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Save energy — 19 free energy saving tips

Today I received the following 19 free energy-saving tips (click image for original article).

I quote the article here with my own observations.

Saving energy isn’t just about helping you to save electricity or be more energy efficient — it’s also a great way to save money.

We all know we could do more around the home to save energy, but where to start? While some of the biggest energy savers require time and money there are still plenty of lifestyle changes you can make that will save energy, and money.

With just a few simple changes to your lifestyle and your home, you could be saving hundreds of pounds on your heating, gas and electricity bills.

So, if you’re looking for ways to cut down on your spending, try these 19 free energy saving tips.

How to save money on heating

  1. Stay warm, cut costs. Turning your thermostat down by 1°C can save you as much as £60 per year. Also, keeping your heating on constantly on a low heat could potentially save you more money than switching it on and off for big blasts of heat. This is where getting to know and understand the timer settings on your thermostat will really pay off.

That I can see both ways. On the one hand not stressing a condensing boiler too much can keep it in condensing mode, and thus increase its efficiency. However keeping the home unnecessarily hot will increase the heat loss to the outside world (which is proportionate to the temperature difference between inside and outside) so an unoccupied house at an elevated temperature will increase heat loss, but might make heat more efficiently.

Also for many people, timers and thermostats are two different components and the use of the timer turns the heating on and off – not between two alternative temperature set points.

Our own smart heating does in fact switch between a high and low temperature (not on and off) but at 10C the low temperature is such that room temperatures don’t generally fall to the low temperature before high temperature is demanded again.

  1. Get cosy. Wearing more jumpers, socks and slippers around the house, and putting an extra blanket on the bed means you won’t be tempted to turn the heating up.
  2. Turn the pressure down on the power shower. A high-pressure power shower is a great luxury to have but you’d be surprised how much water they use – sometimes even more than a bath.

Be efficient with cooking

  1. Save time and stock up. If you’re going to use the oven, bake a few meals at a time to get the most out of having your oven on. After all, oven’s don’t allow us to heat one shelf at a time so why waste your heat?
  2. Heat your home with cooking. Leave the oven door open after cooking to let the heat warm your kitchen. The oven might give off enough heat for you to adjust your thermostat, a far more efficient use of that stored heat than throwing it out of your home with an extractor fan.

Heat from the oven after cooking certainly does heat the kitchen, but personally I would wouldn’t leave the oven door open which provides too much of a heat rush – I prefer to leave the door closed and allow the same heat to move into the room more slowly.

I wouldn’t adjust the thermostat – it’s goal is to control to a comfortable temperature. Does the comfortable temperature change when you’re cooking? If you’re too hot when cooking the thermostat (potentially a TRV in the kitchen) will already have turned the heating off.

As to extractor fans, their purpose is to remove steam from boiling pans and save energy by significantly reducing condensation. Turning off the extractor fan while generating steam is a false economy.

  1. Let the dishwasher do the dirty work . Avoid pre-rinsing the dishes in hot water. Save water and energy by just scraping the dishes before they go in.
  2. Make things easy for your fridge and freezer. Keeping them full means they don’t have to work as hard and therefore they use less energy. Empty space in your fridge or freezer wastes not only space but energy too.

Again not so sure about this one. In general the energy to run a fridge or freezer will be a function of the temperature difference between inside the freezer and the room in which it is found. I can have assume that this point relates to the frequency at which the door is opened where an empty upright fridge or freezer will rapidly dump cold air into the room, whereas a full fridge or freezer has less cold air to dump.

  1. Use the right ring for the right thing. If your cooker has a small ring, use a small pan. You might only be heating up a small meal, and doing so in a big pan wastes a lot of energy. Conversely if you try and heat a large pan on the small ring you’re more likely to end up heating for longer than saving any money or energy.

Be efficient with washing.

  1. Shrink your bills, not your clothes. 90% of a washing machine’s energy expenditure is spent on heating the water, so if you wash your clothes at 30-40 °C you’re saving significant amounts of money.
  2. Hang up your laundry. Air-dry your laundry rather than tumble drying it, particularly if there’s warm or windy weather. What’s more nothing smells better than air-dried clothes.
  3. Save yourself ironing time. Take your clothes out of the dryer before they’re completely dry – they’ll iron much quicker and you’ll use less energy on your drier.

Energy efficiency and electricity saving tips for your appliances

  1. Switch it off and save. Unplug all the appliances that you aren’t using regularly – even chargers continue to use electricity when they aren’t charging. Also, make sure you’re not leaving appliances on standby: it may be easier but it’s also a guaranteed way to waster energy compared to turning things off at the socket.
  2. Get the kids involved. Play energy-saving games with your kids. Get them to spot the areas in the home where energy is being wasted and where lights, switches or appliances have been left on.
  3. Let the sunshine in. On a sunny day, opening your curtains will let warmth into your house, but when it’s colder or the sun goes down don’t forget to close them to keep that heat in.

Be efficient with your whole home

  1. Get free cavity wall insulation. There are now government-backed full and partial grants available to help you pay for insulation if your home has cavity walls. Getting this done could save you around 15% on your fuel bills, so you could be saving on average £98 a year. Even if you don’t receive money from the government insulation is still worth it in the long run.
  2. Get free loft insulation. Because heat rises, as much as 25% of the heat in your house could be disappearing into your loft space. What’s more, even older properties that already have insulation in place may not have the recommended levels, particularly if it was installed in the 1970s or 1980s. If you apply for a loft insulation grant, you could save about 19% on your fuel bills – which works out at an average of £128 per year.
  3. Get free solar panels. Having solar panels installed on your house could save you as much as a third on your electricity bills. What’s more, thanks to the government’s Feed-in Tariff scheme solar panel installers get paid for the energy generated, so they may install them for free.

Indeed they might install them for free, but they do so because they get a good return on their investment via the feed-in tariff. If you have the capital available pay for it yourself, get the feed-in tariffs for yourself, and avoid any legal issues with rent-a-roof if you choose to sell your home in future.

  1. Apply for an energy-saving grant. There are plenty of energy-saving grants available to help with the cost of home improvements.

Don’t overpay for the energy you’re using

  1. Compare gas and electricity prices with to make sure you’re on the cheapest tariff for you. It only takes a few minutes.

Energy Smart in action

Here we have the system in action earlier today.  With 1542 Watts coming from the solar panels, the house (including the PowerVault storage battery) is running at a maximum of 1097 Watts, with the balance of the available power controlled by the ImmerSUN- 410 Watts to water heating and at the point of this snapshot 35 Watts into the grid.  At this moment that’s 97% of generation used as such self-consumption and 100% of energy being consumed coming from the solar panels.

if the ImmerSUN had priority then it would have taken all the available power leaving nothing for the PowerVault storage battery.

Zappi?

It’s now over a year since I built my solar-powered car charger which is enabled automatically by surplus electricity output from my solar panels, but can also be run on a timer when required to use cheap night-time power too.

However since then a new product has come to market from myenergi (a new company led by some of the team responsible for developing the ImmerSUN) which provides the same sorts of capabilities although in a professionally-produced solution. I don’t own one, I’ve never used one, but I think that this is a solution which I’d be seriously considering if I hadn’t already made something similar.

The only downside that I can see is that it’s available in either Type 1 or Type 2 forms with tethered leads only, so if you have a mixture of EVs then a single Zappi may not be compatible with all your vehicles; whereas a charger with a Type 2 socket outlet would be.

You can learn more about Zappi here

An attack of the clamps

In a prior post I described the use of current clamps to prioritise smart loads that are enabled by surplus solar power to maximise self-use of this ‘free’ electricity.  That’s free in the sense that a deemed export tariff doesn’t pay any more for an extra kWh exported, or pay any less for an extra kWh used, and so the marginal cost of using that (and every other) kWh is zero.  In that post three current clamps were visible in the picture – though I described only the function of the right-most.

In fact my home currently has 6 current clamps which is probably more current measurement than the substation that supplies my area.  The six clamps are as follows:

 ImmerSUN PowerVaultData Logger
Solar panel outputReport (1)-Report (4)
Immersion heaterControlMeasure sum (3)-
Import / ExportMeasure (2)Report (5)
Battery In / Out-ControlReport (6)

I’ve tried to distinguish between their functions as follows:

  1. Control – is an output current actively controlled by a device so there’s generally no need to measure it with a clamp.
  2. Measure – a clamp whose output is analysed automatically to create a control action such as divert more or less power to some device.
  3. Report – it’s just reporting something for the purposes of understanding, but it’s not used to directly control anything.

So the 6 clamps are:

  1. The optional ImmerSUN monitoring package adds a clamp to measure the output of the solar panels which then enables the charts and self-use calculations that I’ve used before to illustrate system behaviour.
  2. The ImmerSUN fundamentally operates by measuring export via this clamp and then responding to minimise that export.
  3. The operation of the PowerVault uses this clamp.  In most installations that’s simply around the live of the incoming supply, but for me it’s also around the live feed to the immersion heater to set priorities.
  4. I also have 3 data loggers at my home to provide a year’s data for UKPN around self-usage so that they can assess the impact on the grid from large scale battery adoption.  Each logger measures one of the fundamentals for battery behaviour: output from the solar panels, ..
  5. .. import to / export from my home, ..
  6. .. and current to / from the PowerVault.  From those three you can infer what is being used by my home in its entirety, but not how power is divided between (for example) car charging and water heating.

 

 

Prioritising smart loads for self-consumption

This week I was discussing how to maximise the benefit of self-consumption with an installer.  The issue here is, where one has multiple independent systems (such as a battery and a water heater) each looking to use any surplus self-generated electricity, how does one set the priorities of the devices or is it just a lottery which gets the surplus power first?  In my own case, for example, I recognise that the surplus invested in my battery storage  is better value than investing that surplus in hot water as electricity is considerably more expensive than gas.

I have previously written on this subject Prioritising the battery, but the installer was unaware of my solution and recommended an alternative which I consider flawed. The solution recommended by the installer is to enter the maximum charging power of the battery as the export threshold in the ImmerSUN controller. This does indeed create headroom for the battery to charge, but I believe does not use the ImmerSUN to best advantage. Let me use a table to contrast what might happen at 3kW generation with both the installer’s and my own solutions:

 Installer's solutionMy solution
Total load / total generation3.0 kW3.0 kW
Baseload of house0.2 kW0.2 kW
ImmerSUN Export threshold0.8 kW-
Battery charging0.8 kW0.8 kW
Balance for water heating1.2 kW2.0 kW

The installer’s solution will potentially always waste an amount of power equal to the maximum battery charge power / ImmerSUN export threshold. My solution doesn’t do this, although there is an aspect of immersion heater operation that may or may not concern you.

In my scheme I modify use of the current clamp for the priority device – the battery for me. Such current clamps have the property of summing the current in all the cables which they surround and, as you’ll see from the pictures, my control clamp for the battery surrounds both the incoming power cable from the grid and the outgoing cable to the immersion heater.

The effect of this arrangement leaves the ImmerSUN acting normally – it sees any export and diverts it to hot water.

The current clamp for battery however sees the sum of the export current and the current diverted to the immersion heater, so it doesn’t matter how much the ImmerSUN diverts (and thus reduces the export) – the battery ‘sees’ what would have been exported without the ImmerSUN and responds according.

The ImmerSUN clamp then ‘sees’  the export current drop as the battery charge current increases and  thus reduces its own current proportionately.

To gain access to both the incoming live mains supply cable and the outgoing live feed to the immersion heater, my current clamp is located within the consumer unit.  It’s the blue clamp on the right around the larger incoming cable and the smaller brown cable for the immersion heater.  You need to be a competent person to work inside a consumer unit.  (There are two further blue clamps to the left but their function isn’t relevant to this post.)

The aspect of this that may concern you (but doesn’t bother me) occurs if you want to run the immersion heater from stored electricity rather than just using surplus from the solar panels immediately.  If you turn on the immersion heater using the Immersun (known as ‘boosting’ in ImmerSUN vocabulary) then the current from the consumer unit to the immersion heater is equal and opposite to the current from the grid to the consumer unit, which is summed by the battery’s current clamp to zero and thus the battery neither ‘sees’ that current nor discharges to meet that load.  To me this isn’t an issue as I consider transferring energy stored in one device (a battery) to another storage device (a hot water cylinder) is poor practice; and in any case the battery doesn’t have enough power capability (maximum 1.2 kW) to run the immersion heater at full load (3 kW) so you’d always be importing at least 1.8 kW to run the immersion heater.

As a final note – it is critical to orientate the two cables in the battery’s current clamp correctly for the system to work as intended.  Current from the consumer unit to the grid, and from the consumer unit to the immersion heater, must flow in the same direction through the battery’s clamp.

Smart appliances

I was at a meeting earlier today which prompted some discussion on smart domestic appliances.  Having recently replaced our washing machine I though I’d reflect on progress in smartness.

Around 25 years ago I purchased my first washing machine.  Smart capability was optional – it came in the form of an electro-mechanical timer which allowed the operation of the washing machine to be shifted into the Economy 7 hours with absolute confidence.

Recently I replaced said washing machine.  The new washing machine (my second) isn’t compatible with external timers, instead it offers a pushbutton which delays the start time by one hour every time that it is pressed.  However that doesn’t give absolute confidence of the cheapest energy costs because these days it’s a lottery between will the day be sunny (and thus free solar electricity) or will Economy 7 be cheaper?

Where are the smart controls?  Where are the washing machines that link to smart meters to automatically operate on the cheapest energy?   It will potentially be another 25 years before my washing machine is smart – if I live long enough to buy my third.

(And in case you’re thinking that you can use some sort of smart socket to control the washing machine, turning on the power externally will just get you to the point that you can configure the washing machine program and options, not start a washing cycle.)

 

 

Fundamental rules for smart boiler control

Each rule in the smart home can consist of triggers, conditions and scenes. Triggers consist of one of more alternative events any of which cause the rule to be evaluated. The optional Conditions consist of one or more statements all of which must be true for the rule to be satisfied. Scenes consists of one or more scenes that are set when the rule is satisfied.

For my heating control I have two scenes that set the boiler on or off, and triggers and conditions reflecting the status of the radiators.

TriggersConditionsScenes
Any valve goes to closed .... and all valves are closed .... then cancel boiler.
Any valve moves off closed ..{none}.. then enable boiler.

As an alternative I considered rules using temperature, but that would make things more complicated if the temperature set point is adjusted as you might need to change the rules; whereas by having rules based only on (fully) closed and (partially) open then the set point can be adjusted without issue.  Additionally you can control around a very low vacation set point for frost protection.  Effectively there are four set points:

  1. Closed – which is forced by a summer setting, but also occurs at other times when no heat is demanded.
  2. Vacation temperature – 5 C for me – a low set point for frost protection, but from which it might take an extended period to warm up.
  3. Economy temperature – 10 C for me – a lower temperature limit during normal scheduled operation.
  4. Comfort temperature – 24 C for me – a minimum temperature avoiding complaints from my wife!

My system retains the original 7 day timer, which these days I use only to control water heating.  If I did enable the 7 day timer as well as the smart controls then the boiler would be enabled when either the 7 day timer or the smart controls demanded it.

Advantages of smart heating

I thought that I’d describe some of the features of the smart heating controls versus the prior single zone system with TRVs and a 7 day timer. My main interest is of course to save gas by heating the home more selectively, but there are other opportunities that you may consider significant.

I don’t yet have sufficient data to illustrate any operational savings, but continue to record gas consumption to compare with prior years.

 

 Prior system with 7 day timer and TRVsCurrent smart system with some eTRVs
ZonesSingleMultiple
Schedule7 day - working week plus weekendsInfinitely flexible home / working schedule based on iPad calendar
Adjustment of timers and thermostatsManualvia App (with voice control!)
Remote adjustmentNoYes - enabled by Apple TV as hub
Holiday settingNo Yes - sets low level heat for frost protection
Summer settingNo Yes - closes all valves
Integration with non-heating smart devicesNoYes

Generations of my solar charger

I just came across some of the pictures from last year of different iterations as I was developing my solar powered car charger.


The left picture shows my first attempt using a Mode 2 charger (i.e. one that plugs into a standard socket outlet). The design attempted to turn the car on and off by the equivalent of pushing the latch button on the vehicle connector. That approach stopped charging effectively, but starting charging was subject to long delays so that wasn’t a practical solution.

The middle picture show the second attempt using a commercial Mode 3 charger (i.e. one that’s hardwired into the fixed wiring). In this iteration the commercial charger was gutted so that, although it retained the original external appearance, inside was all different content including a protocol controller and a radio receiver. This was an effective on/off solution.

The right picture shows the third iteration which addd a programmable logic controller to generate a variable charge rate for the electric car i.e. more than just simple on/off. The hardware to achieve this is too bulky for the case of the commercial charger, and so it was repackaged in consumer unit case. A consumer unit case is cost-effective solution for a bigger box to house the DIN rail mounting components, but is of course only suitable for indoor use as it’s not waterproof to the required standard for outdoor use.