Solar

The energy solution I’m implementing (care of Roland Lawrence) is 100% electricity. I’ve modelled three examples of solutions so that you can get an idea of costs and the various ways you can power your house via electricity. You can also go to Solar Quotes to get a quote on a system (I’m not endorsing any of their solar suppliers, I just think it’s an efficient service).

3 reasons I didn’t go with gas

Before we get into more detail on my solar solution, I wanted to outline the 3 reasons I chose solar over gas.

1. Research shows households are likely to generate fewer emissions using electricity when compared to gas, particularly in the future. This is what Renew Magazine wrote in their article ‘Emissions intensity of household electricity vs gas’:

Renew’s research, along with existing studies and academic literature on household fuel choices, demonstrates a strong case for home electrification. The data from this study shows that throughout the NEM, most households would generate fewer GHG emissions when heating with efficient reverse-cycle air conditioning instead of gas units.

 

“Although gas hot water and cooking appliances still produce lower emissions than their electric equivalents in most areas, the difference is increasingly marginal and, because the emissions intensity of electricity networks will continue to decrease into the future, households making the switch to electric appliances today are investing in a low-emissions future.”

2. Gas is not renewable and it’s WORSE than coal for global warming. The sun’s rays aren’t going to run out and we don’t have to dig up the ground to extract energy from it. The Climate Council writes:

 

“It is true that gas, if produced and consumed in Australia without being liquefied, is 30-50% more carbon-efficient than coal at the point it is burned to produce electricity. But this benefit is substantially eroded by the emissions created when gas is vented or flared during the exploration, extraction, transport and distribution processes.

 

Gas is mostly composed of methane, the most significant climate-warming agent after carbon dioxide. Methane survives for a shorter period in the atmosphere, but over 20 years has 86 times the planet-warming potential of carbon dioxide.

 

In 2019, the venting and flaring of methane accounted for 6% of Australia’s emissions – and this is likely a significant underestimate. These so-called “fugitive emissions” massively detract from the purported climate benefits of a gas transition.”

 

3. I want energy security, I don’t want to rely on the grid. (I will also have a battery for this reason). We know that climate change was in part responsible for the worsening fire conditions (despite what Barnaby Joyce says – I prefer to get my information from the experts). If the bushfires over the coming years get worse, I’m not convinced our leaders are well positioned to stop our energy grid from burning down.

Please sign our letter!

Asking Inner West Council to consider letting me install solar panels on my front roof.
My actual solution: 7.11kW solar + 12.0kWkWh battery

 

Roland’s quote estimated that I will use 12kWh a day. I’m almost certain I will use less given my current consumption patterns, the fact that I will be purchasing more efficient appliances and the better designed building once the renovation is complete. So I have used 7kWh in my calculations on the costs and projections page.

 

Roland estimates that there will be on average 25.6kWh/day available for me to either consume, put into the battery or put into the grid (see the chart below).

Of that 25.6kWh, I will directly use about 5.7kWh during the day, with 6.3kWh going into the battery, 13.6kWh going to the grid and 6.1kWh being consumed from the battery.  The chart below does a good job of explaining how it all works. You’ll notice that the estimate says I will be 98% independent of the grid – this is a conservative estimate and I expect to be 100% independent of the grid. That is, I will only ever put electricity into the grid and never take any out of the grid. This set up means that I won’t need a generator either. This is a good thing given the lack of space on my property and the fact that generators aren’t good for the environment!

See my step-by-step breakdown

Everything I wish I’d known before I started
Plugged into the grid vs a battery

So is it more cost effective to have a battery or not? At the moment, batteries are extremely expensive.  You will see my modelling on the Costs & Projections page. It shows how much more cost effective it is to remain connected to the grid.

Is a battery or grid connection better for the environment?

This question comes up a lot. As with everything technology related, things change quickly! On top of that, the modelling usually assumes that the current mix of coal/renewables in the grid remains the same. To do any type of modelling, you need to make assumptions, but you should also be aware of how changes to those assumptions can change the output.

In 2016 Ronald Brakels from Solar Quotes (love your work Ronald!!) wrote:

 

“In Australia, with one main exception, on-grid home energy storage does not reduce greenhouse gas emissions but instead contributes to them. While battery storage is likely to reduce emissions in the future, systems installed now are almost certain to only contribute to global warming over their entire lifespan.  Early adopters would have helped rather than harm the environment if they had instead spent their money on installing larger solar systems or on improving energy efficiency. Home battery storage contributes to increased emissions in two ways. Firstly, manufacturing batteries results in CO2 being released. And secondly, home storage results in clean solar energy being lost because no battery is 100% efficient at storing electricity. More electrical energy has to be put in than can be taken out. If that energy had been sent directly into the grid it would have decreased fossil fuel generation.”

But Ronald also notes:

 

“With enough renewable generating capacity battery storage could allow fossil fuel generation to be eliminated. Excess renewable electricity could be stored in batteries for use when there wasn’t sufficient solar, wind, or other renewable power to meet electricity demand. But Australia is nowhere near the point where battery storage can help us eliminate burning coal and natural gas. Once we reach the point where more renewable energy production regularly exceeds demand then battery storage will be extremely helpful in cutting emissions. Australia would need to generate around 50% or more of its electricity from renewables for us to reach this point. Unfortunately that is still years away for Australia, despite our wealth of renewable resources.”

More recently, Ronald has said:

 

“But when we get to the point where 1 in 100 households have a modern home battery that is part of a VPP there will be a significant benefit to the grid. All those batteries will be able to provide as much power as a medium-sized power station. They can also absorb the same amount of power when renewable supply exceeds grid-demand. When we get to the point where 1 in 20 or 1 in 10 homes have a battery system it will be a huge benefit when it comes to managing the grid. This will help keep electricity prices down for everyone connected to the grid.”

 

And Renew’s Andrew Reddaway adds:

“Installing a grid-connected battery generally doesn’t benefit the environment directly, but does help to develop economies of scale in battery manufacturing and installation which will assist our longer-term transition to a 100% renewable electricity system.”

So I am hopeful that our government will wake up and smell the smoke and materially increase the contribution renewables have to our grid and soon! This, coupled with my desire for energy security is why I am going for the more costly battery option.

Busting some myths

I’ll keep adding to this list as I go, but I think the myth I hear most often is that solar panels do more harm to the environment than good. For these reasons:

 

1. The energy that goes into making a solar panel is more than that panel will produce over its lifetime

 

2. Solar panels are toxic

 

3. They can’t be recycled

Anyway, I found this fantastic website – CleanEnergyReviews.info – that busts the myths I’ve listed above (as well as others). They provide links to actual research so you know it’s not based on ill-informed opinions. But to answer those myths:

 

1. The energy payback time for many modern systems is probably less than 2 years. I’m expecting my system to last at least 20 years given the warranties. So it will more than compensate for that embodied energy cost

 

2. There are no toxic materials except for a small amount of lead used in the solder and the use of solder is being phased out 

 

3. Currently 85% to 95% of a panel can be reclaimed and recycled.

Analytics – How to optimise your usage

 

To make sure you maximise the use of the sun’s power and to maximise your $$$ you’ll need to install a monitoring system. My Dad has Solar Analytics and he thinks they’re pretty good so I’ll be going with them as well. An analytical system will allow you to figure out the most cost-effective time to turn on the dryer, washing machine or dishwasher. It will also help you to understand if your system is generating the amount of energy the system is supposed to and if there are any faults. Once I have the system up and running I’ll add the data here for everyone to see. But in the mean time this is what my Dad (aka Tony Peppercorn – yes that’s his real name!) has to say about Solar Analytics:

 

“Solar Analytics as the name suggests is a product that monitors your solar output and usage 24/7, using a combination of hardware and software. A module installed in the meter box monitors the output of your solar panels breaking it down into the amount consumed on site and the amount exported to the grid. It also monitors the amount of electricity imported from the grid. It does this in real time and sends all this data to a central server via a 4g Connection. This data can be viewed in 5 minute intervals via a web browser. Full details can be found on their website, Solar Analytics how it works.

 

I bought a Solar Analytics subscription at a Sydney Renew Sustainable House Day in September 2016. One of the things that impressed me was that it was a local company and also the product is vendor independent. Since then it has been pretty reliable with only occasional outages which are promptly notified by an email. These seem to be mostly related to extreme weather events.

How I use it: I mostly use it to monitor time of day usage so I can use as much solar output as possible on site. I also use it to monitor the output and efficiency of the panels. I recently got some panels cleaned for the first time since installation in 2011. The increase in output showed up in a Solar Analytics graph which showed output starting earlier in the day, finishing later and peaking higher.

 

One thing you need to watch out for is whether you have an available slot in your meter box. Also, if you get more panels and another inverter you may need another unit and another slot in your meter box.”

Solar panels on my front roof

I live in a heritage conservation area and that means I’m not permitted to put solar panels on my front roof. As you can see, the solar system we have designed uses the front roof. If I want to be 100% self sufficient for energy then I need to use as much roof space as possible. I am 100% on board with maintaining our heritage, but at this stage of the climate emergency, I think the costs of not being able to implement a temporary structure which can be removed outweigh the requirement for aesthetics.

I am extremely lucky to live in Sydney’s inner-west area and the Inner West Council is committed to moving to zero net carbon emissions. So I am hoping they will be supportive of my request when I lodge the final DA soon. I would be extremely grateful if you would sign my letter to the council asking that they consider my request for panels on the front roof given we are running out of time to tackle our emissions crisis.