Nik Spencer, 48, says the device, which is about the size of a washing machine, can generate enough energy to heat a house. Mr Spencer’s invention called The Home Energy Resources Unit, or HERU can recycle most household waste, including nappies, coffee cups and plastic. The HERU is plumbed in to an attached boiler, which ensures potential dangerous gaseous emissions are filtered out. It is then also passed through filters in the boiler, which make the final gas emissions harmless and odourless. It does not recycle metal and glass which require much higher temperatures to break down but if those items end up in the machine accidentally, they will not cause any harm.