Supply and Install the
Now that you have received the design proposal from Brightcell detailing your energy usage, solar panels location, layout as well as capacity of your inverter, you may be wondering how to proceed from here.
Even with these solar solution recommendations, there are still brands from different manufacturers that offer products meeting the criteria set in your proposal.
As highlighted in Design a Suitable Solar Solution, the inverter is one of the most important components of your solar power system, and it is possibly one of the costliest components as well. Therefore we cannot stress enough the importance of investing in a good and reliable inverter. Having said that, there are a few types of inverters in the market, offering different installation configurations, as well as pros and cons. The cost varies from each other as well.
The first type is the most commonly installed in Australian household. As the name goes, a string inverter converts DC generated from a series of connected solar panels in a string pattern to AC. The panels that are connected in series generate relatively high voltage DC. As the Ohm’s law goes, higher voltage system reduces the current flowing through the system, significantly reduces the cable size required to carry the same amount of electrical power, and avoiding significant power lost due to cable resistance.
However, high voltage DC introduces high heat to the inverter itself, resulting in higher risk of inverter failure and fire hazard if it is of poor build. Therefore, if this set-up is chosen for your solar power system, it is paramount to ensure you get a reliable inverter brand.
It is also important to note that while this set-up offers high efficiency with minimum power lost, as the solar panels are connected in series, the maximum power output is limited by the lowest output of any one of the panels. Therefore, if you have 2 panels of which one of their output is at 50% due to shading or dirty surface, the output of the other panel is reduced to the same as well, even though it is technically capable of more output. Same goes that if one of the panels, or even the inverter is out of service, your solar power system would not be generating any electricity.
String Inverter with Power Optimisers
As mentioned above, power output of traditional string inverter array system is vulnerable to a variety of conditions. Any imperfection such as shading or broken panels can significantly reduce solar power energy production. By adding power optimisers on each panel, the performance of each panel is optimised and essentially the total power out can be maximised. With this system, customers can enjoy the benefit of lower cost using a string inverter, as well as individual panel optimisation. Examples of common manufacturers for inverters with power optimisers are SolarEdge and Tigo.
As the name suggests, a micro inverter is simply a small inverter, designed to be connected directly to each individual solar panel. Therefore, a typical household solar system with micro inverter array set up is very likely to have a few micro inverters. Micro inverters were invented to counter issues encountered by string inverter array as highlighted above.
A micro inverter converts the DC output of each panel to 240V AC, significantly reducing the risk of fire hazard. Furthermore, any efficiency drop or failure of any solar panel or inverter would not impact the entire solar power system, as other panels can still contribute to power generation independently. This means you are unlikely to encounter total system failure, unlike the string inverter array. Each faulty component can also be rectified independently, while still having the system online.
However, it goes without saying that nothing is perfect in this world, and so does the micro inverter array set up. Micro inverter system costs significantly more than a string inverter system for an identical power output, and limitation of present technology means that a micro inverter is still less efficient than a string inverter in converting the current. Enphase is currently the leading manufacturer of micro inverters.
Do not hesitate to contact Brightcell and have a chat with us for more information on the topic of inverters.
Solar Photovoltaic Panels
The next big budgeted item on the list is no other than the solar panel itself. Solar panels take quite a lot of abuse during their life span as they are constantly exposed to weather. In Australia where it is possible to enjoy the freezing cold of winter, while having the sun unopposed by cloudless sky and shining brightly, one can imagine the temperature variant these panels are subjected to.
Therefore, quality and warranty of the panels should be your top priority when shopping for solar panels. Careful to check the terms and conditions of their warranties, the extent of damage covered, duration of warranty, and after-sales support.
As for quality, double check the datasheet for the efficiency, as it strongly indicates the quality of panels you are getting. Commercially available solar panels have range of around 5% - 20%, give or take. Needless to say, the closer it is to 20%, the better the products you are getting.
As ironic as it may sound, solar panels lose about 1% of efficiency for every 2-3 degrees Celsius increment in temperature. To put it bluntly, too much sun is not really good for solar panels as well. Therefore, coefficient of temperature is another figure to look out for. Coefficient of temperature of commercially available panels ranges from around 0.2 (very good!) to around 0.5 (not bad), so know your number!
Quite often, quality means higher price tag, but the market is highly competitive in Australia that there may be a reputable manufacturer offering great discount with great quality around the corner. So before you give it a miss thinking it is another con job, “consult us” (link to contact) at Brightcell and let us do the checking for you. Commonly available brands in Australia are Canadian Solar, Trina, LG, and Jinko to name a few.
See our Completed Projects page for visual understanding of good quality installations.
Contact Brightcell Energy for more information and enquiries for your solar panel solution today.