Solar Mounting Systems

Geelong Solar Mounting Systems

One of the least sexy and often overlooked components of a solar power system is the solar mounting system that attaches the panels to the roof or the ground. This is sometimes referred to as a racking, framing or railing system. The mounting system is a pretty important part of a solar system and all mounting systems need to be supplied with an engineering certificate showing they comply with the relevant standards.

At Green Energy Options we think there are a number of benefits that come from using a high quality mounting system, here’s a few examples:

  1. It provides peace of mind that the panels are secure and won’t be blown away in strong winds.
  2. It improves the performance of your solar system, through good airflow around the panels and/or optimising the angle of the solar array.
  3. Minimises potential for corrosion and in turn reduces maintenance costs and helps improve the return on investment of your system.
  4. If there are problems, questions or warranty issues, having a reputable, responsive, local business to deal with is important.

Green Energy Options use the Sunlock mounting systems on our solar installations. Sunlock’s documentation on installation and engineering requirements is probably the most detailed available for rooftop installations in Australia and is backed by a 10 year warranty. Best of all, its Australian made, manufactured right here in Melbourne by Ullrich aluminium. Here are some examples of Sunlock’s fixings for different roof types:

Standard corrugated tin roof

On a standard corrugated tin roof an L-foot is usually used. It attaches into the top ridge of the corrugation and is isolated from the tin by a rubber pad to stop water ingress and electrochemical corrosion between dissimilar metals.

Sunlock L Foot

Tile bracket

On a tile roof, there is no need to drill through every tile, we simply lift the tile, attach the tile bracket to the rafter and slide the top tile back into place. The tile bracket’s arm fits between the two tiles and the rail is then attached to the bracket’s upright arm.

Solar Tile Bracket

Tilt frame

Tilt frames are normally used on flat rooves or rooves with a low pitch. By tilting the panels up towards the north to a steeper angle you are able to optimise the output of your system. Note that tilt framing adds a cost to the solar system so it’s not always the best option for increasing energy harvest. Sometimes it will work out better to spend the money on adding an extra couple of panels to increase output. Green Energy Options is happy to assist you with working out what will be best for your home or business.

Soalr tilt frames geelong

EcoGeneration has also put together a guide called The Australian Mounting System Guide, this provides a great overview of what to look out for in a solar mounting system. Ecogeneration Mounting Systems Guide

For further information, please feel free to contact us on 1300 931 929

Energy Efficient, Solar Home for under $250,000

Holly and I have been keen to open our house for Sustainable House Day the last couple of years, but we’ve always had some excuses, a new baby, a lack of landscaping, too busy….. This year we bit the bullet and said yes. Our house in Torquay is a passive solar, solar powered energy efficient partly sustainable design. Four years ago we were first home buyers and we wanted to have a house that was comfortable, functional and cheap to run, but we, like many other first home buyers were on a budget. I wanted to be able to prove that it was possible to build an energy efficient home on a budget, and not have to make compromises on our lifestyle or comfort. After all the majority of Australian homes are not grand designed, architectural masterpieces. In the end our budget ran out around $230,000 for the house, although we have still a little work to do around the garden, we thought that this was pretty reasonable, and an achievable option for many Australians wanting to build a new home. I probably should give you the heads up now, that this is a longish article.

Solar House

We’ve been in the house now for a little over three years, there are always new things that we would like to do and there are some things that if I had my time again I would do differently, but on the whole we’re very happy with it. We were in the house for a few months’ pre-solar power system and pre-baby and our electricity consumption sat around 4kWhs/day (Kilowatt Hours). Since then we installed a 2.47kW solar system, which generates an average of 11kWh/day. Since we’ve had Ruby our consumption has gone up 1-2kWhs/day, mainly due to more washing and my wife, Holly, being home some days (doing more baking). So our current electricity consumption is about 5-6kWh day, 2kWh of which is being supplied from our 2.5kW solar system, the other 9kWh/day of solar energy that’s generated goes into the grid at 70 cents. Our electricity retailer has been depositing about $1500 a year into our bank account for the electricity we are exporting from the solar system. Any energy we purchase from the retailer is 100% Greenpower too, so although this doesn’t directly power our home it does go towards supporting renewable energy sources. We also have mains gas connected to our Solar Hot Water boost, cooktop and Rinnai Energysaver space heater. Our gas consumption varies quite a bit, from 5-25MJ/day (MegaJoules) during the spring, summer and autumn months through to 40-100MJ/day during winter (the 100MJ bill was the first winter with a newborn). Our bimonthly gas bills range from $30 in summer to $90 in winter.

We built our home through Pivot Homes in Geelong and I think in the end we got a 6.8 star rating for energy efficiency. Pivot were patient with us on the many sustainable design requests that we had and although some of these things were new concepts for them and we had to push them in some areas, we were very pleased with the final outcome. Our home is about 16 squares (150m2) plus the double garage, we found that looking at display homes and talking to a number of builders that the “McMansion” is alive and well in Australia and it was uncommon to find plans for houses under 20 squares. Sizing the house to our needs was important and by keeping a smaller floor space, it allowed us to spend money on other features. It’s basically a three bedroom home with one large open plan living and kitchen area on the north side, two bathrooms, a laundry and a double garage. I work from home and use one of the bedrooms as an office space. Now that Ruby is approaching 18 months, I’m being told that if we have another baby I might need to look for a new office, but at the moment space wise things are still good, the only thing we may be wishing in a few years is that we had built in a study, only time will tell.

Photovoltaic Solar Power System

Because I’m in the solar industry, and I am passionate about renewable energy, a photovoltaic (PV) solar system was always going to be a feature of the house. We installed a 2.47kW CIS (Copper, Indium, Selenium) thin film system, composed of 30 x 82.5W smaller than average modules on our north facing 20 degree pitched roof. The panels were manufactured by Japanese company Solar Frontier and our inverter is a Sunny Boy SB3800 from the trusted German manufacturer SMA. We got a pretty good price for a premium system at the time of about $9,000 (solar system costs have roughly halved since then) and we’re very happy with the system’s performance, pumping out an average of 10.86kWh/day at an efficiency of 4.397kWh/kW. The CIS panels have a special light soaking feature, where they are flash tested off the production line at 82.5W each, but once exposed to sunlight the actual power rating will increase, exceeding the panel’s badge plate rating. Even after nearly three years on the roof, our system on sunny days quite often produces over 3000W of power, I’ve even seen it up as high as 3300W, from a system rated at 2470W it is a great result. So the system is going great guns, but one thing I should mention is that things have changed a bit in the solar industry. The huge reductions seen in the price of crystalline modules over the last couple of years, in combination with the larger number of panels and surface area that thin film systems require mean that it is getting harder for some thin film technologies to compete. Extra costs for panels, racking, installation and fuses come into play. You can now install a larger crystalline system to improve your system’s output at a lower cost than going down the thin film path in most residential scenarios.

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Solar Hot Water

As well as installing a solar power system we also installed a gas boosted solar hot water system (SHW). We chose an evacuated tube system from AAE, 30 tubes tilted up to 60 degrees to optimise the system for winter sun; generally you will get plenty of heating in the summer months, but require boosting from the gas in the winter months. We went with a gas booster and a 315L stainless steel tank for longevity.

Passive Solar Principles

Passive solar design can play a huge role in the thermal performance of your home, orientation, window positioning, shading, ventilation, insulation and thermal mass all are important things to consider. Although our place isn’t perfect we think we got a few of these things right. I found that the website and Renew magazine from the Alternative Technology Association were both fantastic resources for doing research into what things we needed to consider as well as getting inspiration and ideas. We put our living area on the north side of the house and tried to include as many north facing, big double glazed windows as we could to let the winter sun in. We also included one meter eaves on the north side to block out the hot summer sun. This keeps the sun from coming in the windows or hitting our slab in the hottest summer months, but allows the low winter sun through to heat the home when it’s cooler. We also went with a concrete slab for the whole house to help include thermal mass in the design. The concrete is good because it is generally cooler than the air temperature in summer helping to cool the house, and warmer than the air temperature in winter (especially the polished parts exposed to direct sunlight) helping to heat the house. For the outside walls we opted for rendered foam cladding, which has a high insulation value; on top of this we used R2.5 insulation in the walls and R3.5 insulation in the ceiling. The insulation is great as it helps us to contain any heat in the house in the winter as well as insulate ourselves from the outside summer heat.

Heating & Cooling

We didn’t include an air conditioner in the house to begin with, because I expected that we wouldn’t need one, I’m also aware of the large cost that air conditioners place on the electricity grid by increasing peak demand on hot days, this is one of the reasons for much complained about increasing electricity bills. So far weave lasted two summers with minimal discomfort and I’m feeling vindicated. Temperature wise our home normally sits between 17-23 degrees with the highest and lowest temperatures I’ve seen registering at 27 and 14 degrees respectively. We only have one gas space heater in our living area; it’s not really used for eight months of the year, but takes the edge off the winter chill for us when needed, which is usually only winter mornings and evenings as the sun generally heats the house enough during the day. The space heater actually works well enough for us to provide some heat to the bedrooms before we go to bed by opening the hall door and letting the heat travel down the hall. There are also two ceiling fans in the living area and one in the main bedroom; these are helpful mainly on hot days to make us feel cooler.

The positioning of the double garage on the south-west corner of the house was done on purpose to help insulate us against the hot summer afternoon sun; there are also no windows on the west side of the house for the same reason. We do have some cross ventilation from north to south, which we sometimes use to flush out the heat on summer evenings, we just have to make sure the hallway door is chocked, because otherwise you will hear a big BANG as the wind slams the door shut.

Energy Efficient Appliances

Appliances were one of the other things that we had to consider and on moving into our new house we purchased a new fridge and washing machine. The Electrolux fridge was the most energy efficient one that I could find at the time, with an estimated usage of 349kWh/yr it is probably our largest electricity consumer in the house. Our Bosch washing machine was also selected with energy/water efficiency and longevity in mind. When picking lighting for the house I was on a mission not to include any dreaded halogen down lights in our home, a lot of houses that I’ve seen have over 30, 50W down lights installed, which as well as being inefficient, often comes with the added handicap of having square meters of uninsulated ceiling area for heat to escape. We went with good old baton holders and to begin with we opted for compact florescent lamps (CFL) for most of the fittings, however we did also install a few LED lights in the kitchen and bathrooms, which on the most part have been great, although one of them gives off a slightly yellow light. My aim would be to replace these all with LED’s as time goes on, recent technology improvements and price decreases have made this a much more viable option.

Edible Garden

The garden and landscaping has been a constant work in progress for us, sometimes I wish that we had just borrowed some extra money and finished it off to begin with. Before moving into this house I’d had limited experience and success with growing my own food, but food can be a large part of our environmental footprint that we leave on the planet and local food production, I believe, is an important part of the puzzle. We started out with four vege boxes which we rotate with different vegetables across the seasons. Although there have been times when our vege boxes have been neglected, we have had some wins. Tomatoes, strawberries, broad beans, snow peas, spring onions, potatoes, basil, parsley, kale, leeks, mint, oregano, rosemary, corn, chives, cucumbers, chillies, capsicum, eggplant, carrots, beetroot, spinach, lettuce, broccoli and pak-choy have all had a run in our vege boxes, some with more luck than others. An honorable mention goes to the zucchini plague of 2012, where we were inundated with zucchini’s for weeks on end, we couldn’t eat them quick enough or give them away fast enough, by the end of it Holly was sick of cooking them and wrote a great blog post called zucchinis 7 ways in 7 days, on some of the recipes we used.

Zucchini Plague

Along with the vege boxes, we’ve planted a few fruit trees, we had about 100 Gala apples off our dwarf apple tree this year and our lots o’ lemons tree is currently living up to its name, the lime and nectarine tree have been more reserved in their offerings and more recently I’ve purchased a blood orange, lemonade and mandarin, which upon writing are yet to go in the ground.

As far as dealing with food waste, we have got two worm farms going that eat up most of our vegetable scraps, turning them into rich usable compost for the garden. We’ve also experimented with a Bokashi bin, which allows you to include meat scraps for composting as well, but this is currently not in rotation due to us running out of the sprinkly stuff you put in it to help the bacteria “pickle” the contents. We have also installed a 5000 Litre water tank which helps us water the garden as well as supplying water for the toilet and laundry.

As I mentioned at the start there a few things that we would probably do differently next time and a number of things on the to-do list. Grey water is an area we have yet to delve into, chickens will still require a bit of convincing for my wife (although I think I’m nearly there). Wooden window and door frames next time, instead of aluminium due to the high conductivity of the aluminium, the double glazing is doing its job, but is being partly undermined by the heat let into the house through the frames in Summer, more LED lighting and more time in the garden are also on the list. One major thing that I feel was a mistake and I would change if I had my time again is the gas, I’m saying this because I’d like others to consider this when building. The heating itself and the costs are great, but on a larger level the idea that gas should be used as a transition fuel I think is flawed. I agree with Beyond Zero Emissions argument that we need to make a rapid move towards a renewable energy and energy efficient future by electrifying our buildings, and instead of wasting money on gas that will need to be transitioned away from at some time in the near future, we should be spending this on moving towards renewable energy sources to start with. If I had the choice I would put an energy efficient reverse cycle air conditioner in, to be used solely for heating.

I guess that covers a large part of what we’ve been trying to do around the house to live a more thoughtful and environmentally conscious life. The benefits have been great, reduced costs on our electricity, gas, water and food bills and an insight into living a less wasteful life a little closer to nature. Come along on Sustainable House Day, Sunday September 8th 2013 to check it out, the Surf Coast Energy Group and Geelong Sustainability Group have houses open across the greater Geelong region.


Aaron Lewtas


Green Energy Options

Solar Panels and Shade

Shading can have a big effect on the performance of your solar power system. The amount of shading and the time of day may determine whether it is worthwhile putting solar panels on at all. Small amounts of shading at the start and end of the day may have minimal effects on output due to the losses being imposed on a reduced initial output. Ideally you want to have clear access to sunlight during the middle of the day between 9am to 5pm. Clouds will reduce the output of your solar system, but the panels will still receive dispersed light, its direct shading from trees, vent pipes and other objects that are of most concern.

Below is an example of electricity flow in a solar panel affected by shading.

The best way to assess the impact of solar on your rooftop is to have a shade analysis done. Green Energy Options use a SunEye to assess the impact of shade on your rooftop. The SunEye is a professional tool that takes a photograph of the surrounding objects through a fish eye lens, it then lays a sun path chart across the image showing the time of day and time of year that shading affects the location being assessed. The impact of shading for each month of the year is then calculated. We include the shading report in our estimates on your solar system’s output giving you an indication on how we expect your system to perform. Generally once you get above 10-20% of shading you need to consider if the solar system is going to have the effect that you intended, our aim is to put you in a position where you can make an informed decision.


SunEye Shade analysis

SunEye Shade analysis

It is important to be aware that in a standard solar system with a string inverter and 10 panels, shading on one panel can have a “weakest link” effect on the rest of the array, reducing the output of the whole string of 10. One option for reducing the impact of shading is to use micro-inverters. Micro-inverters individually optimise the output of each solar panel, so that shading on one panel doesn’t affect the output of its neighbors.


Shading micro-inverter vs string inverter

Shading micro-inverter vs string inverter

Image courtesy of Greenstar Micro-inverters

Green Energy Options can provide a detailed shade analysis of your site as well as options for both string and micro inverters. Give us a call to find out how you can go solar 1300 931 929.


Solar Panel Efficiency

Most commercially available solar panels have efficiencies around 12-17%. Thin film panels mostly are at the lower end, with crystalline panels at the mid to high end. But what does a high efficiency rating actually mean? Does a high efficiency panel mean that your solar system is going to generate you more kWhs? Not necessarily, here’s why.

Polycrystaline solar cells

Polycrystaline solar cells

The panel’s efficiency rating is based on the amount of the sun’s energy that it can convert into electricity. On a clear day the sun dumps about 1000 Watts of energy per/m2 at sea level. If a panel has a 15% efficiency rating, it means that 15% of that energy is turned into electricity. So if the panel was 1m x 1m it would be 15% of 1000W or a 150W panel. These days, most panels are around 250W and have a larger surface area, more like 1.7m2.

So what happens if we have a high efficiency 250W panel of 20%? Basically the surface area gets smaller; a 250W panel at 20% efficiency has a surface area of 1.25m2. Both panels have the same output – 250W, but are different sizes. So in terms of the way a system with high efficiency panels performs, compared to one with lower efficiency panels, if all things considered are the same the output will be the same. In a 3kW system with 12 x 250W panels, the lower efficiency panels will just take up a larger area – 20.4m2 compared to 15m2.

When you are deciding on which solar panel to choose, there are a number of things to consider. A high efficiency panel can be a good option if you have a restricted roof area, but if you are looking at system performance there are other factors to take into account.

Green Energy Options offer a range of different solar panels including the Sunpower E20/327, which at 20% efficiency, has the highest efficiency of any commercially available panel. If you would like to advice on solar options for your property please give us a call on 1300 929 931 for a free consultation.

Solar panel orientation

Which is the best direction to point your solar panels?

It’s an interesting question and you would think the answer is pretty simple – NORTH.

In many cases you’d be right, a north facing solar array will generate more electricity than an array that faces east, west or south. In Geelong, putting panels on an east or west roof will normally result in a loss of around 15%, compared with a north facing array on a 30 degree pitch. Many people are surprised by how small this loss is and it certainly doesn’t rule out these options. It’s  recommended however to steer away from south facing panels where possible, where losses are in the range of 30-40% on a standard home’s roof pitch.

Solar panel oreintation

With the introduction of lower feed in tariff (FIT) rates for your solar electricity that’s exported to the grid, an interesting discussion about solar panel orientation has come about. Should we be facing our panels west?

Sure a north facing array generates more electricity than one that faces west, but it generates the peak of it’s generation for the home in the middle of the day. For the average working family that has a low electricity consumption during the day it could mean that a lot of the electricity generated is being exported to the grid at the current FIT rate of 8c/kWh. The theory is, that if you were to face your panels west, they would generate more electricity later in the day, when you are more likely to be using the power. In this case you would be able to offset the cost of buying electricity from the grid at the going rate (often over 30c/kWh), which is more valuable to you. This is true particularly in summer when solar production is higher and the daylight hours are longer extending into dinner times.

Another related argument for pointing panels west comes from a Renew Economy article where Adam McHugh, a lecturer in energy economics and energy policy at Murdoch University, where he suggests that pointing solar panels west, would correlate the systems output with times of peak demand on summer afternoons. On hot sunny days when everyone turns their air conditioners on, west facing solar panels would be producing electricity. West facing solar has the potential to compete with the distribution network and expensive peak generators by reducing the cost of supplying electricity particularly during peak demand events.

The orientation of your roof and available space may be the deciding factor in the end, but it’s good to know that there are normally a couple of options. A good solar installer will give you a comprehensive analysis of your solar systems production as part of your quote. This should show average daily kWh estimates broken down monthly and for the year based on your roofs orientation and pitch.

For more info on panel orientation or the potential of you roof give Green Energy Options a call on 1300 931 929.

Six Solar Tips

Six solar tips to consider when buying a solar power system

There’s a lot of information out there in solar la la land and if you are new to solar, it can be tricky to sort through and find the answers you need. I’ve put together a list of six solar tips to help give you a good start on things to consider when buying a solar power system. Here we go…

1. Find out who manufactures the solar panels and inverter.

Do your research. Does the brand have a good name? What have other people’s experiences been like? Some companies are reluctant to give you this information and some are using cheap rebranded or “lucky dragon” panels which have only been on the market a couple of years and substitution of lower grade materials is not unheard of. Choose an installer that is transparent about the components they use and stick with well-known brands that have an Australian office for warranty issues.

2. Make sure you’re happy with the installation company.

Who are they? Are they close to you? What have others said about their service? Are they members of any industry bodies Clean Energy Council (CEC), Australian Solar Council (ASC), Solar Energy Industries Association (SEIA) or the Alternate Technology Association (ATA)? There are a lot of solar installer reviews online if you want to find feedback. Also watch out for the hard sell sales tactics, steer away from anyone trying to get you to make your mind up on the spot.

3.      Don’t buy the cheapest solar system you can find.

Obviously price comes into the equation at some point when you are buying a solar system, but like anything, you get what you pay for. There are many ways to cut costs in a solar business, I could purchase the cheapest panels/inverters that I could find, I could squeeze my installers on the installation cost, buy cheaper isolators, cabling or other balance of system components, or I could skimp on the resources I put towards customer service and post installation backup. Either way, by compromising on the above things you may find you end up with a less than average solar system or less than average solar experience. You don’t have to buy the most expensive option to get a good system, but don’t buy the cheapest!

Ballarat Solar Installation

Ballarat Solar Installation

 4.      Don’t compromise on the inverter.

50% of all system failures have something to do with the inverter. There are heaps of cheap options out there now, often at less than half the cost of the good stuff. Our suggestion is, it’s not worth it, buy a good quality inverter – some examples include SMA, Aurora or Xantrex. If your panels are going to last 25 years+ you don’t want to have to replace an inverter every five years. There are also some fantastic micro-inverter options becoming available, these generally come with stronger warranty periods, better system monitoring and safety and performance benefits.

 5.      Take your warranty with a grain of salt.

Although warranties are an important aspect of buying a system  nearly all panels on the market have a 25 year performance guarantee, stating that the silicon will degrade at a certain rate over time, with the panel still producing a minimum of 80% of its initial output after 25yrs. Note that the panels also have a materials and workmanship warranty normally in the range of 5-10 years. Inverter warranties are normally between 5-10 years with some micro-inverters offering up to 25 years. Then there’s you installation warranty from the installer which usually is 2-5 years. The one thing to be aware of here is that the warranty is only as good as the company behind it, if they go into liquidation or are taken over by another business, you might find yourself left high and dry. Some big panel manufacturers and installation companies have gone bust or dropped out of the solar industry recently, so be careful. Our best advice is to read the fine print, stick with good quality components to minimise the need for warranty claims and go with a company that has a track record and you feel you can trust.

 6.      Size the system to cover your daytime usage.

In Victoria, the Feed in Tariff is now a minimum of 8 cents per kWh. The price you are paying for electricity is probably up around 30 cents kWh. This means you don’t want to oversize your system too much, as you won’t be paid very much for the excess power that you’re not using directly and exporting back to the grid. If you size your system right, you will get a better return on investment and quicker payback period. If you need some help here we can give you some advice. Note that there is currently a great niche for many businesses that use power during the day to capitalise on the benefits of solar power.

I hope the tips help. If you have any further questions, or are after some advice please feel free to give us a call on 1300 931 929.

Cheers Aaron.