Maximise Your Solar PV Investment

I wrote this piece yesterday for the Caroline Springs Community Update which is a monthly publication in our shire.  I write a regular column titled “Green Living Tips”, and thought it would be nice to share it here as well.  It does specify Victorian information, however the recommendations should apply to most owners who receive a Net Metering Feed-in Tariff.

I am the proud owner of my very own power station! I have had a solar power system installed since September 2007 and believe that I was an early adopter of this grid connect technology. I have sixteen Sharp 175 watt panels on my carport roof, and a Fronius IG30 inverter which feed in to the National grid. During that time I have generated 14,612 kilowatt hours (kWh), and avoided emitting 17.9 tonnes of CO₂-e. This equates to $3,067 in savings at the present electricity tariff of 21 cents per kWh. Nice stats and it has gone quite a way to paying for itself already.

As we live in Victoria, we are lucky to be paid the Premium Solar Feed-in Tariff of 66c per kWh for every kilowatt hour we export to the grid via a Co-generation Smart Meter. This is what is called a Net Metering scheme as you only get paid for the electricity that you export above and beyond the amount you consume in your home from the solar PV system first. The other type of scheme is a Gross Metering scheme where you get paid for all the electricity you generate. Unfortunately, this scheme is only available in the A.C.T., so we are stuck with Net Metering in Victoria until a national Feed-in Tariff is announced.

Most of our homes electricity usage is during the night after sunset, because I want every single watt of electricity that I generate to be fed back into the grid during the day, so that I get paid the premium rate. Common sense really. To maximise your return on investment you need to use the least amount of electricity during the day so that the excess is fed back into the grid. Here is a more detailed explanation:

My pool pump only runs at night, as does the washing machine, iron, and dishwasher which are all the heavy energy demanding appliances and pumps we own. We buy 100% Green Power to help with carbon neutrality, which only costs me 25c per kWh, and we try not to use the day time power generated by my Solar PV system which is worth 66c to me.

For instance, if it was a sunny day and I generated 10 kWh, and I used 10 kWh during daylight hours I would mostly be drawing that electricity straight from the solar PV system because my home would use it first. There is none spare to export. Therefore, I would be ripping myself off by 41c per kWh utilised in the home. If I did this every day it adds up to a loss of $4.10 a day or over a 90 day billing period it adds up to a whopping big $369. This is massive loss as you can see. If I had have exported all of that electricity into the grid over the billing period, I would have been paid a massive $594, and would be probably be in credit on my bill. The way I see it, by using most of our electricity during the night from the grid when I am not generating electricity and feeding as much as I can into the grid during the day, I am still carbon neutral (due to GreenPower) and am simply using the Solar PV system to my financial advantage! There is certainly no crime against that. Being green does pay in the long run.

Just because you may have bought your solar power system to reduce your environmental footprint, it doesn’t mean you can’t get the most out of your investment. I highly recommend that you try and restrict your consumption during the day, and think about utilising the heavy powered appliances at night to maximise your Solar PV investment.

While you are at it, have a think about how you use your electricity. If you practice energy efficiency measures around the home, you will save even more on your electricity bill. Turning that light off in that empty bedroom doesn’t sound too difficult once you get into the habit, and you will save a few bucks as well.


  1. says

    Hi Gavin …yes I agree with every thing you wrote…we live in the West …we have 30 solar panels on our fully enclosed pool roof…we get paid 47 cents per kilowatt..40 cents from the state government and 7 cents from our electricity company …but like you we are very frugal with our power usage we want the best return for our money also …so run pool pump at night and early morning before sun has come up …we had a few hiccups with installation cost us an extra $5,000 we didn’t plan on as we live in the bush our cable was to small so that had to be up graded..gggrr…then last year our inverter mother board died lucky still under warranty…so got a new one now a different one that is way more efficient 15 % but we lost nearly $1,000 while we waited for new one to be installed..another ggrrr…but all in all we love our solar panels and doing our bit to make the place greener…

  2. Andrew says

    IN NSW as there is no feed in tariffs now (may-june 2011) so it is best to use the most power during the day and minimise at night. As any extra gets rates of between 0 and 6c only

  3. says

    My big question about solar panels is regarding embodied energy (the energy used to make and install the product). So my question is how long does a solar system take to pay back all the energy and carbon it used in its manufacture? I have heard many things said from 2 to 30 years. I would love to know the real answer.

  4. says

    Thank you so much for this Gavin.

    Right that’s it, I am turning the computers off during the day too, that is the only things other than the fridges and freezers that are running. And will be doing the washing at night, not so good when it has to be hung out in the cold though.

    Our biggest chewer would have to be the pool pump and evaporative air conditioning unit in Summer. I do try and leave the air conditioner off until about 3 in the afternoon, but we do get some extremely hot weather here that can go on for days. Fans might be the way to go. Have “suggested” to hubby to run the pool pump at night. Might have a look at prices for a solar pump.

    Our panels produce less than yours, we only have a 2kw system but are hoping to improve on that with some new panels. We do have back up batteries that get charged as well. And we only get paid 52c/kw.

    Some times common sense isn’t quite so common to some lol. Any advise is very much appreciated.

  5. says

    Got to tell you Gav, it is so comforting to know that you have the knowledge when it comes to the topic of solar panels.

    When we move and it is time to put the solar panels on the roof, you can be assured I will be rereading all your posts on this topic in fine detail.

    Thank you for all your research and for sharing your knowledge with us.

Comments build lively communities. Let me know your thoughts, but keep it clean and green! Spam is removed instantly.