Modern mini PCs are extremely power-efficient. Under load, they typically consume 10-65W — compared to 200-500W for traditional desktops. This translates to annual electricity costs of just £15-50/year, making them ideal for always-on servers, media centres, and budget-conscious home offices.
Power Consumption Comparison Table
| Device Type | Idle Power | Load Power | Annual Cost (24/7) |
|---|---|---|---|
| Mini PC (11th Gen Intel) | 5-10W | 25-40W | £18-46 |
| Mini PC (Ryzen 7840U) | 8-12W | 35-55W | £26-64 |
| Fanless Mini PC | 3-5W | 15-25W | £11-29 |
| Laptop (when plugged in) | 8-15W | 45-85W | £33-78 |
| Office Desktop (i5, no GPU) | 50-80W | 150-250W | £183-365 |
| Gaming Desktop (RTX 3070) | 100-150W | 400-500W | £730-1095 |
| Mac Studio (M2 Max) | 20-30W | 80-120W | £73-183 |
Annual cost assumes £0.34/kWh (UK average 2026). All figures are approximations; actual consumption varies by configuration and workload.
Understanding TDP (Thermal Design Power)
TDP is NOT the same as actual power consumption. TDP is the maximum heat a CPU can generate under worst-case stress testing. Real-world usage is typically 30-60% of TDP.
Example: An Intel Core i7-1365U has a TDP of 15W, but draws only 8-12W under typical office work. Playing a video might spike to 12W, while gaming pushes it closer to 15W.
| Processor Type | TDP | Typical Real-World Power | Peak Load Power |
|---|---|---|---|
| Intel Core i3-1215U | 15W | 8-10W | 12-15W |
| Intel Core i5-1340P | 28W | 15-20W | 25-30W |
| Intel Core i7-1365U | 15W | 8-12W | 15W |
| AMD Ryzen 5 5625U | 15W | 8-12W | 15W |
| AMD Ryzen 7 7840U | 28W | 18-25W | 28W |
| Intel Core i9 (desktop) | 125-253W | 60-100W | 125-253W |
Power Consumption by Mini PC Brand/Model
| Brand | Model | CPU | Idle | Load | Annual Cost (24/7) |
|---|---|---|---|---|---|
| Intel | NUC 13 (i7-1360P) | 28W TDP | 6-8W | 35-45W | £35-50 |
| ASUS | NUC 14 Pro (i5-1440P) | 28W TDP | 5-7W | 30-40W | £28-45 |
| Beelink | SER7 (Ryzen 7 7840U) | 28W TDP | 8-10W | 40-50W | £37-56 |
| Minisforum | HM90 (i5-12450H) | 45W TDP | 10-12W | 50-60W | £46-68 |
| Geekom | A5 (Ryzen 5 5500U) | 15W TDP | 4-5W | 18-25W | £17-28 |
| Lenovo | ThinkCentre M100 Tiny (i5-12500T) | 35W TDP | 8-10W | 40-50W | £37-56 |
| Geekom | A7 Fanless (no active cooling) | 15W TDP | 3-4W | 12-15W | £11-21 |
Annual Electricity Cost Calculator
Formula: (Power in Watts) × (24 hours) × (365 days) × (Cost per kWh) ÷ 1000
UK electricity rate (March 2026): ~£0.34 per kWh
Quick examples:
- Mini PC at 35W (average load): (35 × 24 × 365 × 0.34) ÷ 1000 = £10.42/month or £104/year
- Mini PC at 50W (heavy load): (50 × 24 × 365 × 0.34) ÷ 1000 = £14.88/month or £149/year
- Desktop at 250W (average): (250 × 24 × 365 × 0.34) ÷ 1000 = £74.35/month or £744/year
- Gaming PC at 400W (gaming load): (400 × 24 × 365 × 0.34) ÷ 1000 = £118.94/month or £1189/year
Why Mini PCs Are So Efficient
- Mobile-grade processors: Most mini PCs use 15-28W TDP mobile CPUs, designed for laptops. Desktop CPUs start at 45W minimum.
- No dedicated GPU: Integrated graphics use the same power envelope as the CPU. Dedicated GPUs add 50-350W.
- Passive cooling option: Fanless models eliminate cooling overhead. Fans run at low speed since heat generation is minimal.
- Efficient chipsets: Modern Intel and AMD chipsets optimise idle power, dropping below 1W when the system sleeps.
- No spinning drives: All modern mini PCs use SSDs; HDDs add 5-10W continuous power draw.
24/7 Server Use Cases
Mini PCs shine in always-on scenarios:
- Plex media server: Mini PC cost = £400-700; annual electricity = £100-150. Desktop: £600-1000; electricity = £700-900. Mini PC saves £200-450/year.
- NAS/file backup: Mini PC with USB drives or SATA enclosure. Low power, silent operation.
- Home Assistant / smart home hub: Runs 24/7 to control lights, cameras, locks. Energy cost negligible.
- VPN gateway / network storage: Corporate environments often deploy mini PCs instead of larger servers.
- Cryptocurrency node (not mining): Bitcoin full node or Ethereum staking node runs on 15-30W continuously.
Annual savings: 24/7 Mini PC vs 24/7 Desktop
(£700 – £100) × 5 years = £3000 savings in electricity alone
How to Measure Your Mini PC’s Power Draw
Method 1: Power meter (£15-25)
Plug the mini PC into a power/energy meter, let it run for a week under typical load, then check total kWh consumed. Kill-a-Watt style meters are excellent for this.
Method 2: Linux command line
On Linux, install powertop and run sudo powertop to see live CPU power estimates.
Method 3: BIOS monitoring
Some mini PCs (Intel NUC, ASUS NUC) report power consumption in BIOS settings. Enter BIOS and look for “Power” or “Thermal” tabs.
Method 4: Manufacturer datasheets
Check the official power consumption table for your model. Most reputable brands publish this data.
FAQ
Q: Does leaving a mini PC on 24/7 increase the electricity bill noticeably?
A: No. Running a 35W mini PC 24/7 for a month costs about £10 in electricity. Most people won’t notice on their bill.
Q: Is it cheaper to leave a mini PC on or turn it off?
A: Leaving it on is cheaper if you use it multiple times daily. For sporadic use (once a week), turning it off saves money. Boot time is under 10 seconds anyway.
Q: What’s the difference between a mini PC and a laptop in power consumption?
A: Similar CPUs draw similar power. Mini PCs are usually more efficient because they don’t need to power a display, battery, and touchpad.
Q: Do gaming mini PCs use more power?
A: Yes. Models with dedicated GPUs (eGPU or discrete card) draw 50-150W more than integrated graphics variants.
Q: Can I use a solar panel or battery backup with a mini PC?
A: Yes, easily. A 100W solar panel and 1000Wh battery can run a mini PC continuously. Impossible with a desktop requiring 300+ watts.
Q: What’s the most power-efficient mini PC brand?
A: Fanless models (Geekom A7, Minisforum V3) and ultra-low-power CPUs (Ryzen 5 5500U, i5-1240P) are most efficient at 10-25W.
Recommended Products
These are the products we recommend based on this guide. All links go to Amazon UK where you can check current prices and availability.
| Product | Why We Recommend It | Amazon UK |
|---|---|---|
| Corsair Vengeance DDR4 SO-DIMM 32GB (2×16GB) 3200MHz | Best overall DDR4 upgrade kit | View on Amazon UK |
| Kingston Fury Impact DDR4 SO-DIMM 32GB (2×16GB) 3200MHz | Reliable alternative with tight latency | View on Amazon UK |
| Crucial DDR4 SO-DIMM 16GB 3200MHz | Budget single-stick upgrade | View on Amazon UK |
| Samsung DDR4 SO-DIMM 32GB 3200MHz | OEM-quality for business laptops | View on Amazon UK |
| Samsung 990 Pro 2TB NVMe M.2 2280 | Fastest consumer NVMe — ideal for gaming & editing | View on Amazon UK |
| WD Black SN850X 2TB NVMe | Excellent Gen4 speed with heatsink option | View on Amazon UK |
| Crucial P5 Plus 1TB NVMe | Great value Gen4 SSD | View on Amazon UK |
| Kingston NV2 1TB NVMe | Budget-friendly with solid reliability | View on Amazon UK |
Prices and availability may vary. As an Amazon Associate, we earn from qualifying purchases.
