Don't try to reinvent the energy from waste wheel

Written by: Simon Allin | Published:

Why are established renewable energy technologies being sidelined by emerging ones when it comes to funding and policy support - even when the evidence and experience are that existing methods are more efficient than gasification and ATT? Simon Allin, business development director of sales at Babcock & Wilcox Volund, reports

The majority of waste to energy commentators agree that the UK will require additional WtE capacity alongside the infrastructure currently in build. The need for further capacity includes biomass projects, which have an important role to play in treating waste wood. Veolia's recent report, The Circular Economy Revolution, suggests that up to nine million tonnes of waste wood could be going to landfill.

Why is additional capacity required? The key issues are:

• The UK will export over 2.5 million tonnes of refuse-derived fuel (RDF) in 2015; a market it has no control over in terms of price and available capacity, especially in the medium to long term.

• There is a large commercial and industrial residual waste market in the UK.

• Over 20 million tonnes of waste is still being sent to landfill.

• Although the aspiration is for the UK to recycle 70% of household waste, recycling rates have stalled and the UK faces a real challenge to meet even a 50% target by 2020.

• Authorities are scrapping food waste collections rather than implementing them – for good reasons in times of financial constraints, such as high cost versus low volumes being collected.

(Although one is classed as recovery and the other as recycling, there is an argument to leave food waste in the residual waste stream, noting established waste to energy technologies are a lot more efficient than AD, notwithstanding the financial savings).

Technology choice

There is an ongoing debate between the use of established technologies or advanced thermal treatment (ATT). So why has ATT, e.g. gasification, become the latest vogue for some?

The main reason is that it is driven by the UK subsidy regime, which perversely gives more support to unproven technologies in the residual waste treatment market than to those with a proven track record. For example, under the latest subsidy framework, contracts for difference (CfDs), gasification projects can be electricity-only, but if established technologies are used then the project must be a combined heat and power scheme.

Some key issues arising from the CFD regime are:

• To secure subsidy support, projects now have to go through an auction process. Under the first auction – applications having been submitted in October 2014 – no biomass projects received support. Why would anybody put effort into developing a new biomass scheme when receiving subsidy support is effectively a lottery?

• Why should 'emerging technologies' receive greater support ahead of technologies that are already proven in treating residual waste and other waste streams in the UK? For example, it seems to be forgotten that residual waste is a difficult fuel to handle (it is very abrasive and corrosive).

• No third party is going to give a medium- to long-term contract to use the heat, because in the current economic climate no one can guarantee the future. A classic example of this relates to RWE's development of the Mackinch biomass plant in Fife, Scotland, to service the adjacent Tullis paper mill. The mill has gone into administration and the RWE plant has just been commissioned.

The establishment of district heating networks would give a much more sustainable heat use. However, without clear policy support from the government to develop these, only small-scale developments are likely to proceed – we will continue to fiddle around the edges. It could be argued that the CfD regime has a number of failings. However, why should government effectively be distorting the market, when all renewable technologies should at least be supported in an even-handed way?

Support for WtE/biomass schemes will be even more important for the UK to meet its renewable energy targets. This is especially true following the announcement that, from April 2016, subsidies for on-shore wind are being withdrawn.

Stepping into the breach

It was recently reported that 388 planning applications have been submitted for the development of on-shore wind projects. The energy minister, Amber Rudd, suggested that circa 250 of these schemes are unlikely to go ahead following the recent announcement.

The loss of generation capacity will have to be replaced with other renewable sources.

Meanwhile, various organisations are looking to promote new technologies, when the established ones are at the forefront of technological development.

For example, the Energy Technologies Institute has been progressing a demonstration programme to pick a gasification technology to show that WtE can be developed at small scale and achieve a minimum of 25% net electrical efficiency. However, they are four to five years away from confirming this or otherwise, yet the Peterborough scheme currently being built by BWV and Interserve on behalf of Viridor is an 85,000 tonnes per annum facility and 27% net electrical efficiency has been guaranteed. The R1 figure is 0.77. Why reinvent the wheel when a perfectly good one already exists?

We are also seeing a number of gasification technologies being proposed for projects that have operated on different waste types, either on a smaller scale and are being scaled up or that only currently process a uniform waste stream.

I have seen numerous technologies from other sectors applied to treating waste, only to fail because of the diverse nature of residual waste. You just have to look at how MBT facilities are struggling to operate in the UK because the waste is so abrasive.

For some, ATT is seen to be more acceptable from a planning perspective. BWV is currently involved in the construction of a 600,000 tonne per annum plant in the heart of Copenhagen, to replace a 40-year-old facility.

It has been fully accepted locally as part of using waste as a fuel and developing renewable combined heat and power projects. But consult on a WtE project in the UK and people go into the not-in-my-back-yard mode.

Interestingly, BWV is currently constructing two 40MWe waste wood projects at Margam, Port Talbot in South Wales and Rotherham in South Yorkshire. As such, before financial close both these schemes needed planning submissions; indeed, Margam needed a new application.

As BWV is supplying the same technology as it would for a WtE scheme, the DynaGrate with a waste fired boiler, there was not a single objection to the applications. In fact, the local planning authorities were very supportive, a key issue for them being inward investment and jobs. There is a misconception that established technologies are not moving forward. This is totally incorrect.

The challenge is that there is always a very fine balance to be struck between increasing performance against the very abrasive and corrosive nature of residual waste.

In fact, I would argue that established renewable energy technology is advanced conversion technology when you look at the waste streams that can be handled, the performance and, more particularly, the electrical efficiency that can be achieved: far greater than through gasification projects.

Benefits of established technology

In simple terms, residual waste covers a very wide specification and established renewable energy technologies can handle the majority of this, while ATT technologies need a tightly defined specification to be successful.

Yes, front-end treatment is proposed, but look at the history of mechanical biological treatment in the UK. Furthermore, waste characteristics change over time, and established technologies can deal with ever changing waste streams, whereas ATT will struggle now and in the future. Just consider how many advanced conversion technology (ACT) plants are currently successfully operating in the UK compared to WtE and biomass projects using proven technology.

In considering policy and the associated legislative framework, we try to tread a middle road so as not to upset anyone. Why?

Why reinvent the wheel when a perfectly good established one already exists?

- To take the EfW debate forward, book a place at the International EfW conference that is taking place in London on February 24-25 2016. Visit www.efwconference.com


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