Dr William Ho & Dr Prasanta Dey
Developing a framework for sustainable bioenergy systems in the UK.
My research concerns improving the success and efficiency of new renewable biomass power stations for the UK. The research will produce a method that can be used for determining which supplies of fuel should be contracted to best meet the needs of the new power system. By considering the needs of the multi-stakeholders within the biomass supply chain, the method will enable long term, holistically successful supply chains to be designed at least cost to society and the environment.
Biomass Power Stations
In the coming decades UK industry and government will be investing heavily in new and renewable power systems. Biomass power stations form a key part of our future energy mix and are financially competitive under current legislation and using existing technology. Presently the supply of fuel to power stations presents a hurdle for project finance as the length of supply contracts, quality of fuels and business relationships are unclear at a pre-project phase, reducing the length of loans available.
Optimisation for cost within fuel characteristics
As part of the research an optimisation model has been built. This allows the decision maker to enter information on the chemical and energy properties of a potential fuel supply along with expected price and determines the optimal blend of fuels that can combine to meet the technical operating specifications of the plan.
Whilst much of the supply end of the bioenergy industry is aiming to move towards a commodity based market through the introduction of quality and property standards. However this approach could exclude many viable fuel sources from being used in conversion plants. This research accepts that the biomass market will not include all viable fuel sources and aims to find the genuine optimal blend of fuels. This makes the application of traditional supply chain techniques more difficult. However the overall cost of fuel for a scheme, and ultimately the energy generated, can be reduced by sourcing wastes and materials from non-commodity markets.
Whilst much of the supply end of the bioenergy industry is aiming to move towards a commodity based market through the introduction of quality and property standards. However this approach could exclude many viable fuel sources from being used in conversion plants. This research accepts that the biomass market will not include all viable fuel sources and aims to find the genuine optimal blend of fuels. This makes the application of traditional supply chain techniquest more difficult. However, the overall cost of fuel for a scheme, and ultimately the energy generated, can be reduced by sourcing wastes and materials from non-commodity markets.
A further layer of complexity is added by the significant variation found in these non-commodity materials. Materials such as municipal waste, agricultural arisings, commercial wastes and forestry residues change over time. Sometimes these changes are seasonal whilst in some cases there is a systematic variation in properties, this is particularly the case when looking at waste products.
To deal with this variation the optimisation model was extended and improved to optimise for supply using stochastic techniques. The output of this model is a recommended quantity to take from each supplier in order to ensure that the blend is within requirements as much as possible whilst realising the greatest financial benefit.
The charts below show the constraint regions for moisture content (%) and aluminium content (mg/kg). The shaded area is the feasible region and 3 representative fuels are shown with a Gaussian probability distribution for both properties. The red line shows the property of the fuel blend produced when the recommended mixture of materials is combined, the red line will move around as the properties of the fuels change over time.
A Monte-Carlo simulation was used to measure the performance of the optimization process. This shows that the technique is effective over a long time frame and is not optimized just for one, non-representative combination of properties.
Integrating tacit requirements into the supply chain
The next step of the research will look to help decision makers to understand and cater for a wider selection of requirements. To date the design of the supply chain has focused on the technical feasibility for lower cost, however, given the potential for environmental, social and economic risk were the supply chain to fail or act unpredictably it is important to align the requirements of different stakeholder groups. By selecting a supply chain which satisfies the needs of the financiers, the government decision makers and local interest groups as well as developers, operators and suppliers, a more holistically successful project can be created through good operations management.
The research is currently seeking the opinions of key stakeholders within the bioenergy supply chain. These opinions will form a library of weighted preferences against which each supply, or a whole supply portfolio can be assessed. To participate in this research and communicate your requirements along the bioenergy supply chain please used the contact details on this page.
For further information see Jim's student profile