Tag Archives: Gary Fahy


How to optimise your computer’s power use

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Here are a few quick tips from our energy expert, Gary Fahy, on how to ensure that your computer uses as little electricity as possible. Continue reading


Is your pool pump guzzling energy?

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Your swimming pool pump is one of the highest energy consumers in your household. Our energy expert, Gary Fahy, shows you how to ensure that your pump runs efficiently. So, get your calculator out and start planning what you will do with your extra savings (something low carbon of course!). Continue reading

CFLs – let’s bust the myths!

Project 90 subscribers have from time to time voiced concerns around changing their regular incandescent light bulbs over to the more efficient Compact Fluorescent Lamps (CFLs) so I took a closer look at the pros and cons of these lamps. I’ll share my findings with you here and aim to address some of the many myths surrounding them.

Firstly let’s confirm the pro’s:

1. Not only do CFLs use a fraction of the electricity required by incandescent bulbs (around 70% less) they also typically last a lot longer. Numbers range from 8 to 15 times longer. One or two “duds” may turn up, but the vast majority of good quality CFLs will function for years without any problems.

2. This of course means that you save money – not having to replace bulbs often and using less electricity.

So these are the two main advantages – they save you money and they reduce electricity consumption. They must be good, right?

Well, there are a variety of concerns related to CFLs sent in by subscribers:
The main ones include the environmental and health issues around the mercury which they contain, the dangers for people who suffer from epilepsy and migraines, as well as the most common one that they do not provide and effective and aesthetically pleasing light.

1. Let’s start with the mercury. Yes, it’s true they contain the hazardous element mercury in very small quantities. It is therefore recommended that they are recycled and not discarded.

However, did you know that since you are using coal based power in your home, the amount of mercury released into the environment if a CFL were to be discarded is far less that would be produced as a by product of coal power generation to power an incandescent bulb? So by using less coal electricity you are preventing far more mercury for entering the environment than if you stuck with your regular bulbs. Ok, a broken CFL would expose you to the mercury more directly, but we are talking about minute quantities here. Researchers at Lawrence Berkley in the US (a very well reputed research institute) conducted extensive tests to assess the dangers of CFLs. They discovered that this exposure would be less than that of having a small nibble of tuna! Eating a whole can of tuna – which I do regularly- exposes me to far more mercury than a CFL ever could. So if you are really worried about mercury exposure, stop eating tuna and leave the poor CFLs alone.

But remember to recycle them when they fail. Most large retails stores have boxes to drop them off in. If your local supermarket doesn’t, go and ask them why they don’t. If you do however break one, open the windows, and clean up carefully.

2. I have not managed to find any convincing evidence that there is a link between CFL’s and migraines or epileptic episodes. I don’t discount the fact that some individuals have perceived problems associated with CFLs and they might choose to not use them. But please don’t let this discourage you since these individuals are very rare. Also bear in mind that this is the case for any fluorescent light, not only CFL’s, so these individuals would have the same problem with regular fluorescent tubes which have been around for 70 years.

3. Next is a concern that they emit UV light and are therefore dangerous to your skin. Well, all I can say about this one is that those people who are worried about this should never go outdoors because there is a lot more UV waiting for them there!

4. Finally the concerns about the colour and light quality. What you need to look out for is the Colour Temperature – which should be printed on the box. This is an indication of the colour of the light and ranges between about 3000k and 6000k. People who are unhappy with the light quality have likely bought a CFL with a very high colour temperature (6000k), which results in the typical cold/blue, almost sinister, light. Normal old incandescent lamps have a colour temperature of around 2700k to 3000k, so chose a CFL rated within this range and you should be very happy with the light output. They normally print this number somewhere on the box, however if they don’t they would normally have a description like “cool white” or “warm”. Go for a warmer lamp for rooms like bedrooms and living rooms. If the description isn’t clear, go for a lamp that has the colour temperature specified on it and stay as close to 3000k as you can. I must note here that this has nothing to do with electricity consumption.
So I hope this covers most of the main concerns sent to me regarding CFL’s.

The bad reputation, I believe, is a result of inaccurate media reporting and urban legend and not based on hard scientific evidence. Choose a CFL with a nice colour temperature from a well reputed brand and sit back and forget about all these unjustified health concerns. The carbon benefits of using them far outweigh any potential negatives.

Tip: remember, the average CFL might not work with a “dimmer” fixture designed for incandescent bulbs. You can get CFLs that can be dimmed, but just check this before you buy them. It will be clearly marked.



Gary Fahy’s review of household heaters

Dear friends,

This month I have investigated a variety of common household heaters in an attempt to evaluate the costs, and more importantly, the resulting CO2 emissions associated with their use. This might have come a little late in the year, with spring on our doorstep, however the same information will apply next winter.  First off we should note that the effectiveness of a heater is very dependent on the environment in which it is being used, and for this reason I believe laboratory tests are not very informative.

This article is simply to illustrate the actual cost of using a certain heater, and the resulting CO2 emissions, and I leave it up to you, to evaluate which heater performs better in your environment. I have looked at various wall mounted panel heaters, LPG or Gas heaters, fan heaters, element heaters and oil fin heaters, and these are my findings.

Wall mounted panel heaters are often touted as the most cost effective and energy efficient means of heating and generally consume around 420W of power. Using this heater for an hour  would result in 0.5kg of CO2 emissions and cost about 25c at today’s electricity price. I have one of these panel heaters in my bedroom, and from experience it is only effective if left on for a long period of time, and the bedroom door needs to remain closed.  This type of heater would not be effective in a large, draughty living space.

LPG (Gas) heaters typically have three panels, each the same size and each emitting the same amount of heat. I also own one of these heaters and very seldom use more than one panel. Using the heater on its lowest setting for 1 hour, which is typically how long it takes to heat my living room to a comfortable temperature, consumes about 1.2kW of power. Burning this amount of gas emits approximately 0.3kg CO2, and costs approximately R1.80 an hour. This might seem like a lot, however the heater is very effective in heating the room up and I seldom need more than an hour or two. Multiply this by 2 and 3 to get values for medium and high settings respectively.

Fan/element  heaters and oil fin heaters are typically rated at about 2000W, which means they consume about 5 times more electricity than panel heaters. So using one of these heaters for an hour is going to result in 5 times more CO2 being emitted, and a whopping 8 times more than the gas heater on its lowest setting! They will cost you almost 5 times more than wall panel heaters per hour, and only slightly less than a gas heater.

In a nutshell, a gas heater costs only slightly more than fan/element and oil fin heaters to run, but emits about 10 times less CO2! Compared to panel heaters, gas heaters cost about 7 times more to run, but result in about half the CO2 emissions. So if you can afford it, a gas heater is much more environmentally friendly, and in my opinion, much more effective in certain environments.

I therefore suggest a gas heater for a large living room area, with people coming in and out all the time, and wall mounted panel heaters for bedrooms, where less intense heating is required and where there is not a lot of traffic through the room. They are quite effective in closed spaces, and do not use up oxygen so safe to leave on while you sleep. Which brings up a very important point:  when using a gas heater, always ensure the room is well ventilated. This might seem strange since you want to retain heat, but gas heaters consume a lot of oxygen, and without a constant supply, it will result in a dangerous build up of carbon monoxide. Never use them in closed confined spaces.

That said, burning wood sourced from well controlled and sustainable forests, or from alien species clearing, is still first choice since it is essentially carbon neutral, and let’s face it, much nicer to sit in front of.  So throw out the old oil fin and element heaters, grab a glass of wine and chuck a few logs in the fireplace.

Note: the CO2 emissions calculated for gas heaters did not include emissions through the entire lifecycle of LPG, i.e. manufacture, transport and distribution to the point where it was being used in my heater. They were simply based on the amount of gas consumed, however  the results are still indicative.

An update from a last month’s article:
I installed a R300 water saving showerhead and have been using it for a month, and I must admit I was surprised at how little it affected the quality of my shower. Sure, there was not as much water coming through (the whole point!) but it really did not make a great deal of difference. My wife, however, commented that it took twice as long to wash the shampoo from her hair, so maybe she is not as convinced. Go try one for yourself.

© Gary Fahy

Gary Fahy’s tip to save water and electricity: fit a water-saving showerhead!

Dear friends,

Considering the detrimental effect of pollution on our environment due to electricity production from fossil fuels, as well as the limited supply of fresh water, a device which reduces electricity consumption and water use is an attractive prospect.

Water-saving shower and tap fixtures are not a new concept, but for various reasons they have not made a significant appearance in the mainstream despite the proven benefits. An average household uses approximately 40% of their entire electricity consumption to heat water, and therefore reducing this would have significant cost implications.

A water-saving shower head works by limiting the output of water from your shower to between 6 and 9 litre/min, depending on the model used. Therefore, the potential to save is only really relevant should your water supply/ shower produce water at a rate of more than 10 litres/ minute. So to evaluate whether or not fitting one would result in savings, you should determine the flow rate in your own home.

This is easily done by measuring how much water comes out your shower per minute. To do this, get either a container with a known volume, like a two litre oil container or jug, and calculate how long it takes to fill up while under the shower head. Be sure so set the shower exactly at the pressure and temperature you normally shower at. If the 2 litre container fills in less than 12 seconds, you are using more water and electricity than you could be so you, and the environment, would benefit from a more efficient shower head.

There is a vast selection of water saving shower heads to suit any style and pocket, and they are readily available at most mainstream building supply stores, as well as on line. It is an easy and relatively cheap way to make a positive difference to the environment and your pocket.  They typically cost between R100 and R400 depending on what it is made of, obviously the better the material, the more you will pay. However with the potential savings, it will pay itself off in no time. Most standard showers have a female BSP pipe fitting screwed onto the standpipe. Therefore removing your existing shower head and replacing it with the new one should be straight forward exercise for anyone with even basic DIY skills and tools.

Now the question remains, will it affect the quality of your showering experience? We have experienced the frustration of a shower which does not produce enough pressure.  I have not personally tested one, but I have now bought my own and will be testing it this month, so standby for an update.

Calculating the water flow rate in your home
I carried this test out in my own house, and calculated my flow rate at 15 litres/minute, which is about average.  Eternally solar website (www.eternallysolar.com) provides a very nice, simple calculator to calculate the savings one could enjoy with the installation of a more efficient shower head.

Entering my 15 litres/minute flow rate in the online calculator, and selecting  the entry level R195 shower head, I could save almost R1900 a year with the default electricity and water prices the calculator recommends. Now be careful, this is based on the default values which the online calculator has recommended.  I used my own calculations to determine electricity savings, and the online calculator was pretty much spot on, however, the default values for water and waste water are somewhat overestimated. I would suggest consulting your actual rates account supplied by the council to work out the average price per kilolitre you pay for water, since this is based on how much water you use.

In my case, a two bedroom house with a small garden and only two people showering, my water and waste water account is significantly lower than the default calculator. If I insert my own calculated prices,  this amount is reduced to  about R1500 (my water price is about three times lower than the default). However this number is slightly misleading since the wastewater they refer to is sewerage, which is made up of all waste leaving the house. That said, the electricity savings alone in my household would be in the region R800, which means the showerhead would pay for itself in 4 months.

It should be noted the greater the saving in hot water, i.e. the higher the current flow rate, the greater the electricity saving would be. In my case, the shower would reduce the water I needed heated in half, therefore my savings are particularly high.

Other than the peculiar choice in default water prices, the calculator seems valid and would therefore give you a good idea on potential savings.

Download this article here.

©Gary Fahy, July 2009