Google DIY Solar Australia: February 2012

Monday, February 27, 2012

Design and Location

The size of the Solar System you desire and the location of it are dependent upon each other.  Firstly the place to position your system should ideally be both north facing and without shading for more than 90% of the daylight hours.

Lets consider the fundamentals, just a little.  A (photo-voltaic) Solar System produces electricity from light energy.  Whilst I don't want to bore you with details of the theory,  this is the most important fact and so it is important that your Solar System is exposed to the maximum amount of light energy available. This also means that the panels should face the suns rays directly for the best result.

Keeping this in mind, take a look at your home. 
  • Do you have any north facing roof slopes?
  • If so, are they shaded at any point of the day?
Ideally a home with a roof pitched east-west, i.e. sloping to the north (and South) is the best.  If you don't have this, don't sweat it, there are still several options to take.

As to shading, it will really depend on the area shaded and for what length of the day.  You must also consider winter time shading vs. summer as the shadows from an obstruction are longer (bigger) during the winter due to the low angle of the sun.  There are various calculations to determine the difference in shading, this can be difficult for all but the most mathematics savvy people.  So if you are at the summer end of the year or in the middle when you do this it can be difficult to judge.  I will get into the calculations of this a bit later, but for now a bit of visual inspection may suffice. Take a look to the north, north-east and north-west of the place you might use.  Are there any trees or buildings higher than the lowest point of the roof in question? If so, how far away.  A general rule of thumb is in winter, the shadow will be up to about 2 times as long as the object is tall at midday. This depends on where you live: Brisbane the shadow is as long and the object and in Hobart 2.2 times longer than the object is tall.  Take into consideration the height of the roof, so consider objects twice as high as lowest part of the roof in question.

Keep in mind the shadows are longer near sunset and sunrise so this must also be considered.  In all, unless you have large trees like (gum trees) close to the house, this shouldn't be an issue.  Normally, buildings on adjacent properties are not allowed to "overshadow" so this should not be an issue also.  Various parts of your own buildings and the effect they have on your potential location are more likely to be a problem.  As I mentioned, the calculations, if you are in doubt will be covered later.

Your roof is flat, near flat or doesn't have a north facing surface?  Don't worry yet, there are still ways to do it!  For a flat or near flat roof, there are elevating brackets available, these can also be used to some extent on a pitched roof if needed.

The area of available roof to fit panels will detemine the amount of power you can generate.  A typical 180 Watt panel is approximately 1.6m high by 0.8m wide. So you can detemine from this approximately how many panels will fit the area.  For example a 1.6kW system requires 9 panels of this size and so will need 1.6 x 0.8 x 9 sqm = 11 square metres of roof area.

Look out or more details in the next post.  I shall discuss problematic, less than ideal roof areas and other topics.

Wednesday, February 22, 2012

Where to Start with DIY Solar

A few things to consider...this is important to the success of your project.  I am a qualified engineer and these things are part of the project process one way or another, so please consider carefully.
  • Are you willing to do your installation the right way.  I mean make sure that everything you do is as required and not just "near enough is good enough"?  I completely understand at this stage you may know nothing and that kind of commitment is a little overwhelming.  The intention of this blog is to impart the knowledge required to do the job.
  • Are you willing to talk through your plans with an electrician?  This may require some cost for the service but will allow you to check the plans and also have the electrician's buy in to go ahead and sign off on what you complete. You will need to fina a Clean Energy Council Accreditied Electrician if you wish to claim Solar Rebates.
  • Are you willing to persevere?  As with any project you may find a few roadblocks along the way.  This doesn't mean there isn't a resolution, you just need to figure it out and there is help available here.

So I think that's about everything you need to consider before going ahead.  I am willing to answer questions, just submit a comment.

A few disclaimers: The information I impart will inform you on how to get the most out of sourcing and installing your own system.  It is important that you get the right approval (and advice if needed) from a licenced electrician.  I may earn money from any links you click in this blog as I will suggest certain products and services along the way that may help you.

Still interested?  The next things to consider are where will you will locate your system, the size (physical and power output) you desire and the quality of the components you wish to invest in.  Stay tuned, I will address these things...

Monday, February 20, 2012

DIY Solar Australia

Hi there

This blog has arisen in the light of the changes in the solar uptake in Australia since the Government has cut the Funding for home solar installations in 2011.  Those of you who genuinely want to contribute to reduction of greenhouse gases and save money but may find that now the cost is stopping you from going ahead, please read on...

Now that the cost of a system is increasing, its desirable to look for ways to cut the costs.  There are several possible ways to do this and probably the best way is for you to take control of your of you own installation, rather that relying on another company to entirely supply, install and connect your system.  I personally don't want to leave my solar system in the hands of a company that may not exist in 10 years time, let alone may not be around next year.  We must keep in mind that a solar system should last 30 years or more and if you plan to stick in the same home for that long (as I do) then this is an important point to remember.

Do It Yourself Solar in Australia.
Despite the rumblings of various authorities in the arena, there is no reason why its not possible for the average adept person to install their own Solar Array.  I say this under the caveat that the job must be done in accordance with the required standards and that only a licenced electrician can connect to the mains power of your house and make the connection for providing energy back into the grid.

In This Blog I will detail how this can be achieved.  I am committed to showing the people of Australia alternative ways to generate alternative energy.