Droitwich Dilemma: Radio Relics in the Smart Meter Era
In response to the insights from the article "Does energy supply depend on old BBC radio tower Droitwich?" published on This Is Money, it becomes evident how the intricacies of our energy supply system intertwine with seemingly outdated technologies.
Time of Use energy tariffs may sound like a new buzzword in the world of energy, especially at a time when prices have been volatile and consumers are looking for the best deals available. These tariffs essentially allow you to access the price of wholesale power on a day-ahead basis and shift your consumption to access better prices, ideally suited to storage systems.
Back in the day, it was called Economy 7 or Economy 10, utilising cheap-rate power overnight to charge up storage heaters, which would then discharge their heat throughout the day. Today's version is something like Agile or an overnight EV charging rate, sound familiar?
The Economy 7/10 systems run on an old Radio TeleSwitch (RTS) metering system, which relies on a Radio Transmitter Station in Droitwich. The issue is that the system requires two valves to work, and they are both pushing 20 years old, with no spares available anywhere in the world. If either valve breaks, then the RTS system stops working altogether.
The last paragraph has so many parallels with power generation assets; invariably, a good number I have supported over the last decade have been over 20 years old, with limited to no spares available. When one single control part fails, the whole plant goes down, equating to loss of generation and revenue.
What's the solution?
You either hold enough spares and engineers with the competence and capability to fit them, assuming you can find both. Software can be a real challenge even with the right hardware.
Or... Upgrade while the unit is operational to mitigate and limit downtime.
Both have capital cost implications as well as risk, which need assessing. A new system isn't always the panacea it's made out to be.
The RTS meters also rely on BBC Radio 4 longwave radio to work, and the BBC wants to switch that service off. This would mean energy firms can no longer easily tell what time the customer is using energy, which obviously presents a problem with running peak and off-peak.
It sounds like the energy suppliers are rolling out smart meter upgrades, but you definitely roll the dice when one of those valves will fail, or you lose the service altogether; early planning is key.
I don't do smart meter installs, but I do support aging power plants and new ones too, keeping them running beyond their expected life.
Here's a photo of a RTS unit in case you're wondering what one looks like.

If it's just two valves which are required, then there are still people around who can hand-build them.
Here's a YouTube clip of a very DIY approach:
and an article here on Hackaday shows how it's done too!
Further afield, Changshu Shugang were the world's largest manufacturer of vacuum tubes, specialising in bespoke orders.
The factory closed following a fire in 2019.
Since then some of the craftsmen have started up again.
It's possible that this is the same group who are now working as Linlai.
If Droitwich wants new tubes, then there are routes to obtain them. 🙂
Save energy... recycle electrons!
@transparent might be an idea buying a couple now and sitting on them, so when they go “poof” they should yield a decent return on investment.
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@editor As I understand it Mars, the last of these valves were manufactured some years back - I don’t know for sure but I get the impression only Auntie uses them now. Regards, Toodles.
Toodles, he heats his home with cold draughts and cooks his food with magnets.
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