Wondrwall replicated their regular onboarding process with the tenants, which involved contacting the tenants via phone prior to moving in, followed by a home visit upon moving into the property. During the home visit, the tenants were introduced to the system and controls and Wondrwall staff set up a schedule for heating, based on what the tenants told them about their preferences and daily routines.

Reflecting later, the Wondrwall staff member thought that, at the point of moving into their new home, tenants found it challenging to focus on the onboarding process. Upon moving into the property, the tenants were provided with a significant amount of other information related to their tenancy, which could mean that their heating system was not a priority, particularly given that the heating season had not yet started.

Chris expressed that they were initially worried that they might find using the Wondrwall system difficult and might need to access out-of-hours support if they were struggling. They reported finding the induction process, as well as the system, confusing. As a result, they contacted the Council via email on a number of occasions with various questions. The Council and Wondrwall arranged a number of support visits, which were cancelled or unattended by the tenant, making it difficult to receive tailored support during this stage.

In contrast, Ali found the Wondrwall system “very surprising” and appreciated the space-saving and safety aspect of the infrared panels, particularly given their young children (as there are no hot radiators within children’s reach). They reported that they were pleased with having the system installed in their home and that friends and family also found it intriguing. They reported no problems with the induction process itself, but did flag some minor initial issues with the system not being connected to their smartphone straight away and some light switches not working. These issues were resolved quickly by Wondrwall.

The tenants had mixed experiences of using and controlling the Wondrwall system.

Chris expressed low overall satisfaction levels with the system and difficulty adapting to it, particularly when it came to changing settings and understanding how the heating worked.

Chris and their partner avoided touching the central system controls out of fear of breaking the system and shared that they “found the system quite confusing”. Their confusion with using the system led to them requiring almost weekly over-the-phone and in-person support from Wondrwall. Some of the issues that required support included the “the heating not being hot enough”, a damaged button and an electrical fault. While they were able to contact Wondrwall for support whenever they needed, sometimes a few times a week, they noted that the Council was less knowledgeable about the system and was not able to troubleshoot issues for them.

Chris expressed dissatisfaction with their ability to control the system. They disliked the fact that the system turned on and off by itself (due to the schedule that was set during the initial set up) without the option of easily turning the whole system off. They were unsure of how to change the temperature, and said that their house was often too warm. They preferred the level of control they had with their previous radiator based system, but were unsure whether they would prefer to go back to having a traditional heating system, as they still appreciated “how techy it is”. While running the system was confusing, they appreciated the availability of smart features such as the ability to control the heating on their smart phone.

Ali expressed higher levels of satisfaction with the use of the system, but low satisfaction levels with the resulting energy use (discussed below). Unlike Chris, they found the Wondrwall system convenient and easy to use, particularly when it came to controlling the heating and lighting remotely with their smartphones. They said that they would probably not go back to a traditional heating system if the issue with the high energy consumption was resolved, although their partner said they still preferred gas and traditional heating with radiators. They also contacted Wondrwall for support on a regular basis and felt that the Council was less knowledgeable and able to support them. Both the Council and Wondrwall supported the tenants over the phone or in person on a regular basis, but reported this was often made difficult due to the tenants cancelling or not showing up to appointments.

Tenants reported that the system generally performed well in winter, keeping their homes warm when they used it. Both participants said that on some occasions the system would unexpectedly turn itself off, even when the room temperature was below the set threshold.

Chris reported that their house was warm throughout winter and that they preferred to keep most rooms at a temperature between 20 and 22°C, but that their house was often too warm because the system turned itself on regularly. The temperature measured by the system (discussed in the following section) was significantly higher than their reported ideal temperature.

Ali found the heating to be adequate when the system was on, but reported that it took a long time for the house to heat up, which in turn, led to high energy consumption and electricity bills, which forced them to reduce usage.

Both tenants reported using a secondary heating source (electric radiator) on really cold days.

Both tenants had higher than average energy consumption over winter, which was mostly driven by their heating usage.

Chris had the higher energy use of the two, with an average monthly consumption of 1,449 kWh and a total energy consumption of 10,141 kWh between September and March. Although we were unable to track their energy consumption over a whole year due to the constraints of this study, their total energy use between September and March was already higher than Ofgem’s predictions for the mean annual electricity consumption for low-income households (5,120 kWh), and for all other electrically heated households (7,674 kWh) (3).

Some of this consumption was expected to be offset during summer (after the end of the pilot), when their solar panels should generate more energy compared to the winter months. Wondrwall predicted Chris’ property would generate 3,456 kWh over a full year, which, when accounted for, brings the September to March consumption figures to 6,685 kWh (4). This is still higher than Ofgem’s mean annual electricity consumption for a low-income electrically-heated household, despite only covering seven months of the year.

These energy consumption figures could be explained by the temperature data collected by Wondrwall. Chris had an average home temperature of 24°C in January and regularly heated rooms such as the kitchen and the master bedroom at even higher temperatures of 27°C and 25°C.

Given their total energy consumption and taking into account their solar generation, we estimate that participants’ bills covering September 2022 to March 2023 are likely to have been around £3,200 (5).

Chris said they had not received any information on their energy use or bills from either the council or their energy provider (as of March 2023). This is because their energy provider placed them on a half yearly payment cycle, meaning that they were not issued a bill during the first six months of living in the property. Their attempts at moving onto a monthly payment plan were unsuccessful. The Council said they had advised the tenant to move to a different supplier as soon as they were made aware of the six-month billing plan and offered to support with the switch, but that the tenant did not take them up on the offer.

Chris also did not have an in-home display and smart meter fitted in their property. This meant that they were unaware of their high energy consumption throughout the winter. Towards the end of the six-month period, with support from the Council, they moved from British Gas to Octopus Energy and, while they had still not received a bill for the five months from British Gas, they had received a bill for £400 for their first month of using Octopus Energy as their provider, which was higher than they expected.

Ali’s property had lower energy use compared to Chris’, but still higher than average. Ali’s average monthly consumption was 1,169 kWh and their total energy consumption between September and March was 8,186 kWh.

Wondrwall predicted Ali’s property will generate 2,303 kWh over a full year, which, when accounted for, brings the September to March consumption figures to 5,883 kWh (6). Despite only covering seven months of the year, it is already higher than Ofgem’s predictions for the mean annual electricity consumption for a low-income electrically-heated household (5,120 kWh).

Ali had an average home temperature of 20°C in January and regularly heated rooms such as the living room and kitchen to temperatures of 25°C and 22°C respectively.

Given their total energy consumption and taking into account their solar generation, we estimate their bills covering September to March to be around £2,700 (7). Ali indicated that the high cost of using the system was the greatest drawback of the Wondrwall system. They had been paying for their bills monthly and were very concerned about their high energy usage and resulting high energy bills (they estimated paying around £2,500 since moving into the property), which impacted their ability to use the system consistently. They also noted that, before they received their first bill, they had assumed that their energy bills in the property would be very low. Similarly to Chris, they switched to Octopus Energy from E-On towards the end of the six-month research period.

Participants were told by Wondrwall that they should move onto a special tariff that would allow them to take advantage of the significantly cheaper off-peak rates overnight to charge their battery. Moving to a different tariff was the responsibility of the participant. Neither participant had switched to a recommended tariff by March 2023 and both said that while Wondrwall had mentioned the importance of being on the right tariff to them, this had not been made clear to them by the Council.

This meant that for the duration of the trial, the tenants were unable to make use of the significantly cheaper nighttime energy tariffs to charge their battery. While it is difficult to assess exactly what their energy bills would have been on a different tariff, Nesta believes their bills would have been significantly lower (in April 2023 Octopus Go’s Night Rate for electricity was three times lower than the day rate).

Reflecting on the process of getting the tenants to move to the right tariff, Wondrwall said that this differed from their usual interactions with new system users, who are usually eager to make the most out of the benefits offered by the Wondrwall system.