Free energy management software: free EMS, Excel or paid platform?

Typing “free energy management software” into a search engine is a common reflex for the owner's team of a commercial building equipped with a BMS. The idea is to track the portfolio's energy consumption without committing a budget. OPERAT, the reporting platform of the Décret tertiaire (France's tertiary decree on energy savings in commercial buildings), is free. Reaching -40% by 2030 is not^{[1][1]RegulationLégifrance, “Decree No. 2019-771 of 23 July 2019 on obligations to reduce final energy consumption in commercial buildings”, known as the Décret tertiaire; -40% target for 2030 set by Article L. 174-1 of the French Construction and Housing Code (code de la construction et de l'habitation); OPERAT platform entrusted to ADEME by the order of 10 April 2020See in sources ↓}. Between open-source software, Excel and subscription solutions, the real measure lies elsewhere. Free is judged on your data and on action, not on the entry price.

A free EMS: what is really free?

Collect, normalize, alert: the core functions of an EMS

An EMS (energy management system) is software that collects meter readings and normalizes them with heating degree days (HDD, called DJU in France). It then detects drifts, raises alerts and produces the reporting. Its job is to monitor the consumption of each site, to help the company decide where to reduce it. The EMS does not act on the equipment: it changes neither a setpoint nor a schedule.

Platform, EMS, software: the same thing, three words. Energy management refers to something else, a continuous improvement approach (the EnMS, or energy management system in the ISO 50001 sense, called SMÉ in France). Each software solution equips it with dashboards, which the energy manager and the operator use to spot drifts.

The acronym has three meanings: building energy, the electricity grid, charging stations. Only the first concerns us here, that of an HVAC system already controlled by a BMS.

Dashboards and real-time monitoring: what tracking shows you

Once the points are configured, a monitoring tool displays load curves, comparisons between sites and the breakdown by equipment. The interface serves analysis: spotting a night-time baseload that is too high, a Sunday that consumes like a Tuesday.

Yet this real-time monitoring runs into a limit of its very nature. Tracking shows the past, never the action: no curve, however perfect, lowers a supply air setpoint.

Five kinds of free, five ways of paying differently

Open a list of free energy management software. You will come across agricultural irrigation tools^{[2][2]Press and announcementsGoodinfo, “10 free software tools for businesses to manage energy”See in sources ↓} and utility billing software^{[3][3]Press and announcementsCapterra, “Energy management software”, directory filtered on “free version”See in sources ↓}. These lists rank by brand. We rank by kind of free, because a free EMS is never free in the same way. The grid below sets out five, with, for each, what you still pay for and who bears the risk. None is ranked above the others.

The rule is in the “What you still pay for” column. Every kind of free shifts the cost to instrumentation, BMS integration or in-house time. None of these solutions is bad by nature. Each serves a specific use: reporting, studying, testing, tracking the product you have just bought. The trap is expecting a filing platform to do the work of a tool used every week across an entire portfolio.

Self-hosted open-source software: Emoncms and free code

Emoncms, from the OpenEnergyMonitor ecosystem, is open-source software for tracking consumption. Open source has real virtues: readable code, no dependence on a vendor. It is free to download, not to operate. The server, the security updates and the connectors to each meter still have to be funded. Configuration also assumes a need that is rarely costed: a competent in-house user who stays in the job.

Public calculation tools: RETScreen for audits and pre-feasibility

RETScreen is a Canadian public tool for analyzing energy projects. It compares scenarios, assesses profitability and documents the assumptions used. It is first and foremost a feasibility study tool. It can also track the performance of a completed project. Only its Viewer mode is free: the Professional mode requires an annual subscription. A regulatory energy audit can rely on it to cost out options. A BMS audit asks a different question: does the control do what it claims, and based on which source data?

OPERAT, the public reporting platform for the Décret tertiaire

OPERAT is the public platform run by ADEME for the annual reporting of the consumption of buildings subject to the decree^{[1][1]RegulationLégifrance, “Decree No. 2019-771 of 23 July 2019 on obligations to reduce final energy consumption in commercial buildings”, known as the Décret tertiaire; -40% target for 2030 set by Article L. 174-1 of the French Construction and Housing Code (code de la construction et de l'habitation); OPERAT platform entrusted to ADEME by the order of 10 April 2020See in sources ↓}. It is the only free tool that the regulations already impose. Each year it generates a digital certificate of your final energy consumption. Reporting is not acting: OPERAT records consolidated kWh, it does not touch a single boiler-room heating curve.

Software supplied with the meter or the datalogger

Here, the free part is tied to the purchase of the metering hardware. Socomec, for example, pairs its WEBVIEW software with its metering equipment^{[4][4]Manufacturer documentationSocomec, “Energy management software”, WEBVIEW softwareSee in sources ↓}. On the other hand, the proprietary configuration ties your history to the manufacturer. Any configuration has to be redone in its environment. Changing meters often means changing tools. The data collected rarely follows.

Vendor freemium and “free, pricing on request” listings

The entry-level version is restricted from sign-up: capped number of sites or meters, short history, paid export. Listings marked “free, pricing on request” promise access before redirecting you to a salesperson. Look at what the solution allows on the day your portfolio exceeds the quota.

Directories display stars. The overall rating says nothing about your data: it aggregates the use of other free software, on configurations other than yours.

Excel or a free tool: what is enough and what you still have to cover

What an Excel energy dashboard does well

Is Excel enough? Often, yes. An Excel energy dashboard handles monthly readings and invoices very well. On one or a few sites, the HDD correction can be done by hand.

The spreadsheet is already installed on every computer. It is free in the honest sense of the word: it creates no dependence on a vendor and no subscription creeps up. The dashboards built in it remain readable by everyone.

Where tracking energy consumption in Excel falls short

Readings are entered by hand, the file circulates by email and three versions coexist. The spreadsheet sends no alerts and has no link with the BMS. An AHU running at night therefore stays invisible until the bill arrives.

The level of detail is also lacking. Without hourly data or a load curve, nothing shows what the asset consumes at 3 a.m. On a multi-site portfolio, keeping the workbook up to date becomes a job in its own right.

Metering and instrumentation are still on you

The answer fits in one sentence: the software is free, the meters are not. You still have to buy and install the electricity, water, gas and heat meters, the BMS sensors and the remote reading system. The metering plan and its implementation on site are also on you.

That is where the real cost of measurement lies.

In-house time: who looks at the curves every week?

Monitoring software does not work on its own. Someone has to open the curves, read the alert, call the operator and check the fix. This analysis time has a human cost that free software does not cover. A dashboard that nobody uses produces no energy savings. So, in your team, who looks at the portfolio's curves every Monday morning?

Data export, reversibility and vendor viability

Three questions matter. In what format can you export? Who holds ownership of the history if the contract ends? Are the fields described in a readable document? A free tool can raise its prices or shut down its service without notice. Open code does not protect you any better if its export is not documented.

Is your data ready for software, free or paid?

Eight questions about your meters and your BMS before choosing a tool

Before comparing licenses, look at the actual state of your data. The best software on the market does not repair a meter that has been disconnected for months. The quiz below asks eight closed questions about your metering, the communication of your equipment and the configuration of your BMS. Allow two minutes. Three answers are possible: yes, no or I don't know. The last one counts as unfavorable, because data that nobody can locate is hardly better than missing data.

The result remains conditional and promises no energy savings. It only indicates which part of the work comes first. It also specifies which check to carry out before signing anything. The next two sections explain what lies behind your unfavorable answers.

Data gaps, duplicates, orphan meters: data quality first

A dashboard connected to meters whose data has not been made reliable produces a clean but false chart. The curves are smooth and the totals add up. Yet a data gap smoothed by interpolation looks like a drop in consumption. A meter counted twice inflates a use that does not exist.

The scenario is common: a portfolio has hundreds of metering points. Nobody can say which ones are reliable. Disconnections go unnoticed, invisible drifts set in. Any analysis carried out afterwards is built on sand. The consistency check therefore comes before the choice of tool.

Reading your result: Excel, a free tool or making the data reliable first

Are your unfavorable answers concentrated on gaps, duplicates, the metering plan, data access and manual overrides? Your portfolio then probably needs a data reliability phase. Software placed on top would display errors elegantly.

Your meters do not communicate yet? Excel is probably enough for monthly readings. In the other cases, a free tool could help structure the tracking. Whatever the outcome, the rule holds: make the data reliable first, add tools afterwards.

TAKE ACTION Does your quiz flag gaps, duplicates or manual overrides? Have your history and your BMS reviewed by a team that tests the points one by one before recommending a tool. BUTTON: Book an audit

The signals that free is no longer enough

When should you move to a paid tool? The first signal is scale: a multi-site portfolio, hundreds of meters, several BMS brands. Manual consolidation then ends up absorbing the time the team should spend on deciding. The second comes with the need for real-time alerts, which no free tool guarantees over time.

Then comes the obligation of proof: Décret tertiaire, corporate reporting, carbon footprint in tCO2e. An energy management platform then becomes an enforceable record as much as a monitoring tool. The last signal: several operators to coordinate. Without a common reference, each one defends its own figures.

The criteria to test before signing a subscription

A directory's overall rating is no substitute for a trial on your own sites. Test at least these six points:

• the interface, as used by your operators
• the configuration of meters and end uses
• the BMS connectors actually available (BACnet, LON)
• the raw export, meter by meter
• reversibility written in black and white in the contract
• the total cost over the commitment period

To structure this energy management approach, our method for choosing energy management software details each criterion.

Measure, track, control, verify: where tracking software stops

From the meter to the verification of savings: the full chain

Functions get mixed up in quotes. The vocabulary, however, is clear: the EMS measures and alerts, the BMS acts, the hypervisor aggregates several sites and several brands. The diagram follows a piece of data across six links, from the meter to the verification of savings. It also shows what each regulation actually expects of the system.

Look at where the “tracking stops here” marker sits. Everything before it describes the past: a measurement, a collection, a curve. Consumption only falls beyond that point, when the BMS changes a setpoint, a schedule or an optimal start. It also falls when the operations team removes a manual override. Tracking software does not cross this boundary on its own. The BACS decree (French decree 2020-887 on building automation and control systems) draws the consequences: it requires a system capable of acting, without imposing a class^{[5][5]RegulationLégifrance, “Decree No. 2020-887 of 20 July 2020 on building automation and control systems in non-residential buildings and automatic heat regulation”, known as the BACS decree; requirements codified in Article R. 175-3 of the French Construction and Housing Code, amended by Decree No. 2023-259 of 7 April 2023See in sources ↓}.

The EMS detects the drift, the BMS corrects it

Take an AHU that overconsumes a little more every day: a filter clogging up, a valve that no longer closes completely. The EMS sees the curve rise and raises an energy drift alert. It stops there.

The correction goes through the BMS: checking the sequence, configuring the setpoints, leaving the degraded mode left in place after a VIP complaint. An EMS that does not write to the BMS remains a dashboard. Optimizing consumption means reducing a flow rate or shifting an optimal start.

Is a free tool suitable for the Décret tertiaire?

For the reporting obligation, yes. OPERAT is free and is enough to declare your annual consumption^{[1][1]RegulationLégifrance, “Decree No. 2019-771 of 23 July 2019 on obligations to reduce final energy consumption in commercial buildings”, known as the Décret tertiaire; -40% target for 2030 set by Article L. 174-1 of the French Construction and Housing Code (code de la construction et de l'habitation); OPERAT platform entrusted to ADEME by the order of 10 April 2020See in sources ↓}. Excel can even prepare the data entry.

The target is another matter. The law sets -40% by 2030 compared with a reference year that cannot be earlier than 2010^{[1][1]RegulationLégifrance, “Decree No. 2019-771 of 23 July 2019 on obligations to reduce final energy consumption in commercial buildings”, known as the Décret tertiaire; -40% target for 2030 set by Article L. 174-1 of the French Construction and Housing Code (code de la construction et de l'habitation); OPERAT platform entrusted to ADEME by the order of 10 April 2020See in sources ↓}. An absolute-value threshold can be used instead. No tracking screen removes a single kWh. It takes action on the equipment, measured over time. The point made at the start is confirmed: reporting satisfies the obligation, not the target.

Verifying savings and the carbon footprint: IPMVP and HDD correction

An energy saving is proven by measurement, not by a declaration. The IPMVP (International Performance Measurement and Verification Protocol) compares actual consumption with a baseline adjusted for HDD and occupancy. Without this correction, a mild winter passes for a success.

A reduction measured according to this protocol thus stands up to year-on-year comparison. The kWh avoided are then converted into tCO2e, energy by energy. The carbon footprint in the ESG report then rests on a figure that a third party can audit. Improving that figure becomes a question of method.

What Foobot does when tracking is no longer enough

BMS advisory: making meters and the BMS reliable before adding software

Our BMS advisory starts with the meters: disconnections, data gaps, duplicates, invisible drifts. We test every point and put the configuration back in order. Our operations advisory then tracks down manual overrides, rewrites consistent sequences and keeps only the useful alarms. Across an entire portfolio, this check stands on its own: making the data reliable has value in itself, without an AI phase afterwards.

Before free software, the reliability of your meters

Free energy management software rarely costs nothing. Metering, BMS integration and in-house time remain on you, whatever the license price. Remember that a tool is only worth as much as your meters and what it triggers. A tool connected to doubtful meters shows nothing accurate. A tool that does not act produces no savings.

Is your self-assessment favorable? The free Foobot EMS can handle the tracking. It covers neither portfolio ESG reporting nor multi-country portfolios. Check what it covers on your sites.

Let's talk

Frequently asked questions about free energy management software

Is energy efficiency software free?

The software can be, operating it never is. Metering, instrumentation, BMS integration and the time spent reading the curves still have to be paid for. A free license shifts spending to these items, which are less visible at the time of choosing.

What is the best free software?

No ranking holds up: the right tool depends on the use. OPERAT is for reporting, RETScreen for studying a project, Emoncms or a vendor platform for tracking. Start from your need, then check what your data allows.

How do you choose energy efficiency software?

Start from the intended use: reporting, tracking, alerting or controlling. Then assess the state of your data, because a tool is only as good as its metering. Finally, test the BMS connectors, the export and the cost over the whole commitment period.

How do you choose the best software?

Organize a trial on a pilot site, with your real meters and your operators. Demand a one-year raw export during this trial. A vendor that refuses the export before signing is already showing you how leaving will go.

What types of consumption can be tracked?

Electricity, gas, water, district heating and cooling: anything that is metered can be tracked. The limit comes from the metering plan. Without sub-metering by end use, the tool displays a total it cannot explain.

Why is technology important for energy management?

It determines two things: data reliability and the ability to act. Automated collection detects the gaps and drifts that a manual reading misses. A link with the BMS turns an alert into an actual correction.

Is energy management software compatible with the Décret tertiaire?

It can be if it consolidates consumption by building, keeps the reference years and produces an export usable in OPERAT. Check this format during the trial: filing the declaration on the platform remains your responsibility.

What tools are used for an energy audit?

A regulatory audit relies on readings, invoices, measurement campaigns and pre-feasibility tools such as RETScreen. A BMS audit tests something else: points, sequences and trend logging. The two complement each other without replacing each other.

How can you reduce energy consumption and CO2 emissions?

Act through the BMS: setpoints, schedules, optimal start, removal of manual overrides. Then measure the savings according to the IPMVP with HDD correction. The kWh avoided are converted into tCO2e and make your carbon footprint verifiable.

Sources

Sources and references

5 sources.

Regulation2

1. [1]Légifrance, “Decree No. 2019-771 of 23 July 2019 on obligations to reduce final energy consumption in commercial buildings”, known as the Décret tertiaire; -40% target for 2030 set by Article L. 174-1 of the French Construction and Housing Code (code de la construction et de l'habitation); OPERAT platform entrusted to ADEME by the order of 10 April 202007/2019↑ 1 2 3 4
2. [5]Légifrance, “Decree No. 2020-887 of 20 July 2020 on building automation and control systems in non-residential buildings and automatic heat regulation”, known as the BACS decree; requirements codified in Article R. 175-3 of the French Construction and Housing Code, amended by Decree No. 2023-259 of 7 April 202307/2020↑

Press and announcements2

1. [2]Goodinfo, “10 free software tools for businesses to manage energy”↑
2. [3]Capterra, “Energy management software”, directory filtered on “free version”↑

Manufacturer documentation1

1. [4]Socomec, “Energy management software”, WEBVIEW software↑