Putting electricity data to work for people

This article was first published in Finnish in Kiinteistö & Energia magazine, issue 5/2026.

Property electricity use has usually been checked whenever someone has time. Now electricity data can check itself every day and tell people only what needs a response.

The traditional way of following a property's electricity use has been simple. Someone opens a report once a week, once a month, or when the bill looks odd. That works as long as there are few properties and plenty of time. In practice it is often the other way round: dozens of sites, followed by a small team alongside everything else.

The result is always the same. A deviation is noticed only when someone happens to look. By then, unnecessary consumption may have gone on for weeks. On top of that, traditional data usually comes at hourly or 15-minute resolution. That is enough to follow total consumption, but short power peaks and slowly creeping changes easily stay invisible.

The setup can be turned around. People no longer need to remember to look at the data. The data watches itself.

eWatt Smart Power Systems is a Finnish company specialising in energy data analysis. It has developed a reader that connects to the electricity meter's HAN port. The device collects electricity data every 10 seconds, and besides consumption the data includes per-phase values for voltage, power and current, among others. One device is enough to follow the electricity use of a whole property.

The service goes through the collected data every day. It does not look only at how much is consumed, but at several electrical quantities: consumption and base load, power peaks, imbalance between phases, voltage and current, and reactive power. Each one is compared with the property's own normal. When something departs from it, the service notices. Even when nobody is watching.

A notification when something changes

The biggest change is not the resolution of the data. The biggest change is what people spend their time on. When everything is fine, the service stays quiet. Nobody needs to open a report just to see that nothing happened.

When something changes, a notification follows. For example, the base load rises at night although the building should be empty. Or one phase starts carrying more load than the others. Or power peaks grow in a way that later shows up on the bill.

Silence is information too. It says the property is working as it should.

One building can still be gone through by hand. Following dozens of buildings continuously is not possible, because there simply is not the time.

A daily automatic check changes this. All properties are visible in one view, and the service brings up only the sites where something differs from normal.

Attention goes where it is needed. The other sites can be left in peace.

An alarm alone does not help yet. What matters is knowing what changed, what most likely caused it and what is worth doing about it. That is why the service does not just report a deviation.

It turns the deviation into a finding and a recommended action. The electricity data history is kept, so events can also be examined afterwards.

This helps, for example, when building automation behaves differently from how it was designed, or when the consumption of a piece of equipment grows little by little, week after week.

People still make the decisions. Automation takes care of the continuous monitoring, and people step in where expertise is needed.

The device connects to the electricity meter's HAN port, and the data travels over the mobile network. The device does not join the customer's internal network, which reduces the need for separate IT work.

eWatt is a Finnish service. The device is developed and manufactured in Finland, and the solution has been in development since 2022. The service is already in use in more than a hundred properties around Finland, including cities, educational organisations, retailers and event venues.