David Winterton from Sydney-based consultancy Ecological Design gives us a rundown of solar photovoltaic (solar PV). We find out how it works, what the key considerations are and why prices of PV panels always seem to be coming down!
Interview with David Winterton
Having travelled a lot over the years, David feels that sustainability offers a deeper sense of connection. He's witnessed first hand how indigenous communities have worked within their natural environment to create better places to live. And David believes that the same thing applies in our cities, which should be bustling, culturally inviting and invigorating. Sustainability is about better ways to live.
Around 1 Million People in Australia Live Off-Grid
The situation in Australia is unique because of the incredibly high levels of solar resources. Coupled with high energy prices and a decrease in the price of PV (Photovoltaic) panels, it seems an obvious choice for many to live off-grid. Some states in Australia have over 30% of their energy supplied by renewables.
Solar Panels and Solar PV defined
When people talk of solar panels they might think of them being for hot water. Solar PVs in this conversation relate to the technology which converts sunlight directly into electricity.
The Fundamental Thing to Understand About Solar PV is That it’s Static
While other forms of electrical generation, such as hydro, wind and nuclear, are all based on parts spinning around, the PV’s remain static. The sun coming in creates an electrical current between the different wafers of silicone. From there the DC output from the panels is converted, using an inverter, into AC.
A Number of Factors Have Contributed to The Downward Price Curve of Solar PV
With initial investments in plants and equipment being paid off, and improvements in the manufacturing processes and the way silicone is produced, the costs of panels (but not labour) have fallen.
David emphasises however that he would never recommend selecting panels purely based on price. With most companies offering between 10 and 25 year warranties they are going to be in the building fabric of communities for a long time so it is important that you make the right investment. He gives inverters (the part which converts DC into AC) which should be lasting 10 years as a case in point. Some of the poorer quality ones have been failing within 5 years.
We Should Be looking at Matching Our Energy Consumption With Our Yield
Previously it was the case that we tried to just get the highest yields out of the systems. With so little being paid for over-production that goes back to the grid, it actually makes sense for your peak levels being generated to be at the peak time that you will need it. For example, north facing panels (in Australia) would have a peak production in the middle of the day, and if you’re not there in the middle of the day then it’s not matching your energy requirements. It might be better to have two strings of panels with an east-west array that will be giving you a peak production closer to your waking up and getting home times of day.
The energy density of modern panels has improved meaning that now you can get a lot more power into a smaller panel. This therefore makes them viable to use in more shaded areas where once it wouldn’t have made financial sense to do so.
A Small Energy Storage System Can Avoid The Reliance on Peak Grid Energy Prices
With energy prices going up over 45cents a kw hour during the energy usage peak at night, it might be worth having a battery system to store any excess produced during the day so you don’t have to depend on the expensive energy during this short period of time.
David sees a similar trajectory that has happened with the number of people having solar PV over the last 10 years, happening with battery storage.
Some Key Considerations:
- Avoid low quality systems.
- Future proofing – in terms of battery storage it is worth checking to ensure that any system you are considering has the capacity to feed into a battery storage option.
- Understand your shading – shading on any one of your panels will result in a drop in voltage as it will actually revert to the lowest voltage across all of the panels. A smaller system designed with a different orientation might actually better meet your energy needs.
- Energy efficiency first – there’s always energy efficiency to be found in a house at some level so it is always best to focus on this first.
- Avoid companies which say you can upgrade for example a 3kw inverter to a 5kw inverter in the future – David emphasises that this is not how inverters work!
- Ask solar installers for production graphs of how much energy you will produce, which you can then overlay with your energy consumption.
- Talk to neighbours – particularly those with PV to see how it can work within the community.
There is a Place Within Energy Markets For Community Energy
David feels that community energy can play a strong part. Even if you’re unable to put solar PV on your home it is important to understand community initiatives in your area and what they will mean for the future. He gives the example of New South Wales where he believes that political decisions that have been made about their energy systems have not been in the interests of the community. He stresses the importance of understanding the governance and the capacity for making changes to get those things to work.
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