This is only a preview of the February 2025 issue of Practical Electronics. You can view 0 of the 80 pages in the full issue. Articles in this series:
Articles in this series:
Articles in this series:
Articles in this series:
Articles in this series:
Articles in this series:
Articles in this series:
Articles in this series:
Items relevant to "Mains Power-Up Sequencer, part one":
Articles in this series:
|
Net Work
Alan Winstanley
In this column, I explain how I used a wireless weather station to banish indoor condensation.
You can check the resulting live weather data online. I also have an update on Britain’s Small
Modular Reactor program and electricity generation in general.
A
s I pen this month’s column,
we’ve had a taste of winter, with
early snowstorms battering parts
of the British Isles. Unlike many betterprepared countries, Britain almost grinds
to a halt when the first snowflakes hit
the ground. We are unaccustomed to
wintry weather extremes that invariably
catch us on the hop.
Apart from amateur weather watchers, others interested in the weather
include horticulturists and growers,
small boat owners, fishpond keepers
and owners of solar panels (or home
wind turbines, for that matter).
I introduced my new internet
weather station in the July 2023 and
January 2024 issues. It is an Ecowitt
HP2551 WiFi-enabled system with a
crystal-clear 7-inch (178mm) TFT display that logs various meteorological
metrics on its colourful screen. It generates plenty of data that helps owners to recognise trends and anticipate
weather conditions.
Additional sensors sold by Ecowitt
can measure soil moisture, soil temperature and pond or pool water temperature. Pricier add-ons will monitor
PM2.5 air quality (particulate matter density) and lightning strikes,
although the data captured is only
available on an app. Alarms can be
set to warn of high winds or rainfall,
although I find the console’s on-board
piezo buzzer is quite timid.
The weather station’s 7-in-1 outdoor
array (WS69) measures wind speed,
gusts and direction, rainfall, humidity, temperature, UV index and solar
radiation. It must be installed pointing to true north. European models
use the reliable and less-crowded
868MHz frequency band to transmit
data wirelessly.
Data can be stored on the console’s
microSD card for later use (eg, in Excel),
but it can also upload to Ecowitt’s cloud
server and other popular weather websites. This month I’m sharing an exclusive link where readers can check my
data online for themselves (see later).
A single WH32 sensor is included
that reads indoor temperature, humidity and atmospheric pressure, and
you can add up to eight wireless sensors as your enthusiasm grows. In my
case, this would prove very handy as
I’m trying to tackle a condensation
problem this wintertime, possibly
caused by insufficient ventilation or
insulation in the home.
AI with everything
Since indoor condensation is caused
by warm, moist air hitting cold surfaces, I set up several Ecowitt WN31
temperature/humidity sensors around
the house. I hoped to keep track of
ambient humidity levels indoors, and
I could also check the performance of
a domestic dehumidifier bought especially for the winter season.
The British brand Ebac manufactures dehumidifiers designed especially for the British climate. Some
models use an advanced and unique
“Smart control AI” sensor instead of
a basic humidistat that only measures
relative humidity (RH). “Smart” here
does not imply internet connectivity.
Ebac says its ‘smart’ approach is superior for British weather, as there’s never
an optimum RH figure anyway, because
RH changes when the weather changes.
I chose the Ebac 3650e 18L ‘smart’
model (it extracts up to 18 litres per day),
bought online direct from the makers at
https://ebac.com/dehumidifiers/range
Online buying tip: hold back until
special discount offers appear; direct
The author used an Ecowitt HP2551 weather station like this one to check indoor
humidity levels using multiple wireless sensors.
The
Ecowitt
WN31
indoor
sensor
has an
LCD
screen and
monitors
the local
temperature
and humidity.
4
Practical Electronics | February | 2025
A set of DIP
switches at
the rear of
the WN31
indoor sensor
select one of
eight possible
channels.
operating the Ebac costs about 45p a
day, as shown by my Ketotek power
meter (see Net Work, January 2024).
Indoor humidity has fallen to 4550% or so regardless of the weather.
Best of all, the condensation problem
has disappeared completely.
After 18 months of operation, I’m
also pleased to say that the Ecowitt
weather station still performs flawlessly. I’ve had no problems at all
with sensor communications, even
though the outdoor array is 30m or
more away, and the console is located
well inside the house with quite a few
brick walls intervening.
Net Work’s weather station
sales also attract an extended fouryear warranty.
Moist air tends to rise (it’s less
dense than dry air), so I permanently
plugged in the dehumidifier upstairs.
Keeping internal doors ajar improves
air circulation. The appliance then becomes the coldest spot in the house,
where humid air is forced to condense
before being collected in a tub, emptied daily. Alternatively, water can
drain externally through a small pipe.
Using the Ecowitt weather station
this way was an interesting exercise.
Initially, I was astonished to see some
three litres of water extracted every
day before it settled down over the
course of a few weeks. Continuously
This UK-made Ebac dehumidifier has a
unique ‘Smart AI’ humidity sensor.
Practical Electronics | February | 2025
I’m now pleased to offer readers an opportunity to view some of
my own live data on Ecowitt’s servers, by visiting the special link at
https://www.ecowitt.net/home/share?
authorize=1HJ565
There’s also a QR code you can
snap with your smartphone. The URL
is valid for up to one year and may
change over time.
Graph lines can be toggled to hide
or reveal parameters (eg, click the
small Solar and UVI icons to show
or hide the corresponding lines). The
date range is selectable from a dropdown box.
It has been interesting to compare
indoor humidity against outdoor
weather. I was intrigued to see how
the Ebac operated pretty much continuously during periods of heavy
rain, until indoor humidity fell and
it settled down again. The ‘Smart AI’
sensor is obviously working well.
If you don’t want a fully fledged
LCD weather display console, a simple low-cost ‘gateway’ is available that
works with a smartphone app instead.
The Ecowitt GW1200 would be a good
place to start; a wide range of Ecowitt
products is sold online.
One UK website that’s worth checking is https://weatherspares.co.uk and
Amazon also has a selection of Eco
witt products as well as dehumidifiers.
AliExpress also lists many Ecowitt products, noting that prices exclude VAT.
Other popular dehumidifier brands
include Meaco, De’Longhi and Pro
Breeze, which are sold by the usual
outlets. Many can also be used for
drying laundry indoors. Incidentally,
‘dessicant’ types are the best choice
for low-temperature locations such as
garages, outbuildings or, say, caravans
that are laid up over winter.
If you decide to pipe the dehumidifier’s water outlet outside, remember
to insulate the pipework so it cannot
freeze up.
This QR code will display the author’s
weather station data in your browser.
Next, I’ll try uploading data direct to
the UK Meteorological Office Weather Observation Website (Met. Office
WOW) at https://wow.metoffice.gov.uk
– but that’s a project for the winter
holidays!
A gloomy outlook
There are a few German-language
words that have no English equivalent; schadenfreude (relishing someone else’s downfall) is an obvious one,
but another word that recently joined
our lexicon is dunkelflaute.
Britain’s anti-cyclonic weather in
early November saw a period of some
10 days or more with absolutely no
sun, little wind and low cloud – a perfect dunkelflaute, or a gloomy lull in
the depressing weather.
No amount of renewable solar or
wind energy generation will be of
much use during a dunkelflaute. November’s miserable weather brought
into sharp focus the UK’s ongoing
march towards ‘Net Zero’, as the country strives to move away from fossil
fuels towards becoming self-sufficient
in ‘green’ energy instead.
At such times, to keep the lights on
we rely on storage battery farms, nuclear, biomass and fossil fuels, overseas interconnects and some hydroelectricity to top it up. The highly
informative website at https://grid.
iamkate.com designed by Kate Morley
shows admirably the status of the National Grid as it edges perilously close
to 100% during peak periods. See the
example screen grab overleaf.
Data provided from the last ten years
is insightful, as it also shows how energy costs of £35 per MWh in 2020 increased five-fold in 2022. International Energy Agency (IEA) statistics show
that the UK now has easily the most
expensive industrial energy costs anywhere in the Western world, 4.5 times
higher than Norway’s, for example.
At one time, the UK had an ambition to become entirely self-sufficient
5
Our first new nuclear power station
in decades is long behind schedule,
partly because Britain has had to relearn forgotten nuclear power construction skills all over again, says EDF.
The immense pressure on Britain’s
energy infrastructure has been well
documented, and the rush to meet
‘Net Zero’ carbon emissions has created a perfect political storm. The last
coal-fired power station has closed
and some gas power stations have
been bulldozed. Meanwhile, ‘solar
farms’ are springing up that carpet
agricultural land with Chinese-made
solar panels.
Many ‘green’ ambitions are being
pinned on wind power, such as the
world’s largest offshore wind farms
being built at Dogger Bank and Hornsea, off the UK’s east coast.
A network of undersea power and
data cables now criss-crosses the
world’s oceans. Recently, a Chinese
bulk carrier, the Yi Peng 3, was accused of dragging its anchor 100 miles
to deliberately cut two cables in the
Baltic Sea. Fortunately, the damage
was swiftly repaired, and the ship is
now being shadowed by NATO vessels. However, it’s not thought that
China was behind the episode.
In today’s uncertain times, such
resources are undoubtedly vulnerable to foreign interference. Thus,
in 2023, the Royal Navy Fleet Auxiliary launched RFA Proteus, a converted oil-rig service vessel equipped
with a helipad and remotely operated submersibles. It is dedicated to
safeguarding undersea infrastructure
such as energy supplies and data cables. A second vessel is scheduled to
be built.
Meeting demands
Live National Grid electricity power data compiled by the IamKate website. Roll over the
charts and graphs for more details.
in generating electricity from nuclear
power. That was half a century ago,
in 1975. I wrote about the UK’s chequered history of nuclear power in
Net Work, November 2022, which included details of the 1957 Windscale
nuclear disaster.
Delayed reaction
Sixty years ago, Britain’s forwardlooking Government placed its bets
on the wrong horse, backing the development of its own Advanced Gascooled Reactors (AGRs) to replace
first-generation
Magnox
reactors,
while the rest of the world was opting
for Pressurised Water Reactors (PWRs)
instead.
6
Fourteen AGRs were built after
1963, all of them used exclusively
in the UK. Buoyed by the arrival of
North Sea ‘natural gas’, the famous
1990 Creature Comforts TV adverts
(shown in full on YouTube at https://
youtu.be/fBJ6pixLHtc) implored us to
use as much of this bounteous energy
as we could!
After a two-year long public enquiry
into the nuclear power sector, it wasn’t
until 1988 that construction started on
Sizewell B, our first PWR, which finally went online in 1995. Sizewell C
and Hinkley Point C are currently being constructed by France’s EDF, and
promise to generate electricity for the
next 60 years.
In January 2022, I first described
the prospect of the country adopting
Small Modular Reactors (SMRs) to
fill Britain’s energy gap. For financial
reasons, Japan’s Hitachi and Toshiba
had previously pulled out of building nuclear power plants in Britain,
adding to Britain’s power generation
shortfall.
Hitachi’s former sites in Wales have
since been purchased by Great British Nuclear (GBN) as part of its future
growth plans.
SMRs are nuclear power plants that
can be assembled on-site using major
prebuilt elements that can be transported by road. In 2022, SMRs were
still a decade away, and a government
‘competition’ was held to produce a
short-list of contractors that the UK
would support in developing them.
There was much flag-waving from
Practical Electronics | February | 2025
The new Royal Fleet Auxiliary Proteus is a vessel designed for undersea surveillance and warfare. Source: YouTube (Navy Lookout).
Rolls-Royce, but foreign rivals were
eager to offer SMRs too.
France’s EDF withdrew early from
the race, followed by American company NuScale. The ‘competition’
finalists have now been announced as
Rolls-Royce, GE-Hitachi, Holtec and
Westinghouse.
Holtec Britain is already heavily
involved with Britain’s nuclear construction program and chose Doncaster in South Yorkshire as the site for a
new SMR factory. Some 70% of components are to be UK-sourced. The
world-famous Sheffield Forgemasters
steelworks, now owned by the Ministry of Defence, is just up the road and
produces highly specialised castings
for the nuclear sector.
Holtec fast-tracked the regulatory
approvals needed for its US-designed
SMRs and, once approved, construction could start as early as 2026, the
firm says, with ‘shovel-to-startup life
cycle’ estimated as three years. Rolls-
Royce is also known to be scouting locations to build several factories. GBN
says that they will make the final decision on which technologies to select
in the spring of 2025.
Until SMRs eventually come on
stream and energy supplies loosen
up, UK consumers are going to be
encouraged (or bribed) to cut energy
consumption at peak periods. Previous trials of the so-called ‘Demand
Flexibility Service’ (DFS) over winter 2022/23 were deemed a success
(even winning industry awards), and
the scheme is again being offered this
winter.
In a nutshell, DFS offers consumers
with smart meters a rebate to encourage them to use power-hungry appliances such as washing machines during off-peak periods. This will shift
demand on the electricity supply during so-called ‘DFS events’, when the
supply operators struggle to match
electricity demand with supply.
It’s probably only a matter of time
before ‘Event’ messages pop up on
smart meter displays or via SMS, so
consumer behaviour may well be manipulated that way too.
Hidden deeply in some small-print
from the electricity system operators
is a caveat, though:
Using electrical goods overnight
can create an increased risk of an
incident. We advise all consumers
to follow the guidance offered by organisations such as the [campaigning charity] Electrical Safety First
[https://www.electricalsafetyfirst.
org.uk/guidance/safety-around-thehome] and where possible to avoid
using their electrical appliances overnight.
In the meantime, let’s hope that the
country doesn’t suffer from any more
dunkelflaute and enjoys more sonnenschein instead!
As always, you can drop me a line at
alan<at>epemag.net
PE
An artist’s impression of Holtec’s proposed SMR-300 nuclear reactor site.
Practical Electronics | February | 2025
7
|