E-News Issue #39
Well, Christmas is almost upon us again.
We'd like to thank everyone for their support during the past year.
SEIAA Accreditation Course
The next course will be run from 15th-19th February 2000. If interested send $200 deposit payable to Energy From Nature Home to receive the course notes.
Last month's article on lighting attracted a number of questions and comments.
First, to clarify this comment which I made:
LED lights 'are efficient as they use less than 1% of the power of a 20W light'. I was referring to the energy consumption (20mA@12V) of our single white LED light, which in fact uses 1.2% the power of the 20W light. However, as referred to earlier in the article, they are about as bright as a candle (NOT equal to the light output of a 20W light!)
Another question we received asked for our views on DC versus AC lighting.
So, we have made this the monthly 'feature article'.
AC versus DC lighting
Another aspect of choosing your lighting is whether to use 12/24 volts DC lighting run directly off your battery or whether to use 230 volt AC lights run from your inverter. This debate has been somewhat ongoing in the industry over the years. There are some advantages and disadvantages of both.
The advantages of DC lights include:
- They are generally more efficient. DC incandescent lights have shorter thicker filaments making them more robust and able to be run at a higher temperature.There are no inverter efficiency losses.
- These could be substantial if you are running a single light off your inverter (without any other loads on at the same time). However, if you have the TV or other electrical loads on anyhow, then this efficiency loss will be quite small.
- They are more reliable in the sense that they do not require an inverter to run them. Possibly your inverter might fail at some stage and it could take some days to have it repaired depending on the brand and where you live.
The advantages of AC lighting are:
- They are widely and cheaply available from a multitude of shops, shopping centres etc. There is a huge selection of lamps, luminaires, fittings etc.
- Being a higher voltage, a smaller cable size is required. This could be a significant cost saving in very large homes or other buildings.
- Local electricians are very familiar with how to install them and won't undersize the cable etc.
To conclude, I'd suggest that if you have a small system in a modestly sized building, you should use DC lighting. On the other hand, if it is for a larger system in a building with several or more rooms, then you may want to use AC lighting, particularly if you feel there will be a number of lights or electrical loads running simultaneously off the inverter. However, if you opt for AC lighting, we'd still suggest putting in a few DC lights so you still have some light in the unfortunate situation of an inverter failure. A DC light in your battery/generator room is very handy when you have an inverter or battery problem.
Merry Christmas from all of us!!!!!!
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