FAQ’S on Solar
Here at Green Energy Electrical we’re firm believers in educating you and therefore de-mystifying the complex world of solar so that an informed decision can be made. So before you jump into the world of solar, we’ve put together some frequently asked questions and a glossary of terms to help.
What happens if a solar panel is shaded?
Put simply, if your solar panels are being shaded daily its going to reduce the efficiency of your solar system. Each panel has bi-pass diodes so when a panel is shaded that panel is simply bi-passed as if it was not there. A problem occurs when too many panels are shaded and the voltage level drops low enough for the inverter to switch off. Any consistent shading (occurring on a daily basis) on your panels will reduce the effectiveness of your system therefore loss in energy production can add up making the pay back of the system longer.
Can I remotely monitor the production from my solar power system?
Yes. Some inverters can be connected to the Internet and therefore can be monitored from anywhere in the world. Other inverters have a Wi-Fi or blue tooth display unit that can be put in the house to produce real time read outs. Speak to us about the type of inverters that offer this.
How do I read my electricity meter?
Your meter will be replaced with a digital meter that has two modes: import and export. The screen on the meter will alternate between the two readings. There will be a positive display, which will show your accumulated imported energy to the system from the network. The negative display shows accumulated exported energy from your system to the network. Both readings will be displayed in Kilowatt-hours.
What about hailstorms?
This is an obvious concern considering the storms we experience in Queensland. To answer the question we need to explain the different glass used in solar panels. Quality solar panels are made from tempered glass. Tempered glass, also known as safety glass or toughened glass, is anything up to six times the strength of normal plate glass. It is created by thermal or chemical means and is tested to withstain the impact of hailstones. When tempered glass does break, it shatters into small pieces rather than into large, razor sharp shards as standard plate glass.
Standard plate glass can still be found on some cheaper brands of monocrystalline and polycrystalline panels made by small, unknown companies. On most brands of amorphous (thin film) solar panels, manufacturers can try and make it stronger by using thicker plate glass, but it’s nowhere near as strong as tempered glass. Also with plate glass it can cloud over time, which greatly reduces the solar panels power output. So the moral of the story is its best to invest in quality solar panels compared to cheaper, unknown brands. When buying solar panels it should be clearly stated on the product specifications the type of glass used, if not, it’s highly likely to be plate glass. Quality solar panels are made from tempered glass and designed to withstand hail. Green Energy Electrical only uses solar panels made from tempered glass to ensure longevity of your system.
Will my solar power system produce power on overcast or rainy days? And what about a black out?
Good news, your system will produce energy on overcast and rainy days just at a lower level. Interestingly, the polycrystalline panels (multi) are better performers in low light situations. In a black out your inverter will sense that there is no grid voltage and will shut down, unless you have batteries.
Why type of maintenance is involved once the system is installed?
Rest assured, there is very little maintenance involved in owning a grid connect solar system. It’s recommended that every 6-8 months the surfaces of the solar panels are cleaned. Any dust and grime on the glass will prevent sunlight shining through and as a result the system’s efficiency will decrease. Dirt on your solar panels will greatly reduce your energy production. No sun = No power. To clean your panels we recommend using tap water with no detergents. For your inverter, check that there is enough space around it so that it remains cool, and make sure there are no spider webs or rubbish on top or surrounding the inverter. When performing your maintenance checks ensure that the system has been shut down. Green Energy Electricalreminds you that going onto a roof without the proper safety equipment and training puts you at risk of injury. We’re happy to service your solar system, please contact us for a quote.
Roughly, how much roof space do I need?
A solar panel is approximately 1 x 1.5 metres squared and are approximately 250 watts each. As a rough guideline for a 2.5kW system you’ll need 15 square metres with enough roof space around the panels for servicing.
How much power will I get from my system?
You must remember that each and every home and business is unique to their individual solar system. After an on-site analysis, Green Energy Electrical will put together a comprehensive quote of a tailor made system based on your requirements and budget. This no-obligation quote will include the estimated energy output of your system including average daily out-put and annual output.
While taking into consideration the contributing factors that can jeopardise the effectiveness of your system: roof orientation, shade or dirty panels, roof pitch and weather conditions. The Clean Energy Council (put link) advises that if your home has a north-facing, 20 degree pitched roof that isn’t effected by shade then you’ll get 6.4kW on average per day from a 1.5kW system, 8.6kWh on average per day from a 2kW system.
How can I tell if my roof is suitable for solar?
With an on-site inspection we’ll be able to determine the orientation of your roof (ideal orientation for a system is true north), roof pitch and surrounding shade. Once these contributing factors have been assessed we’ll be able to determine whether a system is warranted. Green Energy Electrical prides themselves on only installing systems that achieve maximum energy output unlike other solar companies who are happy to make the sale regardless of the effectiveness of the system. Please note, we don’t install on asbestos roofs.
Importantly, what cost savings can I expect from a solar system?
Unfortunately this isn’t a simple answer as it depends on your current electricity bill and the size of the system installed.
How long will it take to install my solar power system?
As to not disrupt your home or business life, Steven and his team will install the system in one day (6 to 8 hours), depending on the weather. This is a real plus choosing a boutique solar company compared to national companies that can take a couple of days to install a system.
Is there a warranty if I purchase a system through Green Energy Electrical?
Good question and we’re pleased to answer yes! There is a 10-year manufacturing warranty on your solar panels and 25-year performance warranty at 80% output. Depending on your choice of inverter there is a 5-year warranty with the option to purchase an additional 5 years. And finally, Green Energy Electrical offers a 5-year warranty for work carried out on your system.
Will my system work at night?
No. Once the sun has set your system will shut down for the night. If you watch your inverter at dawn and dusk you will see and hear it performing a series of tests before it either goes into sleep mode for the night or starts up ready for another day of generation. At night your home will be consuming power off the mains grid. Don’t worry, this transition happens seamlessly without any input from you.
Who will buy my excess power?
It depends on which state you’re in and who your electricity provider is. As you would of heard, here in Queensland we have a new feed-in tariff of 8 cents. So your electricity retailer will purchase any excess solar generation that you export back on to the grid. Your electricity retailer will credit your bill with the amount of electricity exported. Homeowners have the option to either leave this credit on their bill or can ask for it to be paid in the form of a cheque. We recommend shopping around to obtain the best feed-in rates as retailers like Origin, AGL, Integral Energy offer different rates.
Do the panels need to be mounted on my roof?
Generally the best location for your solar system is on your roof, however if you have the room we can assemble a specific ground mount system.
What does the terms ‘Grid Connect’ and ‘Off-Grid’ mean?
Grid Connect is when your solar system is connected to the grid and excess power that is created is exported back into the grid.
Off-Grid is when your solar system is totally independent of the main grid and is equipped with a battery bank that will store excess power.
Grid-connected system: PV systems generate energy from sunlight during the day. This energy goes into a grid connect inverter which converts the DC current into AC current, similar to that of the grid. This solar electricity current can then power all the appliances in your home, such as cooking appliances, phones, computers, lights etc. Power can be drawn directly from the solar inverter and any leftover electricity can then be fed back into the grid. If you use more electricity than what is produced by your grid connected solar system, than power will simply be taken from the main distribution grid. On the other hand, if you produce more energy than what you use, then you are credited for the surplus on your electricity bill. Some electricity retailers offer net billing, meaning your supplier buys the excess power you produce for the same retail price they charge you.
Grid connect systems differ from stand-alone solar power systems as they eliminate the need for a battery back-up. At night or during cloudy weather you can draw electricity directly from the grid. To install a grid connect solar PV system, you need sufficient space on your north-facing roof.
Solar module (solar panel): Interconnected solar cells encapsulated and protected behind transparent materials that protect against humidity, air and mechanical damage. Normally solar modules are made with a glass front, a polymer back sheet and aluminium frame. The photovoltaic module, more commonly known as the solar panel or solar module, is then used as a component in a larger photovoltaic system to offer electricity for commercial and residential applications.
Inverter: A solar inverter is a device that transforms DC battery or solar panel voltage into mains type AC power therefore suitable for use by regular appliances. A solar inverter is the heart of your solar system, but attention to this aspect is often overlooked. You can have the best quality solar panels available, but if your solar inverter is of poor quality, the overall system performance can be greatly impacted.
Photovoltaics (photo = light, voltaic = electricity): Solar cells are made of silicon. When a photon (particle of sunlight) strikes a molecule within the solar cell, an electron is knocked free. An electrical field causes this free electron to move to one side of the cell. The accumulated effect of millions of this interaction generates electricity.
mW (megawatt): a megawatt is 1 million watts.
kWh (Kilowatt Hour): one kilowatt of solar panels that receives one hour of sun equals one kilowatt hour.
kW (Kilowatt): Unit of power equivalent to 1,000 watts.
Grid Parity: is when solar cells can produce electricity at the same price as the electrical energy you can buy off the grid, (or less) without subsidies or feed-in tariffs.
Energy Payback time: means the length of time that a solar panel will take to produce that same amount of energy that was used to make it.
There are three main types of solar cells:
Monocrystalline silicon is the most efficient and produces the smallest solar cells and therefore the smallest panels. Monocrystalline solar panels also tend to cost the most due to their efficiency. Green Energy Electrical uses CSUN/CEEG.
Polycrystalline (or multi-crystalline) silicon produces the next most efficient type of solar cell and is the most popular choice as it provides an excellent balance of performance and cost. Recent improvements in polycrystalline panel technology are bringing these modules closer to monocrystalline in size, efficiency and heat tolerance characteristics. Interestingly enough, the European market has now adopted polycrystalline as the standard. One of the world’s leading producers of polycrystalline panels is REC, which Green Energy Electrical recommends.
Amorphous (or thin-film) silicon uses the least amount of silicon and panels are among the least efficient. We’ll only use this type of solar cell upon client request.
Still confused? We’re happy to answer your questions via email, via the phone (04211 62007) or in person.