E-News Issue #102
Our next weekend course for home owners is on the 2nd and 3rd December. It is suggested that you book early as some previous sessions have been booked out!
For those of you interested in a more advanced course, a 5 day Designers course is available (24 - 28 January and the 7 - 11 June).
Our Starter Kit has changed in that the 14W amorphous panel has been replaced by a 16W poly crystalline Kyocera panel. The kit price has had to go up a bit.
The Standard kit now comes with a 45Ah battery and slightly modified box which now has two switched sockets available (for lights etc). After considerable customer feedback our 18W Ulux (CFL) fluoro is now available in the warm colour.
This Ulux is also to be known as a Q-Lite. We are also pleased to now have Ulite CFLs in 24 volts (6 and 9W) in a warm colour. Another new product is the Luna 100 which is a white 1 white LED (in an ES17 base)
Some months ago we decided to change from Flojet to Shuflo range as the Shurflo appeared to be similar quality for a lower cost.
We have some existing stock of 24V Flojet pumps if you are interested in one at a discounted price.
Solar Diesel Hybrid Systems
Off grid customers with large loads such as stations and eco tourism resorts usually find that a solar system to meet all their loads in the peak season or for peak power usage is too expensive. This is particularly true where there are high seasonal loads because a substantial portion of the solar system is under utilized for part of the year. Typically, the system might be designed to meet the load demand for the `best´ month and rely on some diesel back-up for the other 11 months.
This helps to keep the high capital cost down for the solar panels and batteries. The battery bank is typically designed for a couple of days of autonomy rather than for the 7 - 10 days usually found on a typical stand alone solar system. A hybrid diesel solar system is comprised of an `interactive´ inverter charger, battery bank, diesel generator and solar/wind charging sources.
In simplistic terms the inverter charger works in 3 modes:
1) a small load under the maximum inverter charger power rating will run direct off it.
2) a load larger than the inverter charger can handle will cause it to turn on the diesel. The inverter charger will parallel & synchronise its output with the generator. So if you have a 5KVA inverter charger and an 8KVA generator you now have 13KVA of continuous power available (while the battery has sufficient storage capacity);
3) if the battery needs charging, the inverter charger will turn on the diesel; the 230V loads will then run direct off the diesel and any power remaining from the generator will be used by the inverter charger to charge up the batteries. The advantages of such a system include: a) power available 24 hours a day; b) the generator is only run as needed resulting in less noise, running costs etc; c) the generator runs loaded- this optimizes fuel efficiency and prevents cylinder glazing and other costly maintenance problems; fuel and running costs are typically reduced by some 50%;
4) solar and other renewable energy resources can be added to the system at any time to further reduce fuel & generator run times;
5) Unlike a generator an inverter has a good surge ability for starting motors etc. This allows the generator to be smaller than it would need to be without inverter support.
Over the years we have observed that the 120mm fans do not last long (often less than a year) when run on composting toilets. There a few reasons why this may be so:
1) the fumes from the composter could be corrosive
2) the bearings are not lasting - ceramic bearings are now becoming more common and so this may improve the life span;
3) After inquiries to one manufacturer, we have been told that the acceptable voltage window is 10.8 to 13.2V for 12V system (double that for 24V).
Voltages outside the window will 'shorten the life or burn it out'. Daytime voltages on a solar system (when under charge) often approach 15V so we now suspect this is the main problem.
We are further investigating a 'fix' for this problem. Let me know you have any other ideas or information.
Cheers from Dave and all the RPC crew.
Dave Lambert (Director)
- Issue #92 - 06/12/2005
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- 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