Moixa is delighted to work with Alfen in a trial to provide smart charging capabilities to residential electric vehicle (EV) owners by combining solar optimisation, tariff optimisation and grid services into a single user-centric platform.
In 2020, we started a partnership with Alfen, a leading provider of EV charging stations and integrator of smart grid solutions, to conduct a trial evaluating the opportunity for smart charging to reduce EV owners’ energy costs, charge from free solar energy and unlock grid flexibility services.
The trial aimed to create personalised and optimised smart charging plans by using Moixa’s GridShare AI software and Alfen’s EV chargers. This collaboration has been a critical tool in helping us further develop our expertise around smart EV charging for homes and offering EV owners the opportunity to charge their vehicle with the cheapest and cleanest available electricity.
Starting the trial
EV owners with a solar array of at least 2kWp were recruited across the UK to participate in the trial and were installed with the necessary equipment by the Moixa team, free of charge.
The participants received an Alfen Eve Single Pro-line charger alongside a Moixa Hub (connected separately to the home internet network via ethernet) to enable GridShare software to manage the EV charger.
The Moixa App: choosing between different modes to charge your EV
After we successfully installed and tested the system, trialists were given access to the Moixa App to view a summary of their household energy profile, and the energy flows between their assets. Through the app, they could choose between different operation modes to charge their EV: Simple, Scheduled, and Smart.
- Simple mode: this mode allows the user to start charging the electric vehicle immediately once plugged in.
- Scheduled mode: with this mode, trialists could set a charging routine for individual days of the week by setting charge events in ‘’Charge’’ or ‘’Balance’’ modes. During “Charge” events, the EV charges at maximum power. During “Balance” events, the EV charges only from free solar energy.
- Smart mode: by leveraging Moixa’s GridShare software, Smart mode provides an optimal personalised charging plan based on individual household energy consumption, energy tariff, predicted solar generation, and the user’s charging preferences – including target charge and departure time.
Throughout the trial, participants used the modes at their disposal to charge their EV in different ways.
Figure 1: Illustrative image of the Smart Mode settings and plan overview, with tariff and solar optimisation based on the target range and the departure time.
Solar and tariff optimisation through Moixa’s GridShare software
In Smart mode, the charging target for the electric vehicle is met while optimising for both solar generation and time-of-use tariffs.
Moixa’s GridShare software uses weather predictions and meter readings to ensure that the excess solar power generated by the customer’s PV system is being used to charge the EV (Figure 2).
When Smart mode is set, GridShare also uses the trialists’ time-of-use tariff to calculate the optimal charging plan and charge the EV at the lowest possible cost. Tariffs include static time-of-use tariffs (e.g. Octopus GO), and dynamic time-of-use tariffs (e.g. Octopus Agile) (Figure 3).
Figure 2: Illustrative image of the solar optimisation by Moixa’s GridShare, showing how the charger power flow closely follows the solar production readings.
Figure 3: Illustrative image of the tariff optimisation by Moixa’s GridShare, showing a trialist’s EV charging from the lowest dynamic time-of-use tariff.
Key results of the trial: additional savings accessible by smart charging
Overall, Moixa’s optimisation managed to offer savings between 20% and 40% of total charging costs.
The savings compare Moixa’s optimisation to the use of an EV timer. By setting a timer in their car, users choose a time for the charging to begin. Charging will then start and charge until the battery is full. Moixa achieves additional savings by charging from excess solar and optimising for the cheapest possible time-of-use tariff.
The differences among savings were mostly based on user behaviour:
- Savings from solar optimisation varied because of the size of the solar panels and the chosen charging time. We identified that trialists charged more from excess solar when their EVs were plugged in during the day and when their solar arrays were above 2kWp.
- Moixa’s tariff optimisation successfully charged during off-peak times based on static and dynamic time-of-use tariffs. When set in Smart mode, the trialists’ EVs were consistently charging at the lowest available rate and obtained up to 35% savings compared to the mean tariff. Trialists gained more from tariff optimisation when plugging their EVs during the night to enjoy the cheapest time-of-use tariffs.
Understanding the potential of smart charging for grid services
During the trial, we wanted to understand whether we could unlock the potential of EV charging as a flexibility resource through unidirectional charging (V1G), which makes it possible to stop or start charging in response to grid requirements. Therefore, we simulated an aggregate fleet of Alfen units responding to external grid signals by sending commands to the trialists’ chargers.
The results were promising, with 47kWh of energy delivered across trialists and a maximum response time below one minute. The capacity and response time would enable Moixa to participate in some UK local constraint management services. However, the combination of EVs with other energy assets (such as stationary energy storage) offers a more realistic approach to participate in larger-scale grid services.
The measured parameters show the potential for a fleet of Alfen units, aggregated by Moixa’s GridShare software, to participate in various demand response programs in the future. This result represented another key success factor of the trial, showing how smart charging can support grid services and enable households to play a more active role in the move towards zero-carbon electricity.
Proud to be driving positive change in the EV space
We are delighted to have successfully concluded the trial, validating GridShare optimised smart charging and the potential for grid services for the Alfen charger.
As we move away from fossil fuels and increasingly switch to renewable energy sources, the electrification of transport can play a pivotal role in the decarbonisation challenge. However, the rapid growth of EVs could significantly impact the country’s grid system.
Flexibility during periods of high electricity demand will prove crucial to the operation of an efficient and low carbon energy system.
EV Smart charging has the potential to be a hugely important part of how the UK energy system keeps itself operating smoothly in the future, ensuring electricity generation and demand are in balance while helping customers charge their EV with the cheapest and greenest electricity available, and directly benefit from their own flexibility.
Moixa is at the forefront of providing smart charging capabilities to residential EV owners, leveraging AI and collaborating with other leading industry partners to make consumers actively involved in the transition to clean energy.