Cash-strapped headteachers need to scrutinise their water and energy costs as energy experts believe most schools could reduce their bills by up to 30 per cent.
Government figures reveal a wide variation in schools' energy and water consumption. Some schools' energy bills are 60 per cent higher than those of their cost-conscious peers. The range of water costs is even greater, with some schools paying more than twice as much as others.
In 20001, the typical primary school used 194 kilowatt hours of energy for every square metre of floor space, at a cost of pound;3.90 per square metre. On average, each child used 3.8 cubic metres of water, which cost pound;5.90. However, more profligate schools are using 5.6 cubic metres of water per child and 247 kW hours of power per square metre (a single-bar electric fire uses 1kW per hour).
Schools with low electricity and water bills are likely to have been involved in the Government's energy-saving programme that saw pound;8.6 million distributed to 1,800 schools. The money, spent on energy efficiency measures, resulted in some dramatic savings.
At Suffolk's Chantry high school, for example, a combination of low energy light fittings and zoned central heating has reduced electricity bills by 75 per cent.
The school energy funding is no longer available, but Jeff Kinton, Durham's energy-management co-ordinator, believes that most schools could benefit hugely from conservation and efficiency measures. Most schools have some kind of timing and thermostat system, but Mr Kinton recommends zoning - to isolate areas that do not need to be heated.
More radical solutions include grey water - where rainwater is collected and used to flush the building's toilets. Two Durham schools are installing rainwater-collection systems and the potential savings are significant - flush water accounts for 40 per cent of a typical school's water consumption.
Still more radical is the 18-metre 50 kilowatt wind turbine that powers Durham's Cassop junior school. It became the first wind-powered school in Britain four years ago.
"When the wind blows strongly the school turbine not only supplies the whole school, but also exports power into the grid," says Cassop headteacher Jim McManners.
However, turbines such as Cassop's are not an option for most schools.
Durham had only 19 council-owned sites - out of 330 - where a turbine could have been considered. And wind power will take a long time to pay its way - up to 25 years in Cassop's case.
Renewable energy solutions were the subject of a conference in Birmingham earlier this week, when speakers outlined the latest grant funding available to schools (see box).
The conference was also told that the Department for Education and Skills plans to introduce an energy benchmarking scheme along the lines of the Sportsmark. Schools would be able to compare their performance and have their progress towards energy conservation accredited.
"This isn't just about cost-saving," said Anthony Heyward, who addressed the conference. "Global warming means that we all have to take these issues on board."
"Energy and water benchmarks for maintained schools in England: 2000-01" can be found on the DFES website www.dfes.gov.ukstatistics.
* Buy long-life light bulbs.
* Opt for zoned heating, so that the whole school is not being heated when only a few rooms are in use.
* Fit radiator thermostats.
In steel and glass buildings consider replacing some glass with solid panels.
* Switch to flat-screen computers. Turn off screensavers.
* Fit autoflush mechanisms in boys' urinals and use rain-water to flush loos.
* Install solar panels and small turbines.
* Clear Skies offers up to pound;100,000 for renewable energy projects in England, Wales and Northern Ireland. www.clear-skies.org
* Seed is the Social, Economic and Environmental Development programme, with pound;15.3 million to distribute in England by the end of 2004.
* Solar power is the most expensive renewable option, but grants are available through the Department of Trade and Industry. See www.est.co.uksolar