I have compiled the following information as a response to a friend of mine (Arjan) who has been following the Ian Plimer arguments against human induced Climate Change in his recently published book ‘Heaven and Earth’. I thought it would be a good idea to share the main points with others regarding the release of this controversial book. I can’t really analyse the scientific evidence because I’m not a climate scientist nor am I qualified in any similar fields. For this I rely on others who have the knowledge and experience. But I believe it is important to look at both views on the subject to keep the conversation going.
You have SPAM with a huge carbon footprint
You may have come across this news item a couple of months ago but it is worth taking another look. Although, the study was conducted by a major spam-ware corporation, it is clear that junk e-mails have a huge carbon footprint.
(image: www.fotolia.com)
Anything powered by electricity emits greenhouse gases. Recently research was conducted in the US to find out the amount of energy needed to transmit, process and filter spam globally. The results were startling. According to the ‘Carbon Footprint of Spam’ report the average greenhouse gas emission of a single spam message is 0.3 grams of CO2. Is this a lot? Well, if you multiply this by the number of spam sent annually it translates into a huge figure.
It is estimated that there are 62 trillion junk e-mails sent each year. In terms of energy this equals to the energy needed to drive a car around the planet 1.6 million times. If looking at the electricity needed to power these spam it equals to 33 billion kWh. This amount of electricity could power 2.4 million homes for a year! Spam-related emissions for all e-mail users around the world in 2008 totalled 17 million tons of CO2 or about the same as the emissions produced by 3.1 million passenger cars. That’s 0.2% of the total global emissions.
The report found that about 85 to 91% of all e-mails globally is spam. Nearly 80% of the spam-related GHG emissions came from the energy used by the PC users viewing, deleting and searching for legitimate e-mails amongst the junk e-mails. But spam filtering itself accounts for about 16% of spam-related energy use. To view and trash a piece of spam takes about 3 seconds.
If every inbox were protected by spam filters, organisations and individuals could reduce today’s spam energy by 75% or by 25 billion kWh per year. This would save the same amount of greenhouse emissions as produced by 2.3 million cars. In late 2008 a major source of online spam was taken off line and global spam volumes dropped by 70%. However, there are always new ones to take its place.
Which Solar Hot Water Heating System?
One of the most energy intensive (and therefore costly) processes in any house is the heating of water. Heating water accounts to about 37% – 40% of the annual energy consumption in an average Australian household and about 20% of its greenhouse emissions. Therefore it is important to consider all the alternatives, such as using the heat of the sun in solar hot water systems.
Which Solar Hot Water Heating System?
(Part One)
One of the most energy intensive (and therefore costly) processes in any house is the heating of water. Heating water accounts to about 37% – 40% of the annual energy consumption in an average Australian household and about 20% of its greenhouse emissions. Therefore it is important to consider all the alternatives, such as using the heat of the sun in solar hot water systems.
The diagram below summarises the GHG emissions of each type of hot water system.
GHG emissions from hot water systems
There are three main types of roof-mounted solar hot water heating systems used in Australia. These are: the unglazed polymer collectors which are mainly used in the form of black pipes or hoses for heating swimming pools, the glazed panels which are copper pipes insulated within a dark glass panel and the evacuated glass heat tubes which also have copper pipes running through them but are housed in a vacuum-filled environment. The tank maybe located on the roof together with the collectors or could be in a separate location. In passive systems, water flows unassisted between the collectors and the tank. In active systems, water is pumped between the collectors and the tank.
Throughout the day, a sensor monitors the difference in water temperature between the water in the storage tank and the water in the collector (typically mounted on the roof). At a preset temperature difference, the sensor triggers a pump to circulate the water through the collectors where it absorbs solar heat.
Below is a summary of the two types of commonly used domestic solar hot water systems. Both the flat panel and evacuated systems have several versions, where gas or electricity is used to boost the water temperature if it is not sufficiently hot coming out of the water tank. In most cases the sun is simply used to ‘preheat’ the water to higher temperatures (40-70 C) before it goes into a storage tank. A pump may be used to circulate the water from the tank to the collectors until it is used. In addition the flat panel systems may use a heat-exchange mechanism typically where the water may freeze.
Flat panel or evacuated tubes?
In recent years evacuated tubes have become more popular and affordable and together with the flat panels have become widely used in Australia, especially since generous government rebates have been introduced. However, it is still disputed which system is better than the other. Obviously the manufacturers of each type of system claim that theirs is better than the other (sometimes claiming 90% to 160% more efficiency than the other system). The following reasons have been cited: because it captures sunlight better, is better in certain climates, is more cost effective, has better output for dollar spent, has faster payback, is less prone to failure or damage, is cheaper to repair, requires less roof installation area, etc.
It is difficult to find impartial opinions on the subject. It seems that each system should be examined in its own context. The climatic conditions and application will determine the better collector. One of them may be the preferred choice over the other due to a number of variables, such as the environment, availability of sunlight, elevation, orientation, average outdoor temperature, greenhouse gas savings, ease of installation including existing plumbing, payback period, running cost, availability of natural gas to use for boosting water temperature, how well the hot water tanks are insulated and many other factors. So which one is better and how do they compare?
To be continued……..soon……….
Sunlight in a Cable
We are all familiar with the concept of the traditional skylight or solar tube that directs sunshine through a duct or a flexible tube from the roof to a ceiling. This is an easy way to get natural daylight into a room but it is dependent on tube length and on a direct route between the roof top and the ceiling. There is another way known as ‘fiber optic solar lighting technology’.
Parans , the Swedish company behind the ‘sunlight in a cable’ concept, believes that it is possible to have sunlight in every single room of an indoor environment – even underground. The principle of the Parans’ system is simple; first the sunlight is collected by panels outdoors then it is transported through fiber optic cables into carefully designed luminaires located anywhere within a building including between floors.
The system consists of a light-collecting panel called a SkyPort that’s made up of a layer of movable and a fixed layer of lenses that track the movement of the sun through stepping motors controlled via a microcomputer. These can be mounted on a roof, facade or the ground just like other solar collecting devices; however glare shields may be used to throw direct sunlight onto its surface if the orientation is not quite perfect. The SunWire, consisting of a bunch of optical cables, then guides the sunlight indoors with minimum light loss. Very high quality light can be transported for up to 15-20 metres without major losses since the decrease of intensity for visible light is only 4.6% per metre.
The Björk luminaires are designed to give a spectacular sunlight experience both as strong light beams and as ambient light. The luminaires are made from thin sheets of semi-transparent acrylic. The feeling of natural light is immediate. The light intensity under one of these luminaires can be as high as 4000 lux when 100 000 lux outdoors (based on seven metres of fiber optic cable). UV and IR radiation are naturally blocked out by the Parans system making it the perfect solution for environments where these must be avoided. It is possible to ‘switch off‘ the system in case the darkening of a room is necessary for presentations etc.
While the Parans system works perfectly well in reasonable daylight conditions it is necessary to use artificial lighting during overcast days or when the hours of daylight diminish in winter. To counteract this there is a hybrid luminaire that incorporates T5 lighting technology, which dims automatically according to how much natural light is emitted.
However, the main focus of the system is to harness as much sunlight as possible before needing any artificial lighting thus reducing energy costs and most importantly greenhouse emissions. The only power the Parans system uses is 0.9W for the motorised panels and the microprocessor. Using the Parans lighting system can lower energy costs by 20-25% annually and probably around the same percentage of GHG emissions (based on brown coal emissions).
(Ref: www.parans.com and www.skydome.com.au)
Is Plasma Light a serious competitor to LED light?
Controlled Plasma (CP) lighting technology is the latest of a number of emerging innovative lighting technologies that inadvertently help reduce GHG emission through energy efficiency. In fact its Melbourne inventor Graeme Huon (formerly and acoustics engineer) asserted that “If we were to replace 75 % of lights in homes with these globes in the next five years, we could save building one new power station”.
Cold cathode fluorescent lighting (or CCFL) has been around for a few years in the form of inductive lighting. However, what sets CP globes aside from the rest is that it is the first of its kind to be able to be used in homes as well as for commercial applications due to its affordability and design.
CP Light On
What is a CP globe? Graeme Huon explains: “It is a light source that utilises three existing filament-free light technologies; neon, cold cathode and high intensity discharge along with a new type of controller to regulate the way it works. That way you get flicker-free light and cool running temperatures. It only uses 5 watts, is dimmable and has a lifespan of 20 000 hours”. These together with good colour rendition and with very good light flux levels make it a real alternative to LED lamps and actually surpass CFL lamps in many ways.
To further simplify matters the GU10 globe is incorporated into a downlight fitting (similar in appearance to many existing 50 watt halogen fittings) and is fully sealed to keep out insulation, bugs and heat. This creative downlight is also so versatile that the same fitting can be used as a gimbal or flush type fitting or one can remove the globe with the controller and simply insert it into an existing downlight luminaire. It is fully compatible with existing wiring and comes in two versions; with a plug-in lead or as a quick connect system to be used by electricians. Due to their tri-phosphor coating they are available in warm white and cool white but in the future there may even be ‘party light colours’.
But are they a direct replacement for 50 watt halogen downlights? Well not quite. CP lights do have very good lux levels but they have a different directivity of light. CP lights don’t have a bright spot like halogens so they are not directly suited to long throw or spotlight applications. However, they are a possible alternative in some cases as long as one is aware that they provide slightly less but more uniform light. This means that for the same given area you will have to use more CP lights than you would use halogen downlights but since they only consume 5 watts each this is not a problem.
LED technology is developing at a rapid rate with better-brighter light levels and possible dimming capabilities in the near future. Nevertheless they are unable to match the low wattage for the same amount of light or the colour temperatures of CP lights. LED lights also run at a higher temperatures so large heat sinks need to be fitted to cool them. This doesn’t mean that LEDs are worse or can’t compare to the quality of CPs. It is more of a case of the LEDs being suitable for different applications and commercial use due to their own design features and price.
As for the CFL alternatives, they still use up to 11 watts and produce less light. Finally the cost of a CP unit cannot be matched by any of these two. They are rumoured to sell for under $60 per unit, which is less than half of an equivalent LED fitting and probably the same as a non-dimmable CFL fitting with lamp. CP light fittings will be distributed under the Kambrook name and are designed and produced by CP Envirotech.
(References: G Magazine April 2008; Green Lighting in Electrical Connections December 2008).