Resident Technical Working Group update

The following note has been circulated by the Resident Associations on behalf of the Resident Technical Working Group (RTWG). As a reminder, the RTWG are a volunteer group of residents with technical expertise in energy and major projects. A huge thank you to them for their tireless work.

Hello to everyone who has shown an interest in receiving updates from your Residents Associations on the progress of the Future of PDHU project. The RTWG had two updates from the project in recent weeks and we thought we'd provide you with an update ahead of the meeting planned for Wednesday (24th of September). This is when the Future of PDHU project team will be presenting to Residents. There is also an additional Tenants forum on the 25th.

The information below is intended to provide background to the slides that were sent out by the 'Future of PDHU' project.

Here are few important points 

• Following February’s meeting, the project has conducted further technical analysis and restated their assessment of the various technical options under consideration

• The ordering of those solutions has changed but a renewal of the PDHU remains the preferred approach compared to switching to individual electrical systems

• The project now wants to focus on a short-list of options and nominate a single solution by start of 2026

• It looks likely that a Direct Electric option will be removed. 

Given the current rankings, we can assume a similar outcome to what was proposed last year.

Despite promises made by the council, the RTWG does not get to see detailed technical analysis which would help us understand how these decisions have been reached. However, at this point we think it remains important to retain at least one option that uses the existing pipes and one that uses electricity.  This will help ensure a balanced cost analysis for the next phase of work. The proposed changes to the pipes (or switch to electricity) remains one of the biggest areas of cost, disruption and risk to the work.

With the project team recommending options that are all water-based. the following summary is probably true for all the options being carried forward:

• As water-based solutions have to be installed by block, residents may face lengthy disruption to their existing supply and therefore require them to relocate for a time. 

  At completion, the supply of heat will remain with WCC.

• Based on the previous re-piping experience that some residents shared, renewal of infrastructure does not guarantee its longevity or leak reduction.

While OFGEM is scheduled to become the regulator of district heating supplies nationwide in 2026, the exact regulations and timing of when they apply to existing systems like the PDHU is unclear.  OFGEM already provides clear guidance for the tariffs related to commercially available direct supplies (the direct electric options). It feels as though this decision is being rushed through to avoid the additional scrutiny this would involve.

The RTWG remains concerned that it is too soon to make this decision based on the amount and quality of information shared. We’d like you to consider this carefully when hearing from the council this week. This meeting is only for the council to provide an update, not to ask your opinion. We think that is wrong. 

Other information from the recent meetings:

FairHeat review: This is an external review of the existing piping and the heating system which has only been conducted in the last few weeks. The report has not been shared but we understand it considers the current infrastructure to be in reasonable condition but with only 8-10 years of usable life in the best parts.  We haven’t seen the details of this, but we have outstanding questions about how the information is being presented.

Ground-sourced heat (e.g. the Kensa project in Kensington): is considered unsuitable for Pimlico as 'thousands' or boreholes would be needed - up to 200m deep. The RTWG does not consider this new insight, and more clarity is needed to explain why this wouldn’t work here but does one mile away.

SWAN: has been de-selected as they have been unable to provide a formal proposal of how they might supply heat to Pimlico. There was no further information shared regarding the background to this, but it was noted that this now left just one third party heat supplier (Mobile Heat Batteries/Cory) in the long-list of options.

Cory: The approach proposed by this supplier is broadly the same. It has been suggested that the technical solution may now rely on transporting heated water rather than heat batteries. The key difference here would be the improved simplicity when transferring the heat from barges to the PDHU network. A longer-term ambition would be to provide a pipeline directly from the heat generation plant in Essex, to central London. Clearly this is not going to be available quickly and we can assume the investment needed to achieve this will come, in part, from the ongoing heat tariffs (cost of energy)

Electric: The assessment approach for this remains unclear. As we understand it, UKPN has only been asked to provide cost estimates for the network connection to each of the blocks.   The approach and cost for the building and dwelling changes have been developed by the project team and no cost details have been shared.

The project is of the view that the cost of delivered energy (the consumer tariff) remains the highest and that has been key in driving down the overall assessment score for this option. We weren't given any further detail to understand that assessment further, but the result seems to be that this will be deselected for further analysis at the next stage.