SITA UK incinerator heat to grow tomatoes

Waste management company, SITA UK, could see its £185-million waste incinerator at Great Blakenham, Suffolk, used to help local farmers grow tomatoes in a new greenhouse project.

Construction on the combined heat and power plant began in May of this year and, once completed in 2014, is expected to burn up to 269,000 tonnes of residual waste annually and generate enough electricity for 30,000 homes.

It has now been revealed that heat produced from the plant could potentially go for use in a £30-million commercial greenhouse project, and could see local farmers grow up to 7,500 tonnes of tomatoes a year.

In partnership with local farmers Michael Blakenham and Stephen Wright, the project would operate under the name Sterling Suffolk, and would cover 50 acres of land near the Great Blakenham site. Sterling Suffolk has said that the greenhouses would be about 500 metres (m) long and 220m wide.

Michael Blakenham said: “There is a big demand for locally-grown produce which can taste better than anything which has to travel over long distances. It is early days, and there are hurdles to overcome, but we hope to fill some of the gap in the market and at the same time bring much-needed jobs to the area.”

It is hoped that the greenhouses could produce up to 10 per cent of British-grown tomatoes sold in the UK and reduce food miles. All produce would be sold locally and to selected supermarket chains.

£2 million pipeline network

The project reportedly came about after Cliff Matthews, Regional Manager of SITA UK, was tasked with the challenge of finding customers for surplus heat from the Blakenham facility.

Cliff Matthews said: “The plan is to heat the greenhouses using surplus heat from our energy-from-waste plant. The pipeline will also form the basis for a District Energy Network reaching towards Ipswich to provide huge environmental benefits.”

In the past combined heat and power plants have proved relatively unsuccessful at delivering heat energy as the extensive pipe networks involved in delivering the heat are deemed too disruptive and expensive. Most incinerators currently operational in the UK lose a great deal of embedded energy through waste heat; efficiencies for incinerators that only produce electricity are between 15 and 25 per cent, a figure rising to 79 per cent when heat is used, according to AEA. The greenhouse project would reportedly justify the expense of laying down the £2 million pipeline in this instance.

It is thought the project came about after the success at a similar scheme in Wissington, west Norfolk, where heat generated by the British Sugar factory is used to grow tomatoes in two commercial-sized greenhouses.

Negotiations are said to be ‘on-going' with a variety of marketing and growing organisations and it is hoped that a planning application for the project will be submitted to Mid Suffolk District Council by early 2013. If the project is approved, Sterling Suffolk aims to have the greenhouses both built and operational by December 2014, when the facility opens.

Overcapacity

Whether or not the plans to utilise the heat pan out, the Great Blakenham plant will be one of a growing number of energy-from-waste plants being approved and built in the UK, despite a recent report from Eunomia Research & Consulting suggesting that the UK could see overcapacity in residual waste treatment plants by 2015, if the current rate of construction is not curbed.

The report suggests that due to increased emphasis on recycling, reusing and recovering material, residual waste rates are falling, leaving incinerators without the required levels of waste needed to produce efficient and cost-effective processes.

It is feared that this would lead to more recyclable materials being sent for incineration to “feed” the plants.