We are getting a bit technical now but here is a graph of the way the surface temperature of the hotplate increases over time. The hotplate cold on our test cooker had a surface temperature of 16.2°C. It reaches a useful temperature in around 20 minutes and the thermostat turns the hotplate element off at an absolute maximum of 300°C at the 40minute mark. As the element is still hot at this point the temperature of the hotplate continues to climb briefly to around 315°C. This is around 45°C hotter than that of a traditionally powered cooker!
The hotplate takes a few minutes to get going and thereafter increases rapidly over 20 minutes. As the temperature rises the rate of increase slows.
Note... You may have seen claims elsewhere that 'Electrikit' hotplates heat up in 10mins. They don't! Those figures are optimistic guesswork but we wanted to be accurate with our claims; hence this test!
At time of writing our electricity cost per kWh is 14.26p. The element under each hotplate is 1.4 kw so to heat the hotplate to maximum temperature costs 12.93p (1.4x14.26x0.66); not bad! Important to remember too that the hotplate is a heat store so cools slowly - plenty of heat to use for cooking dinner at this point!