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Neil Pickford and Solar Energy

I have been interested for some time in the use of Solar energy to replace conventional energy sources. Previously I have experimented with Solar Hot Water and Photo Voltaic Battery floating. I have attended a number of lectures on solar energy at venues such as the Science Festival (1998) and assisted with communications for the International Solar boat race on Lake Burley Griffin each year it was run.

In October 2010 I proceeded with the installation of 6250 W of QSE Solar PhotoVoltaic panels (25 x 250 W) and three Aurora 3.6 kW Grid synchronised inverter systems on my house. The acredited installer was NU Energy Pty Ltd. The inverters were arranged to supply 3 phase power to the grid via my 3 phase house supply, unfortunately ACTEWAGL (the local energy wholesaler) insisted on fitting a single phase meter to feed all energy from the entire system into one single phase. I am monitoring this system with an Aurora PVI-DESKTOP connected to the RS-485 data bus and loading the daily energy production statistics onto

VK1NP Fraser 6.25 kW Grid Solar PV Array + Solahart 303J - 145580 Bytes

Solarhart Collector & TankWhen my original indoor electric hot water heater began leaking in 1995 I decided to replace it with a Solarhart 302J thermosyphon Hot water system which totally satisfied my hot water requirements from October to May each year when I was single. During late Autum and Winter, occasional electric boost is required to keep the temperature in the tank above 40 Degrees C. This was due, primarily, to the shadow of a neighbors Gum tree which shaded my roof during winter from around 11 AM to 3 PM (See photo in June), eg the best collecting hours. Luckilly the neighbours decided the tree was getting too big and cut it down, providing a big boost to my winter hot water. During Summer the maximum temperature of 85 degrees Celsius is reached before the temperature/pressure relief valve operated, expelling hot water from the top of the tank into the gutter, allowing cool water to enter the bottom and cool the system a bit.

Now I have a family we use much more hot water. During a major rennovation in 2009 I added a raked 22.5 degree roof to harvest solar energy. I have added a third thermosyphon collector panel to make the system a 303J and produce more hot water. With the extra panel I installed a heat dissipation kit to prevent over temperature relief in summer. The thermosyphon flow is restricted on entering the tank jacket once the bottom tank jacket temperature reaches around 80 degrees Celcius. After observing poor performance on the expanded system I made some additions. I have added extra insulation to the tank and collector system and installed 8 temperature sensors around the system and adjacent roof with the primary sensors at the top of the collector and Tank Anode. I have now been logging the Solahart and house environmental performance for over a year. After instrumenting the system in 2009 I subsequently discovered the reason for the poor performance. I opened the thermosyphon glycol loop and found that there was no liquid in the tank jacket. Minimal solar water heating for over 8 months had been occuring through steam in the jacket. After refilling the thermosyphon loop with glycol the system is now performing much better.

6 and 12 Volt solar panelsI was also experimenting with some small solar panels for keeping 6 & 12 volt lead acid batteries fully charged. I had put two panels on my garage roof and ws floating some spare deep cycle lead acid batteries. Unfortunately during the 2009 rennovation these panels were destroyed during brick laying and I have not replaced them.

I had plotted the I/V load curve for both these cells, before installation.

The ANU Photovoltaic (PV) Research Group are also involved in some interesting research at the moment aimed at producing cheaper solar cells and Solar Power Plants. There has been an article on the ANU's Trough Solar concentrator

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This page was last updated on 07/11/2010