Commercial batteries are hardware that requires software to tell the battery when to charge or discharge. The quality of the software’s algorithm and how it takes into account what’s happened at your site determine how much value you get from your battery.
Below, find out how battery storage control works, the two different types of software, and how to tell if your current (or future) setup delivers the maximum savings to your business.
What controls a commercial battery?
There are three main parts to a commercial battery energy storage system (BESS) and they all have separate jobs:
| Part | What it does |
|---|---|
| Battery management system (BMS) | Checks things like cell voltage, temperature and charge level, and keeps the battery within its safe operating limits. |
| Inverter | Transfers electricity between the battery, your site and the grid. |
| Control software | Decides when the battery should charge, supply your site or keep electricity stored for later. |
The control software can tell the battery to charge or discharge, but it cannot make the battery do something unsafe.
The battery management system and inverter can limit or stop what happens if, for example, the battery is too full, too empty, too hot or being asked to charge or discharge too quickly.
Your site can have limits too. One is the maximum amount of electricity it is allowed to send back to the grid. Sending electricity back to the grid is called exporting.
In Great Britain, the company that runs your local electricity network is called the Distribution Network Operator, or DNO. It can set a maximum amount your site is allowed to export.
If your site could export more than the DNO allows, G100 export limitation controls can automatically stop the site going above the agreed amount.
Note: A battery control system and a battery management system have different jobs. The BMS protects the battery, whereas the control software decides how to use it within the limits set by the equipment and your site.
How does battery control software work?
Fixed control and flexible control are the two main ways battery control software can work.
Note: Suppliers may also call this a battery control system, BESS control system or battery energy management system.
Fixed battery control
With fixed control software, your installer will normally have set the charging and discharging times for your battery in advance. Until the software gets reprogrammed, it will follow these times exactly and without variation.
For example, they might set your battery to charge between midnight and 4am, then supply the site with what it’s stored between 4pm and 7pm.
This can work well if your electricity prices and the times your business uses the most power stay fairly predictable from one day to the next.
The problem comes when they don’t. Your battery will still follow the same instructions even if electricity is cheaper at a different time, your site needs more power later than usual or your solar panels generate more electricity than expected.
Flexible control is designed to respond to those changes in real time rather than waiting for someone to reprogramme the battery.
Flexible battery control
Flexible control software can change when your battery charges or discharges as the conditions at your site change.
Here’s what it takes into account:
| What the software looks at | Why it matters |
|---|---|
| Your electricity tariff | The software can charge the battery when electricity is cheaper and use what it has stored when prices rise. |
| Site demand | If your site normally uses more power at certain times, the software can keep battery power back for then. |
| Solar forecast | If strong solar generation is expected later, the software can leave room in the battery to store it. |
| Battery charge level | The software needs to know how much electricity is already stored before deciding what the battery should do next. |
| Recent site data | If your normal electricity-use pattern starts to change, the best charging and discharging times may change too. |
| What the battery needs to do | Backup power, EV charging or another priority may mean some stored electricity needs to stay in the battery. |
These factors can change all the time. A day that was forecast to be sunny yesterday might turn out to be cloudy, leaving less spare solar electricity to charge your battery than expected.
The better the control software, the more often it checks for changes like this and, if it finds them, it comes up with a brand new plan. That could mean charging at a different time, keeping more electricity stored for later or using the battery sooner than originally planned.
Top software also needs accurate, up-to-date information from your site so it can make the right decision. That means having reliable meter data, the correct tariff and realistic forecasts for things like solar generation and electricity use to improve energy optimisation across your site.
Can you improve an existing battery’s performance without replacing it?
If your existing battery and inverter are compatible with newer control software, yes, but first your provider will need to know:
- Battery and inverter: Will the new software work with the equipment you already have?
- Connection: Can the controller read information from the battery and tell it what to do?
- Meter data: Can the software see when your site uses electricity?
- Tariff: Does it know what you pay for electricity at different times?
- Solar: Can it use your solar generation and forecast data?
- Import and export limits: Does it know how much power your site is allowed to take from or send to the grid?
If everything is compatible, the provider can add a controller or gateway that lets the new software read information from your battery and inverter and send them instructions.
Your battery management system still keeps the battery within its safe limits. The new control software simply changes when the battery charges, discharges or keeps electricity stored.
So if your battery is working properly but still follows basic fixed settings, you may not need to replace it. Better control may be enough to get more from the hardware you already own.
Can your battery earn money as well as cut your electricity costs?
Battery energy trading gives the battery another possible job. Instead of only charging and discharging to reduce your electricity costs, spare battery capacity can sometimes be used to make money from the electricity market.
Your site still comes first. If you need electricity kept back for backup, a later peak or another priority, that capacity is not available for trading at the same time.
For eligible commercial sites in Great Britain, trading can add another source of value to a compatible battery. Whether it is suitable depends on the battery, inverter, metering, grid connection and how much spare capacity your site can make available.
Are your battery’s charging and discharging times right?
A good first check is whether those times still match the way your site works today.
Check:
- Tariff: Are you still buying electricity at the same times and prices as when the battery was set up?
- Site demand: Does your business still use the most electricity at the same times of day?
- Solar: Has your solar generation changed since the battery was installed?
- Battery reserve: Are you keeping back more electricity than you actually need?
- Software: Can it change the charging and discharging times when conditions change?
- Last review: When did anyone last check whether the settings were still right?
If the battery follows the same times every day, that is not automatically a problem. But if your tariff, electricity use or solar generation has changed and the charging and discharging times have not, there may be room to improve them.
How GridVolt improves battery performance so you get faster payback and higher returns
If you’ve not got the returns the installer promised on your solar + battery setup, or you want to make sure the software managing your future system gets as much value as possible from it, GridVolt can help.
Tell us your existing or proposed battery and inverter models. Send over your electricity-use data so we can run half-hourly data analysis on it to work out if you could be saving more.
We’ll then get back to you with how much more your battery could save you.
Powering your battery will be our Energy Manager software. This uses your tariff, site demand, solar generation and battery data to keep working out the best times to charge and discharge. On suitable GB sites, our GridTrade platform can also use spare battery capacity to earn revenue from electricity markets without replacing the battery or changing supplier.
Fill out the form on the right or contact GridVolt to discuss your options.