Project Drivers
UK Energy Supply
The UK energy generation mix is changing. Using data from DUKES (Digest of UK Energy Statistics) it can easily be seen that gas and coal are large contributors to the UK electricity supply. With the expected decommissioning of multiple gas and coal fired power stations, the UK may struggle to meet future demands as a result [1]. In order to reduce the risk of blackouts, National Grid are telling industrial and large consumers that “at certain times of the year… switch off the energy please, because we do not have enough" [2].
This will impact large industrial consumers more so than anyone else, heavily influencing their production and having negative consequences on their commercial viability. The decision to ask larger industrial consumers to switch off has been reinforced by UK legislation.
UK Electrical Generation Mix 2014 (DUKES)
Figure 1. UK Natural gas production and consumption [3]
There has also been a decrease in gas production in the UK. Figure 1 [3] shows the change in production and consumption over a range of 10 years, and it is evident that as production is decreasing significantly, consumption remains approximately the same with little change. This has led to gas demands not being met by UK gas production.
Due to the nature of the supply of electricity and gas, the prices have began fluctuating which has created another strain on large industries.
Additionally, companies will also wish to promote a greener image, which requires them to consciously reduce their CO2 emissions, while still obliging to their carbon obligations by law. This is why it is of the utmost importance that industrial users who wish to avoid restrictions on energy usage should focus on achieving energy autonomy, to the fullest extent possible, and of course why this was the main focal point throughout the project.
Plant Demands
Typical heat and power demands of a large scale industrial plant are displayed below:
It is easy to see that both demands vary dramatically throughout the year, and that both have a very large base load. Commonly, the heat demands are met using a boiler which burns a type of fossil fuel, usually gas, and the power demand is met through a grid connection. Some companies have also installed greener on-site generation, in a bid to meet the green goals mentioned previously, such as wind turbines and/or solar panels. Although these will reduce their emissions and costs, they are unpredictable energy sources as they are fully dependent on weather conditions.
For such a scenario, it may prove useful to install a combined heat and power (CHP) plant as it is able to meet a proportion of the power and heat demands of an industrial plant. CHP has many benefits; it has high fuel efficiency, is despatchable and will provide a secure supply thereby increasing autonomy.
Some large companies have considered biomass to be a suitable option, such as Caledonian Paper, Drax power station, and GSK [4] . As wind and solar generation is intermittent, it is difficult to establish a constant supply of energy, while biomass as a CHP fuel source is able to provide a more secure and reliable supply of energy compared to stochastic renewable energy sources. As there are many different types of biomass, there are also multiple fuel options which can be considered, and also a possibility of sourcing biomass locally, compared to traditional methods where biomass is sourced from America. Biomass is often viewed as a “renewable fuel”, but is this always the case? This question is something we hope to explore in this project.
These drivers allowed us to develop aims and objectives for the project.