Smart cylinders – What installers need to know

Jon Tedstone, UK Sales Director at Mixergy, talks about smart cylinders – what they are, how they work and the part they could play in the journey towards decarbonising homes:

It’s important that installers understand the differences between smart cylinders and existing ‘dumb’ products, and the benefits they can bring to their customers – saving money on their gas bills now, while being ‘renewable-ready’ for the future.

A key conundrum for homeowners is ‘I’ve got a boiler that’s around five years old, along with a cylinder. Do I keep the boiler going until it comes to the end of its life, or (if the fabric of the house allows) should I invest in a heat pump? My regular cylinder is just a ‘dump’ cylinder for hot water. How can I make that system more efficient?’.

The Mixergy smart cylinder can provide higher efficiency and lower operating costs working with a gas boiler now, and be a stepping stone towards the renewables space in the future. Replacing a ‘dumb’ cylinder with a smart one now could save circa 20% of current gas use straightaway, then when the boiler needs replacing, there’s already a heat-pump-ready cylinder in place. It’s a nice bridge product for future-proofing the property, and for the heating engineer, the installation of the Mixergy cylinder is no different to that of a regular cylinder. It will also give the householder access to excess energy from solar PV which is either already in situ when the cylinder is installed or at retrofitted any time in it’s life, again future-proofing the property, reducing energy and saving money.

If their customer has an all-electric house – a house with storage heaters or an electric boiler – then a smart cylinder is an absolute no-brainer! It’ll can save hundreds of pounds on their hot water bill.

These conversations are starting to take place now, and, in our experience, newly qualified heating engineers are particularly open to talking to their customers about different technologies.

In addition, consumers are becoming more and more important and having much more of an influence on what heating engineers are fitting. By the time they contact the installer, they’ve already done their research and have a much better understanding than ever before about the heating products and systems available to them, checking all the different products, looking at reviews etc.

In the past, an installer would just tell the homeowner what they need, and the homeowner would accept that they were the expert and go with what the installer recommended. This is starting to change, and homeowners are telling their installers what they want.

So, in order to make sure installers are more focussed on renewable technologies and the associated heating systems, our training and support has to be tailored to educate them. We need to help at every touchpoint, so they understand the benefits and can relay them to their customers: this smart cylinder is going to be in your home for at least the next 25 years, whatever your heat source is going to be, now or in the future!

What is a ‘smart’ cylinder?

Anything ‘smart’ is, by and large, connectable to the internet, and to other ‘smart’ products. This connectivity opens up a raft of opportunities.

Firstly, there’s the Mixergy app. It will tell you how much hot water is in the cylinder, heats only the hot water that is required for the day or can boost it to provide 100% hot water, if required. It will tell you what the temperature of the water is, and you can use the app to change the temperature if you need to.

There’s a holiday mode, so you can set your departure and return dates and the temperature you want while you are away. And you can set a pasteurisation cycle for the day before you come back, to destroy any Legionella that may occur if the water is left standing for too long. This is a really useful feature if you have a void property – for example if the cylinder is installed in a housing association or privately rented property – and the cylinder is switched off. Once a week you can run a pasteurisation cycle to make sure the water is clean, and before a new resident moves in, so you won’t be wasting energy having the cylinder on when it is not needed.

The cylinder will also start to learn when you want hot water and will start to provide only the amount of water needed, rather than heating the whole cylinder. For example, if you play a sport every Tuesday evening and have a shower when you return, the cylinder will learn your habit and ensure there is hot water for your shower every Tuesday evening. The cylinder heats water from the top so the user has close control over how much hot water is generated for the day without wasting energy, and benefits from the cheapest method of heating their hot water.

The smart functionality is a mix of being able to control your cylinder remotely and also the self-learning, so you only heat the amount of water you need. With the app, you can see how much hot water you’ve used over a period of time, what temperature it is and how much it’s cost you.

You can also integrate your Mixergy cylinder into your existing home automation systems, for example it can be controlled using Amazon Alexa, Google Home and Hive from British Gas.

The benefit of the Mixergy app over a programmable heating and hot water control is that you don’t need a dual twin channel programmer. You just need a single channel programmer for your heating, and the hot water is controlled via the Mixergy app.

Secondly, you can set a smart tariff. Tariffs are really key now for households to try and reduce their energy bills and many energy providers are offering tariffs for Electric Vehicles (EV) or off-peak use. Mixergy has an API for some providers (for example, Octopus Agile) and you can link the app straight into your account. Then the cylinder knows to only work during the times when the electricity is at its cheapest level. If you are on a tariff where Mixergy doesn’t have an API straight into the provider, you can put in the details manually and still take advantage of the cheaper electricity.

Thirdly, demand-side response. An increasing amount of our electricity is being generated by wind farms and solar panels, which is driving down the carbon intensity of our electricity supply. However, we can’t turn off the wind or the sun, so an ever-increasing ratio of our energy is unpredictable and we need to have back-up ready for days when there isn’t enough wind or sun and, conversely, the times when it is really sunny or windy doesn’t always align to when the demand is at its highest – usually between 4pm and 7pm.

The National Grid has to keep the electricity supply at a frequency of 50 Hertz; if it goes up or down too much, it’s dangerous to sensitive equipment like computers, heart rate machines, life support machines etc. Demand side response (DSR) is a tool used by the National Grid to try and match demand to the available supply. When the frequency goes above 50Hz this is an indicator that there is a surplus of demand with respect to supply, and devices like Mixergy can be switched on remotely to help stabilise the power system and the homeowner can benefit from receiving the excess electricity.

Any type of home could be suitable for a smart hot water cylinder installation, from a small, one-bedroomed flat that’s all electric to a four-bedroomed detached house, as long as there’s a cylinder. There’s a massive argument for telling installers and homeowners ‘don’t rip out your cylinders because you’ll need them again in the next few years – replace them with a smart cylinder’.

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