Shade is the number one enemy of a high performance solar power system.
If your roof has substantial shading between 9am and 3pm then installing solar panels is probably going to be a really bad investment.
If you are confident that your roof roof has absolutely no shading, then solar can be a great investment thanks to the current handouts by the Federal and State governments in terms of Solar Rebates and Solar Feed In Tariffs. [Read more…]
A recent solar panel test by German outfit “The TEC Institute for Technical Innovations” which put 15 Solar Panels under identical conditions for a month had some surprising results.
The test measured the power output of the following brands of solar panels:
Here are the results:
(click here for full size image)
Of course your panels have to keep producing power over 25 or more years and the test doesn’t help measure the longevity of the panels, but the results are pretty interesting nonetheless.
How does the Aussie heat affect your solar panel performance?
One of the main factors that makes Solar Power so popular over here (apart from the Aussie Pollies throwing wads of money at in in the form of Solar rebates and Solar Feed In Tariffs) is the fact that the Sun is so damn strong down here.
It’s not rocket science to work out why Solar Power hasn’t really taken off in less sunny climes like my homeland; grey, drizzly old England.
In fact the same 1.5kW system on a roof of my Mum’s quaint cottage in Northern England will produce 45% less energy than if it was on my roof here in Sunny Adelaide.
So does that mean the more sun the better, when it comes to generating Solar Power?
That would kind of make sense, right?
Unfortunately, as with most things in this life, it is a bit more complicated than that. [Read more…]
How do you know if they are going to perform on your roof?
There are a bewildering array of solar panel brands out there. How do you sort the wheat from the solar chaff and be sure you are getting the best solar panels for your roof?
My advice is go thru the spec sheet for each panel and judge them on the following criteria.
If you haven’t got a spec sheet, then get another quote!
If the spec sheet combined with the quote doesn’t have the answers, call up the solar supplier and ask. If they don’t know the answers, that’s a bad sign.
The Top 10 Criteria [Read more…]
All solar panels should come with 2 types of warranty:
1. The Power Output Warranty
This covers the power from the panels. Usually if the power drops to less than 80% of the specification in the first 20-30 years, you can make a claim on the warranty.
That’s all well and good but you need to be confident that you will firstly be able to measure and prove that the power has dropped, and secondly be able to contact the correct company to get any warranty claims honored.
Ask to see the warranty details in writing. Get the installer/salesperson to show you where it states how the power from your panels will be measured if you suspect that the power has dropped, who will measure it and if they will charge you for the privilege.
Also ask them to show you where it says how the warranty claim will be handled, who is responsible for honoring it and what costs you might incur. Will they charge you to remove, ship and test the faulty panel and then ship and install the new solar panel.
If your solar installer or salesperson can’t answer these questions then that is a sign that they are badly trained or inexperienced or both.
If the warranty is covered by the installing firm, ask what the backup is if they are not around in 20 years – (This even applies to the bigger solar installers – one thing the world has learned recently is that even huge companies can go bust if the economy changes…). If you have to go back to the solar panel manufacturer, then go to the manufacturers website and see if you can find warranty details. If you can’t find the website or the warranty details that is a bad sign…
Another great question to ask is: “What % of your revenue do you put aside for future warranty claims?” and also “What % of the solar panel manufacturer’s revenue is put aside for future warranty claims”.
The final thing to check out is whether this warranty is “linear” or “stepped”. A linear warranty of 80% (i.e. a 20% power drop) over 20 years would cover you if the output dropped by more than a twentieth of that 20% in the first year (i.e. 1%), then 2% in the second year and so on… at that linear rate of 1% per year until the solar panels were 20 years old.
Linear warranties are rare, but some of the more expensive panels do have them. The more common “stepped” warranty means that, for the “80% over 20 years” example, your panels can lose 19% in the first year and you won’t be covered unless they lose another 1% in the remaining 19 years to get under that 80% threshold.
2. The Material Warranty
The material warranty (2-10 years) is usually for defects that may cause the power of your panels to drop – but don’t cause the power to drop below the “power output warranty” threshold.
So if you have a power output warranty of “80% over 20 years” and some water gets into one of your panels causing the overall system power to drop 19% – this would be covered by the “material warranty”, not the “power output warranty”.
This can be for stuff like delamination of the backing sheet, discoloration of the solar panels (can look really naff!), solder joints coming undone and bypass diodes failing.
Again – ask your solar installer or sales person to give you a comprehensive list of things that are covered by this warranty.
Finally: watch out for get out clauses
In some of the small print in the terms and conditions published by the bottom end of the solar market, I’ve seen clauses that say your warranty isn’t valid unless you get your system “serviced” every 2 years.
If you have one of these clauses, find out exactly what defines “serviced” and how much it is going to cost. This is especially important if you are buying a really cheap solar system with panels of questionable lifespan. The last thing you want is for your panels to fail after 3 years and then have the warranty knocked back because you didn’t get your panels “serviced” within 2 years!
I had a cracking couple of days at Narnu farm, 1hr south of Adelaide, a coupla weeks ago.
We go there with the kids who love it. It’s a hobby farm where the kids can feed the animals and go horse riding and all that good stuff.
As soon as you drive in, you can’t help but notice their 2kW Solar System made up of about 30 60W Kaneka Solar Panels on the roof of the office building.
So is this blog post going to be singing the owners’ praises for getting solar and doing their bit for the planet?
Short answer: no.
Being the grumpy old contrarian that I am, I’ve got 2 big problems with this particular install.
Here’s the first error with this install:
This photo of the solar system (see the panels on the roof on mounting frames) was taken at 10:30 in the morning. Can you spot the problem?
Solar panel shading
The tree on the right is casting a bloody huge shadow across almost all the panels! Ouch!
That’s bad. However my real problem with the install is this:
They have made zero attempt at energy efficiency before or after installing solar.
It is about five times cheaper to perform energy efficiency than it is to install solar to save the same amount of electricity.
So, although solar is a wonderful thing, you should always do everything you can to maximise the energy efficiency of your home or business first.
Here are some examples of really bad energy wastage that could have been addressed with minimal time or investment:
1) They are still using incandescent bulbs! Check out the photo – I haven’t seen these old things in years.
I counted about 16 of these energy guzzling devices of satan. Let’s do some really simple sums:
Assume each one is on for 4 hours per night (a conservative assumption – I saw lots of them left on all day).
The amount of energy they will consume in 1 year is: 60W x 4 hours x 365 = 87.6kwh per year per bulb = 1401.6kwh per year total.
A CFL bulb will use about one tenth of the electricity of the incandescents, so they are wasting about 1250kWh per year, for the sake of spending about $60 on new bulbs.
That energy that is being wasted is probably close to the amount of electricity generated by 1kW of solar panels – half of their solar system!
Next: Check out the fridges…
They have at least 6 of these antiques.
A modern fridge of a similar size can be had for about $500 and will use a quarter of the electricity!
So for about $3,000 they could be saving about 3000kWh per year. That combined with the bulbs should easily give them energy savings greater than the output of their entire solar system (which probably cost them about $20,000 when they bought it).
Other shockers which should have been replaced are the antique window rattler Air Conditioners and the electric storage hot water systems. The latter is especially crazy for accommodation that is most likely empty for many weeks a year, because you get hot water whether the place if fully occupied or not.
The moral of the story is: Yes – solar is fantastic. But before you get that solar system at least do the most basic energy efficiency measures: i.e. bulbs, appliances, hot water, draft sealing, window shading… Otherwise you are getting a much bigger system than you really need.
A good solar installer will talk you through all this before selling you a system.
Short Answer: no
If you are buying a solar system for your home, I would strongly recommend using a firm that will organise the new meter, grid connection (including new meter calibration) for you.
Trust me: you really don’t want to try and deal with the electricity companies’ bureaucracy yourselves, leave it to the solar supplier who has done it a thousand times before.
Here’s a story that Gary emailed me yesterday. Basically, even though he paid for the solar supplier to organise the install for him, he ended up organising the final part himself! The moral of the story is: Get in writing a date by which you will be connected to the grid with a fully functioning import export meter correctly configured for billing.
“My wife was a contracts manager for a commonwealth department managing a large staff base with a 26 million annual budget. I have been a businessman, purchasing manager and finally a business analyst with the department of defence.
We foolishly thought we were ideally setup from a competency point of view to analyse the whole solar market.
We needed all this background experience and more, including professional experiences to achieve a successful outcome with solar home generation.
Some additional comments to your questionnaire:
We were very happy with Solar Charge the company that installed our system.
They were not the cheapest, but we believe they were the best as regards quality of components, customer service and qualified careful installing
tradesmen.But in many ways the acquisition process, selection of a competent cost effective solar company is the easiest part of the whole exercise.
The most difficult parts are-
When we bundled initially with a energy retailer provider, that was a pleasant exercise, 17.9 cents net per KW hour for electricity and a similar outcome for our gas needs.
But as soon as we went to solar all previously contractually agreed bets were off and our electricity charge from the grid from [all retailers seem to be a similar cost] our charge jumps to 29.9 per KW hour from 7 am until 11 pm weekdays. our off peak charge is only 11 cents per KW hour 11 pm until 7 am in the morning.
[note from Finn: this doesn’t have to be the case see here to find a retailer that won’t increase your tariff for getting solar]
So from 17.9 cents per KW hour after discounts jumping to 28 after discounts.
but in someway it gets even harder-
To get our so called smart meter recalibrated to recognise and meter our solar generation was a nightmare from an admin point of view.
I initially was told by our retailer provider that it would take 26 working days to process our paperwork through to our distributor who is responsible for reconfiguring our smart meter.
Solar Charge told us it would cost $136 dollars which they included in their quote.
Our retailer provider told us it would cost $196 and if we wanted to speed the connect up we could pay an additional $50 to get the truck to visit our suburb out of turn so to speak.
When I got rather firm [not abusive at any stage] with the retailer with finally a senior customer service person she said her company’s performance to date was poor and she would husband our paperwork [which Solar Charge had submitted in a timely manner] as quickly as was reasonable.
Which was the case exactly in fact.
The retailer got our paperwork to the distributor in 3 working days, very reasonable.
The large distributor did the reconfiguring in 3 working days [also reasonable] from their workshops and here is the good news, at no cost.
Because these smart meters in my suburb can be reconfigured from their workshops via a computer download.
No visiting truck is required we were told.
[We need to see this in actual reality if true in future bills, I have made a record of conversation regarding who I have spoken to and the undertakings given to me].
Solar Charge has without any hesitation agreed to refund our $136 but after a few weeks period that allows for any unexpected bill arrival from the distributor [they don’t totally believe this is ttrue yet].
*Our solar installation was finalised on the 5 November and our so called smart meter was recalibrated on the 23 November.
All that is reasonable, but it would certainly not have happened without an enormous persistent personal involvement from ourselves.
Speaking to a neighbour living on her own, it took her 9 months [for some months she did not entirely understand the whole process] to get her system connected to the grid from a metering of her solar power point of view.”
Avoid this experience by getting in writing the absolute latest date at which you will have your system connected to the grid and properly metered.
Please note: As you can see from the date of this post – it was written in 2010 – it was accurate then, but now it is out of date – most inverters in Australia are now ‘transformer-less’.
In my “Dummies Guide” to Solar Power I provide a very brief (some may say shallow!) overview of what a grid connected solar inverter does and why.
For those of you who want to know more details about how inverters really work, including the nerdgasm inducing concept of “Maximum Power Point Tracking” (which is all about maximising the power from your panels), then this blog post is for you!
I get a lot of emails from people asking “Which is the most efficient solar panel on the market?”.
Last time I checked, the awesomely awesome Sanyo HIT 195DA3 (note: now manufactured under the Panasonic brand) laid claim to the most efficient panels in production at a whopping 20.5% panel efficiency!
(And before you SunPower fans swamp me with emails – yes, I understand that this is including light coming into the back side of the panel, which is would require special mounting – see the pic below. On a typical roof, the Sunpower E20 327W will be the most efficient at 20.4% panel efficiency)
An example of Sanyo HIT solar panel mounting to maximise efficiency.
But whilst solar panel manufacturers like SunPower and Sanyo battle it out for the “most efficient panel” gong, the question we really need to ask is: “Is the most efficient panel the best option for your roof?”.
Click the image to enlarge… (it’s worth it!)
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