E-News Issue #96
Price Rises & Shortages
There is a lot of upward pressure on prices these days. A month ago our dollar devalued by 10% against the US $ (although it has now recovered). We all know what the price of oil is doing. This not only raises freight costs but a lot of manufacturing uses petro-chemical type products. All metals like gold, lead and copper have seen massive price increases. The price of copper went from about US$5500/ton on 1st April to US$7200/ton some three weeks later. So stay tuned for more price rises for cable.
Solar Panel supply remains tight, however we have good supplies of Kyocera panels and 64W Uni Solar. We are still unable to get any Uni Solar amorphous panels less than 64W in size. We are also unable to get 12V power points until late June.
So, if we tell you the price has gone up, it is because of worldwide issues beyond our control.
Our 18/20W straight fluoro has an Australian made inverter that has proven to be reliable. We have supplies of these but are unable to get the luminaire (metal casing) to make up more for another month. For all our other 12V fluoro requirements, we are shifting to the Sundaya range as these have proven to be the most reliable. The range includes 6 & 10W straight fluoros as well as 3, 6, 9 & 18W compact fluoros (CFL). The CFL all use the ES17 (mm) base. A variety of lamp-holders and lamps are available which are attractive, high quality and economical.
Washing Machine Power Consumption
In the next newsletter I will take another look at washing machines, so, I welcome any input you have about their power usage. I am mainly interested in how much they use per load of washing so if you can, let me know what model machine you have and how many amp hours it uses on 12/24V (if you have a Plasmatronic regulator) or watt hours (if you have one of our Energy Monitor 3000´s).
For those of you in Australia, you may be interested to check out a 17" TV at Dick Smith Electronics for $399. It comes with a 230V plug pack but one of our staff has been running it direct off his 12V battery system without any problem. It uses 2.5 to 3 Amps (depending on volume) if you run direct off the battery.
As previously advised, these TV´s are designed to run off a 12V power supply (not on the fluctuating voltages of a solar system). They seem to run ok, however, we advise you that this is at your own risk unless the manufacturer advises that it is ok.
We get a lot of requests and inquiries from people about LED lighting. Unfortunately, there are quite a few misconceptions and myths about them:
1) Super Efficient: Many claim that they are superbly efficient. It is true that they are very bright to look at as they give a very intense narrow focussed beam coming from a very small surface area. This is usually referred to as luminous intensity and is measured in milicandelas at a certain degree beam. It measures the light that falls on a surface - say your book. As the surface area increases, the candelas decrease but the lumens stay the same. Lumens are sometimes defined to be the total light output at the source.
Most light bulbs are rated in lumens and that gives you a measure of how well they will 'light up a room' (in simplistic terms).
LEDs, due to their focussed light beam, are very efficient at lighting up a small surface like a book or small table. However, their total lumen output is quite small and they don't do much to 'light up a room'.
You can convert candelas to lumens with this online calculator.
Now, getting back to my initial point - efficiency. The efficiency of a light is usually given as lumens per watt. Even good quality 5mm white LED´s only have an efficiency similar to an incandescent bulb, e.g. 15-20 lumens/watt. The 12V fluoros which we sell range between 30 and 52 lumens /watt. So, as a general rule, any fluoro is 2-3 times more efficient than an LED.
Some unusually high claims to LED efficiency are driving them at a high current which will quickly shorten their life or do not take account of the inefficiency of the electronic circuitry to run them. More are designed to operate direct off 12 or 230 volts.
So to conclude, if you are looking for an efficient light for a room, we´d normally suggest you use a fluoro.
2) Longevity: A frequent claim is that they last for 100,000 hours. While this may be true with good electronic circuitry at a low current, the accepted life is usually more realistically given as 10,000 to 20,000 hours before the light output reduces to say 70% of their initial output. Few LED enthusiasts or manufacturers mention this light output degradation. Googling 'LED degradation' will bring up several hundred references to the problem.
Other disadvantages of LEDs are their relatively high cost per lumen of output and their poor colour rendition. They generally give a fairly blue or grey coloured light.
Their main advantages are that they are very robust (because they are made of a polycarbonate rather than glass and they do not have a fragile filament). Their focussed light beam makes them ideal for torches.
Cheers from Dave and all the RPC crew.
Dave Lambert (Director)
- Issue #92 - 06/12/2005
- Issue #91 - 15/11/2005
- Issue #90 - 20/10/2005
- Issue #89 - 29/09/2005
- Issue #88 - 01/09/2005
- Issue #87 - 29/07/2005
- Issue #86 - 04/07/2005
- Issue #85 - 03/06/2005
- Issue #84 - 05/05/2005
- Issue #83 - 01/04/2005
- Issue #82 - 03/03/2005
- Issue #81 - 23/02/2005
- Issue #80 - 02/02/2005
- Issue #79 - 05/01/2005