Reducing the amount of energy we use cuts our household bills, so going greener can help you keep out of the red.
More than one third of British households are paying more than they need to for their energy bills, research has suggested.
Research carried out by Citizens Advice and the Energy Saving Trust found that 36 percent of homes have not changed the way they use energy in recent years, equivalent to 9.7 million households.
Home energy use is responsible for around 25 percent of carbon emissions in Britain, but researchers said changes such as filling the kettle with only the water needed could stop two million tonnes of carbon dioxide being released and save households £1.1 billion per year.
The survey was released to mark the start of Big Energy Saving Week, run by the two groups and the Department for Business, Energy and Industrial Strategy (BEIS).
Nearly nine in 10 households (87 percent) surveyed said they thought making small changes would make little or no difference to their finances.
However, the research found by spending one minute less in the shower, a family of four could save £75 a year on energy and water bills - and replacing an inefficient showerhead with a water-efficient one could save £185.
Turning off lights when they are not needed could save around £14 a year, and changing all the bulbs to LEDs would nationally save £230 million.
Citizens Advice chief executive Gillian Guy said: "Our homes are responsible for nearly a quarter of British carbon emissions, so this is a great opportunity to really make a difference.
"Reducing the amount of energy we use cuts our household bills, so going greener can help you keep out of the red."
The research also found that if British households turned down thermostats by one degree, changed all lightbulbs to LEDs, used the right amount of water in the kettle and turned appliances off rather than leaving them on standby, it would save the equivalent of taking around three million cars off the road in carbon emissions.
During Big Energy Saving Week, more than 450 events will be taking place across the country, including at Citizens Advice centres, to provide advice and help households save money and reduce their carbon footprint.
Jess Glass is a reporter with PA.