The next regular meeting will be on Thursday 03 August 2023 at 16:30 – 18:00  (and every 4 weeks thereafter). This will be by zoom.

Only a few attended this session, but lots of topics raised/sent in, we managed to discuss a few.

Heat Pump (HP) Case Study:

The detailed data sent in by an Energy group regular is revealing many interesting aspects of HPs and heating systems in general.  The daily meter readings for a building with several occupants cover two years, one with mains gas heating and the other with a HP.  This has allowed for a more accurate calculation of this particular HP system’s Seasonal Performance Factor (SPF) was.  The resulting SPF of ~2.4 is slightly less good than the average of 2.7 for the most recent study of a large sample of UK HP systems. The heat energy calculation was adjusted to allow for differences in external temperatures for the two study years using monthly degree-days.

The analysis identified a number of issues relating to incorrect setup of HP controls as well as particularly low efficiency when used for water heating.  These shortfalls as well as other installation problems, were confirmed by independent heating engineers.  These investigations were a consequence of the homeowner undertaking a self-help ‘simple’ heat assessment programme (E-Pack), they are now starting targeted remedial action.  By continuing to monitor consumption (monthly is ideal) they will be able to quantify the energy, and cost, reduction of these actions.

CFT & new feature:

Lookout for the new Carbon Intensity Search facility in the CFT.  This is for anyone who wants to undertake more detailed calculation of their food, good and services.  The source data is the same as that used in the CFT, but we are looking to expand this to include more detail and more accurate Carbon Factors (e.g. kg CO2e/kg of item).  Take a look under the help panel for food/stuff and give us your feedback.  If this search/lookup method proves useful, it may find an application in other areas like finding a safe action to mitigate climate change or how/where to recycle x item.

Community Energy England (CEE) webinar recordings:

For those that missed the CE fortnight series of webinars, you can see them here.

We also talked about the Devon Community Energy Network, a forum for member organisations involved in helping their local community in various aspects of low-carbon energy generation and use.  You can find and contact your local group if you want to find out more.

Cinema development in Newton Abbot:

ACT commented on energy/emissions related aspects of the initial (controversial) proposal for this town centre development (22/01129/MAJ).  This latest proposal has an improved statement on emissions and energy use, but falls short on some detail.  In particular the lack of a design target for energy use and emissions as well as the lack of a reassurances that the essential fit-out of Mechanical Ventilation and Heat Recovery (MVHR) systems will not incur addition retrofit costs or compromise the building’s specified air tightness.  Based on the data provided using our calculations, the heat energy loss is expected to be ~62 kWh/m2/a if full MVHR is implemented, ~103 kWh/m2/a if not.  This compares poorly to the AECB recommendation of 30 kWh/m2/a for new buildings (<40 for heating and cooking).

Bovey Tracy/Newton Abbot rail link:

This Heathfield line has come up several times over the past 10 years, most recently at one of this group’s meetings last year.  A good analysis of capital costs has been undertaken recently, including the tricky level crossing.  A Bovey based ACT member is advising the group who is preparing the business case for this project.  We discussed some of the more significant short falls, such as market/demand analysis, operating costs and alternative options.

Urban wind turbines:

Again, a topic previously discussed, focusing on vertical axis turbines which do not appear to have ‘taken off’!  There is now a new design/concept which uses a large ‘collector’ to focus wind speed/volume onto a smaller turbine.  More on this at the next meeting.

Offsetting:

The pros and cons of this are worth discussing as it is being promoted as an alternative to reducing ones own emissions.  Unfortunately, we ran out of time, so we’ll be discussing this at our next meeting.

Home battery:

There was a request for advice on adding a 10kWh battery to an existing PV system.  We have discussed this on several occasions, but can cover it again at our next meeting if time allows.  In the meantime, information on residential battery systems and how to correctly size them and calculate their carbon/monetary pay-back can be found here.

Best wishes
Fuad
Coordinator for the ACT Energy group
covering energy, built environment and transport