THE first brisk days of autumn brought some chilling news from energy companies. Four of the “big six” firms have announced yet more price increases as soon as November. This came weeks before a new bill aiming to make energy “secure, affordable and low carbon” is published. In the heat of the moment, David Cameron, the prime minister, promised to force energy companies to offer customers the lowest possible tariff. Perhaps it would be wiser to look more closely at the substance of the bill, which threatens to raise electricity prices, not lower them.

It is full of plans to spur the construction of pricey low-carbon power stations, fuelled by renewables such as offshore wind. The bill will raise the price of electricity but provides no extra measures to manage demand. Yet conservation is the cheapest way to cut carbon emissions. McKinsey, a consultancy, found that demand-reduction schemes could curb electricity use by 40% by 2030, saving more than £10 billion ($16 billion) a year. A parliamentary committee has called the bill’s neglect of the demand side of the equation “fundamentally flawed”.

Because consumers pay for each unit of electricity they use, neither generators nor suppliers have an incentive to reduce demand. If the government hopes to curb the national appetite for electricity and diminish the need for expensive new generators, it needs to create a market for savings. The best approach, according to a new report from the Green Alliance, a think-tank, would be to reward those who cut their use of electricity. Like similar schemes that pay suppliers for the units of clean energy they create, an efficiency feed-in tariff would pay for each “negawatt” generated—that is, each unit of electricity saved. This would lower bills for users and encourage innovation.

The energy department says it will consider such suggestions, but its consultation on demand-side policies will be separate from the energy bill. This is a shame, as conservation measures would presumably alter supply-side expenditures. Energy generators are more formidable lobbyists than conservationists, says Tom Burke of E3G, an environmental consultancy.

Instead, the government has been trumpeting the energy savings that will come from its new Green Deal, a “revolutionary” programme to make Britain’s housing stock cheaper to heat. With little fanfare, the programme hissed into life on October 1st, though the first contracts are not expected until January. The plan lets consumers insulate their homes at no initial cost, paying for it through an extra charge on future energy bills, which must be less than the money saved in heating costs. The government says the Green Deal will retrofit some 14m homes in a decade and create tens of thousands of jobs.

So far, so cosy. But there are problems. The Green Deal only addresses housing, and it lacks incentives for consumers to invite the hassle of big renovations. It is not enough to say that bills should be lower; it will be tricky to ensure that they are. And it is unclear how big and expensive the loans will be, as the programme’s financing has yet to be established. The government’s own projections predict a steep fall in the number of homes insulated each year in the short term, as the Green Deal replaces schemes in which energy suppliers make a percentage of homes more efficient.

There is also a difference between energy efficiency and conservation, warns John Constable of the Renewable Energy Forum, a think-tank. If there is no incentive to conserve, lower costs tend to boost demand. Hardly a warming thought.