to the numb of the problem regarding the conversion of any hydrocarbon fuel. Most of the alternative systems today are simply less efficient than the best available combustion plant. So if your deriving your energy from fossil sources in the first place, and most of what we use is, this is probably still the way to go.

But it’s a matter of scale and use. Not everyone wants a two-stroke engine attached to their laptop or mobile phone, and in this case batteries have the edge on small fuel cells for me; the main problem being the fuel storage.

Batteries also start to win out is when coupled with local alternative generation technologies. This could be solar panels on your roof or pocket calculator; or a small wind turbine in the garden. This type of distributed power generation has promise, especially in locations without a grid supply and suitable environmental conditions. Batteries also provide the technology behind hybrid vehicles that can charge from electricity generated locally by combustion of fuel. This combines the advantages of both approaches. But, these types of application are where the environmental impact of manufacture raises it’s ugly head. A topic for another day.

I’m having a crisis. Maybe I’m losing my will to technophile?? No that can’t be it, I’m probably just feeling more guilty about it as I get older. That happens, doesn’t it? As you get older life has given you both wisdom to think about what you’ve done and an ever increasing collection of things consider. Anyway, this particular crisis is environmental in nature.

We use too much.

I’ve always been aware of our global environment and the fact that we all share responsibility for its well being. It’s also been evident to me from an early age that we’ve not done the best job of it so far.

The official targets are full of promises to halt or even reduce the overall emission of CO₂, thereby putting a stop to climate change. This supposes that climate change is entirely dependent on CO₂, an assertion that is far from bullet-proof. Attaining these targets must require the global economy, population and… dear God I can hardly think it… even the supporting technology to substantially reduce its rate of growth. Unfortunately, it seems to me that the world is confidently waiting for this same technology to solve all its problems: like the fat guy, I’m not slim so I can say this, expecting the next pseudo-science diet to shed that excess weight when he really just needs to eat less and exercise more. The same basic principle applies to our environment: if we want reduce our impact we need to use less stuff!

Is my life environmentally friendly?

Now this is the focus of the crisis in question. Can being a technophile, or just working and living, ever be reconciled with this principle. I’d love to say yes; but, I just don’t know. Clare and I gave up commuting for personal reasons, one of which was its clear environmental impact. Doing this just about halved our household income and not everyone can afford that type of compromise: However, doing the majority of my work from home using broadband should be possible, especially in IT. The question is does it help?

Some maths.

My equipment uses a lot of electricity and there’s no doubt that our domestic utility bills have generally gone up whilst I’ve been around the house. But it has to be offset against the effect of using my car: assuming Petrol/Gasoline has an energy density of 9.5 kWh per litre, I used to commute 15,000 miles each year at a good average fuel consumption of 40 miles to the UK gallon; or about 8.8 miles per litre, it’s a small car. I made that an annual energy consumption of around 16,190 kWh. I’ve measured, remember I’m a technophile, an average increase in electricity use of 280 Watts whilst I’ve been at home. I make that an increased energy usage of about 2,500 kWh each year, nowhere near that used for commuting. Doubtless I’m using more of the other utilities but, looking from an environmental perspective, I used at least the same whilst at my employers premises. So, at a relatively superficial level I’m obviously doing the right thing.

Think of the toys!

What concerns me is that this lifestyle is supported by the use of lots of high-tech gadgets. These become redundant much too quickly to be sustainable, despite the claims of some manufacturer to be producing what they call ‘Carbon Neutral’ hardware. These usually consider only the energy used in running the equipment and not that consumed in design, manufacture and disposal: if they did I doubt any hardware could be carbon neutral without either generating excess energy from nothing whilst in use or planting a major forest for each chip! Don’t get me wrong, I think that any green initiative is to be supported, but don’t let the marketing men get too close.

Getting fewer toys.

Applying my principle to this issue, it follows that equipment, or any physical possession, should be designed to be as reusable and long-lived as possible. This means choosing your toys in the expectation that nothing particularly new is going to come along for sometime, and if it does you can’t buy it until your old one is well and truly broken. This isn’t a good thing if you hold stock in the companies producing this stuff. The problem is that I probably do and I like getting new toys, hence the crisis.

Using less power.

One upside is the fact that the focus of the computing industry appears to have shifted from ever increasing processor speed to maximising processing speed to power consumption ratio. I suspect this is mainly due to the temperature problems the waste heat was causing the old processors rather than to a green conscience, but the final effect is much the same: it fits nicely with the ‘use less’ principle. Less waste heat improves processor efficiency and reduced the power demands for cooling, both in the machine and often building air conditioning.

Change is possible.

The real problem is that society and the environment share a common trait: inertial. Changes implemented today won’t have quantifiable effects on either for decades. Basing policy on the belief that consumption and population are going to fall in the next few years is clearly crazy. But climate change is only one facet of the threat to the environment. There are a range of other ethical issues that need to be addressed and some of these could see change in a shorter time-scale. In the end, it’s mostly a state of mind. Forcing people to comply with a set of hastily implemented rules rarely results is real change. People actually do things that they personally believe in and at best pay lip service to rules. I guess I just need to make the effort to figure out in what I truly believe. I hope others choose to do the same.

I was reading the latest issue of PC Pro (145) when I found a news item on the development of gas turbines for powering laptops and other mobile devices. The MIT research team claim that such a turbine built up of silicon components could provide power for 10 times as long as conventional batteries for the same mass. This is an interesting use of gas turbine technology, not least because I used to design large power generation turbines.

The competing technologies are likely to be enhanced batteries and fuel cells. Based on my experience, I can’t help wondering why there is any practical advantage to the gas turbine option since all mobile devices struggle against temperature and fragility problems.

It’s hot!

Gas turbines burn fuel in order to generate mechanical power through rotation. In conventional turbines this results in a lot of radiated heat energy which, as the MIT team suggests, can be contained by controlling combustion air flow. However, this doesn’t reduce the thermal load, just redirects it. You still end up with a hot exhaust that must be vented somewhere, not comfortable if it’s your lap!

Don’t drop it.

Modern mobile devices are generally reducing the number of vulnerable moving parts. The last remnant is usually in data storage media where solid state components are gaining in popularity and I suspect may become the norm in future years. The spinning platters of a hard drive are not unlike the rotor in a gas turbine, give it a good knock and the spinning parts hit the static parts resulting in… well have you ever heard the grinding of a hard drive failure? Not pretty as components spinning at thousands of revolutions per minute carry a lot of kinetic energy.

What type of power?

As you might have noticed above, a gas turbine alone generates mechanical power not electrical power. Unfortunately, it’s electrical power that your laptop enjoys most. In conventional power generation you need to attach a generator set to the gas turbine to convert the mechanical power of the rotating parts into electrical power. None of the articles I’ve read so far mention MIT developing a tiny generator set!

Interesting it may be, but useful?

The attractions of the fuel cell lie in its ability to convert chemical fuel energy directly into electrical energy without any moving parts and at a much lower temperature than a combustion gas turbine. Whether you really want a computer full of highly flammable fuel sitting on your lap is open to debate, especially since batteries have been exploding recently. But if you do, I personally feel that a gas turbine is definitely not the way to use it. The future of power for the mobile technophile is much more likely to be small polymer based fuel cells or advanced batteries.