energy saving – My Shed and Other Environs

Energy – eliminating waste

During the current and previous huge price increases in energy costs, there has been a lot written about “vampire” devices that waste £100s .

Sadly, I think this is an exaggerated figure.

But there are potentially some savings to be made, by tracking down things that can be switched off that maybe you forgot (or didn’t know) were switched on.

This sequence here is a recreation, but the data is entirely factual and I have previously done this process to spot things that were wasting electricity.

First, you need a smart meter. And, specifically, the smart meter display.

Here’s mine. Ignore the “Weekly budget exceeded” message, I set a budget several years ago and of course I exceed it every week because the costs are so much higher now!

You need to set the display to show the actual live electricity usage. That’s what my meter is showing here. You might need to refer to the instructions for your display, but for this model, you press the button marked “now” (2nd from left).

To confirm that you’re looking at the live data, put some water in the electric kettle, switch it on and make a cup of tea. Watch the display while the kettle is heating up.

There, the meter has jumped from 49 Watts to 2.97 kiloWatts. The kettle is boiling. And we’ve prove we’re watching the live usage display. (Note there is usually a slight delay – wait 10 – 15 seconds before the display responds)

What we’re going to do is find out what was using those 49 Watts of electricity we saw before we boiled the kettle. That’s not historic usage, that’s actual live being-used-now usage. 49 Watts. Yours may be lower or higher. But what is using it?

First, eliminate fridges and freezers. These will be switching on and off automatically, and their usage will confuse what we’re doing here. Switch off all fridges and freezers, even the one out in the garage. They will be fine being switched off, it’s not going to be for very long.

So that you don’t forget that you’ve done this, write yourself a note and stick it to the fridge!

Look again at your display. Note down the usage. Here it’s 49 Watts. But what is using those Watts?

It’s time to walk around the house with the meter (they’ve usually got a small rechargeable battery in them so will run unplugged for 30 minutes or so) and find out what’s being used.

I’ll take you on a tour here to give you some ideas and notes along the way.

I have a pumped electric shower. Hot water from the stored hot water cylinder is pumped via an electric pump out of the shower. As soon as I turn the tap, the pump starts up.

And the pump was powered all the time, ready to start up. But powered by this chunky transformer on the right. Which would get hot. It’s wasting electricity!

So, I wired it through a disused pull-cord for an instant electric shower that the previous owner of the house had removed.

Switching the power to the pump off drops my current usage from 49 Watts to…

22 watts. A saving of 27 Watts! That was just being wasted.

Now, that one was a bit tricky and wasn’t quickly resolved (I had to do a bit of rewiring). But you get the idea. Walk around and see what might be using electricity. Lets do some easier ones. What else is using those 22 Watts?

Did someone leave the TV and satellite box on standby?

If you can arrange for the power to be physically switched off to such devices, by wiring them to a mains socket that you can easily get to to switch it all off, you can save a few Watts. Whilst EU legislation allows a modern appliance to use no more than 0.5 watts in standby, this won’t be the case with older devices, and if you’ve got several – DVD player, recorder, satellite, surround amp.. those 0.5 watts each soon add up.

And indeed they did add up. By unplugging the TV and satellite, we’ve gone from 22 Watts to 19 Watts being used, a saving of 3 Watts.

Lets chase those remaining 19 Watts!

What’s Watt in the kitchen?

Combi Microwave and small electric oven / grill

Large electric oven with clock and ignition for gas hob

The combi microwave / oven / grill is switched on, as is the large oven. Do you ever use the clock on those things? Countdown timer, maybe. But clock? So they can be switched off when they’re not being used.

Any saving?

Another down to 17 Watts from 19 Watts. Another 2 Watts saved.

This next one annoys me a little.

It’s my recently fitted gas boiler. It’s not a combi, it heats a tank of hot water and runs the central heating. Right now, it’s not running. But that light shows it’s powered up. And if I switch it off with the control on the left…

.. we save another 3 Watts! This is frustrating because it’s a saving I want to make, but it means that I can’t have the hot water or (in the winter) the heating on a timed schedule, because I have to physically switch the boiler on first. But it’s saving me 3 Watts! If this applies to you, that’s for you to decide if the small extra usage is worth the convenience. Here, I’m just going around showing you what might be sapping those Watts when you thought everything was off.

So, what else is there?

Ah, some idiot has left two chargers plugged in, and they’re not charging anything! That’s sure to be wasting loads. Lets switch the Samsung phone charger off first.

Huh? It didn’t change.

That’s because a modern phone charger barely uses anything when switched on but not charging anything. This is one of those bogus claims in energy saving advice “unplug your chargers when not in use”. Well, yes, for safety and for a very small amount saved, but here the difference is not noticed by my meter. You’re going to save practically nothing by unplugging chargers, and it’s false to say otherwise.

That said… lets unplug that other charger, the Skil one on the left.

We’ve saved a Watt, 14 down to 13. But I just said that chargers are negligible, so how come this one did register?

It’s an old charger, and it’s got a transformer in it. Modern ones, that’s pretty much any made in the last 10 years or so, will be switch-mode power supplies. These are very efficient, and use practically nothing when not powering anything. Ollder transformer adaptors on the other hand, such as this Skil drill charger, are less efficient, will sit there getting warm, and waste electricity.

A simple way to tell which is which is by weight – a transformer-based power supply or charger will be heavier than a modern switch-mode one.

Switch them off, and save a Watt or two.

Still chasing 13 Watts. Where is the thing that’s using it?

Ah. The internet! That just sits there. What if we switch it off?

13 Watts to 3 Watts – another 10 Watts saved! Now, it’s generally not a good idea to switch the Internet router off – when powered up it will adapt the line speed to best suit your conditions. Leaving it switched off may mean that when you switch it on again, your Internet speed will be slower, especially if you switch it off and on a lot. So sadly, these 10 Watts for me are required background usage. I am wondering if I can run this off a solar panel though…

So, that was all staged, because I’ve done this already some time ago, but wanted to illustrate how you can go round the house looking for things that are using electricity that maybe don’t need to be.

Except here, I expected the meter to now show 0. But it’s showing 3 Watts. So something that I’ve overlooked is still using electricity. Now I was on a real hunt, looking for the rogue device!

After a bit of searching, I looked under the Television. I’ve got a robot vacuum cleaner, and it’s base station is there. It trundles back there to charge up, then rests there until its needed or summoned.

It hadn’t been used today, so I didn’t expect it to be charging. But when I switched it off at the mains…

Hurrah – 0 Watts being used! And now I have something to investigate, because I don’t think the cleaning robot should be using 3 Watts when it’s sitting idle and not charging. Something isn’t right there.

Switching the Internet back on, we return to

12 Watts, which is the background usage I’m happy with at the moment.

So, here I’ve shown how I’ve previously dropped my background electricity usage from almost 50 Watts 24/7 to 12 Watts. Try it for yourself, it might be less, it might be more for you. What’s your background Wattage?

And when you’ve finished, don’t forget to switch the fridge and freezer back on!

Energy Usage (updated)

I’ve written a new guide to tracking down energy wasting devices here

My previous post on energy usage was popular and people found it helpful, so I’ve updated it and added some more explanation along the way.

The data is real-world usage information, collected with a plug-in energy monitor.

The items are sorted in usage order, from lowest to highest. The coloured columns show the cost of that activity, taken from the prices I was paying for electricity in May 2018, March 2021, April 2022 (current prices) and predicted prices for October 2022.

I find this data much more useful and realistic than predictions that bills will rise by over £1,000. Here you can see the real world outcome, that cooking pizzas and sausage rolls in my large oven cost me 31p in 2018 but will cost £1.23 in October 2022!

The table is also very useful for seeing where savings can be made. If you look at the usage for the Washing Machine, the main cost is for heating the water. The lower the temperature, the lower the cost. Fast wash with no water heating costs only 1.41p , the same as boiling water for 2 cups in the electric kettle.

Washing machine temperature of 0C actually means there was no heating, so the water is a cold-tap temperature, not actually 0C freezing water! So far I’ve found the cool and cold washes to be effective. I use mostly Ecover biological washing liquid.

Choosing a different way of cooking is also a way of making some savings. The small oven uses much less electricity compared with the large oven (for one, it heats up much faster). The air fryer and slow cooker use much less to cook a meal compared with either sized oven.

electricity-appliance-consumption-sheet1-3 Download

If the above pdf isn’t very readable on your devices, here’s an image of it instead :

To help compare washing machine energy usage, here’s a list of just that appliance, see how a 27.5p wash in October 2022 could be a 2.5p wash by dropping the temperature and wash cycle :

Here’s a comparison of a few different lightbulbs. IKEA have a good range of cheap LED bulbs, and their new Solhetta range are even more efficient than their older Ryet bulbs, though both are still far superior to the traditional incandescent bulb.

This last table should give you a better real world idea of the efficiency of modern LED lightbulbs. For 1 unit of electricity, (that’s 1 kWh), how long can you use the light for?

1 unit of electricity gives how many hours of light?

For 2p at current prices, you get 17 hours of light from a traditional 60 watt bulb, or 333 hours from a similar-brightness LED bulb!

And although the difference in running cost isn’t so great, you can see that changing from one of those compact fluorescent (CFL) energy saving bulbs to an LED bulb gives you double the running time for the same amount of electricity.

I hope this update has been useful. If you’ve any questions, or want me to try some other tests, leave a comment and I’ll see what I can do in a future post.

I’ve written a new guide to locating energy wasting devices here

Energy Usage

There’s an update to this post here, though it’s still worth reading the current post first for background.

There’s also a guide to finding what’s wasting electricity here

With the recent rises, and further predicted rises, in energy costs, I’ve been monitoring my usage of electricity for different things over the past few months.

I thought I’d share that data here, as it helps identify which devices use more electricity than others, and also how changing some settings can save money.

For example, in the table below you’ll notice the item I’ve logged the most is the washing machine. The main difference in energy consumption is how hot I’ve set it.

I’ve been experimenting with lower temperatures, and also no heat at all. Since the washing machine only fills with cold water, this is in effect a cold wash. So far everything has washed fine, usually using Ecover biological laundry liquid.

The other difference in washing machine usage is the programmes that I use. Fast wash is a total wash, rinse and spin of 30 minutes. Anti Stain Quick runs for 1 hour. Anti Stain Full runs for 3 hours. It’s interesting to note than when no heat is used, none of these programmes use very much electricity.

I’ve sorted the table by overall usage. It’s interesting to see that a fast wash of clothes with no heat costs the same as making 1 cup of tea in the electric kettle or toasting 2 slices of bread.

And looking at the cooker, cooking a pizza in my small electric oven currently costs around 20p, doing the same in the large main oven costs around 64p!

Since the original post, I’ve amended the table to include extra pricing columns. These show the cost as it was in May 2018, March 2021, April 2022 (current), and the expected increase in October 2022. With the exception of the predicted October 2022 cost, these are the actual prices I was paying to my provider in my region. Yours may vary slightly. As indeed will your appliance consumption, these are MY actual measured usage.

Looking at the highest consumption (pizza in the main oven) this cost almost 30p to cook in 2018, it is predicted to cost £1.23 in October 2022!

Enough waffle, here’s the table :

A point of interest is that I’ve done a rough calculation on how much it currently costs me to boil water for 1 cup of tea in a kettle on the gas hob. This seems to be about 0.83p compared to 1.13p in the electric kettle . That’s for about 250ml of water, clearly the cost difference will be more if more water is boiled. I’ll do some more gas vs electric comparisons soon I think.

There’s an update to this post here with more comparisons and considerations

And a guide to saving some electricity by finding rogue devices here

Cosy nest

After the grief with my previous smart thermostat, I’m very happy with it’s replacement. The nest thermostat switches on and off, is easy to control, and detects when I’m not home. I can switch heating or hot water on and off from my phone. It does all that I wanted.

I was concerned that all this functionality would come at a cost of increased electricity usage. I’m trying to get the background electricity consumption down to zero, removing or changing things that idle away. The old boiler control was a simple electronic timer and LCD display, this new one has WiFi, internet access, remote control and a brightly lit LED display.

But, having recently wired it through a usage meter, I notice the nest system uses 1/2 watt electricity. The old system used closer to 2 watts. So I’ve gained in functionality and I’m using less electricity!

My attention now turned to the boiler. It’s an efficient condensing boiler from around 2012. But it uses 8 watts of electricity when it’s idle

It needs to control the pump, to let it run after the boiler stops heating, so it can’t simply be switched off when heating or hot water is no longer needed.

(Technically, there’s a permanent live that uses 8 watts continuously, and a switched live that causes the boiler to start heating).

Since the permanent live is only needed for 5 minutes after the boiler has finished running (to allow the pump to overrun so the boiler doesn’t overheat) I wondered about a timer that disconnects everything when heat is no longer required.

A search on eBay found a timer module from China, designed to run a cooling fan for a preset time after a heater has been running. I wired this into the live and switched live of the boiler.

Now, when the switched live goes off, the boiler is allowed to run for 5 minutes, and then the permenant live is also cut off.

This saves the 8 watts that was being wasted all the time the boiler wasn’t running.

I need to tidy the wiring (it’s got live mains on it!) and put it in a box, but here it is, and it’s been working fine for 4 days now.

8 watts might not seem a lot, but it’s 8 watts that was being wasted for no gain, and it’s 8 watts nearer my goal of zero watts background usage.

Stats not what I wanted

As the weather turned colder, I used my central heating more. Although there’s a timeswitch, I’ve just been turning the whole lot on and off as I wanted (the boiler and timeswitch, when idle, were wasting 8 watts of electricity and this annoyed me).

The thermostat in the living room was very old, and did not work well. The room was either too cold for too long, or too hot for too long. The stat would take a long time to react to either temperature rise or temperature fall. The reading on the dial also bore little reality to room temperature.

IMG_20181101_213156 It was a mechanical Honeywell thermostat, as manufactured since the 1970’s and probably the original that was installed when the house was built.

I looked at getting a new one; first at a new mechanical stat similar to the one I’d removed, then wondered about a programmable one.

These can be very good; instead of setting one temperature and having a timer switch the heating on and off, you set temperatures for different times of day – warmer in the morning and evening, cooler in the day and perhaps coolest overnight whilst not letting the house get too cold.

I’d seen some that were reduced in price and nearly bought one, but found that the replacement model for these had a feature that I wanted – being able to “hold” the program rather than fiddling with it every few hours. So I put off buying it while I re-thought what I wanted.

At the moment I’m not following a fixed schedule; and probably won’t be in the medium term. Some days I’ll be in, some I’ll be out. So running to a program isn’t that helpful.

In the end I decided to get a smart thermostat, one that would automatically adjust the heating and switch itself on and off depending on if I was at home or not.

This feature is called “geofencing” – and relies on your phone detecting you being near the house, or moving away from the house, and the heating will start up or switch off. This is an excellent idea. I could also control the heating from the phone, so I could switch it on 30 minutes before I arrive home to warm the house up, or control the temperature from another room. I could say “OK Google, set temperature to 21 C” and it would do it. I was excited about this.

I looked at different models; there’s a variety few to choose from. Nest and Hive are the most well known, but there are quite a few others. I chose Tado, a German brand which was apparently the top seller in Europe and had good reviews. It did the geofencing, and it would allow me to divide the house into zones.

Zones particularly appealed – I’d wonder about this a while back. In the past you’d have to modify the plumbing a fair bit to divide the radiators into groups that could be switched on or off as needed.

With the Tado system, you fit electronic thermostat valves to the radiators, and they are controlled by the main system. So, for example, I could have a valve on the bedroom radiator, the office radiator and the living room radiator, and choose which rooms to heat at what times, and to individually regulate the temperature of each room.

I might only heat the bedroom in the evening, and the office room only when I’m in it.

This would be really great, save gas and save money!

So I ordered the starter Tado system, which comes with a thermostat that replaces your old room thermostat, and a wireless bridge unit that connects to the internet.

This soon arrived and I set it all up; this was straightforward enough. The online guide lets you choose which boiler, thermostat and programmer you currently have, and it shows you how to wire it up.

All going well. My first doubt was raised when I installed the phone app, and it told me that there were “in app purchases”. What would I want to buy in the app for a thermostat?

Well, what I’d want to buy was a plan to make it all work as I’d intended. If you want the geofencing to switch the heating on and off as you arrive or leave the house, you have to pay a subscription for this! If you want weather compensation, you pay extra.

This was not how I’d understood the system to work (indeed, it seems this pay model has only been introduced very recently).

tado3

If you don’t pay the monthly fee, the thermostat sends a message to your phone to get you to manually switch the heating on or off via the app.

Now, you might think that’s no problem and I’m just lazy wanting it to do it automatically, but

a) If I’m driving or cycling away from the house, the phone beeps and I have to stop and fiddle with my phone to switch the heating off. I could not see a way to do this before I left the house, I had to wait for it to detect me leaving and then switch it off through the app.

and b) the reason I bought it was so that it would do this automatically for me.

I also found that the geofencing wasn’t very responsive – it could often take 30 minutes or more after returning home before it asked me if I wanted the heating switched on. Rebooting my phone would speed this up, but that’s hardly convenient.

I thought I’d try it for a few days though, and set some programmes for heating, and let it run.

I did like a lot of the features. It would draw graphs in the app to show room temperature over each day – you could see the temperature drop overnight and how it warmed during the day; you could also see that the thermostat wasn’t just switching the boiler on when too cold and off when warm enough, it was anticipating the room reaching the required temperature and switching off early to save gas. A radiator full of hot water is going to continue to release heat for a while after the boiler is switched off.

Screenshot_20181103-120351

The graphs also showed room humidity, and air quality – though this seemed to be based around when it last detected an open window (and it didn’t seem that good at doing this).

Ultimately, I felt let down that the subscription fee on an already expensive thermostat hadn’t been obvious when I bought it, and so I sent it back. I got the refund today.

I looked again at smart thermostats, and looked at how they integrated with other devices and could control zones. I ordered a Nest thermostat which seems to integrate well although I haven’t yet installed it, I’ve been busy with other stuff. I recently learnt that the thermostat runs Linux and it is possible to replace the proprietary Nest software with a 3rd party open-source system, so there’s endless tinkering potential!

For the moment, my heating is working by virtue of me joining the two thermostat wires together in the living room; next week I shall fit the Nest thermostat and I’ll be reporting back if it’s any good. My expectations are high, will I be disappointed a 2nd time?

Watts the point of my solar panels?

The reason I’ve been tinkering with solar panels recently is this : it’s fun.

Also : I want to cut my background electricity consumption a bit. Most of the things that are running all the time are low voltage things that use a plug in transformer or switch mode power supply to drop the voltage, often to 12 or 9 volts.

These things could easily be moved over to solar power.

So far, I have some low voltage panels on the shed that output around 18 – 21 volts unloaded in full sun. These are wired in parallel into a charge controller that is connected to two 12 volt lead acid car batteries. (The charge controller prevents the batteries from being overcharged). This means I have power available day and night, not just when the sun is out. I also hope to add more batteries soon, so I can store more energy to last for longer periods when it’s cloudy.

I’ve now run a cable from the shed to the office room, and I intend to loop it further into the corner of the living room.

From there, I can connect various things, using cheap DC to DC converters. These things really are the miracle of the modern age, you can set your output voltage, be it 12 volts, or 9 volts or whatever, and you can give it a varying input voltage, from 10 volts to 16 volts, and it will continue to output exactly your chosen output voltage, it doesn’t fluctuate even when the input does.

This is important, as a 12 volt lead acid battery can be as low as 11 volts when it’s going flat, as high as 14.8 volts when it’s being (a bit over)charged.

What’s more, these converters are very efficient, and cost a pound or two each on ebay. We are living in the future.

So, instead of having various items plugged into the mains via power supplies, I’d have these items plugged into my “12 volt mains” via DC-DC converters.

But what items? Well, I did a quick audit of the house at present, looking at things that are typically left on all the time. Using a plug-in current meter, I measured the consumption of the item as it sat in standby, or worked in its normal background mode.

Item	Watts in Standby	Can be solar?
Boiler & Programmer	7.5
Bedroom Radio	3	Y
Shower Pump	32
Microwave	1
Cooker	1
TV, Sat box & net hub	1.5
Router/Modem/DHCP server	16	Y
Network Switch in office	5	Y
Energy Monitor	3	Y
Total	70 watts	27 watts

So potentially here I am using 70 watts of electricity all the time, when I’m doing nothing. Of this 70 watts, 27 watts worth of items can easily be moved over to my solar scheme. That’s a reasonable saving.

Of the other items that I can’t easily move over because they run on mains voltage, one idea would be to have professionally fitted solar panels that generate mains voltage and store surplus in a battery bank. This is my long term goal, but for now I’m just tinkering with low voltage and low cost solutions that I can do myself.

So what to do about those other wastes of energy?

Boiler and programmer – I was surprised to see that the boiler and timeswitch uses 7.5 watts when it’s sitting there doing nothing. Currently, I switch it off at the mains when I’m not running the heating or the water, so there’s no waste here.
Shower pump – I mentioned this before in a previous blog post. I was amazed at how much electricity was being wasted by the transformer for the shower pump. I currently switch it off at the mains when the shower isn’t being used. I intend to wire it to a pull-cord switch in the bathroom to make this easier to do, and to connect some low voltage downlighters in the shower, such that the shower will light up when the pump is on, and it’ll be obvious that you’ve forgotten to switch it off.
Microwave – This uses 1 watt just to show it’s built in clock. I switch it off at the mains when not in use, though the mains switch is low down on the wall and thus difficult to get to. I intend to put a new socket higher up the wall in the kitchen to make it much easier to switch it off when not in use.
Cooker – the cooker has a gas hob but an electric oven. It also uses electricity to run the built in clock, and to drive the spark ignition for the gas. Like the microwave, I switch this off when not in use, and also like the microwave, the socket is difficult to get to, so it will share the microwave socket when I install it. This oven is wired to a 13 amp plug, not a cooker outlet (it doesn’t need more than 13 amps) so will be easy to move to a higher socket.
TV etc – I switch this off when not in use. In fact, the network hub behind the TV had been arranged to be on all the time, but in the process of doing this audit, I realised I could switch it off with the TV, so moved the wiring accordingly.

So, by moving some items to solar, and by changing the way things are switched on and off, I can avoid wasting around 70 watts of electricity. That’s 70 watts, 24/7 , 365 days. It adds up, and it’s not just monetary cost, it’s a waste. I don’t like waste.

Heat Loss

A few months back, I noticed how warm the utility room got when the boiler was running, and I’d insulated the pipe runs from the boiler to the hot water cylinder. This made quite a difference. I also realised that the insulating jacket around the hot water cylinder wasn’t very thick, and that the airing cupboard was still quite warm.

Clearly, this is a benefit when you want to air clothes. But at the same time, it meant that the hot water tended to cool down quite quickly. If I left the boiler on, it’d cycle every 1 1/2 – 2 hours as the tank cooled down.

The old cover. It looks neat, but it’s thin, and there are gaps.

So I finally got a new cylinder jacket. Premium Deluxe! None of your tat!

It’s 80mm thick, but when I opened the packet it was much thinner than this. So I laid the panels out on the floor and left them to plump up a bit, which they did.

There are four panels, 1 metre high by maybe 50cm wide. The plan is that you tie the tops to the top of the cylinder, drop them down around it and slightly squish it all around the tank with some string. Easy!

Or not. My hot water cylinder is tight up against two walls, even removing the existing jacket was quite a struggle. Putting the new one in was a frustrating hour of poking it with a stick and trying to reach around the back of the cylinder through small gaps. It wasn’t helped by what I saw as a design flaw with the cylinder jacket.

Although the vertical strips are tall and not all that wide, inside there were horizontal strips of insulation, which were loose inside the plastic bag covering. From trying to manoeuvre the jacket panels into place, these had moved and slumped down, so some areas of the tank had a double thickness of insulation, other parts had none at all.

I had to rip two holes near the bottom of two of the panels to re-arrange the insulation inside. I also found that two of the eyelets at the top (used to tie it all together) had pulled through, so I had to make additional holes for the string.

Tying the strings around the sides was also very fiddly, as space was so restricted.

Even after doing this, and much fiddling to make the coverage as even as possible, whilst it was an improvement on what was there before, I didn’t think it was all that thick.

So I wrapped the old jacket around the tank over the new one, paying particular attention to the top of the cylinder where the most heat would be lost. It doesn’t look pretty, and still probably needs a few more strings to tie it together a bit better, but it seems to have made a big difference. There’s much less heat that hits you when you open the airing cupboard, though it’s still a warm place to air clothes.

Hopefully this will cut my gas usage a bit.