We recently took a trip to London to visit my sister and brother–in-law. I love San Francisco, but after a week of exploring the parks, promenades, and museums of London, home always feels like a sleepy beach town. Thanks to the pansy-ass strength of our currency at the moment, most of our meals were prepared in my sister's European kitchen. One night, while running the puny kitchen at an American-sized volume, we were plunged into darkness accompanied by that ominous electronic “sighhh.” Power's out in London?

And what was my sister doing digging around for coins in her purse? While I tried to avoid pouring our dinner all over the carpet, she crawled under a cabinet with some coins in hand, and voila, the lights were back. This was weird. Apparently, there was a light meter in their flat. It seemed that all our cooking and baking had quickly eaten away at the money she’d deposited the previous day.

Prepaid electricity meters that use hard currency or tokens to pay-as-you-go for power turn out to be fairly common in England, and indeed in many other parts of the world. This system is sometimes used for logistical reasons. For example, many grand old buildings that once housed wealthy families have been broken up into smaller flats, and in this case the personal meter system allows a landlord to retain the wiring infrastructure but simplify the payment scheme. It’s also a good system for those on a tight budget, who can deposit money when they have it and get by without electricity when they don’t. This works in developing nations in the same way that pre-paid phone cards work. Top it up when you’ve got some cash and hope for better times ahead.

Over the course of the ten days that we stayed in the flat, my sister noticed that she was paying about one pound every day. According to her, this was about double the normal energy consumption, which made sense since we had double the usual number of people and were cooking often. Interesting, I thought, that one would have such a simple index for tracking your personal energy consumption. There seemed to be some good applications for this source of information.

Unsurprisingly, I'm hardly the first person to think along these lines. The general idea is that consumers benefit from more information about their consumption, and if they're able to monitor their energy usage, they are more likely to identify energy-intensive practices, which could in turn lead to reducing these practices in the interest of saving themselves money. There have been some fantastic design spinoffs, like the Saver Clip that can help pinpoint energy-drainers in your home. Or, my favorite, a glowing tumor-like thing called The Energy Orb that changes color to indicate levels of consumption.

This is a simple cure for energy-consuming oblivion. It provides the resident with immediate information about real costs. Motivated by a desire to save money, they can utilize the information to make better decisions about their personal energy usage.

There are many applications of this principle. Pop quiz: what's the single best way to improve your fuel efficiency while driving? Answer: Drive 55! Yup, according to the EPA, speeding can reduce your mileage by as much as 33%.

If we all had some kind of Fuel Orb on our dashboard, we'd know this by now. If you’ve ever driven a Prius you’ve had the experience of watching your mileage crash and burn when you overtook that Pinto on a hill. If efficiency meters weren’t limited to Hybrids, we could all benefit from immediate information that would help us to train ourselves to be more efficient drivers. In the days of $5/gallon gas, who doesn’t like that idea?

It’s time to look at new ways for each of us to improve our efficiency. No mandates are necessary. People like to make decisions for themselves, and they certainly like to save money. Why not give them the necessary information to do both?

As for me, I’m off to do some online shopping. I don’t have the option of a pre-paid energy meter in my San Francisco flat, but I do have a blue coffee table that might look good with a green tumor resting on top of it. An Orb, I mean.