Hybrid boiler converts domestic waste to heat homes

A washing-machine-sized incinerator which converts household rubbish into energy that can heat the home has successfully come through 8,500 hours of field trials.

The HERU, or Home Energy Resources Unit, takes everyday items which would previously have been destined for landfill, such as coffee cups, plastics and nappies, and uses the process of pyrolysis to convert them into energy to heat water for households and commercial buildings.   

The process uses controllable heat pipe technology, enabling a highly efficient, low-temperature pyrolysis process to take place, creating outputs that are used to fuel the home. The small amounts of emissions are cleaned before being released to air and sewer without posing risk of harm to human health or the environment.

Consultant Ricardo Energy & Environment found that, compared to traditional waste collections, the HERU had 300% less global warming than co-mingled collections and 280% less than kerbside collections. 

The HERU process can generate up to 2.5 times more energy than is required to operate it. 

Six months on from installation at Wychavon District Council in Worcestershire, the HERU, which has been operating five days a week, every week to date has processed 3-4kg of waste a day, resulting in a total of 420kg from entering the UK waste system. 

The trials showed that the energy produced during the six-month period was 1.050 kWh for one unit. This means that if the HERU was adopted in each UK home, material that was once thrown away could produce 28.3 billion kWh of energy directly for domestic use. It could also prevent 13.5 million tonnes of resources entering the UK’s waste system. 

Nik Spencer, founder and CEO of HERU, commented: “We hope these trials will drive policy change, so when new homes are built, they don’t have to contribute to the ever-growing problems. We are very much looking to our political figures to be part of this change and help Britain cement itself as pioneers in green technologies on a global basis.”

The ongoing evaluations of the domestic 12-litre HERU are also driving the design of the 240-litre unit, which will be approximately 12 times bigger in capacity, utilising 12 times more resource and is expected to produce 12 times more energy for commercial buildings. 

Image: HERU founder Nik Spencer (left) and Vic Allison, deputy managing director, Wychavon District Council