Are you interested in upgrading/expanding your solar power system? Here are a few things you may want to know

44 cent Feed in tariff customers – This is a worthwhile exercise in most cases. Especially if you are fortunate enough to be on the 44 cent feed in tariff. It would usually take 2 years for an upgrade to a solar power system to pay for itself in revenue generated.

8 Cent Feed in tariff customers – This depends on your power usage and if you are using more power during the day than you were when you installed your existing system. If you are using more, it would be worthwhile. If not then we would not recommend it as there is no financial gain to be made as you are only going to get 8 cents per kWH you export in to the grid.

Here are some points to consider

• How much more power can the inverter take?

• In some cases people have installed a larger inverter with the intention of adding solar panels to their system at a later date. In this case an upgrade would be relatively simple as long as the initial installation was done with the possibility of an expansion in mind.
• Inverters that have the max power going in already can also be upgraded. This is known as oversizing. This is a common practice in the solar industry today. An example of oversizing is installing a 5kW inverter with 6.5kW worth of panels. We are able to do this because panels will hardly ever put out their maximum power in the real world due to a number of factors such as weather, angle of the sun, temperature, voltage losses in cabling etc. Oversizing your system will just make the inverter sit at or close to its max power output for a longer period in the day. (more excess power to be sent back to the grid)

• Can I upgrade my inverter to a larger capacity inverter?

• If you are on the 44 cent feed in tariff the answer is NO! If you do this you run the risk of losing your 44 cent feed in tariff and being reduced to 8 cents. When your initial installation took place an application was sent in to Energex/Ergon and you were approved for a certain size inverter. If a larger inverter is installed and energex picks up on this, they will cancel the 44c incentive with immediate effect. (They do check)
• If you are on the 8 cent feed in tariff you are able to upgrade you inverter if you wanted to. Another application would have to be placed with Energex/Ergon and once approved the upgrade can take place.

• How much roof space is there?

• This sounds pretty obvious but I feel it needs to be mentioned. A lot of the time if you are interested in upgrading and you call a number you saw on the TV or in the paper you will be given a quote. Should you chose to accept they will ask for a deposit, only to arrive on site and find that there is not enough space on the roof to add the extra panels. (Get someone out to take a look at your roof)
• In most cases the new panels will have to face the same direction as the existing panels to ensure that the system is as efficient as it can be. If they are facing different directions it would affect the generation quite drastically as not all of the panels are receiving the same amount of light. String inverters work off the lowest performing panels in a string. If a group of panels are getting less light they will in turn produce less. As a result the rest of the panels, in full sun or not will drop down in production to match the lower performing panel/s.

• How old is the existing installation?

• An older installation may require a complete rewire with the addition of roof top isolation, earthing and other items to bring it up to the latest standards. It is important to get the right advice. In most cases however the initial installation would be up to standard.
• Older installation may have used solar panels that are no longer available or being produced. 5 years ago 170W – 190W panels were the common panels used. Now the most common panels are 250W panels. These lower wattage panels can be hard to come by in the market today and in some cases are simply not available. Don’t be disheartened as there are still options available to you if you have the older panels.
  Take 180w panels as an example. If we are asked to do a 2 panel upgrade on a system with 180W mono crystalline panels we would simply use 2x 200W mono crystalline panels as the voltages and currents of the panels are very similar. We would not be able to use a 250W mono panel as the voltages are too different.

• What if a suitable matching panel cannot be sourced?

• In this case we would look at the installation and determine whether the inverter has two inputs with two MPPT trackers. If it does, then a simple rewire could be done placing all of the existing panels on one input and adding the new panels to the second input. This would have to be determined by the person assessing the job.
• If the inverter is a single string inverter with one mpp tracker then the only option is to remove the old panels and sell them privately and replace them with new panels. In a lot of cases people would snap these older panels up due to the shortage on the market.

 
If you are considering expanding your solar power system then we would suggest getting the right advice. Get someone out to your place and let them check what options you have. A lot of anger and disappointment will be avoided if the existing system is inspected and the installer knows exactly what he is dealing with. Don’t rely on quotes where the site is unseen. How can someone tell if upgrades are needed to the cabling etc if he has not seen the job.
Here at Evolution Solar Sunshine Coast we offer obligation free site visits in and around the Sunshine Coast. Give us a call and you will not be disappointed.