How does a solar system work?
The majority of solar electric systems are grid-connected; i.e. they are connected to the main power grid via an inverter.
The inverter converts Direct Current from your solar panels to Alternating Current and delivers that energy to your switchboard in a form which matches power from the grid. If power from the grid is lost, the inverter must automatically shut down to isolate the solar system; it will start itself again when grid power is restored.
The inverter constantly monitors grid Voltage and frequency and has in-built safety features. A high quality inverter is crucial for the safety and performance of a solar system.
What size solar system should I install?
A system size that maximizes your return on investment will depend on a number of factors, but a good place to start is with your current electricity usage. In Melbourne, the AVERAGE DAILY electricity generation of a solar PV system is about 3.6-3.8 kWh per kW of installed capacity.
Other important factors influencing solar generation are the available roof space, its orientation in relation to North and potential shading.
With export feed-in tariffs now reduced to minimum levels it’s also important to consider when you use power through the day, as well as a system size to maximize your payback.
I’d like to go ‘Off-Grid’ – is that a good option?
‘Off-Grid’ or ‘Stand-Alone’ solar systems are installed where it’s impossible or impractical to connect to the main power grid.
If you’re already connected you don’t have to go off-grid to minimize utility costs. A smarter option is to use battery storage to store excess solar generation during the day and then use that power to extend your usage of solar energy. A ‘smart’ inverter will automatically manage operation of the system and ensure you get the most from your solar energy production.
What happens to my solar system when it’s cloudy?
Your solar system will continue to generate; however, output will be reduced in cloudy conditions.
What happens when the grid goes down?
When grid power is lost, a grid-connected inverter must shut down and isolate power from the solar system.
If you want solar power during a power outage, the system must have battery storage to provide that power independent of the grid. There are now ‘smart’ inverters that will automatically manage your solar system, battery storage and the grid.
Why is a site inspection important?
An on-site inspection is essential to properly assess your premises.
There are a number of variables to consider when installing a solar system; e.g. available roof space, potential shading and/or orientation issues, length of cable runs, suitable inverter location, type and condition of the existing switchboard and whether electrical upgrade works are required.
In the solar industry quoting ‘sight-unseen’ from satellite images has often lead to short-cuts and inferior workmanship – this creates significant on-going problems with both system performance and safety, negating any cost-savings.
We will always provide a no-charge, obligation-free site inspection prior to giving you a detailed written quotation and energy yield estimate. This allows us to design the system properly and ensure there are no nasty surprises.
It also allows us to advise you on potential energy reductions in other areas of your home; an added bonus that can’t be offered without a site inspection.
How do I know my system will be safe?
High quality equipment is very important for maintaining system safety and our high quality European inverters have in-built safety features. Switch gear, cabling and accessories are all vital components which must be able to withstand extreme conditions for a very long time – high quality is essential.
What maintenance is required for my solar system?
We recommend an annual system check by an accredited technician and regular panel cleaning to keep your system in optimal condition. Keeping panels clean maintains maximum system output. Good quality solar panels will ‘self-clean’ when it rains, so frequency of rainfall makes a difference; however, over time some dirt and dust will collect on the panel surface. Large leaves or similar debris sitting on the surface of a solar panel will make a big difference to energy produced.
Some important points on cleaning solar collectors:
- Work on roofs should only be performed by suitably qualified and equipped persons.
- Don’t use abrasive or harsh cleaners or chemicals – just a soft cloth/squeegee and generous amounts of clean water.
- Avoid hot days, as cold water is not good on hot solar panels.
What’s the difference between SHW and PV?
Solar PV collectors generate electricity and feed it into your power supply – solar hot water collectors collect heat and transfer it to your hot water system.
What is the warranty?
Industry standard solar panel warranties are 25 years on panel output and 10 years on materials and workmanship.
A more important question in today’s market is ‘Will your manufacturer still be around in 25 years?’ World-wide over-supply caused wholesale panel prices to plummet, which is forcing many manufacturers out of the industry.
What does Accredited mean?
To be eligible for government rebates, the designer and installer of your solar PV system must be accredited by the Clean Energy Council. The Clean Energy Council’s accreditation scheme ensures that accredited designers and installers of solar PV power systems:
- have undergone necessary professional training
- comply with Australian/NZ Standards
- follow industry best practice guidelines
- regularly update their skills and product knowledge.
My roof sometimes has shadowing – what can be done about it?
A site inspection is vital in determining how much shading will impact your solar energy output. Analysis with a solar access tool provides the best method of calculating expected yield.
It’s important to know that if only a small section of one solar panel is shaded, output will be reduced from the rest of the panels connected in that electrical string – which could be a large part of the array.
Careful string design can reduce the impact of shading; D.C. optimization will minimize output loss by isolating the problem to only the affected panel.
My roof has different angles; can I still benefit from a solar system?
Yes you can. Systems which incorporate D.C. optimisation can overcome output problems created by varying orientation or pitch angles, as well as from shading issues.
What are important issues to consider?
- High quality equipment from financially sound, reputable and well-established manufacturers is crucial. No matter how tempting the up-front price, problems with equipment failure, system down-time and maintenance will quickly cause your pay-back to disappear and could well start costing you more.
- Solar panels and the ancillary equipment must endure extreme conditions for decades. Don’t place your investment with equipment that doesn’t have the very best of credentials.
- Accurate assessment of solar energy yield against energy usage profile is required to properly assess your financial benefit. Interval usage data can be obtained from your electricity provider; that allows us to estimate solar energy to be consumed on site and energy exported, which gives an accurate payback calculation.
- Network connection: depending on system capacity and your location, there are likely to be specific requirements to be met before network connection is approved by your electricity supply authority.
- Careful consideration of system size: in times of low export feed-in tariffs, maximum benefit from solar will be obtained from solar energy which is consumed on site. System size should be carefully considered by an accredited system designer.