FAQ
What are solar photovoltaic (PV) panels?
Solar PV panels are made up of a group of silicon cells to create an electronic device that captures and converts sunlight into electricity. They have no moving parts, work silently, and produce electricity from a renewable resource: the sun. Hence, photovoltaic panels are electronic devices similar to the components used in computers. They are like mini power stations on your building.
Do solar photovoltaic (PV) panels directly heat hot water?
No. Photovoltaics use the physical property of light, called photons. They do not use heat. In fact, in extreme heat the efficiency of a solar panel will decrease.
What then are solar hot water systems?
Solar hot water systems do not use photovoltaics. They simply put water on the roof in collector pipes where the water can absorb the heat from the sun. Solar hot water systems can easily be confused with solar panels, as they are both referred to as ‘solar’ since they both use energy from the sun. The difference is that solar panels use the sunlight only (not heat) to generate electricity, while solar hot water systems use the sun’s heat (not the light) to heat water.
What is an inverter?
The inverter converts the power that the panels generate from DC (direct current) to AC (alternating current) power so that it can be fed into the public electricity grid.
What are grid-connected PV systems?
Grid-connected PV systems are the most common system type. These systems feed the electricity they produce into the electricity network. They have no ability to store the electricity they produce.
What are stand-alone PV systems?
Stand-alone PV systems are not connected to the public electricity grid. They do not have a meter and the electricity they produce cannot be sold. These are a less common type of system and are usually only installed in remote locations in order to power, for example, remote telecommunications equipment or in order to be used for water pumping in remote locations.
How long does it take to install a grid-connected PV system?
A grid-connected PV system is installed in one day with the solar meter usually being installed in the following few days, once approval from the electricity infrastructure provider is obtained.
Can a grid-connected PV system power a house?
Your system can be sized to generate the same amount of power as your house uses, or lesser amounts. A 1.5kW system generates about 6kWh per day, on average. If your house consumes 10kWh per day, this system can provide 60% of the power the household uses. You can increase the % of power your solar system provides by lowering your energy consumption. This is easy to do with some simple energy efficient changes. Blue Green Engineering can provide an energy efficiency assessment to pin point real savings for you.
Which solar panels should I choose: mono, poly or thin film?
The difference between these technologies is their efficiency. Mono-crystalline panels have the highest efficiency, followed by poly-crystalline, with the thin film being the least efficient panels. Efficiency is important to consider. Using mono-crystalline panels means you need less roof space than you would if you chose thin film. For example 1.1kW of mono-crystalline panels covers 7.5 square meters, while 1.1kW of thin film amorphous silicon would cover 17.3 square metres. If you have a limited roof area, mono-crystalline panels will give you the most powerful system and therefore the highest output for the given area.
Which sized PV system should I get?
This depends on what you want to achieve and on the roof area available to you. Speak to one of our engineers to discuss your electricity use. You could have a system that reduces your bill or one that brings it to $0.
How much roof space does a grid-connected PV system take up?
A typical solar panel has the following dimensions: 1.6 x 0.8m or 1.3m² each. A 1.5 kW system, which is eight panels, would therefore be 10.4m².
How much electricity does a grid-connected PV system produce?
A small system (1.1 kW, 6 panels) produces 4.5kWh of electricity, on average, each day. Our engineers can give you an estimate of how much a system could produce for you, based on the location and system size you choose.
What happens during a power blackout (with regard to PV systems)?
The inverter detects blackouts. By law a solar system must not feed power into the grid during a blackout, as it can be dangerous. When a blackout occurs, the system is switched off at the inverter and does not produce power. For this reason, a grid-connected solar system cannot be used as a back-up system during a blackout.
What happens on cloudy days (with regard to PV systems)?
A solar PV system generates electricity from the sun’s light, not heat. Therefore, it performs best when the panels are in direct sunlight. Cloud and shade from trees decrease the output of the system.
What happens at night time (with regard to PV systems)?
At night the panels do not produce power. When the inverter detects there is no power coming from the panels, it shuts the system down until it is light again the next morning.
What is a solar meter?
Solar generation is measured by a solar meter. This is similar to a house electricity meter and is installed in the same meter box as the electricity meter. While our electrician is working on the meter box, your electricity provider may require we upgrade parts of your meter box. We will notify you during our site visit if this is required. We include solar meter work in our final price to you.
Do solar panels break in a storm?
International certification authorities independently test panels. Some of the many rigorous tests conducted on panels ensure panels are rated for wind loads and hail.
What government funding is available for solar systems?
There is still government funding available for solar photovoltaic systems. These are one-off payments called Small-Scale Technology Certificates (STCs). Blue Green Engineering includes the value of these in our quotes and handles all paperwork on your behalf. The funding is not means tested and depends on the size of your system. For more information, see our funding section. (Neal to add the link to the funding page)
What is an STC?
An STC is a Small-Scale Technology Certificate. This is a tradable commodity that the government issues for installing renewable power generation. You can hold your STCs and sell them at later date or you can assign them to us and we will deduct them from the price of your system, reducing the amount you have to pay.
How do I access the government funding for solar systems?
Blue Green Engineering handles all government paperwork for you. In fact, we deduct the government funding from our price, so that you don’t have to wait for cheques from the government to arrive. For more information, see our funding section.
What is the life expectancy of a solar system?
Panels have a 25-year performance guarantee. Some panels are still performing after 30 years. If installed and cared for properly your panels can last decades.
Does a solar system have batteries?
No. Grid-connected systems send all electricity into the electricity grid or to be used in the house/premises. There is no electricity storage or batteries.
What roof types are solar panels put on?
Solar panels can be easily installed on metal and tile roof types. Slate and asbestos roof types are not suitable for solar PV panels. Each panel weighs around 16kgs and is mounted in framework which is fixed to the load bearing structure of your roof.
What maintenance needs to be done to a solar PV system?
Almost none! There are no moving parts and the only maintenance needed is to check everything is secure and clear of debris once a year.
How can I find out how much my system is generating?
The inverter unit has a display screen where you can read statistics about your system. We also sell a portable monitoring station, the ENVI, which will allow you to view your data from the web. For more information, see our energy meters sections. (Neal to add links to the two pages: 3.3.5 and 4.3.7 for Homes and Businesses/Government)
What is the feed-in-tariff (FIT)?
The feed-in-tariff pays you for the electricity you generate. Just as you pay power stations owners for the electricity they generate for you to use, your electricity retailer will pay you for electricity you produce. There are two types of FIT: gross and net.
What does gross or net FIT mean?
Which one is best for me?The gross FIT will pay you for all electricity generated. The net FIT only pays you for excess electricity. Power from your system goes to your house first. If there is excess power, this will go to the grid and you will be paid for it. A gross FIT generates more cash for you if the rate is higher than the rate you pay for electricity.
Is my roof suitable for a solar hot water system?
The best spot for a solar hot water system is in direct sun and facing close to north. The roof-mounted part of the system weighs 120kgs, so most house roofs are fine.
What happens to a solar hot water system when it’s not sunny?
Blue Green Engineering solar hot water systems have a booster to make sure there always is hot water. This booster can be electric or gas and raises the temperature of the water on cloudy days or heats water when the full tank has been used.
How long does a solar hot water system installation take?
Weather permitting, installation can be done by two installers in one day.