E-News Issue #22
Aussie Goods and Services Tax
I'm still in the dark about the dreaded GST but my feeling is that our products won't be exempted which means inverters, panels, regulators,wire, 240V switches and fittings and batteries will all go up by 10% for Australian customers. Overseas customers will be exempt from this tax.
Rainbow Hydro Upgrade
And lastly, I'm pleased to advise that our hydro with the upgraded digital display should be ready for sale by the end of this month. I'd appreciate any advance notice or speculation you can give me about upcoming sales for our hydro. We always find it difficult to predict how many we need to keep on the shelf ready for sale.
Paul Edwards spotted an error in the last article of our last newsletter about saving power etc. He was correct that 2 x 20W bulbs for an hour is 40W/hr and not 80W/hr. Re the washing machines: we have measured the power consumption on the AC side at 87W/hr per load. The technical division of Fisher & Paykel have advised that the 500 series model uses 107 W/hr/load (21.4 W/hr/kg). The 600 series was 18.6W/hr/kg.
Computers on Renewable Energy systemsComputers are very much a part of our modern society even for many people living in the bush. Consequently, we are often asked to design systems for people wishing to use renewable energy. For the home or small office there are two main choices - a conventional desk top or a laptop.
We have measured the power consumption of a number of computers (without the monitor). The results were: 286 vintage 27W, 386DX 43W, 486 and 2 drives 40W, Pentium 51W.
We also tested several monitors: 14" monochrome 19W, 14" colour 60W, 15" colour 80W.
So to conclude, a desk top computer will draw around 120W on the AC side. We also measured the DC amps (e.g. after inverter losses) and this has generally been in the region of 12 - 15 Amps @ 12V.
So, depending on where you live, a rough guide is that you'd need a 60 - 80W panel to run such a computer for about 1 hour per day.The other option is to consider a lap top. In general, we have found that these draw about 1.8A @ 12V on the DC side. One problem is that most lap tops run on something like 18V. We've found the easiest solution is to run the lap top off our micro inverter which retails for AUD$100. So a lap top is in the order of 8 times more efficient than a standard desk top. This means that one 60 - 80W panel could run your laptop for 8 hours per day. Unfortunately, lap tops have some limitations and are more expensive to buy and repair than desk top units.
It is not cost effective to convert computers to run directly off 12/24V DC. The other problem is that such a conversion would usually void the warranty. The good news is that we've generally found computers to run okay off modified square wave inverters.
That's all for this month my friends. Please send us your news, views and comments!
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