Microwave oven efficiency.

Bod_1234

Now I am closely monitoring my usage around the home usage is static around 0.3Kw, the huge spikes are washing machine, kettle and microwave.



My oven is 800W however it's quite old (15yrs) wondering if there are any efficiency savings by buying a new one.

In other words

A) has microwave oven technology improved so they are more efficient?
do microwave ovens lose efficiency over time?

Obviously a new oven would be about £100 ish (likely to go for one without a rotating platen)

redbuzzard

I think they lose power over time, not sure whether they lose efficiency.

Have you actually calculated what it's costing you to run?

I'd be more interested in effectiveness than efficiency.  We had a wonderful Panasonic combi that microwaved without hotspots and could knock out perfect baked potatoes in minutes. The grill was fast and it was a very handy second oven. We lost that in a house fire, and bought a cheap basic Toshiba for the rental house.  It's rubbish by comparison, things need far more stirring and moving around.

matelodave

There are basically two sorts of microwave, those that you can hear switching on and off and those which are inverter controlled.

The sort that switch on and off, just squirt the power at full blast in short cycles, low power is shorter burst and higher to high power is in longer or on continuously.  Firing up the magnetron in short bursts isn't everso efficient.

Conversely an inverter driven unit can control the magnetron and run it at a lower power when low power is called for and so should theoretically be more efficient.

Whether anyone has actually put the effort in to find out whether its worth forking out the extra or even swapping a servicable microwave to to get a slightly more efficient machine is probably debatable, although I'm sure that manufacture's of inverter machine will extoll their virtues over a cheaper basic machine.

That said, we've got an inverter unit and it doesn't seem to be any better at cooking than the defunct basic machine that we had, except that its 900w rather than 800w .It is a bit bigger than the old one but I have no idea of its efficiency compared with the old one.

Stuff takes slightly less time to cook but that's because it's a more powerful machine and doesn't clunk on and off like the old one did.

macman

Those spikes may look dramatic, but because both the kettle and the microwave are only going to be used for just a few minutes at a time, the actual energy consumption is fairly minimal. With the washing machine, it's only going to use any appreciable power to heat the water, which is a short part of the whole wash cycle. Spinning the drum doesn't use much.
To get back the capital cost of a new microwave will take you years, and it's daft sending a working one to landfill or scrap.