The former Ebbw Vale steelworks in South Wales is home to a potentially game-changing regeneration project. Marc Rees explains what’s so special about it.
The Works, a community redevelopment joint venture between the Welsh Assembly Government and Blaenau Gwent County Borough Council, is a flagship for sustainable development in Wales. The project will transform the site of the old Ebbw Vale steelworks with new housing, a hospital, education facilities and a business hub. What’s interesting about The Works is the project’s whole-scheme approach to reducing carbon emissions, using technologies implemented on site.
From 2016, the carbon emissions from energy use in new-build housing schemes must be 70 percent below what they were in 2006. The code for sustainable homes – the national standard for sustainable design and construction – uses a six-star scoring system to rate the performance of new homes, with a mandatory four-star rating applying from 2013.
The Works is going above and beyond these legal requirements by voluntarily adopting a five-star rating as its minimum building standard for new homes and an additional 60 percent emissions reduction in all non-domestic buildings.
To meet these statutory and voluntary targets, the project must address the question of how best to deliver low-carbon heating. This has provided industry experts and academics with a major challenge in recent years. Cardiff University found The Works invaluable as a case study. Under the Engineering and Physical Science Research Council’s Flexnet project, the university has been developing a new set of integrated design and analysis tools to help assess the viability of different technology options when building new infrastructure.
One insight these tools have provided is that the least-cost mix of on-site technologies is sensitive to the carbon intensity of electricity supplied by the grid.
For example, the analysis shows that if The Works was to be completed in 2012, the most cost-effective heating option would be a combined heat and power (CHP) system, running on natural gas and supplemented by solar photovoltaic (PV) panels. But, by the time the scheme is actually completed, this may no longer be the case.
This is because the mix of energy-generating technologies that supply the UK’s electricity grid is changing, and the associated level of carbon emissions is set to fall. CHP systems burn fuel to generate heat and power, reducing the amount of grid electricity the site consumes, but increasing the fuel consumption on site. As long as the additional fuel emissions do not exceed the savings from on-site electricity generation, the CHP system is reducing emissions overall. But, as the carbon intensity of grid electricity falls, so does the emissions reduction CHP can provide – until CHP actually starts increasing the site’s overall carbon emissions.
Heat pumps, on the other hand, rely on a decarbonised electricity grid to deliver on-site emissions savings. Assuming now that The Works will be completed in 2020, the analysis shows that a least-cost solution would be predominantly based on heat pumps and solar hot-water heating.
A coherent framework
However, this does not necessarily make heat pumps the best long-term strategy for new-build schemes. External factors – such as a renewed dash for gas, the regulation of district heat and alternative fuel resources, as well as the stagnant economy – all place question marks over the performance of either option.
Many avenues of research still remain. Natural gas-based district heating, for example, may prove a transitional step towards lowercarbon heating resources such as biomass, municipal waste or low-grade heat recovery.
So it remains to be seen whether Ebbw Vale will emerge as a template for new building developments in South Wales. However, the project’s whole-scheme approach will provide others with a framework for determining which of the available solutions can deliver genuine emissions reductions, across the whole site, over the long term – even accounting for the largescale decarbonisation of the grid.