EV Smart Charge

Owned by Atharv Gokhale
Last updated: Oct 18, 2024 by Anne Wilson
4 min read

 

Function

SolarPlus helps calculate how much solar energy is available for EV charging with a smart charger that uses excess solar, and optionally tops up the car from the grid on days when there is not enough sun.

SolarPlus calculates how much excess solar there is available (that would normally be exported to the grid), and allocates it to EV charging instead.

EV charge starts when the amount of solar production is 1.4kW higher than load consumption and battery charge. For example if between 10am and 11am, 5kWh of solar is produced, and only 1kWh is needed for other loads, then there is 4kWh will be sent to the EV.

If there is only 500W excess solar available, then the EV charger will not start.

EV charge stops when the target kWh/day charge requirement is reached, or if available excess solar drops below 1.4kW.

When grid boost is selected, if the target kWh/day is not reached by solar by the time that the grid boost is available, (ie if it is cloudy, or the other loads are too high), then the remainder of the target kWh/day is drawn from the grid at the time you specify. Therefore, it is recommended to specify that grid boost starts in late afternoon or evening, depending on charge time requirements and off peak tariff times.

Eg if they really need at least 40% charge by 3pm to go and pick up the kids, then set 2 grid boost time ranges, 1 at 2pm for an hour, and the other later in the evening during off-peak tariff period.

Saving and Loading profiles

We highly recommend starting with one of the profiles already in the library, then adjust it to suit your customer.

 

Give the profile a meaningful name (eg ABC Smart Charger with grid boost for Tesla 3, 50km/day)

The saved profile contains all of the information entered on the page, including other features like battery set points, hot water diverters, etc.

You can also choose to save the profile to your library for future use on other quotes. Once saved, please refresh your browser in order for the profile to appear in your list of profiles.

Once saved you can check the performance with and without the EV charger by unloading the profile. Ensure you save it to your library so you can re-load it again easily. When it is loaded, the Green tick appears.

EV Specs

Firstly, you need to know how much energy the EV requires per day. Most customers don’t know the kWh figure, so to calculate it,

  1. Select the EV model from the drop-down. Most of the EVs available on the market are present in that list. If you do not find the model you are looking for, email us at support@solarplus.co with the EV details (mainly the kWh capacity and the driving range on full charge). You can override the default battery capacity and range for the vehicle.

  2. Enter how far they drive on average per day.

From this, SolarPlus calculates the total daily EV energy needs. You can also override this figure (eg increase it if they drive fast or carry big loads)

Current EV scenario

Next, enter how the EV is currently being charged from the grid. The time ranges can be entered at an hourly level on the 24-hour clock. To specify multiple ranges for the same weekday, click on “+Weekly Range”.

Click on the “Copy weekday to weekend” button to copy the same ranges from the weekday to the weekend.

Set the charge rate - maximum power rating in kW.

Click on the “In addition to load profile” checkbox if the EV details mentioned are not a part of the consumption profile loaded on the Energy page.

If “In addition to load profile” is not checked, make sure there is enough power in the consumption profile, as the load will activate only when the power is equal to or greater than the kW power value set in this section.
If “In addition to load profile” is checked, you are adding additional loads and therefore adding more cost to the before scenario. The total energy consumption on the reports page will be the load profile from the Energy page, plus the load from the Smart Energy profile.

If you are comparing a quote without a Smart Energy Profile to one that has a Smart Energy profile, make sure that the energy consumption on both are the same.

Smart charge scenario

In this section, enter the details of when the EV will be plugged in for charging. The time ranges can be entered at an hourly level on the 24-hour clock. To specify multiple ranges for the same weekday, click on “+Weekly Range”.

Click on the “Copy weekday to weekend” button to copy the same ranges from the weekday to the weekend.

Set the charge rate from solar - maximum power rating in kW. This should match the capabilities and programming of the smart charger you are installing.

Based on the time range, solar will be used for EV charging when excess solar is available.

Boost from grid

This option can be used to trigger EV charging from the grid when there isn’t enough solar to meet the daily charging needs.

The time range needs to be entered to specify which times of the day grid charging can be activated.

You will also need to mention the maximum allowed power drawn from the grid in kW.

Boost from battery and grid

If a battery is also included in the design, then you can select whether the EV will get its boost charge from the battery, or from the grid only.

If no battery is included in the design, then only the grid option will be visible.

EV export to grid

This feature is still in the development and testing stage.