How the Mixergy cylinder helps you to harness free solar energy to help decarbonise and save money on bills
At Mixergy we are focused on supporting households to transition from fossil fuel heating to low and zero-carbon alternatives, while also helping reduce energy bills. One of the ways that we do this is by connecting a solar photovoltaic (PV) array to the cylinder, enabling Mixergy homes to use the spare electricity generated from the sun to heat their hot water rather than being lost to the grid. In this way, the Mixergy cylinder acts like a lithium-ion battery solution, but 4-5 times less expensive.
How it works
Using thermal stratification, Mixergy cylinders heat from the top down, which means faster heating and lower heat losses. Mixergy cylinders only heat the hot water you need—actually, this is typically just 40% of the cylinder’s volume—and energy and money are saved every time a full cylinder is not heated. Using this volumetric heating approach and a unique smart sensor arrangement to constantly monitor the state of charge, the cylinder creates the headroom to optimise the consumption of free solar energy from a solar PV system.
A conventional hot water cylinder will typically heat to 100% using grid-imported energy (gas or electric) first thing in the morning. As a result, even after you have your morning showers, there is a limited amount of headroom in the cylinders available for surplus solar energy that you generate throughout the day.
The Mixergy cylinder on the other hand, can be automatically programmed to optimise the use of solar energy by leaving maximum capacity available to be heated for free by the sun during the day.
In this example, the cylinder heats just what you need using your boiler, heat pump or by direct electric to get through the early morning demand for showers. The vast majority of the cylinder is left available to be heated by surplus solar energy throughout the day. And because of the top-down volumetric heating and tracking of the cylinder’s state of charge, the primary heating source can always intervene to make sure you don’t run out of hot water.
Reducing import of grid energy by more than 35%
Through BEIS and Innovate UK-funded trials, we have been able to demonstrate that a Mixergy cylinder and solar PV system can reduce the import of grid energy (gas or electric) by more than 35%.
The reduction in grid energy depends on the size of the PV array, its orientation and the capacity (size) of the cylinder. As shown in the graph below, a typical 4kWp PV system installed alongside a 210 litre Mixergy cylinder gives a reduction in grid export of more than 35%. This increases to almost 40% with a 300 litre cylinder.
Installation of a Mixergy cylinder is broadly the same as with a conventional cylinder and requires no specialist training. All Mixergy cylinders are also ‘Heat Pump Ready’: this means they can be connected to a heat pump using a plate heat exchanger should you ever decide to switch to a heat pump.
Key benefits of the Mixergy cylinder include:
- Maximise the self-consumption of your solar energy whilst reducing the import of grid energy by as much as 35%.
- The ability to monitor and control hot water through the Mixergy App and gauge.
- Operating a smart ‘IoT’ device that can be connected to other platforms such as Amazon Alexa and Google Home voice control systems.
- Using dynamic time-of-use electricity tariffs to provide low-cost hot water in off-peak periods.
- Heating just the hot water you need (typically around 40% of a cylinder’s capacity) ensures faster reheat times!
- Reducing energy wastage by lowering heat losses; storing less water and optimising your schedule using machine learning.
- Reduce gas consumption and prevent boiler short cycling. EST Verified.
- Providing a more accessible and affordable energy storage solution than a lithium-ion battery storage.
Find out more about our solar cylinder, the Solar X.
