Energy options for the Oxford-Cambridge Arc

Dr Modassar Chaudry, Senior Research Fellow in the School of Engineering at Cardiff University, introduces his analysis for ITRC on the proposed Oxford-Milton Keynes-Cambridge Arc development

Integrated energy supply systems are my research specialism and my area of focus for the modelling that ITRC (UK Infrastructure Transitions Research Consortium) recently completed on the proposed new Oxford-Milton Keynes-Cambridge Arc development.

Various teams within the ITRC programme are modelling sectors like green capital, transport and so on. Looking at all the key infrastructures together is what makes ITRC modelling unique – we can run scenarios analysing various infrastructure sectors across various spatial resolutions and within detailed temporal time steps.

The ITRC models work in tandem to produce certain data and reports. To achieve this we use a consistent set of inputs and get outputs or metrics specific to our particular field of study. For energy we focus on energy demand and the energy-supply mix. This can include emissions, operational costs and the economic impact of the pathways or scenarios that we’re considering. The analysis my colleagues and I have carried out on energy is also unique; what differentiates it in particular is the modelling framework that we use and the integrated energy systems set-up. This is backed up bya very specific energy-demand model run at the University of Oxford; and an energy-supply model run at Cardiff University.

The energy model is very flexible, so we can vary the inputs –for example, local authorities or planners can decide the parameters they want to look at by, say, adding in more detailed geographic set-up.

For this initial analysis of the Arc, the ITRC’s infrastructure modelling has looked at various high-level scenarios that examine how the Arc might develop in the future:

  1. Baseline – business as usual;
  2. Unplanned development within the Arc, (such as transport links, which might impact on the area’s energy supply system);
  3. Two development scenarios – an Expansion scenario, where existing towns such as the Oxford suburban area, Cambridge or Milton Keynes expand; and a New Town scenario, where additional towns are to be built around those three main conurbations.

For the energy model, we looked at three key strategies within the four scenarios; each of which represent different technical pathways by which energy might be supplied within the Arc:

  • Electrification: representing an Electric Future, where everything throughout the Arc – heating, transport and impact on energy systems –  is electrified.
  • Heat Networks: where we examined energy supply and demand if there was a high penetration of heat networks within the Arc.
  • Green Gas: where we analysed how energy demand and supply could be met by decarbonising gas to a degree, pumping hydrogen into existing gas networks, and making use of new biofuels and new hydrogen pipelines.

In this initial pass of the analysis we focused on the impact of the three strategies on energy demand and emissions for the four development scenarios, how the supply mix might look and the costs involved.

As part of each scenario we examined how wind power and PV (photo voltaic) solar power might be used. Whilst PV did quite well for energy generation, onshore wind generation was shown not to have high capacity – partly because the region’s geography does not lend itself to this and partly because the development of onshore wind in the UK is still in its infancy. In the UK, renewable energy is dominated by PV and this showed as being the case across all the scenarios and strategies we ran for the Arc.

Looking at overall energy demand across the three strategies and four scenarios, we found that in the Electrification strategy, energy demand decreased from 2015 levels of 80TW hours to 58TW by 2050, thanks to efficiency improvements in dwellings and homes in an Electric Future, driving down energy per dwelling and overall energy consumption, despite the population increasing. Heat pumps play an important part in an Electric Future, with an efficiency of between 200-300%, using less energy to produce the same amount of heat output, which drives down the amount of energy needed.

For Green Gas and Heat Network strategies across scenarios, we found that energy demand was a little higher in our 2050 scenarios than in 2015 – mainly based on the use of combined heat and power (CHP) units, which weren’t as efficient as heat pumps. CHP has an efficiency of only around 40-50%, which drives up energy demand compared to other heating possibilities.

As might be expected, the highest demands for energy occurred in the Expansion and New Town scenarios, driven by population growth.

Electricity demand

The Electrification strategy produced the highest demand for electricity out of our three scenarios, with demand for electricity more than doubling from 2015 to 2050.

All strategies resulted in an increase in energy requirements from 2015 but the Electrification strategy showed a higher demand for electricity than the Green Gas or Heat Networks options.

Meeting the electricity demand

Within the Electrification strategy, our analysis showed that demand for electricity would mainly be met by renewables, with around 12% of electrical generation for 2050 produced within the Arc, plus around 60% provided by generation via transmission lines outside the Arc. The transmission system which cannot be controlled by the Arc development, is hugely important across the whole of the Arc.

In the Heat Networks and Green Gas strategies, the transmission percentage went down to 30% – ie  more local generation of electricity was happening through CHPs and renewables, , across all four of the scenarios studied.

We found that gas demand would reduce across all strategies and scenarios.

Emissions

In 2015, across the Arc, around 11,000 ktonnes of Co2 were emitted.

We found that in an Electric Future, those emissions would likely drop to around 1,800 ktonnes of Co2. In the Expansion and New Town scenarios, figures were slightly higher but still demonstrated a huge reduction. The latter two scenarios represent the equivalent of a net-zero strategy and approach a near-zero scenario in an Electric Future: residential and commercial emissions dropped hugely; emissions which remain would be mainly in the industrial sector and are hard to decarbonise.

For the Heat Networks strategy, emissions drop to around 5,500 ktonnes of Co2, and for the Green Gas strategy to around 3,500 ktonnes.

Costs

To make the figures more digestible, we presented annual energy costs per dwelling, represented by capital and operational costs divided by the number of dwellings.

In 2015, average cost per household across the Arc area was £820 – this represents all energy needs: electric, heat, gas, infrastructure of plants, electrical distribution networks, PV panel, and so on.

In 2050 we estimate costs of around £950 per household for an Electrification strategy, around £1,200 for a Green Gas strategy, and around £1,850–£2,000 for a Heat Networks strategy.

Our figures only include the infrastructure costs within the Arc. For Heat Networks this represents mainly the cost of laying pipes and creating the infrastructure, especially if work needs to be carried out around existing structures and roads (it’s cheaper to lay when making new roads).

Overall, the Electrification strategy was more beneficial in terms of both emissions and costs.

Our analysis also looked at the impact of Demand-side Management (that is, initiatives and technologies that encourage consumers to optimise their energy use)– for example, shifting 10% of peak demand into off-peak hourssaw a 1GB reduction in demand that had cost savings across the Arc.

Overall, our analysis showed that electrification of heating within the Arc would be the most cost-effective way to meet heating demand, despite the requirement for significant additional network capacity. However, the majority of existing dwellings would need radical, potentially disruptive change, such as the installation of heat pumps. And before contemplating any of these energy strategies, efficiencies and insulation should first be performed on existing dwellings.

Efficiency initiatives

As a whole, capital costs of new energy strategies for the Arc will be significant and are only likely to be driven down if there are considerable efforts to learn by implementing new methods which reduce energy usage going forwards and increase efficiencies across the development.

Projects such as Leeds’s “High Hydrogen Deploy” look at using hydrogen in existing gas pipes or new purpose-built pipes to supply heating, and could provide exemplars and inspiration for what can be done. Whilst costs are still likely to be high, repurposing the existing gas network could be quite competitive over a number of years.

As per the National Infrastructure Commission’s recommendations, the UK has already embarked on replacing metal domestic pipes in UK with polyethylene ones, which are suitable for carrying hydrogen. The Government plans to convert the whole pipe system by 2030.

We can also learn lessons from countries such as Denmark and Sweden, which switched to hydrogen decades ago – but such changes must have buy-in from local government and politicians.

Find out more about Modassar’s work in the Executive Summary of the ITRC-MISTRAL report on the analysis of the OxCam Arc or request the full report here.