Electricity optimization

Wizard · 2012-08-12T10:42:58+00:00

We have a prepaid electricity meter. We bought a LOT recently ... which only lasted 2 weeks. Sent the wife into a panic ... which sent me into a panic. Bought an electricity monitor from Brights Hardware for about R 900.00 and started measuring: http://www.theowl.co.za/ Really cool device that responds immediately ... so you switch the kettle on and immediately see what it uses. Inevitably leads to a spreadsheet where you can calculate your costs and start optimizing. Our learnings: 1) Those "econo" panel heaters run at 400w and eat electricity. We had 3 on all the time. :-[ 1.2kw of constant drain. Got those on timers now. Use blankets. 2) 50w halogen downlighters eat electricity too. We have 50. :-[ Am swapping those out for 20w in the meantime. Getting too much conflicting advice on LED's. Will wait until the story matures a bit more on those. 3) We were running 2 geysers fulltime. A 200l 3kw and a 100l 2kw. The latter for the guest shower and the kitchen sink. Have switched this off, but are now pondering what to do about hot water for the kitchen sink 4) Tumble dryers are death. I think that's where all the damage was done. So ... just too scared to use it now. 5) A pvr consumes 38w all day every day ... ☹ 6) Buying an "eco-kettle" that only heats the number of cups of water you want ... will see how that works when I get it 7) Pool pumps eat electricity. 750w while its running. Switched the pump off for now. I'm probably going to go for a heat pump. Need to figure out what to do with 2 geysers though. Here's my dilemma & need your advice: The small geyser is being used for the guest shower and kitchen sink. And we don't often have guests. So ... the kitchen sink. It's located a LONG way from both geysers ... so when you switch it on the cold runs for a long time before getting hot ... with corresponding cold going into the geyser. Hence a LOT of reheating required for a little hot water. I'm contemplating getting an instant electric heater for the kitchen tap. But ... such conflicting opinions are returned by google. Views?

PJH

We completely renovated our house about a year ago. We went with 16 LED downlights in the lounge/dining room. We put 8 downlights (LEDs) in the kitchen and also 9 in the main bedroom.

Each LED uses 3W and runs virtually cool. So in the main bedroom I'm using 27W for 9 lights.

It's the best decision I've made and the lighting is really good. If you have downlights in your house that run halogens I would suggest getting the LEDs. I did a massive amount of research and also went to different suppiers to actually see how their LED lights worked. There's quite a big difference between manufacturers regarding actual light and price.

I can recommend the supplier that we used if anyone is interested.

These LED lights are the 220V type so no transformer is needed.

Cheers,

Peter.

Wizard

PJH wrote I can recommend the supplier that we used if anyone is interested.

The inevitable questions:
- which supplier did you use?
- which make of LED did you get?
- cool white or warm white?
- how much were the bulbs each?

PJH

Wizard wrote
PJH wrote I can recommend the supplier that we used if anyone is interested.
The inevitable questions:
- which supplier did you use?
- which make of LED did you get?
- cool white or warm white?
- how much were the bulbs each?

Ok some guys have asked who I used and pricing.

Bob, I'll respond here as well.

We tried just about every supplier and actually went to their premises (where possible) to see just how effective their LED lights were. I can say that the amount of light differed quite drastically from one manufacturer to another.

I even had lights posted from Bloemfontein to test.
The prices also varied ridiculously. From R35-00 to R350-00 per bulb.
I eventually found a supplier called Tytan (somwhere in Honeydew) and their cost was around R68-00 per bulb. This was a while ago so I'm not sure if their pricing is the same. I went to check the quality of light and it seemed to be the best overall. Some manufacturers say that their lights are rated at 4W or 5W but the 3W from Tytan was far better.

We went with "warm" lights in the lounge and bedroom and "cool" in the kitchen. They've now been in the house for almost a year with no hassles. I'm in the process of replacing all the flourescent downlights with LEDs in the studio as well.

The other thing to be careful of with halogens is the temperature that they work at. If you google house fires on the net you'll see that quite a few have started because of halogens starting fires. This could be because of poor installation etc. The good thing about LEDs is that there is no heats given off.

Hope this helps.

Cheers,

Peter.

Wizard

PJH wrote I eventually found a supplier called Tytan (somwhere in Honeydew) and their cost was around R68-00 per bulb. This was a while ago so I'm not sure if their pricing is the same. I went to check the quality of light and it seemed to be the best overall.

This is seriously useful.
I like the prices very much.
I like your endorsement very much.
[/quote]

henrebotha

V8 wroteApparently the coils are the issue - I just nod and say ok.

Coils represent an inductive load, which causes some power transmitted to the load to be stored in a magnetic field and later returned to the source, instead of being used. This affects your power factor, which means you end up paying for kilowatt-hours you can't actually use. ?

V8 wroteLuckily, my house has three phase power, which I'm told (and again do not understand) is more efficient than two phase (provided the applicances are three phase as well - E.g. borehole pumps, pool/jacuzzi pumps/heaters).

I didn't know houses could have three-phase in this country. You learn something new every day. ?

Trippp

henrebotha wrote
V8 wroteApparently the coils are the issue - I just nod and say ok.
Coils represent an inductive load, which causes some power transmitted to the load to be stored in a magnetic field and later returned to the source, instead of being used. This affects your power factor, which means you end up paying for kilowatt-hours you can't actually use. ? .

Not exactly correct. Yes, coils are an inductive load, which affects your power factor (the little coil in there hardly represents a large load). Power factor cannot influence the amount of REAL power (kilowatt-hours) you use. It affects the reactive power (killoVAR-hours) and thus also the apparant (or total) power (kVA-hours).

Residential users only pay for REAL power consumption(kWh). Industrial users pay a maximum demand charge on top of their consumption. Maximum demand is measured in kVA, so power factor is important for industrial users only.

Wizard

Trippp wrote Residential users only pay for REAL power consumption(kWh). Industrial users pay a maximum demand charge on top of their consumption. Maximum demand is measured in kVA, so power factor is important for industrial users only.

So ... is this device any use then?
http://www.mrpowercape.co.za/Products/PowerFactorCorrection/tabid/1065/Default.aspx

Trippp

This is their claims, with my response to it:

Your electricity bill will be smaller.

- Only possible if you are billed for the VAR's "consumed" by reactive loads , which is not true for pre-paid residential users.

Lower power factor requires an increase in the Eskom's generation and transmission capacity to handle the reactive power component caused by inductive loads.

- Correct. You have to understand that the size of the inductive load needs to be significant to be an issue, like large inductive motors in indsutry. In a residential area you have what is called a diversified demand - some reactive loads are inductive, some are capacitive, not all of them are active at the same time etc. Inductive and capacitive loads of equal size cancel each other out in terms of their effect on power factor. This device is nothing else than an capacitive load to counter the inductive loads listed on their site. Should you not have any inductive loads, this unit will in effect worsen your power factor, as it introduces a capacitive load.

Utilities usually charge a penalty fee to customers with power factors less than 0.90% You can however avoid this additional fee by increasing your power factor.

- This is not true with pre-paid meters, which is what I commented on. Residential pre-paid installations are single phase installations that gets billed for real power usage only.
Three phase connections are industrial connections, and this statement might be true for that - as they claim "usually".

So in summary, not quite snake oil, but not relevant for pre-paid single phase connections (probably post paid single phase as well).

If you are a post-paid client with a three-phase connection you will know of this "penalty", as it has to be reflected on your electricity bill. If the amount is large, you can then take appropriate measures to reduce it. Products like this cannot magically fix problems that are not visible to you. Remedies also needs to be sized appropriately to your speicific inductive loading - a one-size-fits-all approach is suspect, unless the device has multiple capacitve units inside and switches them in and out dynamically in response to the measured power factor.

Ask them for some technical specifications and see the response ?

Edit: This device is listed as a three-phase device, and you have a single phase connection. Not relevent to you at all.

Wizard

Thanks very much Trippp.
Thanked.

Ray

I have a bit of a situation. Some years ago we converted to this pre-paid thing becasue noone was really checking what we were using most of the time and when someone did come around it was a young buck who pranced around pretty confident until Spike came to say hello.

Anyway, we been noticing that it's becoming pretty expensive and my wife found out about different plans or something. So, Friday she goes over to the municipal offices and converts and she gets a bunch of codes that she needs to enter. But on Sunday when she enters them nothing works and we were about to run out. So, she phones up some or other help line and after about an hour someone speaks to her and they say they'll send someone out.

The guy who got here was such a nice person but thick as two short planks hey. And he switched off all the spark and dismantled this and adjusted that and achieved nothing. Then he wanders out to the box outside and opens it and i am with him. And he breaks a seal and installs some or other bypass thing and all the time I'm looking what he's doing and also expecting his hair to straighten out any minute. And then he says there you go, you've got electricity. And I said but what is that going to set me back now - I'm prepaid son. And he says no, it's free electricity. So I ask him like Izinyoka and all and he says aye but dont tell anyone. Someone will pitch on Monday to sort the whole thing out.

So noone has pitched up yet. And I'm not going to be the one to inconvenience anyone with such a trivial matter as leaving me to run on free electricity.

But I am a bit worried. Because I reckon it's not impossible that they'll slap me with a spark account sky high. Regardless of what this Bongani oke said. And I'm sure I'll get charged for this callout which was caused by Sipho giving wrong codes to my wife according to Bongani. But as I said, Bongani wasnt too bright and according to my wife, Sipho left some to be desired as well. And Bongani told me that Sipho is not so good and causes everyone a lot of work.

So, does anyone knopw much about these different plans?

flatfourfan

Big thing that we've noticed is a heat pump installed instead of our geyser generating hot water. Our Geyser is a 50 gallon copper unit from the 60's, runs on a trickle charge so doesn't really chow that much sauce, but it's on all the time. We had a heatpump installed that now uses our old copper geyser as a storage tank before use. The heatpump on a warm day only kicks in every 3-4 days when the water in the storage tank gets below a certain temp.

Saving is about 60% over our old geyser.

Can also vouch for the panel heaters.......they really chow the juice, the 400watt panel in my daughters room chowed about R300 per month during winter.

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