Comments on The Art of Engineering: 7 best ways to stop load shedding

With the stringent energy conservation approach th...

2010-07-28T10:58:16.143+02:00

With the stringent energy conservation approach that is being used most modern devices have power factor correction built in. I can't say for certain, but I am quite sure that many CFLs have power factor correction. LED lights required internal power converters to obtain the correct output for the actual LED, so they would suffer from power factor issues as well. Again, a well designed LED light would compensate for the power factor.

With regards to the energy loss, it is only the energy loss from transmission that will increase, and that extra loss will be far lower than 40% of the total energy. The reactive power is not consumed, just passed backwards and forwards causing higher transmission losses which are a small factor compared to the actual power consumption.

CFLs do have mercury, but are a huge improvement over incandescents in this regard as coal power stations emit mercury. LEDs definitely improve on the mercury levels though.

It's great to see a focus on conservation, this me...

2010-07-27T03:50:03.050+02:00

It's great to see a focus on conservation, this message is getting a little lost among all the talk of recycling and green power generation. It's better not to use the power in the first place, than to waste it but just try to generate it in a greener way. One point about CFL's, because of their lower "power factor" they are not quite as energy efficient as they appear. Most have a power factor of about .6, which means the utility has to deliver about 40% more power than the bulb uses. That means the transmission costs are higher and there is more load on the utility. As well, the mercury content of CFLs has to be a serious concern. That is why LED lighting is a wiser choice in the long run. Although the upfront costs are considerably higher, on a bulb-replacement basis the cost of quality LED light is comparable to halogens, incandescents and CFLs because of the very long LED lifespan, and the huge energy savings and high power factor make them almost a "no brainer" if you're using your lights many hours per day.

Hi Duncan to switch off the Air conditioning sound...

2010-07-25T16:35:04.951+02:00

Hi Duncan to switch off the Air conditioning sounds like a good idea, that's if the South African summer never happened. So here is my thoughts, and correct me if I'm wrong but for heating purposes, air conditioning is one of the most cost effective solutions available today with saving of up to 70% compared to conventional heating methods, do people who use air conditioning then not actually save on electricity in winter compared to say people using underfloor heating or oil heaters.
So the extra electricity we use during summer we more than make up for by saving electricity in winter.

Luckily there are people out there who are trying ...

2008-02-26T02:13:00.000+02:00

Luckily there are people out there who are trying to help. I stumbled onto a site the other day called www.SheddingAid.co.za. They have a useful service that allows you to search for Generator Powered petrol stations and atms in a suburb. All I can say is big up, keep up the good work and thank you for trying to make a difference.

Great Post,I want to only comment on Computers tho...

2008-02-18T18:29:00.000+02:00

Great Post,

I want to only comment on Computers though. Switch to Notebook computers as they average around 55 to 65 watts versus 300 to 450 watts for a PC plus another 50 watts or so for a CRT monitor. Plus, when you are load shedding you can still use the Notebook (bearing in mind the cheapest notebooks normally only run for 1h30 versus 3 hours for the better ones). Assuming 2,5 million PC's in use at any time the savings would be at a minimum 250w x 2 500 000 = 625Mw. Rough estimate off the top of my head but the savings might be real enough.

Just for those that haven't thought about it: Bewa...

2008-02-12T08:39:00.000+02:00

Just for those that haven't thought about it: Beware when deciding to turn down the temperature on your geyser's thermostat. Having less-warm water in your geyser will make you use more of it (usually you use more water from the cold pipe to even out the final temperature). This then requires more cold water to be heated again in the geyser. I'm sure there is some optimal point, though, because you also don't need to heat the "fresh" water as much as with a hotter setting. But, I haven't done the calculations yet.

Hey Duncan,Great tips, here's another more radical...

2008-02-06T16:48:00.000+02:00

Hey Duncan,

Great tips, here's another more radical approach to energy saving:

http://earthlandscapes.blogspot.com/2008/01/green-roofs.html

I have put my 2 geysers on swimming pool timers an...

2008-02-06T15:11:00.000+02:00

I have put my 2 geysers on swimming pool timers and my electricity bill was reduced with R460 the last 8 months average compared to the previous 8 months average.

My geysers are only switched on 1,5 hours in the middle of the night and again 1,5 hours in the middle of the day. We are 5 people in the house and have warm water all the time.

My usage also went down 44,4 % over that period (from average 2250 units/month to average 1250 units/month).

I have ignoramuses that belittled that. They even said it is impossible, my accounting is wrong etc. Even the technical director said in the newspapers that it does not work.

However, my accounts proves my point.

I have done my MBL at the School of Business Leadership, UNISA.

Yehuda, thanks for popping by and leaving a commen...

2008-02-05T12:06:00.000+02:00

Yehuda, thanks for popping by and leaving a comment. Unfortunately you seem to have missed the gist of the post, namely that in South Africa we are experiencing load shedding, and this is about trying to shift that load and gain a more stable supply through the whole day.

Rather than just copying and dumping another article of yours here, why not engage in the conversation, and link to articles when necessary?

Thanks.

Dave, in this document they recommend 55ºC....your...

2008-02-05T10:48:00.000+02:00

Dave, in this document they recommend 55ºC....your mileage may vary.

Dave, it is a tricky one. It depends on how you us...

2008-02-05T10:27:00.000+02:00

Dave, it is a tricky one. It depends on how you use hot water (bath, shower, dishes, etc.), when you use hot water, and how well your geyser insulation.

When we moved into our house the geyser was set at 55º, but that was a little low, so I tuned it up a bit.

With your thermostat a bit lower you will conserve a small amount of energy and also cause your geyser to be on a little less.

Insulation of your geyser and pipes will be the biggest win in my opinion.

Hmmm, you run a electrical inspection company....I wonder if the clients would mind if you tuned all the geysers you inspect down by 5º? ;)

Hi Duncan,Great blog!Given the comment about tempe...

2008-02-05T10:19:00.000+02:00

Hi Duncan,

Great blog!

Given the comment about temperature differences being a factor, how about dialing down the geyser thermostat as an option.

What would an optimal temperature setting for a geyser be?

Paul, the energy saving is not really that big (en...

2008-02-04T21:15:00.000+02:00

Paul, the energy saving is not really that big (energy = power x time, hence measured and sold in kilowatt hours - kWh).

Like you said, it is about moving the demand to another time, which is the current issue we have.

You probably will save a small amount of energy by doing it, but nothing too significant. Think of it this way: the greater the difference in temperatures the faster the geyser will cool down. So if the geyser cools a little, then it starts to cool a little slower.

If you keep the temp high (like a thermostat does) then it has to use a little more energy (because it cools faster) to keep it close to the set temp. Turning it off for a while means it will be on (consuming energy) for a little bit less in a day.

Probably easier to explain with a picture.

Most importantly though, you got the point with the load shifting.

Hi Duncan - congratulations on a great post. I inv...

2008-02-04T20:13:00.000+02:00

Hi Duncan - congratulations on a great post. I invite you and your readers to take a look at http://www.energycrisis.co.za .

Peter

Hey Duncan - does switching off the geyser really ...

2008-02-04T19:02:00.000+02:00

Hey Duncan - does switching off the geyser really help? I've heard conflicting reports. Apparently heating a geyser from cold uses more energy. Okay, so now that I've typed that sentence I'm thinking, perhaps it does use more energy, but using that energy at night when demand is low decreases the daytime/peak demand.

Thank you, Love the positive side.Switch off your ...

2008-02-04T13:58:00.000+02:00

Thank you, Love the positive side.

Switch off your aircon (please), and dress according to SA climate. (SA people dress lovely anyway).

Hmmmm....quieter pool pumps? Or possibly noise red...

2008-02-04T10:45:00.000+02:00

Hmmmm....quieter pool pumps? Or possibly noise reducing housing?

Hey Duncan.Great Post. I think there's a small pro...

2008-02-04T08:56:00.000+02:00

Hey Duncan.

Great Post. I think there's a small problem with running pool pumps at night - the noise factor. Most pool pumps are situated close to the pool. An open water area acts like an acoustic amplifier - and this is worse at night when things are quiet.

My dad did this and received multiple complaints from the neighbours.

I can suggest people shift from chlorine based pools to salt-based pools. It requires far less maintenance and the motor only has to run about 2 hours a day.