DL opted to add extra solar panels to his system rather than to use a back-up generator during inclement weather.

"I am pleased with my system design because even in prolonged rainy weather I have enough power for my fridge, television, lights and computer." In sunny weather DL uses his surplus power to cook with.

DL's house has most of the mod cons including DVD, satellite television, vacuum cleaner, ceiling and pedestal fans, bread maker, microwave, fridge and a few power tools.

DL monitors his system with a Plasmatronic PL40 regulator. Besides monitoring and logging his solar input, DL uses the optional PL Interface to monitor his outgoing loads. This in turn gives a display called % State of Charge. He leaves his regulator set to this screen.

"When I arrive home, I have a bit of a guess as to what the State of Charge will be. Then I press the display and see how accurate my guess was. I don't get much practice at guessing because my batteries are usually 100% charged!!"

New Adventures for Dave Lambert

Dave Lambert's New Energy Efficient Home.

In February 2006 Dave made the move out of the bush and into the suburbs of Nimbin. He bought a 6yo three bedroom brick veneer house and now walks to work.

The house has a reasonable ‘solar' design. It faces north and in the winter, sun streams into the eastern glass door at 7:00am and begins to warn the house. Some sun also enters the northern windows during the winter. During our hot summers, little sun enters the house. Being brick construction with slab floors means that it has good thermal properties.

The house has a lot of glass windows and doors – about 25 sq metres in all! In summer the southern and northern doors can be opened to allow a nice breeze to cool down the house on a hot summer day.

All the windows (except the back glass door) have thick lined ceiling to floor curtains. This helps to keep the heat out in the summer and in during the winter (once it has heated up during the day).

During the past 530 days I used an average of 4.06kWh/day for off peak hot water heating and 4.47kWh/day for general power. The off peak daily cost was AUD$0.22 plus .04 (access fee) and the peak power daily cost was $0.73 plus .40 (access fee). So the daily total comes to 8.53kWh costing about $1.39.

While Dave lived alone for over half this period, he feels his power consumption is quite reasonable. It is an ‘all electric' house with no gas or wood used for cooking or heating.

When Dave moved in he replaced all the lights with energy efficient compact fluoros. Dave said “I'm amazed how even a 5W fluoro is plenty bright for small areas, like the toilet, hallway and laundry room and as a background television light. I use 15 – 18W in the larger rooms such as the kitchen”.

Dave often raises eyebrows among his colleagues when he tells them he has a large reverse cycle air conditioner. However, during the two colder winter months, this is the most efficient method to heat a house – some 2.8 times more efficient than a bar heater. “I only use it for 15 – 30 minutes a day. I close off the two spares bedrooms and it heats the house in an incredibly short period of time. Similarly in summer a 30 minute cold blast will remove that sultry sticky summer heat you sometimes get in December and January”.

During July 2007 Dave made some further changes to increase his energy efficiency. He purchased a heavy curtain for $100 for the northern sliding glass door and spent $750 to have the ceiling insulated with R3 glass wool batts. Dave said “The difference was noticeable on those cold nights – the house stayed comfortably warm until I went to bed. I'm told that it will make the house 6 – 7C cooler in the summer. This means I'll use the air con even less and my fridge won't work as hard in summer. I decided to insulate the ceiling now even though I understand there is a $300 NSW gov't rebate for insulation commencing in September 2007”.

The other big change is that Dave had a 1.04kW grid feed solar array fitted to his roof. The super efficient Latronics inverter starts exporting power to the grid at 7am even in July! Dave expects to generate about 4.8kWh/day from his array which will completely offset his peak power!

In fact, he should even become a net daytime exporter now that his ceiling is insulated. Dave commented “I'm thrilled to become carbon neutral at last for my peak power”.

Dave has a few more plans up his sleeve in coming months. The western wall gets very warm during the hot summer months as the sun begins to set. Dave intends to invest in a $100 cream coloured shade cloth (which will match his bricks). This will block out about 90% of the sun over a 9 x 2 metre area. The final plan is to acquire a solar hot water system after 1 January 08 at which time he has heard the NSW government will be offering a $1,200 rebate.

Dave said “By early 2008 I expect to become 100% carbon neutral which is a fantastic feeling”.

Is Solar Power only for Hobbits?

Let me begin by saying we all have different financial abilities, desires and priorities. For the two billion people in the world without grid power, a couple of electric lights would be an amazing luxury. For others, it would be worse than a camping trip without the fridge, TV, etc.

To a large extent, anything can be powered by solar. It is a question of money and relative affordability. By the same token, some people struggle to pay a basic grid power electricity bill of $100 per quarter - for others, paying $400 a quarter to power their air con and swimming pool is acceptable. I sometimes tell people that we sell solar systems from $500 to $50,000!

Going back to the hobbit question, I would not describe my lifestyle in this category! My 'medium size' solar system of 1000 Watts runs my widescreen LCD television, satellite dish, my DVD/VCR 5:1 surround music system, computer, breadmaker oven, toaster, coffeemaker, microwave oven, vacuum cleaner, washing machine, fans, fridge, blender, power tools and lights!

However, I don't have enough power for air con, an electric oven, 500 litre fridge, or to have a 56" Plasma TV on all day!

Because I choose to have a small battery bank, and not to have a back up generator, I do have to moderate use of a few items after a few days of cloudy weather. I've always had enough power for my lights, fridge and TV. (I find life pretty bearable all the same!!!)

Dave Christmas has worked for the Rainbow Power Company since its inception in 1985. He is commonly referred to as DC, which is not a bad handle to have in this industry.

Dave's system consists of 14 x 52W Photowatt double glass solar modules. These modules charge a 24V 438Ah Trojan battery bank, controlled by a Plasmatronics PL40 regulator. All lights are 24V either Halogen or fluoro. A Selectronic SA21 Inverter, rated at 1600W on 24 volts, supplies the 240 volt AC for the house.

Dave also uses a Jaycar 8A continuous switchmode power supply to provide power to run his UHF & VHF two-way radios. He also recharges his mobile phone with this unit.

The Selectronic inverter is usually loafing running a 63cm TV, a Panasonic DVD player and a JVC video. The washing machine is a 5.5Kg Fischer & Pykel and has run faultlessly for over 6 years. The only time his inverter really works is when he runs his 1600W vacuum cleaner. Dave only uses the vacuum when there is full sun on his panels. By using it this way half the power comes directly from the sun whilst the batteries supply the rest. The only other 240Vac loads are a 1000W toaster, a 300mm pedestal fan for those long hot Nimbin nights and an assortment of power tools for building and furniture renovation.

Previous to this system Dave ran with a 12V system using three solar panels with a combined wattage of 190 Watts and a second hand set of wet cell Ni-Cads of 139Ah capacity. He used a gas fridge in this set up but still managed to run his washing machine. This system was used for over ten years. Before that Dave used one 42W Solarex panel charging a second hand set of 90Ah ex Telecom batteries, with just a few lights and a black & white 12V TV. Dave has lived on solar now since 1984.

A Plasmatronics PL40 regulator is used to monitor & record the volts, amps & amphours history of the system & boost the batteries.

Cooking is done with gas or combustion fire. The hot water is heated with a stainless steel 300L Edwards Solar Hot Water System, backed up by the combustion fire whilst heating the house in cold or wet weather.

An efficient solid fuel electric generator is on the wish list.

The Solar Power System at the Installation Managers premises.

Started out with 8 x 83W solar panels and too many “necessities”. The latter were trimmed back or changed so that instead of running a desktop computer all day, a laptop was used instead. My first experiences with solar power were interesting and, in hindsight, amusing.

Solar power systems are not like mains – you can run out and you need to be conscious of what you’re running and when you’re using it. Living on a solar power system also makes you more aware of just how much we take for granted and how reliant most of us are on plentiful supply – solar power makes us much more involved in the whole process: anyone on a solar power system needs to know their system to some degree. This doesn’t need to be too involved, but you can’t just sit back and consume.

I believed many of the myths and misconceptions about what solar power systems can and can’t do from well-meaning griddies (folks on the grid) and for a year or so I tore out my share of hair. For instance “computers use negligible power”, “you can’t run washing machines off solar power”. After talking to Dave at RPC I bought a few more solar panels (4 x 120W Kyocera solar panels) and upgraded a few other things, and most importantly, I started to take a real interest in the solar system and how best to look after it.

Haven’t looked back since – the solar system is charging along, the poor generator is feeling rejected, and Mernisa and I haven’t had to make painful compromises. There are more additions planned in the future (e.g. 12/24V fridge) but for the moment everything is going just fine. Solar power is important to me from a philosophical point of view as well as financial one: I don’t miss power bills or black-outs!