RO banding: advanced conversion or primitive combustion? – By Rolf Stein, CEO

There is enormous potential for the energy from waste (EfW) industry globally. Using waste to deliver renewable energy reduces dependence on fossil fuels, lowers the carbon footprint of power and heat generation and offers a sustainable, clean way of diverting waste from landfill. There are many advanced conversion or gasification technologies (ACTs) that offer ways to “green” our power generation and waste management infrastructure without incineration. However, the ACT industry faces many challenges before it can achieve mass commercialisation.

In July, nine months after its consultation began, the government published the Renewables Obligation banding levels. Contrary to earlier proposals and to expectations, all “ACTs” were awarded two Renewables Obligation Certificates (Rocs) and the minimum qualitative qualifying criteria were removed. October 2011’s consultation document had suggested that there should continue to be a tiered level of subsidy for “standard” and “advanced” ACTs based on the efficiency of the power island or generating station. By putting all ACTs in the same bracket of financial support, the government has perhaps sought to ensure the success of a number of EfW projects – albeit with unintended consequences and on the basis of questionable data.

The failure to distinguish between the different types of ACT available could lead to a proliferation of technologies that, in truth, are not advanced or innovative at all. Furthermore, it could damage the nascent advanced gasification industry in which the UK is leading the world. The Department of Energy and Climate Change’s (Decc’s) initial tiered classification for ACTs would have clearly differentiated between the more efficient and innovative methods of energy recovery and the well-established alternatives.

The proposals released in July allow for no such distinction and were apparently based on data gathered during the consultation, which suggests that standard, established technologies were in some cases 50 per cent more expensive than emerging, advanced alternatives and therefore, taken as a whole, required the same level of support.

Although the draft order issued by Decc at the end of August this year seems to maintain the distinction between standard and advanced in the definitions, it does not distinguish between the level of financial support. The draft Renewables Obligation Amendment Order 2012 differentiates between advanced and standard gasification by setting out the calorific value of the gaseous fuel (syngas) required if a technology is to qualify as an “advanced” ACT. The order requires that advanced technologies must have a value of at least four megajoules per cubic metre whereas standard gasification would be anything less than this.

This is an important distinction because genuine advanced gasification technologies operate more efficiently by producing a syngas suitable for use in higher efficiency power islands such as gas engines or turbines. For this purpose, the gas must be of a high quality, both energetically and from the point of view of contaminants. As the government acknowledges in the banding consultation response, the production of such higher quality syngas is desirable not only for power generation but also in the context of alternative fuels. For instance, the syngas can be converted into bio-substitute natural gas (bio-SNG) that can be injected into the national grid. It is estimated that bio-SNG could meet as much as one-fifth of the

UK’s total heating requirements by 2050, currently responsible for 35 per cent of the UK’s carbon emissions. With the necessary investment, advanced gasification technologies could therefore contribute significantly to greening the UK’s energy network.

By supporting ACTs, the government has indicated that it favours such a technological approach as the gateway to future downstream syngas applications. However, although the draft order seems to continue to recognise that there is a difference between standard and advanced technologies, this is not reflected in the levels of financial support. If implemented in this form, the RO band will be open to abuse by more conventional combustion technologies that offer no advantage over incineration and do not serve as a gateway to further downstream syngas applications. This cannot be the objective of the RO and there is consequently an urgent need to clearly differentiate between genuine gasification and combustion technologies at the very least on the basis of a minimum syngas quality standard. Only in this way will the policy objective be realised, allowing advanced technologies to come to the fore.

By compelling advanced technologies to compete on a level playing field with their well-established competitors, the government’s decision could undermine the expansion of an efficient and low-carbon waste-to-energy infrastructure.

Rolf Stein, CEO, Advanced Plasma Power

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