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Comment by imdsm | Hacker News Reader

Remember, P=IV, Power (watts) is Voltage (v) by Current (a). Things like toasters and kettles tend to use around 13 amps, though voltage differs by country. In the UK, we have 230 V, so that's 2,990 W. In the USA 120 V so 1,560 W. In comparison to something like a laptop that may use 3 A but at 12 VDC it's only 36 W.

One of the best things people can do to save money from energy consumption is optimise how they use the high-power devices -- swap your conventional oven for an air fryer, for example. Trying to optimise the smaller items, as we all here know, rarely returns the investment of time and (human) energy.

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On the other hand, remember that energy = power * time. Yes a kettle 13A kettle pulls 2990W in the UK and 1560W in the US... but it would take twice as long to boil the water in the US.

For the energy consumed the voltage is close to irrelevant.

In the hydraulic metaphor, which is easy to reason about for nearly everyone around the world, voltage is the steepness of the water pipe. If one wants to fill a tank faster, it's either a steeper pipe (Volts) or a larger one (Amperes) or both.

A 26 A cable and appliance?

If you buy a mains power meter, it should have a "W" mode rather than make you do maths.

I do wish panel-level monitoring was cheaper, though; does anyone have any suggestions for this?

There are ways to read out your meter readings into e.g. a Raspberry Pi (using the P1 port if you have a smart meter, or with a stick-on sensor)

Do you have a link to more info on this? Thanks.

Here's some documentation from Home Assistant: https://www.home-assistant.io/integrations/#search/dsmr

There's this forum thread on Tweakers.net (Dutch): https://gathering.tweakers.net/forum/list_messages/1578510

There are also plug-and-play devices like https://www.homewizard.com/

Other than that, I think the meter types and data standards differ somewhat between countries, so it's probably best to research how it works in your own country/area.

Oh, here's some other, pretty useful-looking documentation from Home Assistant touching on multiple different scenarios: https://www.home-assistant.io/docs/energy/electricity-grid/

Who runs their home toaster for hours on end each day? Even throwing the thing out and never cooking at home with it is unlikely to save much electrical consumption.

If you live in a net heating environment then the cost of running something like a toaster is basically zero. You're getting to cook with and getting the heat in the inside of your home as well. Not as great as a heat pump, but there is a reason why heat pump toasters don't exist.

>If you live in a net heating environment then the cost of running something like a toaster is basically zero. You're getting to cook with and getting the heat in the inside of your home as well

I'd imagine most people run an extractor fan in their kitchen to get rid of smoke, aerosolised oils, etc. in which case almost all of that heat's lost.

Depends on the home. My parents house wasn't designed with one. My house is designed with one. It took me about a month to understand that it acted like a giant leak in the house. When the wind blows across the exhaust it pulls air in or out. Also, it allows rodents and insects to come in & out as they please. So I just plugged the thing up with some old rags.

>I just plugged the thing up with some old rags

Another option is an anti-backdraft cowl and some insect mesh... if you have an air quality monitor take a look some time at what happens to the air quality in your kitchen when cooking (especially frying) - it generally takes quite a dive, particularly if you have a gas cooker.

indoor CO2 goes from like 500 ppm to 950 ppm. It's awful. I avoid using the natural gas oven and range when I can. I intend to install an outside air exchanger, but haven't got around to it.

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