Battery optimisation software decides which actions your commercial battery takes, based on a number of factors, including grid prices, site demand, solar output and current state of charge (how full or empty the battery is).
Battery trading software works in conjunction with optimisation software to decide whether the battery should change when it charges, holds power or discharges to take part in a market trade.
In this article, we explain how battery trading software works and how it behaves according to what is happening on the site and in the market.
How does trading work for commercial batteries?
Commercial battery trading works by changing the periods of time when your battery charges or discharges to make more money from market opportunities.
It does this by factoring in:
- How much electricity the site is likely to use
- How much solar it might generate
- What electricity prices are doing
- How full the battery is
First, the optimisation software uses the site’s data to work out when the battery should charge and discharge over the next 24 hours if there is no trading. This becomes the site’s normal plan, although the software keeps updating it as conditions change.
The trading software might late spot a market opportunity that would pay the site to change part of that plan. It compares the payment you would receive from a trade with the amount you would save or ean by following the plan. It also checks at the same time if any change will leave enough energy for the building and keep the battery within its operating limits.
If the trade pays more and leaves enough energy, the software approves the change. It produces a new battery schedule and then sends new instructions to the battery - either to charge less, charge later, or export (sell) back to the grid.
The site’s half-hourly meter records how much electricity the site actually takes from or sends to the grid. The trading provider compares this with the normal plan and calculates the payment based on how much the site changed its electricity use and the price agreed for the trade.
Battery trading in the variable GB climate
In Great Britain, where we can get four seasons within the same day, the best battery trading software updates its plan of action constantly so it can make the best decisions for the site.
However, not all software works that way with many working to fixed schedules, meaning they charge and discharge at the same time every day.
It follows the clock and not the needs of the site. That means it might charge when it does not need to, use the power too early, or sell it when keeping it for the site would save more money.
Let’s look at two different days in the life of battery software like GridVolt’s GridTrade which does react to changes in the weather, prices and site demand, and how it changes its decisions based upon the data.
Battery trading software on a summer day
A warehouse has a 150 kW solar array, a 100 kWh battery and uses electricity during the working day for lighting, equipment and other operations.
The optimisation software uses the weather forecast, the amount of electricity the warehouse is likely to need, electricity prices and how much energy is already in the battery to plan what the battery should do that day.
The forecast shows a long sunny period. The plan is therefore not to fill the battery overnight with electricity bought from the grid. Instead, the plan is to store 60 kWh of surplus solar power in the battery between 11am and 2pm.
The plan also includes a half-hour top-up from the grid during the afternoon, adding another 10 kWh before the evening peak. Electricity is still cheap enough at that time for the warehouse to save money by charging the battery and using that power later.
The trading provider then uses the trading software to check whether skipping that top-up would earn the warehouse more money.
The provider checks two things:
- Would the payment for taking 10 kWh less from the grid be greater than the saving from using that extra 10 kWh later?
- Would the battery still have enough energy for the warehouse during the evening?
In this case, the answer to both questions is yes.
At the planned time, the on-site controller stops the battery from taking the 10 kWh top-up. The warehouse therefore takes 10 kWh less from the grid than expected and delivers the agreed reduction for the trade.
The optimisation software then carries on managing the battery for the rest of the day.
Between 4pm and 7pm, grid electricity costs 28p/kWh. The warehouse has two choices:
- Use the 60 kWh stored in the battery, avoiding £16.80 in grid costs
- Export the 60 kWh at 10p/kWh, earning £6, then buy the power the warehouse needs from the grid
Using the energy in the warehouse is worth £10.80 more than exporting it, so the battery supplies the warehouse instead.
The warehouse earns money by taking less power from the grid during the afternoon, then saves more money by using the stored solar power during the evening.
A winter day, when timing matters more than solar volume
In winter, shorter days and heavier cloud mean solar panels usually generate less electricity. Sites may therefore charge their batteries overnight, when grid electricity is cheaper.
In this example, a hotel has a 100 kWh battery. The software expects little solar power during the day and high electricity use during the evening.
The optimisation software first works out that the hotel will need 50 kWh from the battery during the evening.
Overnight electricity costs 16p/kWh, while electricity during the evening peak costs 48p/kWh. Charging 50 kWh overnight costs £8. Using that energy during the evening avoids buying £24 of electricity from the grid, giving the hotel a £16 saving after the charging cost.
Before the overnight charging plan is completed, the trading team finds an opportunity to sell another 30 kWh to the grid during the evening. The hotel would receive 42p for each kWh it exports.
The trading software checks that:
- There is enough room in the battery for the extra 30 kWh
- The hotel will still have the 50 kWh it needs
- The site can send 30 kWh to the grid during the agreed time
- Selling the electricity will earn more than it costs to charge
All four checks pass. The final plan is therefore to have 80 kWh stored by the evening:
- 50 kWh for the hotel
- 30 kWh to sell to the grid
During the evening peak, the battery uses 50 kWh to power the hotel. At the agreed time, the on-site controller tells it to send the other 30 kWh to the grid.
Using the first 50 kWh saves the hotel £16 after the overnight charging cost.
Selling the other 30 kWh earns £12.60. It cost £4.80 to charge that energy overnight, so the hotel makes £7.80 from the trade.
The hotel’s electricity meter records how much electricity it sends to the grid. The trading provider uses that reading to confirm how much was exported and work out the payment.
That gives the hotel two gains:
- A £16 saving from using cheaper overnight electricity during the evening
- A £7.80 profit from charging extra electricity overnight and selling it later
The optimisation software works out how much energy the hotel needs. The trading software then adds the extra 30 kWh because selling it later will earn more than charging it costs.
Five factors battery trading software checks before it makes a decision
The optimisation software uses this information to plan what the battery should do for the site. The trading software then checks the same information before adding a trade to that plan.
1. How much electricity the site needs
The software needs to know how much electricity the site is likely to use and when it will need it.
If you use a lot of power in the late afternoon, the battery may charge up ahead of that peak. If the site uses very little power overnight, the battery may not need to stay full all night.
Before adding a trade, the software makes sure the battery will still have enough energy for the site.
2. How much solar power the site is likely to generate
The software can adjust its instructions based on whether it’s going to be sunny or cloudy.
If it’s going to be sunny for a prolonged period, it may avoid filling the battery from the grid so there is room to store solar later. If cloud cover is expected, the software may top up the battery with cheap grid power rather than relying on solar alone.
If the forecast changes, the software checks whether the planned trade still makes sense.
3. Electricity prices and the trading payment
To decide whether a battery should charge or discharge, the software needs your actual electricity rates. That’s because it needs to know when power is expensive and when it's cheap.
The bigger the gap between those rates, the bigger the saving can be. The battery can charge at the lower rate, then use that power on site or export it when the financial return is higher.
Before adding a trade, the software compares what the trade could earn with what the site would save or earn by sticking to the original plan.
4. How full the battery is
A full battery can't capture any more electricity, whether it’s solar or grid. Likewise, an empty battery can’t help you reduce an immediate peak import.
The software needs to know how much energy is already stored in the battery before it decides whether to charge it, use it, hold it back or include it in a trade.
5. The site’s rules
The software needs to respect limits like export caps, import caps and minimum reserve levels.
It also needs to know whether the battery must keep power back for essential site use, backup requirements or other operating limits.
The site’s needs always come before trading.
Software, trading layers, and virtual power plants
If you already have a commercial battery and solar on site, or you’re planning to install one, GridVolt adds the software, the on-site gateway and the trading layer you need to save money on your electricity bill and take part in wholesale trading.
In most cases, clients don’t need to replace their battery or change their electricity supplier. GridVolt technology is compatible with many commercial battery systems and adds the control, optimisation and trading layer alongside existing systems such as a building management system, inverter controller or battery management system.
Energy Manager creates and keeps updating the battery’s normal plan for running the site. GridTrade then checks whether changing part of that plan could earn more money without leaving the site short of power or breaking the rules set for the battery.
To check whether your site is suitable, send us:
- Battery and inverter make and model
- Meter details
- Half-hourly data
- Electricity tariff and export rate
- Site import and export limits
- Details of any solar already installed or planned
We’ll review whether your setup is compatible with:
- Energy Manager: GridVolt’s control and optimisation software, which decides when the battery should charge, hold or discharge to reduce site energy costs.
- GridTrade: GridVolt’s GB trading layer, which connects suitable commercial batteries to VPP trading opportunities when the battery has spare capacity to use.
To get in touch, visit our contact page or fill out the form on this page.
If you are an installer or an EPC, contact us for free access to the GridVolt simulator so you can model the battery case against real tariff inputs before quoting savings, payback or trading income to a client.