AMI and Submetering: Use the Data You Already Have
Your utility meter may already be recording your power use in short blocks. This guide shows you what to pull from the utility this week, where submeters earn their place inside the building, and when to buy them so they still work after the utility replaces its meters.
Who this is for
- ■Facilities managers and plant managers responsible for the power bill at a manufacturing plant or industrial facility.
- ■Owners and operators of multi-tenant buildings and commercial real estate who allocate power costs across tenants.
- ■Operations directors and CFOs at K-12 districts and municipalities planning metering or energy management capital.
- ■Anyone who pays for power they cannot see inside their own building.
Does the free interval data from your utility's AMI meter answer your cost questions, or do you need submeters to see inside the building?
Once a month you get a power bill. It shows one total for energy and one number for billed demand. When that demand number jumps, nothing on the bill tells you which day or which hour drove it. Meanwhile your utility meter may be recording your power use every 15 minutes, and that record sits in the utility's system.
Your bill is built on two terms. Energy is how much electricity you use over time. It is measured in kilowatt-hours (kWh), and energy is billed per kilowatt-hour. Demand is how much power you draw at one moment. It is measured in kilowatts (kW), and demand is billed per kilowatt.
On many commercial bills the demand charge comes from your single highest block of use in the month, often a 15 minutes block. Your average does not set it. One bad block can set the demand charge for the whole month. Find the line on your bill labeled billed demand or maximum demand, in kilowatts. That is the number your interval data can explain.
Advanced metering infrastructure, or AMI, is your utility's system of digital meters. The Federal Energy Regulatory Commission (FERC) defines AMI as a metering system that records consumption at least every 1 hour and sends those measurements at least 1 per day over a communication network to a central collection point. The network carries information both ways, so the utility can send commands back to the meter, like a remote disconnect or a firmware update.
A submeter is a meter you own. It is installed behind the utility's main meter, and it measures one tenant, one department or one machine. The AMI meter can show you when your building used power. It cannot show you which part of the building used it. So the decision is whether the free AMI data answers your cost questions, or whether you need submeters to see inside the building.
26%of this guide, read. The rest of it is below.
The older metering technology was automatic meter reading, or AMR. AMR is one-way: it only sends a reading to the utility. A lot of facility managers inherited AMR-era assumptions and still treat the meter as a billing device. So the interval data sits in the utility's system while the bill still shows a monthly total. That data only works for you when you request it or export it.
How AMI data travels from the meter to your deskThe customer interface is where your own submetering either reinforces the utility data or pays to measure the same thing twice. City of Palo Alto UtilitiesWhat one municipal utility puts in front of you
The City of Palo Alto Utilities is a municipal utility. It gives commercial customers with demand charges their daily peak demand alongside their monthly billed demand. Its portal shows an hourly view and a 15 minutes view, 1 day at a time. And it lets the customer export 36 months of history.
What a full interval export gives a commercial customer in Palo Alto36monthsHistory a Palo Alto customer can export30demand numbersDemand readings a month with daily peak100,000data pointsReadings in that export, more thanDaily peak demand and a multi-year export turn one demand number a month into a record tied to every day and time.Daily peak demand turns one demand number a month into about 30 demand numbers. A full export of 36 months of interval readings comes to more than 100,000 data points, every one tied to a day and a time. Your utility's offer can differ, so check your own portal for the interval length and how far back the export reaches. A strong position is 3 years of interval data exported and saved in your own files. A weak position is a stack of monthly bills and nothing else.
Use oneDemand charge management
Find the days and hours behind your demand peaks and work to bring them down.Use twoLoad shifting
Move a flexible process to a different time of day, using the interval record to pick the time.Use threeChoosing a time-of-use rate
AMI is what lets a utility bill a time-of-use rate. Your interval data tells you whether that rate helps you or costs you.The interval export costs you nothing beyond the time to pull it. A utility bill audit recovers overcharges after the fact. Interval data gives you a running record of your own use, so you can check each bill against it while that bill is still current.
The problem shows up in two places. Your interval data shows a demand peak, and nobody can say which machine or which department caused it. Or you run a multi-tenant building, a tenant disputes their share of the power bill, and you have no reading of their own to show them.
The utility's AMI meter measures only at the main meter, the point where the utility connects to your building. The City of Palo Alto Utilities states that its AMI meters cannot be connected to appliances or devices, so in Palo Alto the meter cannot feed your building management system. Every tenant, every department and every machine shows up as one combined number. A submeter sits downstream of the main meter and measures only the part of the operation wired through it.
The cost question Main meter interval data Submeter on that load When does the building peak? Answers it Not needed for this question Which machine or process caused the peak? Cannot answer it Answers it, on the right equipment What is each tenant's actual share? One combined number A reading per tenant you can show them What did on-site solar produce? AMI can report it; Palo Alto shows usage and generation separately before netting Plan around what the utility already gives you Submeter the tenants, departments or equipment where you need the answer to who or what, and nowhere else. If you have solar or storage on site, coordinate the submeters with the utility's AMI data. Some utilities, Palo Alto among them, bill solar customers under net energy metering, where the bill is based on the monthly net of what you used and the excess solar you generated. Plan your submeters around what the utility already gives you, so you pay to measure each thing once.
Data accessWho else sees your load shape
Your interval data draws a picture over a day or a week: when your power use climbs, when it holds steady, when it drops off. That picture is your load shape, and for an industrial plant a load shape can reveal your production schedule. There is no line on your bill for who sees it. You find it in your utility's data access and privacy disclosure.
Palo Alto shows how far utility data access can reach. Its meters collect usage and voltage information only. The customer sees the data through the utility's portal. A customer service representative may view your usage history when you call about a bill. Select utility departments get aggregated usage for rate analysis, efficiency programs and transformer load analysis. Cloud vendors host the data, and the utility says those vendors meet national, state and industry standards for privacy and cybersecurity.
AMI and submetering can hurt you in three situations. The first is buying submeters before you have looked at the free interval data from the utility. The second is buying hardware that may not work with your utility's next generation of meters. The third is billing tenants from submeters nobody has checked for accuracy.
What operators assume What actually happens The utility smart meter is a billing device. AMI records interval data and runs two ways. The data only works for you when you request it or export it. The utility meter shows which tenant or machine used the power. The AMI meter measures only at the main meter. Everything inside shows up as one combined number. Scope the submeters first, then study the data. Pulling the free data first shows where the main meter leaves you blind and can keep you from over-engineering the submeter system. Submeters bought today will line up with whatever the utility installs next. Without the utility's replacement timeline you may end up with data gaps and hardware or firmware that do not work with the new meters. AMI 2.0 timingThe utility's first meters are aging out
Deloitte reports that the first wave of AMI meters went in between 2,000 and 2,010. Those meters and their internal batteries had a life expectancy of 20 years. Failure rates are rising as those meters approach that mark, and early adopters are planning replacements that can take 3 years to 5 years. Deloitte calls the next generation AMI 2.0: edge-computing meters that do more of the data processing in the meter itself, so usage and generation can be read in real time.
How long first-wave meters last and how long replacement takes20yearsFirst-wave meter and battery life expectancy3yearsReplacement program, low end5yearsReplacement program, high endA utility replacement program runs for years, so the timeline belongs in your submeter and software purchase plan.You may also be planning an energy management system, the software that collects and displays your meter data. If you buy submeters or that system without knowing the utility's replacement timeline, you may end up with gaps in your data. You may also end up with hardware and firmware that do not work with the new meters.
The first warning sign in a metering proposal is that it opens with hardware. If nobody evaluated your existing metering and data, the scope came from the vendor's default recommendation. Acting in the right order prevents that, and the first step is free.
- 1 Pull your interval data and daily peak demand from the utility. It is free, and it shows where the main meter leaves you blind before you spend any capital.
- 2 List the cost questions the main meter cannot answer, by tenant, department or machine. That list is your submeter scope.
- 3 Ask your utility when it plans to replace its AMI meters, and ask for its data access disclosure.
- 4 Run the submeter procurement in sequence: evaluation, cost and benefit analysis, technology choice, then design and install.
A vendor's framingRun the procurement in sequence
Ameresco, a firm that sells metering work, lays out this sequence, so treat it as a vendor's framing. Start with an evaluation of your existing metering and data. Next comes an unbiased cost and benefit analysis. Then choose the technology: which submeters, how they report data (automatically to your own software or by reading on site), and how they line up with the utility's AMI data. Only after that should you design and install. Ameresco also offers delivery at a firm fixed price. Doing the cost and benefit analysis before you pick a vendor keeps that vendor's default hardware from setting your scope.
Before you buyThe payback test you can run from your own bill
- 1 For a demand peak, take the kilowatts you think you can cut and multiply by the demand rate per kilowatt on your bill.
- 2 Multiply that by 12 months to get the annual demand saving. 12 months
- 3 For tenants, estimate the dollars you are under-recovering each year, and add that to the demand saving for your annual figure.
- 4 Divide the installed submeter quote by that annual figure. The result is your payback in years, the time it takes those savings to cover the purchase.
Ask the vendorWhat did you find first?
What did you find in our existing metering and data before you picked hardware?Ask the vendorDid you compare options?
Did you compare more than one type of submeter and data system, or only price your own?Ask the vendorWhat happens at replacement?
How will your system work through our utility's AMI meter replacement?Ask the vendorHow is accuracy checked?
If we bill tenants from your submeters, how will you verify meter accuracy?Ask the vendorIs the price firm?
Is the price firm fixed, one agreed price for the whole job?- Decision matrix
When AMI data and submeters are worth acting on
✓ Act on it- You pay demand charges and cannot say which day or hour set last month's billed demand.
- You are weighing a time-of-use rate and need interval data to see whether it helps or costs you.
- You allocate power costs across tenants or departments and need a reading for each.
- You have solar or storage on site and need submeters coordinated with the utility's AMI data.
- Your load shape is competitively sensitive and you want equipment-level data under your control.
✗ Hold off- You have not yet pulled the free interval data from your utility.
- You cannot name the dollars a submeter would save or recover each year.
- You do not know when your utility plans to replace its AMI meters.
- The proposal opens with hardware and nobody evaluated your existing metering and data.
- You plan to bill tenants from submeters nobody has checked for accuracy.
Questions for your morning huddle- Have we exported our interval data and our daily peak demand from the utility, and how many months back does it go?
- For our engineer: which loads drive our billed demand, and can we prove it from the main meter, or do we need submeters on that equipment?
- When does our utility plan to replace its AMI meters, and will anything we buy now still work with the new ones?
- Who at the utility, and at its cloud vendors, can see our load shape?
The one thing to rememberThe cheapest metering data you will ever get is the data your utility may already be recording at your main meter. It tells you where the main meter leaves you blind before any vendor does.
Pull the free interval data before you buy a single submeter. This week, ask your utility what interval and daily peak demand data you can export and how far back it goes, save it in your own files, and find the block that set last month's billed demand.
The Energy Decision BlueprintKnow if the numbers actually pencil out before you sign anything.
A written second opinion on the project in front of you, whether that is a rate change, new equipment, or a renewable installation.
- 01A short call, to figure out quickly whether we can actually be helpful. If we can't, we'll say so on the spot.
- 02We pull the data, your bills, your rate structure, vendor proposals, project specs.
- 03You get the verdict in writing: whether the payback will materialize, and the opportunities or risks nobody has raised.
Get a Blueprint at blueprint.tac-nrg.com Free for Indiana-based operations spending five figures or more a month on electricity. No obligation. You keep the write-up either way. - The Energy Decision Blueprint
Know if the numbers actually pencil out before you sign anything.
A written second opinion on the project in front of you, whether that is a rate change, new equipment, or a renewable installation.
- 01A short call, to figure out quickly whether we can actually be helpful. If we can't, we'll say so on the spot.
- 02We pull the data, your bills, your rate structure, vendor proposals, project specs.
- 03You get the verdict in writing: whether the payback will materialize, and the opportunities or risks nobody has raised.
Get a Blueprint at blueprint.tac-nrg.com Free for Indiana-based operations spending five figures or more a month on electricity. No obligation. You keep the write-up either way.does my utility smart meter replace submetering
No. A utility AMI smart meter measures only at the main meter, where the utility connects to your building, so every tenant, department and machine shows up as one combined number. It can tell you when the building peaks. It cannot tell you who or what caused the peak. For tenant billing, department allocation or equipment-level answers you need submeters you own, installed behind the main meter.
how do I get interval data from my utility portal
Log in to your utility portal or call your account representative and ask what interval data and daily peak demand data you can export, and how many months back it goes. As one example, the City of Palo Alto Utilities lets commercial demand customers export 36 months of history. Export the data and save it in your own files. A strong position is 3 years of interval data kept on your side.
what is the difference between AMI and AMR meters
AMR, automatic meter reading, is one-way: the meter sends a reading to the utility and nothing more. AMI, advanced metering infrastructure, records consumption at least every 1 hour, sends it at least 1 per day, and runs both ways, so the utility can send commands such as a remote disconnect or firmware update. Facility managers carrying AMR-era assumptions often leave the AMI interval data unused.
who can see my facility's smart meter data
It depends on your utility, and you find it in the utility's data access and privacy disclosure. At the City of Palo Alto Utilities, the customer sees data in the portal, customer service may view usage history during a billing call, select departments get aggregated usage for rate analysis and transformer load work, and cloud vendors host the data. For an industrial plant, the load shape in that data can reveal a production schedule.
should I wait for my utility's meter upgrade before buying submeters
Ask the utility for its AMI replacement timeline before you buy. Deloitte reports first-wave AMI meters had a life expectancy of 20 years, failure rates are rising, and replacement programs can take 3 years to 5 years. Buying submeters or an energy management system without that timeline can leave you with data gaps and hardware or firmware that do not work with the new meters.
what is the difference between AMI and AMR meters
AMR, automatic meter reading, is one-way: the meter sends a reading to the utility and nothing more. AMI, advanced metering infrastructure, records consumption at least every 1 hour, sends it at least 1 per day, and runs both ways, so the utility can send commands such as a remote disconnect or firmware update. Facility managers carrying AMR-era assumptions often leave the AMI interval data unused.
who can see my facility's smart meter data
It depends on your utility, and you find it in the utility's data access and privacy disclosure. At the City of Palo Alto Utilities, the customer sees data in the portal, customer service may view usage history during a billing call, select departments get aggregated usage for rate analysis and transformer load work, and cloud vendors host the data. For an industrial plant, the load shape in that data can reveal a production schedule.
should I wait for my utility's meter upgrade before buying submeters
Ask the utility for its AMI replacement timeline before you buy. Deloitte reports first-wave AMI meters had a life expectancy of 20 years, failure rates are rising, and replacement programs can take 3 years to 5 years. Buying submeters or an energy management system without that timeline can leave you with data gaps and hardware or firmware that do not work with the new meters.
how do I calculate payback on submeters
Take the kilowatts of demand you think you can cut, multiply by the demand rate per kilowatt on your bill, then multiply by 12 months. Add the dollars you under-recover from tenants each year. Divide the installed submeter quote by that annual figure to get payback in years. If you cannot name the dollars, you are not ready to buy the submeter.
- Advanced metering infrastructure
- AMI. The utility's digital meters, a two-way communication network and a data system. Records power use at short intervals and sends it to the utility at least daily.
- Automatic meter reading
- AMR. The older one-way metering technology. It sends a reading to the utility and cannot receive commands or deliver interval data to you.
- Submeter
- A meter you own, installed behind the utility's main meter, that measures one tenant, one department or one machine.
- Main meter
- The utility's meter at the point where the utility connects to your building. Everything downstream shows up on it as one combined number.
- Interval data
- A record of your power use broken into short blocks of time, such as hourly or shorter, in place of one monthly total.
- Billed demand
- The demand charge line on your bill, in kilowatts, often set by your single highest block of use in the month.
- Load shape
- The picture your interval data draws over a day or week: when use climbs, holds and drops. For a plant it can reveal the production schedule.
- Time-of-use rate
- A rate that sets a different price per kilowatt-hour depending on the time of day, in bands a utility may label on-peak and off-peak.
- Revenue leakage
- Money you were owed and never collected, for example from an inaccurate submeter used to bill tenants.