A letter I wrote to radio manufacturer Pure:

Hi Pure. Your adverts boast your radios’ green credentials, in particular their low power consumption. I thought I’d test whether my Pure radio deserves celebration.

Your advertising badges your Tempus-1S radio with the label ‘Ecoplus’. According to your website the radio consumes 2.48 Watts while playing and 0.9 W on standby. At current UK electricity prices of 12p / kilowatt-hour, this radio would cost £1 per year to run 2.

I own a Pure Tempus-1 radio, an earlier model in the same line. I’ve long been curious to know its power consumption, knowing the transformer is always hot (I’ve previously written to Pure about this and been ignored). Uselessly, the radio’s manual doesn’t specify its power consumption. However, yesterday I measured the radio’s power consumption using a simple gadget. I found my Pure radio consumes 9 W when playing, and the same power 9W on standby. You read correctly, this radio consumes as much power OFF as it does when decoding digital signals and blaring music (on investigation, I found it consumes 11W at the loudest volume).

For comparison, here is the power consumption of some other devices I keep:

  • phone charger: 0.3W
  • Tempus-1 radio on standby: 9W

The power consumption of 9W means it will cost me £9 to run my Pure radio this year. Pure sold me this radio in 2003 and its been plugged in all that time. Assuming an average electricity price of 10p / kWh over those 9 years, the radio has cost me £70 to keep! That’s about as much as it cost! The radio today costs £81 to buy on Amazon.co.uk.

I expect you might retort “unplug the radio when not in use”. Let me reply now. The Tempus radio is advertised with an alarm function—I wake up every morning with Radio 4’s Today programme. For the alarm to work, the radio must be plugged in. In all but Roger Taylor’s household [7], I expect most radios spend much more time on standby than playing.

The low power consumption of 0.9W of Pure’s new ‘Ecoplus’ radio is laudable, but the ten-fold standby power consumption of my Pure radio is shameful. Presumably Pure sold tens of thousands of the Tempus-1 and the similar Evoke-1 model in the UK (do you care to tell me exactly how many?). It’s shameful that Pure never measured—or never published—the mega power consumption of these radios.

So I must ask you, what makes Pure’s new ‘Ecoplus’ radios efficient, or equivalently, what makes Pure’s older radios so awfully wasteful? Is it a change in internal components? I can tell you that my Pure power adapter consumes 3W alone without the radio on the other end. A sound adapter draws negligible power in such a case. Perhaps efficient radio internals were expensive in 2003, but Pure could have saved me and thousands of others £3/year simply by shipping radios with well-made adapters. If you do care about energy, you might offer to replace old adapters.

Favourably, I must commend Pure that my radio has worked well for 9 years (much longer than many other electrical gadgets). When it does expire, I will be sure to replace it with a more efficient radio. I don’t know if it will be made by Pure.

I look forward to hearing from you

They never wrote back :(

[7]: All Queen hear is ‘Radio Ga Ga’.