More efficient consumption also required

That is SO true, all of us who started way back did that, we ensured our loads are lower to accommodate a smaller system or some such.

That cost a pretty penny at the time.

Today, bah, just get a bigger inverter and more panels man,it is “cheap!” … compared to what?

The point is though, for renewables to work right, the world needs to become more efficient.

What’s a sort of average consumption for a suburban house? Anybody?

For reasons too boring to relate here, I googled this morning to try to find the kWh equivalent of a banana. Difficult because it turns out that the banana is one of the most radioactive foodstuffs, and so Google gives you lots of data about radiation levels. But I found some calculations that say 429 trillion bananas to power a house for a month, and the figure they used for consumption was 829 kWh per month (I assume this is in the USA, but they don’t state that).

We need to become more efficient. There is a huge drive to put smart meters into homes in the UK. Not a smart meter like COJ are installing, but a nice little device that sits in the front room and tells you how much energy you are using right now, how much you have used in the last 24 hours, how this month compares to last month, and all in nice fonts and colours and accompanied by graphics in graduated colours.

Two reasons for that

  1. Customers are better able to control their usage and anticipate their bill at a time when energy costs are starting to hurt people who aren’t members of the Royal Family (I presume Harry has to pay his own bills in that ex-colony, but also that he can afford it).
  2. To make people aware of their usage in the hope that they start cutting back and/or buy a heat pump and/or upgrade the insulation in their home.

I have seen several of my neighbours convert to pre-paid meters, and a side-effect of that has been that they become more concious of usage when the meter starts beeping half way through the month because it’s feeding time.

500 to 800 kWh for me. I run everything electric but have a solar geyser with 2kw element.

For sure! I think that Mr Piccard’s wasted power figure of 75% is credible. We firstly need to know what power we are consuming and then consider if this can be reduced with better efficiency.
The more you get into this the more you become aware.
PS: My wife turns the electric kettle on to make coffee. I boil water on the gas hob. I think I’m saving energy but that’s not the whole story…

Annual figures:
Eskom - 34% - 4424.82 kWh
Battery - 29% - 3846.22 kWh
Solar - 37% - 4835.53 kWh

7 people household.
3 geysers.
5.2kw Array
5kva inverter
17kWh battery

I disagree. A tiny bit. There are times we don’t care about efficiency. Solar panels are about 20% efficient (and it won’t get too much better, it is limited by the amount of light in the spectrum that can kick an electron out of orbit in a silicon atom) , but we don’t care, because we have no shortage of space and the panels are cheap enough.

As another example, if we want to power cars with green hydrogen, which is generated at 72% efficiency, than has to be compressed, transported, and converted back to energy at 50% in a fuel cell, it yields an overall efficiency of maybe a bit more than a Diesel car… which is terrible, but since it is clean, that is a compromise we may be okay with.

But, when we consider that a poor efficiency like that (compared to battery storage) means I need to build 4 to 5 times more generation capacity, with all the energy that goes into mining, refining, transport, and eventual recycling, then we do care about efficiency. Especially since, during the transition, we have to do a lot of this work with fossil fuels.

It’s a case of picking your battles.

I’m also interested in consumption and can attest to the fact that as the family becomes aware of consumption so it improves. What also helped is use of Bneta and sonof plugs/switches to track consumption.

We’re a family of three with a flat with one person.
In the 12 month period prior to using solar Feb 20219 to Jan 2020 our monthly consumption was 1007 kWh
In the following 38 months it dropped to 716 kWh
In the last 12 month Feb 2023 to March 2024it is down to 557 kWh per month - not sure it will decrease further. I am able to feed back into the grid. So actual power use from grid less than 50kWh per month, but its a burden to ensure meter reading is higher than reported figure.

In addition to the above
We mostly shower and use a heatpump that uses 0.7 kWh per hour, we only heat the water to 45 degrees, estimated monthly use 55 kWh
Pool pump uses 50-60 kWh per month and is shut down mid April to Sept
I installed a gas hob, gas cost probably similar to electricity.
We purchased energy efficient fridge freezers when current units gave problems, combined use about 35kWh per month.
New energy efficent dishwasher finishes cycle in 45 min, together with washing machine uses 40 kWh per month.
Started using an airfryer instead of oven, we dont iron clothes or use a tumble dryer, aircon only used when temp exceeds 35 degrees, using induction cooker to boil water and for limited cooking (wife prefers gas).

1 Like

What!!! No no no. Dryers fall under the “bugger this nonsense, I have money” appliances!

Saves time, no regs needed, and no ironing. And it is A+ rated.

Geez, we are 21st century. We can have some luxuries … now and then.


You can. But what the powers that be want you to have is a heat pump driven tumble drier. The down side to these is that there is a little catch tank on the side of the drier that has to be emptied at regular intervals.

I remember reading comments from people who are now on this forum which I then discussed with the missus before starting our ‘solar journey’ and most of it related to being more efficient.

We moved into this house knowing we’ll eventually get solar and did things similarly to @bgb by focussing on energy efficient appliances and running heavy users during the daytime where possible to allow it to be run from the sun.

We put in a heatpump for water heating to reduce consumption and allow a smaller system like @TheTerribleTriplet alluded to. At the same time we put in an ET112 meter with a VenusPi to monitor consumption of loads moved during the daytime to properly size the system.

The dishwasher takes 4 hours, but I happily schedule that during the day while the sun is shining. The washing machine needs the ECO button to be pushed to reduce consumption and is also scheduled during the day. Pool pump also only runs during the day.

I think I’ve mentioned before that just the swapping of the 40W/80W GU10/down lights to 5W and the rest of the bulbs to LEDs combined actually made a huge difference to nighttime consumption.

We also have a gas hob, but after trying to understand the @plonkster math on boiling on gas vs electricity we’ve gone back to only cooking on it.

We really struggle with getting clothes dry in the winter and I am sick of the hanging and folding and will gladly replace that with moving into the tumble dryer and folding.

which is what I’m looking at and already have 8 tabs open. Just waiting for the next clothes not dry event and then I’m pulling the trigger.

1 Like

When my 6 year old Bosch condenser tumble drier chewed through the second belt in about 8 months, I knew that it was more worn than you can fix for a few thousand bucks (the belt alone is around R800), and decided it is time for something new… and since the price difference between a condenser drier and a heat pump model is no longer “double”, we went with a heat pump model.

That is also the case for condenser driers. Only the cheapest (and least efficient) models still blow the hot air (and all the lint) straight out. The condenser units at least use some of the outgoing heat to heat the incoming air, and is in terms of efficiency non-negotiable in my opinion. That is the least you can do for the planet :slight_smile:

Other upsides of the heat pump model, is that it does seem to be less harsh on the clothing. It is definitely less hot (it also takes longer to dry for that reason). In the beginning, when you take the clothes out, it almost seems a little damp still, but within seconds you realise it is just cooler than you expected.

In my experience, the heat pump model does not save you energy/money in the same ratio as the one that heats your hot water. The COP seems to be lower, although this is just a feeling, I have not measured it. I know our tumble drier now uses 1.5kWh per day for the one load we put through, but the trouble is… I cannot remember how much the condenser drier used to be. I don’t recall it being three times more.


Give that man a Bells!

Sommer two Bells!

Have the power, spare power, use it!
Cents on the rand compared to “before solar”.

Sommer a bottle of Bells …

Get the right equipment and relax a bit. :innocent:
… it saves marriages.