Anna / amaho's post

[c*p]

Re: Introduce Yourself
Postby amaho » Tue 31 Jan, 2012 11:02 am
Hi, my name is anna and I'm starting a reno this year. I'm researching which solar panels would be best for our lifestyle and house design. We have an old cottagein Brisbane that mus be restored due to DCP (Demolition Control Precinct) requirements. I am trying to find out which solar panels/system will save us on electricity costs. Presently we can have a 1/4ly bill cost to $900, we don't have a pool, we have one split system a/c (non-inverter) and I'm tired of paying so much for electricty. We are considering installing Ducted a/c but have been told split systems are the way to go, hence trying to decide which solar system / panels are the best to go for... Any help would be greatly appreciated.

Hi Anna. It is not appropriate to respond under "Introduce Yourself" so hopefully you'll find this post.

The first thing I'd consider is solar hot water. It will greatly reduce your electricity costs if the current hot water system is electric.

Secondly, you need to consider how much electricity you want to generate, and how much you are prepared to pay. According to the CEC Consumer Guide, in Brisbane, a 2kW system generates on average (North facing, tilted 20 degrees) 8.4kWh/day, or ~3,000kWh/year. This is about half of a typical household's consumption. I don't know how many kWh your $900 per quarter buys in comparison.

Thirdly, do you have the roofspace, preferably facing North, essential to be unshaded and no shadows (beware of chimneys, flues, vent pipes as well as adjacent trees) for most of the day, to place the system size you would like? Typically you need around 8 square metres (m2) per kWh system size, so the 2kW system would require 16m2. This could be one row of panels, say 1.6m high and 10m long, or 2 rows at 3.2m high and 5m long. And don't forget the space for solar hot water panels if you choose these too.

Fourthly, there is some difference between the outputs of different panel types. This can be seen in the live data on this DKA site. You can compare traditional silicon mono or poly panels and the newer technologies. In particular the Q-cells (system 27) and others such as system 17, seem to produce up to 8-10% more kWh for the same system size. However they might cost more, so you'd need to do the research.

The first three considerations are more important than the last. The last and possibly third, should be discussed with potential installers once you have answers for the first two considerations. c*p