Energy Saving

Note – some of the figures in the first few articles are not quite consistent.  This is because with the chaotic situation in Westminster the energy prices kept changing.  The figures were correct when I wrote them, but may have changed since then. 

Liz Truss and her trussty  Quasi chancellor have frozen the price cap to £2500 (or about twice what it was in January). But, she, in an act of monumental stupidity has decided that this will be paid for by a loan, as opposed to a windfall tax on the obscene profits being made by the energy companies.  We (not including the very rich of course) will have to pay this back for years to come, long after Liz Truss has been discarded.

(David Cameron, Theresa May,  Boris Johnson, Liz Truss, it just gets worse and worse.)

I’ve been looking at ways to minimise our energy bill as the energy prices are about to rocket as the government loses control of the economy and the fat cats pounce.

Shell Energy does not help.  It would be nice if they could spend a very small percentage of their gross (in all senses) profits on a decent server then we would not get these messages. 

502 Bad Gateway
This is Shell Energy’s login page!!
Our website and phone lines are really busy today. Really?? 11pm Sunday Evening??
It wasn’t! Or the next day, Or the next day. Or the next day. They have told me the amount, but not how it was calculated. Perhaps they were too busy spending their money to work out the bill.

All in all a website done and hosted on the cheap.

On a personal level, if the tariffs were the same as they were in March THIS year, and our consumption was the same, then we would have expect a bill of £1315 and to pay £110 per month.  We were around average consumption so without any changes our bills would be £2559 or £213 per month. Shell are suggesting £205 per month as a direct debit payment.

Current charges are 

  • 33.859p per Kwh plus 52.64p per day Electric (was 21.607p plus 25.66p)
  • 10.425p per Kwh plus 28.48p per day Gas (was 4.197p plus 26.11p)
    Our boiler has a claimed efficiency of 92% so our cost for Kwh into th house is 11.33p
  • 9.54p per Kwh from the multifuel burner (assuming 75% efficiency)
  • £4.89 per cubic meter plus 11p per day water and sewage.

This means we are paying £337.55 per year in standing charges before we use any energy or water.


Cooking with gas.

Our total daily consumption of gas for cooking is around 60p, and the oven and hob are used every day but we don’t have kids). And, think about it, all of the heat off the cooker ends up in the house. We also pay a standing charge but we can’t do anything about that. Our is 28p per day. 

Cooking with the microwave.

A typical microwave uses about a Kilowatt. Only around 70% the heat goes into the food and the rest comes into the house. Running the microwave on full power for 10 minutes costs around 6p. 

The toaster

A toaster is around the same power as a microwave.  Of course it depends on how you like your toast but a typical 3 minute cycle will cost around 1.7p.

The electric kettle

The best way to save money with the kettle is only to put the right amount of water in it. We have a jug which hold the same amount as mug – around 300cc.  It costs up around 2p to boil the water for two cups of coffee.

The Shower or Bath?

Most people think the shower is cheaper, but is it?  Assuming that the shower runs on electricity, and the bath from a gas water heater it is not so obvious.  

A normal electric shower runs at 10Kw and delivers around 5.5 litres per min. At the new electric tariff of around 34p per Kwh the shower is using electricity at around 6p per minute. Water costs are around 0.5p per litre, so it is using up water at 2.7p per minute. So the shower costs 8.7 pence per minute

A typical bath is 70 litres and heating that amount of water from 15C to 40C takes  2KWh. The Gas cost of around 11p per KWh is Gas cost to heat this water is 21p.  The water cost is 35p, so the bath costs around 46p.

So a shower of longer than around 5 mins is more expensive than a bath.

Local Monthly Temperatures

Local average temperatures

It has been a much hotter summer than normal. We had a spell where the temperature was 30C. We can see that January and February are the coldest months.

Our summer consumption.

I have monitored our gas consumption, which in the summer, is only water heating and cooking. It averages out at about 5Kwh or 52p per day. (plus an additional standing charge of 28p per day).

I have also monitored our electricity which is lighting, shower, kettle, fridge, TV and this comes out at around 5Kwh or £1.70 per day plus an additional standing charge of 53p per day.

The usage for water heating and cooking will be fairly constant throughout the year. The lighting costs will rise in the winter although the shower and kettle usage will remain constant.

Our winter consumption

This is the killer!  As the cold weather draws in we switch on the heating. As it gets colder we light the fire. 

Last year, we were not so concerned about our energy bills.  We kept all of the radiators in the house on and generally stayed very comfortable.

Our Gas usage in January was 2430Kwh which then cost us £114.25. Next year the cost for that amount would be £262

Our Electric was 242Kwh which cost £60.25 Next year it will be £98

We were also using the coal fire, with 1-2 buckets per day. That is an extra 1100Kwh and cost around £71 per month.  That would be £106 now due to the increase in the price of coal.

With a more doubling of the bills and rampant inflation which will almost certainly outpace our income, Yes, we are bovvered.


Winter consumption will be similar to summer consumption with the exception of drying washing.

We do not have a tumble drier.  Instead, if we can’t hang the washing out, we dry our washing by hanging it up in the basement, with a dehumidifier.  This takes 500W and takes around 8 hours to dry the washing, so that is 4Kwh or around £1.35 per wash.  The basement gets quite warm, and as there is only an uninsulated wooden floor between the basement and the room above, a significant amount of heat will come into the house.

According to Which Magazine, a heat pump tumble drier could do the job with 1.3Kwh or 44p, saving around 90p per wash.  But such a machine costs between £600 and £1200, so we need 650-1300 washes for it to pay for itself.  This would take 12-25 years if we never dried outside and I’m not sure the machine would last that long. If we manage to dry outside 50% of the time then it would take 24-50 years, and I don’t think we will last that long. 

Multifuel fire and Gas central heating

Our multifuel fire is an Aarrow Becton 7 and we use it to burn smokeless fuel.   Smokeless fuel generates about 8.4Kwh per Kg and the fire is around 75% efficient so we get 6.3Khw per Kg into the room. We paid around 60p per Kg so the price of heating from the fire is about 10p per Kwh.  The fire is in the living room so only this room is heated unless we open doors to other rooms. The fire needs about “a bucket full” of fuel to operate, and this is around 3.8Kg so the minimum we can get from the fire is 24KWh which costs around £2.30

Our gas heating can heat the whole house. Current price is 10.4 per Kwh. Over the last few weeks we have just had the heating on for three and a half hours at night with only the living room radiators turned on. We seem to be using an extra (over the cooking consumption) 7.5KWh per day indicating that the room takes around 2.5KW to keep it at around 21C with an outside temperature of around 13C (a 8C differential).

In the winter we will need heat for longer, and the outside temperature will be lower. If we assume we need 3.5Kw (for an outside temperature of 7C (a 14C differential) , and for 14 hours per day, that is 49KWh per day or 1520KWh per month – and that is just one room!  

The thermostat – a vastly overrated Worcester FW100 unit is pretty useless.  I often find the radiators very hot when the room temperature is way over the programmed temperature, and lukewarm when it is below the temperature.  It is basically over complicated. It gets very confused when there is another source of heating in the same room, like our burner. I would prefer the old on/off with a simple bimetallic switch.

Savings to make are:-

  • turning of radiators in rooms when not in use.
  • keeping an eye on the room temperature and manually switching off the heating when the temperature gets too high.
  • Try to adjust the thermostat:
    I’ve moved the “Room Influence” setting from 30% to 70% and changed the “Room influence enabled for levels” setting to “Comfort/Eco/Frost” Hopefully this will make the unit care more about the room temperature than the outside temperature)
  • Switch the heating off when the fire is on.  In the winter we can check the effectiveness of this on a day to day basis. 
  • Air the rooms in the morning after turning off the heating or radiators. Then leave windows closed.
  • Minimise the number of washes and drying cycles per week.
  • Wear a heated waistcoat and/or a thick pullover.

Lets see how we do….