Getting value from rooftop solar

I have been investigated pricing for rooftop solar for my house but the numbers don't add up!

I will be paid just 8c per kwH for feed-in. When I connect to solar my tariffs will be increased by 20 percent to 35 percent depending on which retailer I use.

Is it possible to save any money at all on rooftop solar? How many years can the panels be expected to last before needing replacement? Or have energy retailers successfully colluded with governments to remove all saving for the consumer?

I'd love to "do the right thing" and instal solar but the numbers don't work for me…..

Any advice???

Comments

  • i think you can get the real benefit only if you apply under old rules ie 5-6 years ago.
    or, if you have families stay at home where most of the usage is during the day.

  • +3

    "Or have energy retailers successfully colluded with governments to remove all saving for the consumer?"

    Got it in one - rampant corruption.

    Short of waiting till a real government gets in, you're going to need to have batteries and go off grid to really win today.

    • How much would that sort of setup cost?

      • A huge amount of money in batteries.
        For example, this is a quick, dirty approximation:

        The average 4 person household uses 20kWh per day.
        -Lets say for arguments sake this is the desired battery capacity (in reality, to be kind to batteries you shouldn't be draining deep cycle batteries below 50%).

        I've trawled through eBay for a decent sized AGM deep-cycle batter, a 270AH battery costs around $600, lets say 2$ for 1AH (these figures are relating to 12V). Converting this to kWh, you multiply by 0.012.

        With this in mind, you need 1666AH of 12V batteries to service the 20kWh daily.
        So you will need around 6-7 of these batteries to cover 1 days worth of electricity ($4200).

        In reality, this would need to be doubled to ensure the batteries are not overly drained, and would need to be multiplied by the number of days you will be without sun for (in winter for example).

        There are then energy losses when discharging and recharging.

        All in all, batteries are expensive!!

        • All in all, batteries are expensive!!

          At the moment..
          Tesla have made their battery technology patents (perfect for Storing PV power) royalty free and there's a battery mega-factory being built to churn out millions of units per year.. These events will see battery prices plummet as the price has to drop to maintain a good Demand ratio to match the new Supply level.
          It'll also spur existing battery manufacturers to rebuild/upgrade existing plants so that they stay competitive in the market.

  • What state are you in that the Import tariff is higher cause you have solar panels?

    Even assuming you do have a higher Import Tariff, the rule is to use the power you generate as much as possible.. therefore don't pay to import, therefore save money.
    That means putting appliances like the dishwasher and Washing Machine on timer (if you're not at home during the day).
    Maybe buying a slow cooker so you can cook meals through the day.

  • +1

    Can't comment on how to justify getting in. But interested to know the answers as I have been myself thinking about it since the last year.

  • My parents want to get solar panels for their new house next year. Is it still worth doing??? As long as it reduces the power bill and pays itself off within 10 years I think its still worth it. Is that the case??

  • +1

    How much you got for a system in $$$$$?

    A system can pay for itself, depends on your use and how much you include the externalities such as CO2-e pollution.

    The electricity price at the moment adds in around $26 tonne per carbon (this is about to be repealed),the real cost of mitigating a tonne of CO2-e can be over $100 (mitigating to 390 ppm).Without the environmental externalities included in your paybacks, the overall pay back time will be longer.

    Also no point getting a PV system to run an inefficient household, when your appliances are beyond repair spend your "solar" money on super efficient appliances, LED's, fridges etc. Also have you reduced heating and cooling costs? put in solar hot water? there's heaps of info out there.

    All this can add up to a bucket load of cash and seriously worth doing as its mostly low cost and easy (not the solar water heating).
    It's also worth putting on a whole of house energy meter,these typically save you 10-20% by making you more conscious of where your electricity is being used. Local Councils have kits (in NSW) you can borrow ( also see
    https://www.clipsal.com/Home-Owner/Products/Energy-Efficienc…).

    If you done all that,go the PV.

    As scubacoles mentioned, its best to use the power when its generated. In summer that can mean running your aircon in the middle of the day to burn up the extra kWh. Nice if you want to come home to a nicely cooled house!

    FYI it will cost you a tadge under $20,000 for a PV and battery system that is grid interactive. Hopefully the price of batteries will continue to drop over the next few years making a pure PV stand alone system a relatively good proposition!

  • I've installed a 2kw from AGL for $4.5K incl switch broad upgrade last year. (expensive but they possibly won't bankrupt in the warranty period)
    for my household, 4 adult + 2 kids (2 at works during daytime)
    every Q, saving around $300-$350. used to pay around $600-700 a Qtr in Electricity.
    I've expected 3 - 4yrs to break-even.
    If you schedule better, you will get more, i.e. showers, charging, washing, cooking on daylight only. I tried that in the 1st Qtr and save around $20 extra, but too lazy after that

  • -1

    Not worth getting in the game now as its now over, I really dont think most systems will even last 10 years….

    I have a 1500 Kw system and personally it was a waste of time but hey my brother inlaw has one (not sure on size and hasn't had a power bill after getting it…
    If prices came down it might be worth me getting a bigger system as I did get in early and have the rebate.

  • Lot of nonsense in this thread from people who think their circumstances apply to everybody.
    If you use a reasonable amount of power during the day, because there are often people home and/or you run AC etc. then solar PV will pay for itself in approx 5-7 years, assuming you sell the STCs and get a reasonably competitive system price ($2/watt or less).
    What is pointless is installing a great big system that produces vastly more power than you consume.
    Here is a table from the ATA showing how long it will take to pay off a system with various levels of on-site use of the power.
    So a small system where you use 90% of the power it produces, and therefore dropping your grid buying by the same amount, will payback in as little as 4 years. If you don't use the power and export 90% at the paltry 8c kWh, it can take 20 years or more.

    These figures ignore both inflation and the time cost of money. So depending on whether interest rates change and power bills rise the payback could vary.

    Bottom line is, if you use a reasonable amount of power during the day, it is well worth it.

    • That's what I wanted to know, thanks.
      Oh and you forgot to link the table from ATA

    • +1

      Oops. Left off the link:
      http://www.ata.org.au/news/latest-solar-payback-times

      And as a guide, the average Aussie house uses about 20kWh per day. a 1kW system will produce on average, 4kWh per day. So estimate what fraction of your power use is in daytime, divide by 4 and that is the right size system for you.

  • Thanks so far for the advice and comments. I live in Victoria and the here the electricity retailers have 2 price structures: one lot for folks without solar and another (20% to 35% more expensive) for folks with solar. So you start out right away with a price handicap. You get just 8c per kwH for any feed in, but pay up to 30c per kwH to take power from the grid: a mark-up of more than 350 percent….
    I figure it would take me 15 years to repay $6000 (@ $400 per year)for a 3KW system, by which time half the panels will probably be cactus and need to be replaced!

    • +1

      I think you first must not think of it as a investment, if it provided a no brainer IRR, then everyone should just do it and send the grid to the death bed. But the fact is, it doesn't, most people who does have panels, either got in in the old system, where the pricing regime was much better, or they just want to be green.

      Now assuming you want to be green at the small extra cost, you might want to consider not telling your retailer you have solar, so you keep ur old pricing scheme. The offset is that u don't get credited for feeding into the grid, so u have to use ur oslar power or else u lose any benefit.

      This is what occurs in my house, both my parents are retired and use most of the power during the day, some is wasted but we only have a 1kw system anyway. I calculate the fridge and tv uses all the solar during the peak of a winters day. No solar power wasted.

      • I think you have hit on a good idea to avoid the higher tariffs: don't tell the retailer that you have solar! Yes, you lose the 8c feed-in (in Victoria) but realistically this is only worth an annualised average of 40c per day (on a 3KW system). So lose 40c a day but save as much a $4 per day by staying on the non-solar tariff………sounds like the way to go.

    • +1

      The panels are likely to last 25 years+, the inverters have a realistic life of 10 years. Of course, some die earlier, and some will last much longer, just like that 30 yro washing machine your aunty still has.

      Can you post a link to the retailer price structure? I am assuming it is time of use based, not just a straight up more expensive tariff?

      • The electricity retailers only seem to publish their non-solar tariffs on their websites so you actually need to ring them and ask for the solar tariff. I suspect the retailers are a little publicity shy about their solar tariffs, hence the reason for not posting them up on their websites. The price structure IS time of use based so if you are happy to wash and iron and cook between 11pm and 6am there might be some "savings" to be made……………………….

  • If you think VIC is bad for feed in tariffs check out NSW. energy australia just dropped the feed in tariff to 5.1c which in realistic terms probably reduces my credit from it to about $16 per quarter. Some other retailers in NSW dont even pay a feed in tariff at all.

    • We're a lot better off than VIC.

      We'll head VIC way if full deregulation goes ahead like there's has.

      We have regulated prices, they have crazy cowboy prices

  • +1

    I'm not sure whether you all have heard the news, but Australia doesn't need to worry about carbon pollution. According to Tony Abbot its someone else's problem.

    So smash up yah panels, crank up the fan heater and lets burn some coal baby!!

    • +2

      This seems to be the message we are getting from the governments through the retailers and power generators, isn't it? Makes me want to go "off grid" just to stick it to all of them!

      • Yep, off-grid is the future and in fact is already justifiable now for some situations.

        Recently built a house (2 years ago) and purposely designed it to be as solar passive as we could afford so although it still gets hot & cold it definitely doesn't need AC in Summer due to ceilings fans and good cross ventilation and only light use of a heater during the coldest Winter days (QLD afterall). Filled it with LED lighting, spec'd a kill switch near the front door to turn off all but the critical circuits whenever we go out and got a change-over breaker fitted to the board with a 100A cable run out to the side of the house to act as a generator input which is also handy as a DIY injection point from an inverter.

        Didn't get solar with the build but made sure the large roof sections were angled & primed to fill with panels and as the house is off the ground (like a traditional QLD'er) there's plenty of space for battery storage underneath. I've done some quick calcs and thanks to the latest hike in the connection charge going off-grid is already VERY close to being a good investment based on the fact that quality panels & batteries will last approx. 20 years.

        I'll give it another year or two yet for efficiencies & lifespans to improve and costs to reduce but I'm really looking forward to the day I get the system installed and I call the electricity supplier to ask them to disconnect me :) Ahhh!

  • IF YOUR HOME ALL DAY USING ELECTRICITY THEN ITS STILL WORTH GETTING A 3KW+ SYSTEM but if your not then your not worth getting a solar system when your only getting a 8-10c feed in tarrif (QLD click electricity is 10c)

    BUT YOU HAVE OPTIONS

    You can spend extra and go off grid, with deep cycle batters or one that uses a chemical process to store energy but these are expensive (think 20-60k) and your best to wire your home for 12vDC (i.e., pretend its a caravan) as you loose a lot of energy going DC>AC>DC ext…

    You can also HARD wire aircon, hot water washing machine & heaters to OFF PEAK tarrif

    Going solar for hot water also pays for itself over time too (I kept my boost ON and i used the cover min connection tarrif every month)

    Alas, if you can use the electricity during the day the new feed in tariffs are a bad joke and i don't expect any change as the states own the power companies and the government docent like competition in organised crime, i.e., PROFITS

  • Thanks for some good suggestions…..

  • The ATA is an expert on this stuff. They have forums where you can ask if there is a VIC retailer that offers a better deal. I know Red Energy has been mentioned positively previously, but I am NSW and don't know about current stuff in VIC.
    www.ata.org.au/forums/

    Also, Whirlpool has a green tech forum where you can ask similar questions.

  • There is only one question to ask, the supplier, and that is, how long till it's paid for itself,
    If it's over 5 years choose another supplier.

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