I thought of a trick question which could be wanting an answer, but is obscure enough to not be in the corpus.
Along the lines “why is it OK for my oven to have an inefficient lightbulb?”,
ChatGPT 4o has a valid answer but it really misses the point in several ways.
Q:
My domestic oven has a lamp which is always on when the oven is running. This lamp is a tungsten filament, not a modern efficient LED.
In the context of domestic energy efficiency, should I be concerned about the energy usage of this lamp?
A:
The energy consumption of a tungsten filament lamp in your oven is relatively small compared to the overall energy usage of the oven itself. A typical tungsten filament bulb in an oven is likely around 25-40 watts. Let’s say your oven runs for an hour, and the lamp is on the entire time. Here’s a rough calculation of energy consumption for a 40-watt bulb:
40 watts = 0.04 kW (kilowatts) If the oven is on for 1 hour, the lamp consumes 0.04 kWh (kilowatt-hours).At the average domestic electricity cost (which can vary, but let’s assume around £0.30 per kWh), the lamp would cost around £0.01 to run for an hour.
In the grand scheme of energy efficiency, the energy used by the oven lamp is negligible compared to the total power consumed by the oven (which can be around 2-3 kW when cooking). If you are concerned about overall energy efficiency, focusing on how efficiently your oven heats food, or using it only when necessary, will have a far greater impact than worrying about the lamp.
While it’s always a good idea to reduce unnecessary energy use, replacing this small lamp with a more efficient LED bulb (if compatible with the oven’s high-heat environment) would likely save only a tiny fraction of your overall energy usage. Therefore, it’s not a significant concern for domestic energy efficiency.