Standby Surprise

On the UK government "Act on CO2" website there is clear advice, which no one would disagree with: Don't leave it on standby
"If everyone in the UK switched off unused appliances it would save £800 million a year. Leaving appliances plugged in and switched on at the socket means they're still using energy – so turn TVs, games consoles and mobile phone chargers off at the mains to save yourself money."


This is self evident advice and easy to implement. Why would any one question it? Turning something off that you don't need will save energy and save the planet. But is it always true?


Here is a simple quiz question for all you energy gurus out there:
I go out for the evening and despite my usual vigilance I leave my phone charger switched on, my TV on standby, and (horror of horrors) an electric light on. The room is heated (it is winter) by an electric heater, which has a thermostat. So here is the question, does leaving the electrical devices on unnecessarily:

1. Use extra energy, contributing to my carbon footprint?
2. Make absolutely no difference to my energy consumption, but increase my carbon footprint?
3. Increase my energy consumption by the wattage of the devices left on, but make no difference to my carbon footprint?
4. Make no difference to either my energy consumption or my carbon footprint?
5. I need more information and need to thermally model your home and the insulation system on a computer before I can say.

So here is the surprise (for some people). If you want to be pedantic and very accurate, the answer is (5), but to a very close approximation, the answer is (4). The reason? Let me go over some very simple physics.


All these electrical devices convert the energy they use into heat (I'm assuming that the phone is not plugged into the charger so we are not converting any mains electrical energy into battery energy). Actually, conversion of electrical energy into heat energy happens at 100% efficiency for almost all electrical devices. The electric heater does the same. The thermostat on the heater does not know if the heat delivered to your room is from the heater or the other devices; it is all just heat. So whilst you are heating the room, the job of the thermostat is to maintain the room at a particular temperature. Everything else being equal, it will turn on the heater for slightly smaller periods of time to exactly compensate for the heat generated by the offending devices. The energy you use will be whatever is necessary to maintain the temperature difference between the outside and the chosen thermostat temperature inside. Which electrical device generates that heat does not matter. Obviously the thermal installation makes a massive difference and air flow from the outside through your room (a draft) is probably even more important. But the TV on standby makes no difference at all.


So why might answer (5) be important. We let us suppose that the phone charger is on the window sill, behind the curtains. It might then lose the heat it generates without contributing so much to the heating of the room. There would then be an argument for switching it off to save energy. I mention this only because there will be people who spot this and then claim that my argument is completely wrong. I will let you judge, on this.


Don't be complacent if you are in a hot climate with air conditioning running. Unfortunately the physics works the other way around in this case. Because air conditioning uses more energy than it shifts, the extra devices in your home now get multiplied by the efficiency of the air conditioning. A TV on standby using five watts now needs, maybe, another 5 watts of air conditioning to keep the room at the same thermostatically controlled temperature. And this will increase both your energy costs and your carbon footprint.

Global Economy - Personal Choice

I ordered two tickets for the ballet from londonwestendtheatretickets.com. Seven days later, they arrived - from Oslo. Curious?

So what is happening here? londonwestendtheatretickets.com has clearly chosen to contract its ticket distribution process, and the best bid was from a company in Norway (!?). The tickets were sent by airmail. The risk of them arriving late was compounded by their long journey - they warned me to leave 7 days before they might arrive and they were not wrong. Obviously, their carbon footprint must have been a little larger than being printed and posted from London, but for something so light, is that important? However, unless londonwestendtheatretickets.com is run by idiots, it must make commercial sense to use this contractor.

Of course today we should all been concerned about carbon footprint. For example, shipping tomatoes and other produce from Israel to the UK, by air freight is often quoted. In this case, however, it may make sense, commercially and environmentally. The cost (and environmental impact) of heating a greenhouse in England to grow the same product is actually higher than the airfreight footprint (the necessary sunlight in Israel is free). However, the irrigation needed to grow organic carrots in Israel for consumption in the UK could be destroying the environment.

Perhaps this highlights the need for sensible restrictions of air freight. It is reminiscent of the use of containers, which in recent decades have allowed a free economy between road and rail. Who won? Well, left to commercial pressures, always the lowest cost options – very often road, although the use of rail has actually increase in the UK in recent years. So is this where government tariffs come in? Just make it the lowest cost to use the most environmentally friendly option.

Come to that, a ticket is not something that should need to be sent through the post, anyway. When you check in to an airline, all you need is your passport and a reference number (often, only your passport). Why can’t I check in to the theatre in the same way? Well of course I can, but using a credit card. However, my expectation is that this will be arduous and stressful. I have to use the machine in the theatre to get the tickets printed – I’ll probably be arriving at the last minute. Will there be enough machines. If I can’t get the machine to work, say I can’t work out which card I used, what will I do? Will there be adequate support? Will the box office even be open? So I opt for making sure that I have the physical tickets in my hot paw. I truly didn’t expect that I would be using airfreight in this process, though. It is my choice - maybe next time I will make sure I use the environmentally friendly option.