Every three years the invoice arrives: fifty laptops out, fifty three-year-old machines to the remarketer. The warranty runs to month 36 and “we refresh on a three-year cycle” sounds like good governance. It is also most offices’ biggest carbon decision of the year — and it barely saves money.
The carbon is spent before you open the box
Every manufacturer’s lifecycle assessment tells the same story: impact is front-loaded into manufacturing.
- Apple’s MacBook Air 15-inch M4 report: 155 kg CO2e, split 71% production, 25% use, 3% transport, under 1% end-of-life (March 2025).
- Company-wide, Apple puts manufacturing at 74% of its footprint (Environmental Responsibility Report, 2019).
- Dell’s XPS 13 (9340) report: mean 263 kg CO2e, manufacturing 83.4%.
- Dell’s Latitude E3440 study: 314 kg CO2e, manufacturing roughly 70% — laptops are the exception; for desktops and servers, use dominates.
Across these reports, 70–85% of a laptop’s lifetime emissions are spent before the first login. Call it three-quarters. One implication matters: spread those ~155–263 kg over more years. Four years instead of three cuts annualized embodied emissions 25% — from 70 kg CO2e per machine-year to 52.5 kg at a conservative 210 kg midpoint. The electricity saved by the newest model is real but small: our measurements put a modern office laptop at ~30 kWh a year, about 7 kg CO2e on the EU grid. You cannot out-efficiency a factory.
The euro math: 3 vs 4 vs 5 years, 50 machines
A transparent model for a 50-person office buying €1,650 business-class laptops (ThinkPad T14 / Latitude 7000 class, ex-VAT), electricity at €0.2058/kWh (Eurostat, German business rate, H1 2026):
| Line | 3-year cycle | 4-year cycle | 5-year cycle |
|---|---|---|---|
| Purchase, net of resale value | €1,188 | €1,503 (incl. €150 warranty upgrade) | €1,752 (incl. €300 warranty upgrades) |
| Support & out-of-warranty repairs | €180 | €290 | €470 |
| Downtime allowance | €45 | €70 | €120 |
| Electricity (30 kWh/yr) | €19 | €25 | €31 |
| Total per machine | €1,432 | €1,888 | €2,373 |
| Per machine-year | €477 | €472 | €475 |
Residuals are ITAD benchmarks: roughly 28% of purchase price recovered at three years, 18% at four, 12% at five (Hummingbird International), with resale of $150–350 for a three-year-old business laptop falling to $75–200 at four (Altech ITAD). The warranty upgrade is a real quote: Lenovo’s 3-to-4-year Premier Support extension runs €147–244 per machine at Bechtle. Support and downtime step up in years four and five, consistent with Dell’s failure-cost study, which pegs one out-of-warranty repair at $1,425.
The result is almost embarrassingly flat: the four-year cycle is cheapest, but only by about €5 per machine-year — €260 a year across 50 machines. The argument is what those years do to the other two lines:
- Capex timing: a 50-seat office buys 16.7 machines a year on a three-year cycle, 12.5 on a four-year cycle. That defers roughly €6,900 of purchasing per year.
- Carbon: 4.2 fewer machines per year × ~210 kg embodied = ~875 kg CO2e avoided annually, a 25% cut in the fleet’s amortized laptop footprint.
That is the entire prize, and the three-year cycle throws it away for €5 a machine-year.
The studies that say three years — and why they say it
A May 2026 IDC survey of 735 organizations (sponsored by Qualcomm) found a three-year refresh runs 14% cheaper than five years — $1,993 per PC over five years. A Wipro-for-Dell study of 106 firms reached the same verdict in 2010.
Look at the drivers: IDC monetizes productivity loss and IT staff time on $70,000–100,000 loaded salaries plus a 15% revenue margin — “user impact” is their fastest-growing line, not hardware or support. If your workloads are Office, browser and video calls, a maintained year-four machine is not losing anyone’s week — and IDC’s own figures show costs compounding hardest in year five. The Wipro study is fifteen years old, from the era of spinning hard drives and 4 GB RAM.
The failure folklore points the same way. The oft-quoted “one in three laptops fail in three years” comes from SquareTrade’s analysis of 30,000 consumer warranty claims — student machines and dropped MacBooks, not warrantied enterprise fleets. Enterprise hardware with next-business-day support has no cliff at month 36; it has a gradual slope, insurable for €147.
What you save
Moving 50 laptops from a 3-year to a 4-year refresh saves about €260 a year in hard cost and defers ~€6,900 a year in purchasing — while avoiding ~875 kg CO2e annually, a 25% cut in the fleet’s amortized laptop carbon. The euros are modest; the carbon is the whole point — the cheapest tonne your company will ever not-emmit.
Two conditions: buy one spec above today’s workload — the four-year cycle fails on under-specced machines, not old ones — and buy the year-four warranty extension at purchase, not after the failure. Thoughtworks moved from three to four years in 2024 on exactly this logic and reported a 34% cut in laptop emissions in the first full year.
Methodology
Embodied carbon: 210 kg CO2e midpoint of Apple’s MacBook Air M4 (155 kg, 71% production) and Dell’s XPS 13 (263 kg, 83.4% manufacturing); Latitude-class machines land higher (314 kg). Price €1,650 ex-VAT; electricity €0.2058/kWh (Eurostat nrg_pc_205, H1 2026) at 30 kWh/year from our 2026 measurements. Residuals 28/18/12% from ITAD benchmarks. Warranty upgrade €150. Support €60/machine/year in-warranty, €110 in year 4, €180 in year 5; downtime €15/25/50. No productivity-loss monetization — that is where the three-year-campaign studies inflate their totals.
Sources
- Apple, MacBook Air 15-inch M4 Product Environmental Report (March 2025): https://www.apple.com/environment/pdf/products/notebooks/M4_MacBook_Air_PER_March2025.pdf
- Apple, Environmental Responsibility Report 2019: https://images.apple.com/environment/pdf/Apple_Environmental_Responsibility_Report_2019.pdf
- Dell, Carbon Footprint Report, XPS 13 9340 (PAIA): https://www.delltechnologies.com/asset/en-nz/products/laptops-and-2-in-1s/technical-support/xps-13-9340-pcf-datasheet.pdf
- Dell, Carbon Footprint of a Dell Latitude E3440: https://i.dell.com/sites/csdocuments/Corporate_corp-Comm_Documents/en/PCF-WP-E3440.pdf
- Dell, Keeping Notebooks Past Their Prime (failures and costs): https://i.dell.com/sites/content/business/smb/sb360/en/documents/wp-nb-failures-costs.pdf
- IDC for Qualcomm, Cost of Aging PCs, three-year refresh study (May 2026): https://www.qualcomm.com/content/dam/qcomm-martech/dm-assets/documents/IDC_Qualcomm-PC-Impact.pdf
- Wipro for Dell, Using TCO to Determine Optimal PC Lifecycle: https://i.dell.com/sites/content/business/smb/en/Documents/Using-TCO.pdf
- SquareTrade, Laptop Reliability Study (30,000 laptops): https://www.squaretrade.com/htm/pdf/SquareTrade_laptop_reliability_1109.pdf
- Hummingbird International, Monetizing Retired IT Assets (residuals by age): https://hummingbirdinternational.net/10-ways-to-tackle-global-waste
- Altech ITAD, Where Do Refurbished Laptops End Up: https://altechco.com/where-do-refurbished-laptops-end-up-the-full-story
- Bechtle, Lenovo 3Y Premier to 4Y Premier Support upgrade: https://www.bechtle.com/be/shop/lenovo-3y-premier-to-4y-premier-support–4491376-73–p
- Foxway, Handprint Report 2023: Laptops (citing EEB: EU-wide 1-year laptop life extension = 1.6 Mt CO2/year by 2030): https://www.foxway.com/wp-content/uploads/2024/05/handprint-report-laptops-2023-eng.pdf
- Thoughtworks, A better laptop for the job: https://www.thoughtworks.com/en-gb/insights/microstories/a-better-laptop-for-the-job-lower-emissions-and-costs
- Eurostat, electricity price statistics (nrg_pc_205), H1 2026: https://ec.europa.eu/eurostat/statistics-explained/index.php?title=Electricity_price_statistics
Next leak to fix
The policy is right; now the machine is the wrong question. Half your office never leaves a desk, and the laptop you hand them costs more and idles hotter than the €599 desktop that would do the same job. Before the next purchase order, rank your fleet by who actually closes the lid: The most energy-efficient office computers of 2026, ranked by real cost puts measured watts, annual kWh and euro cost against every candidate.
—
Carla Lavigne is Green Ops Editor at mycompanyisgreen.org and the colleague who brings the calculator to the audit.











