The research and development being undertaken for this project is to research into hot water tank controllers and what effect they could have on reducing carbon emissions, the research done into the controllers was what they are capable of, what’s currently on the market and how they can be improved or better used to reduce carbon emissions. The development part of this project is to build a functioning prototype controller that will have 2 inputs and 2 outputs and then could potentially be controlled by a mobile phone. The two inputs will consist of measuring the household input current and the temperature of the tank which is measured at the top of the tank and the bottom of the tank so a good overall temperature reading of the water can be taken from the whole tank. The output signals from the controller will function two relays opening and closing the latches, these relays will be controlling the emersion heaters in the hot water tank by allowing or not allowing electricity to flow through to heat the water. It is believed that this project could help in reducing power consumption of a household, which would in turn help people save more money on their energy bills and lower the carbon footprint produced from energy consumption and reduce the amount of wasted low carbon electricity which mainly comes from renewables.
As global warming is occurring, many countries and companies are trying to help reduce the amount of carbon produced, in households having a smart controller is one way of doing that. Some of the companies that are trying to reduce carbon emissions build these controllers to help with the control of a central heating and hot water systems which as stated can help to reduce carbon emissions, this is because central heating and hot water uses up to 80% of the household’s energy consumption and the main companies that build these types of controllers are, Hive, Tado, Google, Honeywell, Siemens, Drayton Wiser and Bosch but there are many more companies with their own versions of controllers with similar and different functions to these companies’ controllers stated as well.
The idea was come upon as it was thought that hot water tank controllers could have better control over a household heating system and the hot water then the current style of controllers on the market today, this is due to hot water and heating systems having a big contribution to the carbon footprint of a household and this project will take theses type of controller designs into the next stage of development, this next stage development would be done by the controller having a more intrusive monitoring system and different sensing methods compared to the controllers on the market today, using these methods it will give the controller a way to have much better control of the home’s heating and energy use.
To proceed with this project the methods of background research on the current market, comparisons between controllers, brainstorming, meetings, use of data sheets, building a model of the hot water tank (HWT), building a prototype controller, using testing equipment to check functionality of the prototype, installation into a test rig based on a live circuit and result comparisons, these were the outcomes that was believed could be achieved but not all were able to be done due to the problems that occurred and the pandemic which put a stop to most.
Through the course of this project, it was discovered around 80% of a household’s energy consumption goes towards central heating and hot water supply, so if more control over the amount of energy consumed, when the energy is being consumed or if more control over when the system is functioning can be acquired, then less carbon will be produced due to reducing the amount of unnecessary energy being used or the use of more lower carbon energy sources to supply the system, from this more money will be saved by the consumer because of these outcomes.
There were many problems that occurred during this project with the pandemic itself caused a lot of issues with the building and testing of the controller as access to equipment for construction was restricted and being unable to have access to testing equipment for testing of the controller interrupted progress. The progress that could have been made was the controller would have been testing on a simulation with support from tutors to make sure a correct testing regime was used and in place, testing on an actual hot water tank and also receiving face to face teaching and support to help with this also, this is so if there was an issue or help was needed to resolve a problem it could be resolved more easily, but it became more difficult to overcome the issue/problem instead. Meaning other means of construction and testing had to be found. To resolve the issue of construction, the components were sent to my address for the controller to be built at home and for the hot water tank, a model was created in MATLAB/Simulink to produce a simulation of a hot water tank. But in doing this it came with few problems itself and some problems occurred with the building of the controller, the first problem that occurred was testing of the Wi-Fi module as there was an issue finding a testing regime for the module through the software and when going to test with another Arduino with a Wi-Fi module, it was not delivered through the post in the time scale, so only connectivity to a wireless router could be achieved. The second issue was testing the current clamp meter as it requires a single phase to measure current and as there was no access to testing equipment results for this could not be shown. There was also an issue with building the model in MATLAB/Simulink due to it was missing some variables needed to configure the model so assumptions had to be made to get the model working until these results could be verified, to clear these assumptions up an email was sent to the author of the paper to clarify the missing variables.
Overall, the project was a success as it showed that more can be done to lower the carbon emissions of a household by having better control over the heating and hot water system, furthermore by if we decarbonised hot water the carbon footprint can be reduced, and more low carbon energy sources can be used or used more efficiently instead of wasted meaning a greener UK which in turn would save the user some money.
Rhys Jones is an MRes student supervised by Dr Yousaf Khalid.