What if there was an energy source that could meet half our needs by 2030 (but was not coal seam gas)? A source so cheap it could halve your energy bill (but was not coal), so clean it had zero emissions (but was not wind or water), with no capital costs?

Surely such an energy source would sit at the heart of our national energy policy, argued Chris Dunstan of UTS's institute for sustainable futures at a recent forum run by the Australian Alliance to Save Energy. Stupid not to, right?

Well, here's the good news. We have such a source. Here, now, available. The bad news is we ignore it. This mysterious power has a name, though not a sexy one (which is part of its problem). It's called switching off.

The cost of power has doubled in five years. It will double again over the next five. This is due not to the carbon tax, which pales by comparison, but to the immense costs of infrastructure to accommodate not average demand, but the early evening peak.

The national broadband network will cost $36 billion by 2020. Energy infrastructure will cost more, sooner; at least $45 billion by 2015. And because we disdain anything clean or clever, this means more, bigger coal-fired power stations. These decisions are under way right now. If we cannot reduce our peak, we'll pay the bill - environmentally, as well as financially - for a generation.

At my house, the next doubling will bring the bill to about $1500 a quarter, or $6000 a year. Something's got to give.

So, alternatives. We can invest in solar panels which, at $6000 a year, would be paid off in no time. Then we could squander energy like our parents squandered petrol; like it was costless and meaningless.

Or we can save. But we don't, which is in itself mysterious. If saving meant losing your fridge or dishwasher, or forswearing one's expanding plethora of rechargeable devices, our thrift-resistance might make sense. But if all that's cut is waste - and yes, there's a definition question there - or spreading usage into off-peak, is that really so hard?

Dunstan showed a graph of average household energy use across Sydney. Ku-ring-gai tops out, naturally, at 28.6 kilowatt hours a day, while the City of Sydney is lowest, at just 12.4 kWh/day. Which goes to Edward Glaeser's point about high-density city living being the greenest possible living pattern. The burbs waste vast energy heating and cooling big rooms with unshared walls.

Even without another price doubling, energy saving is clearly sane and obvious; the low-hanging fruit of the energy scene. Why do we still look away?

Answer: in part, because we're not that kind of primate. For a desire-driven creature, doing is always preferable to not doing. You can't crave not doing something. To eat, then exercise, is way more fun than not to eat.

So how to persuade the recalcitrant human animal? How to make the negative feel positive? I toy sometimes with a shame system, a bit like the sumptuary laws of mediaeval and Renaissance Europe when, in an effort to curb consumption, only the nobility could wear ermine or split sleeves.

In the same way, you could require huge real-time readouts on the front of every house, with metre-high neon letters showing in micro-increments how much greenhouse weight its denizens are adding to the atmosphere.

But, yes, sadly, there are civil rights issues. Privacy issues. Fairness issues. Policing issues. Cruelty issues. (For all you know they could have someone in there on dialysis three times a week, or an iron lung.) There's also the law of unintended consequences.

Many sumptuary laws ended up achieving the opposite of their desired effect. Laws restricting certain colours or styles to the nobility rendered those fashions immediately beloved of the aspirational classes to whom they were forbidden. Laws meant to impose a stigma, such as the prostitutes' striped hood, doubled as advertisement.

There is also the need, Dunstan points out, to ''decouple'' energy producers' profits from their production so that - this is deeply counter-intuitive - the per-unit price they can charge drops as demand rises.

But from the international speakers at the forum, one thing became blindingly apparent: just how backward Australia is in taking energy efficiency seriously.

In Britain, where ''fuel poverty'' is real and deadly, the remarkable new ''green deal'' is almost ready to launch. It's a bit like a phone contract. A consultant devises a savings-renewables package to bring your house up (or down) to scratch; solar panels, insulation, smart meters, whatever. The regime you choose is then installed, free. Costs, up to £15,000 ($22,000), are bundled into your mortgage, with a 25-year payoff and quarterly repayments set below the energy savings, leaving everyone better off.

I know what you're thinking. We've been burnt by pink batts before. But that's where upskilling comes in. Already the green deal is spawning a new industry: trainers, assessors, installers, certifiers. The scheme should benefit half of Britain's homes and create 100,000 jobs within three years.

In the US, where energy saving has been big for decades, you can read your usage in real time, online. In 2008, says Laura van Wie McGrory of the Alliance to Save Energy, saving ''generated'' 52 quadrillion British thermal units, or 15.2 trillion kWh - as much as coal, natural gas and nuclear combined. That's big.

But the upskilling must include government, not just tradies. Here, December's draft energy white paper pays lip service to efficiency. It also notes, with undisguised glee, that "by 2035 ... global energy demand will grow around 40 per cent ... [and] Australia is well placed to export into these markets". Our prowess in coal, gas and uranium, it boasts, will "support improved living standards ... in our region".

I must have missed something - the bit where clean air and food is no longer part of ''living standards''.

We may not have fuel poverty, but only because we're a nation of pathetic fossil-fuel junkies. Fossil fuel, fossil brains. Decoupling energy producers from the profit wagon is hypocritical at best until we're prepared to decouple ourselves.

It's time to switch on to the great switch off