Expert article
Modifier 16 April 2024
by Donal O'Herlihy

Challenges adopting Circularity in Energy projects

Used cables
Recycled cabling
RE/SOURCED aimed to construct a DC Smart Grid using circular principles at Transfo, a former coal fired power station site in Belgium. The original project design included a range of electricity generation and storage technologies as well as the construction of a Smart Grid.  This article explains how the application of circularity was implemented.

RE/SOURCED initially aimed to utilise a range of reused components serving its Smart Grid including:

  • Second life solar panels
  • CHP plant
  • Small Scale Pumped storage
  • Battery Storage
  • Flywheel storage
  • Re-use of a steel super-structure from an existing building for the car park on which the solar PV array could be fitted.

While the project made very good progress, it encountered challenges with its “circularity” implementation. We consider below the electricity generating technologies, then the storage technologies and the car park infrastructure before drawing conclusions. However, before considering specific technology challenges that an Urban Authority might encounter when attempting to replicate a project of this kind, it is worth first highlighting the key strategic decision Leiedal made when procuring the technologies.

In order to ensure that the supply chain was embracing circularity, Leiedal integrated circularity into its tender design procedures.  This was not a “light touch” request – suppliers had to demonstrate their commitment by providing Bills of Materials showing the proportion of “circular” content in their proposals. This proved to be a real challenge for many suppliers as they were simply not set up to respond to requests of this kind.  And it became very clear that they perceived little commercial incentive (yet) to incorporate circularity into their core business activities.

This feedback made it clear that the market for the products and components Leiedal was attempting to purchase was not well developed – in fact it was, and still is, very immature where circularity is concerned.

However, it also shows the important role that public bodies can play in driving good practice in the market through their procurement processes. Like all aspects of circularity, "designing it in" at the start of a project will greatly increase the impact downstream.

Second life solar panels

The team initially considered sourcing second life Solar PV panels but encountered a fundamental challenge - no providers of second life Solar PV panels could be found. 

Unlike second life batteries for which there is an established and growing supply chain, this supply capacity is absent for Solar PV. There are four likely reasons for this:

  • First and most significantly, global supply volumes (driven by China) of new Solar PV units has grown substantially over the past five years leading to much lower unit costs (estimated recently at circa 30% the cost of European equivalents)
  • Second, the operating efficiency of solar panels decreases with time so for older units, the realistic achievable output will be notably below their original rated specification (which would be their operational specification when new)
  • Third, technology improvements have resulted in modern panels producing much more electricity than those manufactured 15-20 years ago.  In 2004, the typical efficiency was around 12.5%. By 2012, it had risen to ~15.5% while currently it is around 23%.
  • Fourth, and linked to the previous two reasons, the cost of removing (deinstalling) and testing second life panels adds to their unit cost - so older units will not only be notably less efficient than modern counterparts, they will also be comparatively expensive. It is unsurprising that a commercial market has not yet been established.

The efficiency of Solar PV is particularly relevant at Transfo as the buildings have a “heritage listing” status so there are constraints on how the site can be developed and in particular the number of panels that can be installed and the modifications that can be made to accommodate Solar PV on roof spaces. There is relatively limited space available so the project needs PV Panels with as high efficiency as it can acquire.

Second life CHP plant

RE/SOURCED was offered a CHP plant by Ecopower. The RE/SOURCED team carefully considered this opportunity but chose not to install the plant as:

  • It was designed to run on rapeseed oil so would be exposed to potential supply and price risks in sourcing the raw fuel when operating over its lifetime
  • The GHG emissions would be high compared to other fuel sources
  • Its design was obsolete so maintenance would likely be problematic as spare parts would be hard if not impossible to source. 

It was therefore decided not to take up this offer and instead install a more efficient, modern CHP unit that was lower power and uses gas as the fuel source (lower carbon emissions).

The challenge of maintaining obsolescent equipment is very real in the energy sector.  Developers who invested in wind energy between 2000-2010 are finding it increasingly difficult to maintain machines due to obsolescence and a consequential lack of spare parts.  These investments were justified on the basis of turbines having a 25 year lifetime so if they fail prematurely and cannot be repaired, this undermines the historical commercial justification.  But more importantly, it puts off investors from making new strategic investments in low carbon technologies – this is bad for energy security as well as just energy transition.

Small scale pumped storage and Flywheel Storage

For pumped storage, the project aimed to use the water tower at Transfo that served the former power station site. The aim was to pump water up to the storage tank and then use this stored resource for short term “bursts” of electricity production (less than 15 minutes) at peak times.

For flywheel storage, this was a very innovative concept.  Excess electricity would be used to “spin” a large, low resistance flywheel when there was excess capacity.  When demand for electricity increased, the stored rotational energy of the flywheel would drive a generator that would help meet this increase in demand. 

Both of these elements of the project were scheduled to be delivered during what became to be the COVID-19 pandemic. The team found it impossible, despite repeated tendering, to attract any successful bids to deliver and commission the equipment associated with these technologies. For this reason, and given the impending completion date for the project, it was decided to exclude these elements from the programme at this time. It is still the intention to implement them in the future, perhaps through a collaborative research project with a University. (e.g. funded by Horizon Europe).

Second life battery storage

Second life batteries are used to store excess electrical energy when production levels are high on site. These are housed in a dedicated facility adjacent to their main points of use. This aspect of the project has proceeded as planned and the batteries have been acquired. Currently, they are in the process of being installed and their control systems (EMS) commissioned.

This aspect of the project was comparatively straightforward as the supply chain for second life batteries exists (three out of five tenders offered second life batteries) and there is a support infrastructure in place within the market to extract, test, recommission and maintain these units.

Steel structure for carpark

There is one significant Solar PV array on site positioned on the roof of a newly constructed car park that will have EV charging points. It was proposed that the steel superstructure from a derelict building would be extracted and reused as the superstructure for the new car park.

The building from which this steel structure was to be extracted was chosen specifically due to its proximity to the site to minimise transportation.  It was inspected when designing the project and the structure was deemed to be suitable.

However, there were problems when it came to demolishing the building, and in particular extracting the steel superstructure intact. Specifically, the superstructure (over 100 years old) was constructed in a way that was not designed to be removed, let alone dismantled - it was not designed with circularity in mind. Consequently, attempts to remove it without damage proved impossible and further investigations indicated that it could not be removed without causing substantial damage to the structure - thus rendering it unusable at Transfo.

It was decided therefore to purchase a new steel structure for the car park, but one that would be designed for disassembly and reuse should that be required in the future.  This was also cheaper than reusing the existing superstructure.

At first sight, it might seem that the project has been unsuccessful in adopting circularity as a core operating principle - it had aimed both to utilise novel energy storage technologies and re-use building structures and materials.  

The experience of RE/SOURCED suggests that there are four practical factors to consider when contemplating a renewable energy project using circularity, namely that it:

  • Can be (much) more expensive to deliver when compared to a similarly specified project using contemporary off the shelf solutions
  • May deliver less efficient/lower performance solutions than a project using contemporary off the shelf solutions
  • May mean maintenance is challenging as spare parts may be difficult if not impossible to source
  • May mean manufacturers warranties have expired. 

So why might we bother pursuing circularity in a project of this kind?  There are two key reasons:

  • first, to minimise the loss of key elements and materials that could otherwise become waste - especially where this waste ends up as landfill or is disposed of at sea; and
  • second to retain the embedded carbon within the materials and components used (see separate web article).  Thus, if we are really committed to reduce carbon emissions, we must adopt circularity to do so.

What the RE/SOURCED experience shows is that even when you are fully committed to embracing circularity, it can be a challenge to deliver effectively.  It also points to big opportunities for policy makers to stimulate circular supply chains and develop remanufacturing competencies in targeted areas – especially for energy assets that may become prematurely obsolete.  Exploiting these opportunities could make a significant contribution to just energy transition, broad spectrum employment creation, energy security and sustainable economic growth.  So circularity really is worth it when designing energy projects.