Home tech
Backup power, Wi-Fi, smart home and security cameras, explained with real numbers.
Calculators
- Power station size calculator
List what you want to keep running in an outage and get the battery size, inverter rating and runtime you need.
- Generator size calculator
List what you'll run in an outage to get running watts, peak starting watts and a recommended generator size with a 90% margin.
Guides
- How much electricity does a computer use?
An efficient mini desktop idles near 4 W. At 65 W for 8 hours a day, a computer uses about 190 kWh a year, or about $34 at 18¢/kWh.
- Do smart plugs save electricity?
Only if they cut real standby loads. A plug drawing 1 W costs about $1.58 a year at 18¢/kWh, so it must cut more than that to save money.
- How much does it cost to charge an electric car at home?
At 18 cents/kWh, an EV using 27 kWh per 100 miles costs about $48.60 to drive 1,000 miles on home charging, or about 4.9 cents a mile.
- How much electricity does a game console use?
A PS5 draws about 100-200 W while gaming. Xbox Sleep reportedly uses 10-15 W vs 0.5 W in Shutdown. Cost tables at 12-30 cents/kWh.
- How long will a generator run on a tank of gas?
Honda inverter generators run about 8-16 hours per tank at 25% load and 3-6.5 hours at rated load. Spec sheets and fuel math inside.
- How long do portable power stations last?
How long a power station lasts: LiFePO4 models we checked are rated 3,000 cycles (about 8 years daily); the NMC Yeti 1500X is rated 500.
- How much electricity does a TV use?
Most new 55-inch TVs draw 70 to 120 W and 65-inch TVs 110 to 135 W. At 5 hours a day, that is about 128 to 246 kWh, or $23 to $44 a year at 18¢/kWh.
- How much electricity does a Wi-Fi router use?
Most Wi-Fi routers draw about 5-20 W, or 44-175 kWh a year. At 18¢/kWh a typical 10 W router costs about $16 a year to run 24/7.
- Is a surge protector worth it? What the ratings mean
Yes for electronics. Look for a UL 1449 listing, a low VPR, a high joule rating and a protection light. Replace it when that light goes out.
- Matter vs. Zigbee vs. Z-Wave: which smart home standard should you choose?
Matter runs over Wi-Fi and Thread; Zigbee uses 2.4 GHz mesh; Z-Wave uses 908.42/916 MHz in the US. Which to pick for a new or existing smart home.
- Mesh Wi-Fi vs. Wi-Fi extender: which do you need?
One dead room? An extender may do. Big or multi-story home? Mesh. One eero 6+ covers up to 1,500 sq ft; nodes reportedly draw 4-9 W each.
- How much power does a portable solar panel really produce?
A portable solar panel usually delivers about 67-75% of its rated watts in real use. A 200 W panel with 4 sun hours gives roughly 600 Wh a day.
- Portable power station vs. generator for home backup: which should you buy?
Power station or generator for outages? Compare runtime, power, cost, noise and safety for short outages, long outages and apartments.
- How much storage does a security camera need?
A camera recording 24/7 at 4 Mbps uses about 43.2 GB a day, or 1,296 GB in 30 days. Use the formula and table to size your drive.
- How much does a smart thermostat actually save?
ENERGY STAR says the average home with a certified smart thermostat saves 8% on heating and cooling costs, or $50 per year. Here is the math.
- Standby power: which devices waste the most electricity when 'off'?
A 2015 NRDC study found always-on devices average 164 W per home, about $165 a year. See which gadgets waste the most and what to unplug.
- What size UPS battery backup do I need for a home office?
Add up device watts, add at least 15% headroom, then check the VA and watt ratings. A 1500VA/1000W UPS runs about 10 minutes at half load.
- Can you install a video doorbell without existing wiring?
Yes. Battery video doorbells need no wiring; you recharge them by USB. Wired models need a doorbell transformer that matches the model's specs.
- What can a 1,000Wh power station run, and for how long?
A 1,000Wh power station runs a Wi-Fi router about 40 hours, a full-size fridge 14 to 17 hours and a CPAP 2 to 3 nights. Runtime table and formula.
- What size generator do I need for my house?
Add running watts, then the biggest motor's starting watts, and stay under 90% of capacity. Our essentials example needs about 10,300 W.
- Where should you put your Wi-Fi router?
Put your Wi-Fi router central, elevated and in the open, at least a few feet from metal, fish tanks and microwaves. Never in a closet or on the floor.
- Why is my Wi-Fi slow? 10 fixes to try first
Slow Wi-Fi? Test wired vs. wireless speed, restart the router, update firmware, move it central, and use 5 GHz. 10 fixes, in order.
- Wired vs. wireless security cameras: which should you choose?
Wired PoE cameras get power and data over one Ethernet cable and can record 24/7. Battery cameras skip wiring but need recharging. Compare both.