A fifth of all battery storage projects suffer from reduced returns because of technical underperformance, according to a study by ACCURE. They were still operational but not delivering the savings or the value expected by businesses.
Below, find out what battery storage monitoring is and how it can help you spot when something is not working as well as it should.
What is battery storage monitoring and how does it work?
Battery storage monitoring software allows you to keep track of the performance of your battery over time.
The software takes readings from:
- The battery or BMS: How much electricity is stored, plus information such as temperature and battery status.
- The inverter: When electricity is moving into or out of the battery and how quickly.
- Your site meter: How much electricity your business is taking from the grid or sending back to it.
- Your solar power system: How much electricity your panels are generating.
The software needs a reliable connection to your battery and other equipment. If that connection drops out, the information you see may be missing or out of date.
The software then shows the readings in a dashboard, so you can see what the battery is doing now and look back at what it did earlier.
Which battery monitoring figures matter most, and why?
The most useful figures to check are:
| Metric | What it tells you |
|---|---|
| Battery charge level | Is the battery often full when you would expect it to have room for solar, or empty before electricity becomes expensive? |
| Charging and discharging | Do the times still suit your tariff and when your site uses the most electricity? |
| Site electricity use | Is the battery supplying the site when demand is highest? |
| Solar generation | Is there enough room in the battery to store spare solar electricity? |
| Grid import and export | Are you still buying expensive electricity while the battery has power stored, or exporting solar because the battery is already full? |
| Battery status | Are faults or warnings appearing more often? |
| History | Has the way the battery behaves changed over the last few weeks or months? |
How can you tell if your battery is losing capacity or efficiency?
Battery monitoring can show whether your battery is losing usable capacity or becoming less efficient as it gets older.
Three figures are especially useful:
- State of health: Shows how much usable capacity the battery has now compared with when it was new. Batteries normally lose some capacity as they age.
- Round-trip efficiency: Compares how much electricity goes into the battery with how much comes back out. Some energy is always lost, but a falling figure can be worth investigating.
- Cycles and throughput: Show how much the battery has been used. One cycle is roughly a full charge and discharge. Throughput is the total amount of electricity that has gone into and come back out of the battery over time.
One unusual reading does not necessarily mean there is a problem with the battery. Temperature, operating limits and how deeply the battery charges and discharges can all affect the results.
Check whether its usable capacity or efficiency is falling consistently over time instead. This is often called battery health monitoring. If either keeps getting worse, ask your installer or service provider to find out why.
How can monitoring show whether your battery is being used well?
Battery monitoring can show whether the battery is being used in a way that still suits your tariff, solar generation and electricity use.
For example:
| What you see | What it might mean |
|---|---|
| Battery empty before electricity gets expensive | It may have supplied the site too early, leaving nothing stored for later. |
| Battery full while your solar panels are exporting | There may not have been enough room left to store the spare solar electricity. |
| Battery charging while electricity is expensive | There may be a good reason, but it is worth checking why it is happening. |
| Battery stays full while your site buys expensive electricity | Some electricity may be deliberately kept back, or the current settings may be stopping the battery from being used. |
| Battery does exactly the same thing every day | That may be fine on a predictable site. But if your tariff, opening hours or electricity use have changed, its old settings may no longer suit the site. |
These signs do not necessarily mean there is a fault. They may simply mean the charging and discharging times no longer suit the way your site works.
Can battery monitoring tell you how much money you are saving?
Battery monitoring can show how much electricity went into and came out of the battery, and when, but to work out what that means in pounds, you need to know what you would have paid to buy the same electricity from the grid instead.
For example, your battery might charge when electricity costs 15p/kWh and supply your site later when electricity costs 30p/kWh. The saving comes from the difference between those two prices.
Solar works slightly differently. If the battery stores spare solar electricity, you compare what you would have earned by exporting it with what you save by using it yourself later.
Half-hourly data analysis lets you do that across your site data. If you are not confident doing the analysis yourself, ask a specialist to check the data and work out what the battery is actually saving you.
How GridVolt can help you get more from your battery
If your battery is not delivering the returns you expected, GridVolt can check how it is being used and whether there is room to improve the savings.
Tell us your existing or proposed battery and inverter models and send over your electricity-use data. We can run half-hourly data analysis to see when your site uses power, how the battery is performing and where it may be missing opportunities.
We’ll then show you how much more our analysis suggests the battery could be saving you.
For compatible sites, our Energy Manager software can then use your tariff, site demand, solar generation and battery data to keep working out the best times to charge and discharge.
On suitable sites in Great Britain, GridTrade can also use spare battery capacity to earn revenue from electricity markets, without replacing the battery or changing energy supplier.
Fill out the form on the right or contact GridVolt to discuss your options.
Battery storage monitoring FAQs
Is battery monitoring the same as battery storage control or a BMS?
No. Battery monitoring shows you what the battery is doing. Battery storage control tells the battery when to charge, discharge or keep electricity stored.
A battery management system (BMS) has another job. It checks things like cell voltage, temperature and charge level and keeps the battery within its safe operating limits.
What happens if your battery monitoring data is missing or wrong?
Battery monitoring is only useful if the readings are up to date and complete.
A lost connection can leave gaps in the data. A reading that has stopped updating can make it look as though the battery is doing nothing, even when it is still charging or discharging. Missing site or solar data can also make it harder to work out why the battery behaved as it did.
Before deciding the battery is underperforming, check the timestamps and look for obvious gaps or readings that stay unchanged for too long. If something does not make sense, compare it with your site meter or electricity bill where you can.
If you are still unsure, ask your installer or monitoring provider to check the data feed. Good battery monitoring software should make missing or stale data easy to spot rather than leaving you to guess.