Your electricity meter used to do one thing: count kilowatt hours while a reader walked past once a month. A smart meter counts your usage every 15 or 30 minutes, stores it, transmits it, and in many countries keeps it for years. That interval data is precise enough to show when you woke up, when you showered, when you left for work, when you were away for the weekend, and what you run inside your house. Police, insurers, immigration authorities and landlords have all worked out what that is worth. Most people have never asked who holds it and for how long.
What the meter actually records
Interval data is the prize. Half-hourly readings show the shape of your day. Researchers demonstrated years ago that consumption curves alone can identify which appliances ran and when: the spike of an electric shower, the flat plateau of an air conditioner, the small constant draw of a device left on standby. Aggregate analysis across a neighbourhood can infer occupancy with uncomfortable accuracy. A house that shows zero variance for eleven days looks like an empty house.
Alongside the readings, the system stores alarms and events: power cuts, tamper flags, reverse energy flow, failed communications. A tamper flag is the record that gets cited when someone disputes an electricity theft charge. Reverse flow flags matter to anyone running solar panels, because export patterns are recorded on the same schedule.
What the utility holds is only half the picture. In the UK and much of the EU, the communications infrastructure runs through a dedicated network, and the data can be shared with third parties under loose consent language. In the United States, meter data frequently sits with the utility, the meter vendor, and sometimes a commercial analytics platform under a smart-city contract. Data requests have been granted in drug investigations, cannabis grow-house cases, theft of service disputes, and immigration enforcement.
How long it survives
Retention varies by country and by provider, which is exactly why a generic answer is worthless. Common patterns: interval data is kept anywhere from 13 months to 7 years; event and tamper logs often longer, because they support billing disputes and prosecutions; aggregated profile data can be kept indefinitely. In the UK, suppliers can access half-hourly data only with explicit consent for some purposes, but daily data can be collected for billing without asking you again. The consent you ticked during installation governs far more than most people read.
Utility staff can typically see a rolling window of your usage through a web portal, sometimes with a “privacy mode” setting that hides granular data from the supplier. Few customers are told that mode exists. Fewer still switch it on.
Who asks for it, and how
Requests arrive in three flavours. Law enforcement requests usually come with a court order or, in weaker regimes, a plain letter of request to the utility. Civil litigants request data to prove or disprove occupancy, for example in disputes over residency, inheritance of a tenancy, or insurance claims after a house fire. Government agencies request it for welfare and immigration checks, since a long zero-usage period is treated as evidence a property is vacant. The pattern echoes what we documented in the piece on what modern vehicles record: a convenience sensor quietly became a witness that reports on its owner.
What makes smart meter data different from phone records is that nobody carries it with them. You cannot leave the meter at home. The data is generated by staying somewhere, which is why it has been used to prove that someone lived at an address, worked from home, or did not. In tenancy disputes that is a double-edged record: the same curve that proves you occupied the flat proves exactly which nights you did not.
What you can actually request
You have more rights over your own data than over anyone else’s, and the requests cost nothing.
- Data subject access request (UK/EU). Ask your supplier in writing for all personal data held about you, explicitly including half-hourly interval data, event logs, and any disclosures made to third parties. By law the answer is due within one month. Most suppliers have never processed one for interval data and will take several tries; persistence is the price.
- Disclosures log. Ask separately whether your data has been shared with police, government agencies, or commercial partners, when, and under what legal basis. Suppliers in the UK are not obliged to tell you about law enforcement disclosures in all cases, but the internal log exists and a well-worded request sometimes surfaces it.
- Privacy mode. Ask your supplier to switch your meter to the mode that prevents collection of half-hourly data, keeping daily reads for billing only. This reduces the record created going forward. It does nothing about data already stored.
- Freedom of information requests. For state-owned utilities, FOI can reach retention policy documents, contracts with meter data analytics firms, and aggregate statistics on police data requests. Ask for the retention schedule and the last three years of law enforcement request counts. The technique is the same one that worked for the breach-response records in our earlier piece on FOI-ing a government breach response itself, and it fails on the same ground: private utilities are outside FOI scope in most countries.
The uncomfortable structural point
None of this data collection started as a surveillance project. It started as grid management, and the surveillance properties arrived as a side effect that regulators priced at zero. That is the standard pattern for infrastructure snooping, and it is why the retention clock matters more than the collection: a meter reading nobody can retrieve after 13 months is a grid signal, while a meter reading retrievable for 7 years is a diary of your house written by someone else. The same retention arithmetic that governs call logs and CCTV applies here, and the request techniques are largely the same ones covered in how long UK call records survive. Find out your supplier’s retention period before you need to, not after.