Solar Proposal Figures Vs Real World

Lbozzabear on 17/12/2023 - 21:36
Last edited 17/12/2023 - 23:20 by 1 other user

I live in SE QLD and I've signed up for with a local solar company that provided a seemingly good deal. Did the solarquotes thing and they were one of the 3 quotes I got. Of the 3 they sold me on their warranty above all else. It's a 10.56kw system, Seraphim panels, Sungrow 8KW inverter, and the best warranty of the 3. Final price came out to just under 10k.

I chose the bigger system because, although we're not currently a high-usage house and I am on a great fixed rate deal with Nectr til Aug 2024, I work from home 4 days/week and we did just got an EV that I can charge at home during solar hours (2-3 times a week, ~30kw each charge) and also try and do other stuff in solar hours like run our appliances. It'd be great if I can get a decent enough FIT to offset my usage that I'll still need from the grid at night.

The solar proposals show huge amounts of money I'll save, however after doing some online research on energy comparison sites (wattever, energymadeeasy, etc), punching in my details, trying to estimate my future usage and considering solar, it still comes out crazy expensive! Cheapest was $1800/year so either I'm not doing something right or maybe these solar proposals are misleading?

I guess my question is: for those who have switched to solar, and maybe paid extra for a larger system that they've tried to utilise as much as they can during solar hours: has it been worth it and your ROI time has been relatively short, or do you regret the money you've dropped on solar in the end?

Anecdotes so far from friends has been mixed, which is why I'm trying to gather a bit more evidence!

Also, we do plan on living in the house for at least 5-10 years as we like the area…

Cheers.

Electrical & Electronics Solar Energy System

Comments

  • SydStrand on 17/12/2023 - 22:09
    +3

    Like most solar owners here, I have a 6.6kW system, and it's definitely worth it. Other than small things like trying to maximise daylight use for laundry, dishwasher, etc., it's pretty fool-proof so I'm about halfway through an approximate five year payback period. I've gradually transitioned off gas appliances, so induction hob, replaced wall furnace with split systems, and last upgrade was heat pump water heater which only runs when the sun is out, so it's basically free. Turned off gas cap, so no more daily supply charge.

    • bozzabear on 17/12/2023 - 22:56

      Cool thanks. I have gas cylinders for instant hot water but everything else is electric. Will prob invest in water heater if my cylinder bills go up or if the instant system starts playing up.

      So for non-solar hours do you still pay a fair amount for supply and use? I guess that's what I'm trying to work out, if that's still gonna cost me a fair chunk…

  • mskeggs on 17/12/2023 - 22:10
    +2

    What other investments return $1800 a year for a $10k investment. Not sure what you are asking? You want a higher rate of return?

    • bozzabear on 17/12/2023 - 22:53

      Sorry should have clarified, but the comparison sites are saying that it will still cost me 1800/yr, that I'm guessing is for the non - solar hours usage… Even though this is probably blown out a fair bit, could it still be pretty costly?

      • mskeggs on 18/12/2023 - 06:55
        +1

        Did you do your own calculation?
        The 8kW system you suggest will produce a tad over 32kWh per day, averaged over the year. More in summer, less in winter.
        If you pay 25c per kilowatt and use 32kWh in daylight, the system will save you $2920 per year.
        If you don’t use all the power, some will go to the grid, getting you whatever the feed in tariff is.

        You will always pay the power company connection charge, likely around $1 a day. Most homes use about half their power in daylight, and half at night. This is why you see encouragement to use pool pumps, hot ware, dish washers etc. during the day, to use more power then when you don’t have to pay.
        You can look at your bill and see how much energy you use. The average Australian home uses about 22kWh per day, and would offset their daylight usage with about 4kW of panels with no behavior change.

        • bozzabear on 18/12/2023 - 09:20
          +1

          OK great, thanks for your help with that. Gives me a good idea what to expect.

          My current bill doesn't split up day/night use as it's just a flat rate but I do know that we use a fair bit still up to about 8pm, esp in summer in QLD with the aircon running til late.

  • jinx83 on 17/12/2023 - 23:29
    +1

    If you have an EV, u can get access to EV electricity plans by OVO energy or AGL, which gives you access for 8c per kw of electricity from 12-6 am. I have solar system around same size and wish I had a bigger one. Also WFH with EV. FIT is currently 8c uncapped. But I’m pretty sure you’re getting a double digit return with the amount you spend.

    • bozzabear on 18/12/2023 - 09:23

      Thanks. I did look at their plans and their supply charge and grid rates seem pretty high still, outside of that 12-6 8c period. Plus I'm pretty confident I can charge the car 90% of the time using solar only. But the 8c FIT does sound very good. Will keep it in mind when the panels are up.

  • brad1-8tsi on 18/12/2023 - 00:52

    I've done 3 systems.
    The first 1.5kW system paid for itself in 15 months (had a crazy gross FIT).
    The 2nd 6.4kW/5kW $4k fitted 2018 paid for itself in 4 years.
    3rd was 5.4kW/5kW $5.3k fitted Jun 2023. My estimated payback is 6 years but I think it will be quicker.

    Winter output is usually 40% of summer output. I haven't changed plans and my $120/month bill should result in a net zero cost over a 12 month period.

    I'd suggest finding a plan with unlimited export.

    Change your usage habits. I do all my laundry and dishwasher during peak periods. Have a timer on the fridge from 10.pm-6am. Run my AC at 27c all day to keep the house cool. Use other electrical appliances.

    • bozzabear on 18/12/2023 - 09:24

      Thanks. Yup will try and hunt down the best plan. And yeah def planning to change the habits to try and get max usage out of the solar when I'm WFH. My AC is about to get a workout hehe

      • ESEMCE on 18/12/2023 - 10:09

        Yeah, think of the household Air temp as a "battery". If you can eliminate/significantly reduce heating/cooling outside of solar hours, that's a huge win.

  • Sal in SA on 18/12/2023 - 06:44

    If you use most power when you are not generating power then the gain is limited, the FIT is almost not even worth taking into consideration these days.

    For use 35-40KWh a day easy - 60-70% of all our consumption is during the day / period of generation so solar makes a decent reduction to bills.

    • bozzabear on 18/12/2023 - 09:26

      Great, thanks. Yeah the plan is to try and move as much consumption as we can to solar hours. I really just want to keep my grid charges as low as possible.

  • ESEMCE on 18/12/2023 - 08:57
    +2

    energymadeeasy is useless in its calculations. Even when you supply them a full year's worth of data by quarter, their calculations bear no resemblance to reality.
    Use it as a guide only and make up a spreadsheet to calculate costs of their top 5 against your historic usage.

    I tend to find that it's generally the 3rd-5th recommendation that is actually cheapest for me.

    This is of course difficult when you've only just put on solar.

    As a rule of thumb for my usage patterns and generation, I find that minimising the daily surcharge is the most important factor with Import Tariff the second most important. FIT is a distant third.

    • bozzabear on 18/12/2023 - 09:32

      Thanks. Good to know. I like that prioritisation - I'll keep that in mind when hunting around.

      My current Nectr plan is fixed to Aug 2024 and is only 27c anytime rate with 103c daily supply, which it seems by comparison is very competitive. They only have a 4.4c FIT but it appears to be unlimited, so I might just see if I can get that added on when I get my solar, and just see what that looks like for a few months.

      • DiscountForThee on 18/12/2023 - 10:10
        +1

        I just moved to Red Energy. In my suburb, 28c usage rate, and their FIT is one of the highest available. 16c first 5kWh, 8c for the rest. If you were to feed in 40kWh a day, 4.4c FIT would only net you $1.76 a day. With Red, I'd be getting $3.60 a day.

        My daily charge is closer to $1.40 but the FIT more than makes up for it

        • bozzabear on 18/12/2023 - 10:14

          Ahhh nice! Thanks! Will put them on the short list ;)

  • DiscountForThee on 18/12/2023 - 09:17

    It's a 10.56kw system, Seraphim panels, Sungrow 8KW inverter, and the best warranty of the 3. Final price came out to just under 10k

    Recently had my place done in SEQ and got 13kw panels and 10kw inverter, $6k. I did get about 20 quotes, though, so I had lots to choose from

    • bozzabear on 18/12/2023 - 09:27

      Wow, that's amazing! What company did you go with? Also what brand of panels and inverter?

      • DiscountForThee on 18/12/2023 - 10:06

        Few months ago now so the company name has blurred in my head into all of the other ones (they legit have all similar names lol)

        Panels were "Tongwei" and inverter from Goodwe. No complains yet, but I do acknowledge that neither of these are gold standard so we shall see how they go long term…

        • bozzabear on 18/12/2023 - 10:12
          +1

          Nice. Yeah I got sold on the warranty, support and reputation of the company I ended up going with, plus the panels and inverter seem a decent enough product according to online reviews and such. Not gold standard either but wasn't willing to pay even more $ for top shelf stuff.

          Hope that system works out for ya!

  • KaTst3R on 18/12/2023 - 09:30

    I got a 6.6kw system. Everything is according to my calculation with the exception of winter production. Before I bought the system, it was estimated that winter production will drop 30% to at most 40%. But real data shows i am only making 3.0kw per hr at most during peak winter. What I found was that temperature (in addition to low sunlight during winter) is a big factor that causes the panels to lose efficiency. So in your calculation, be a bit more conservative for winter.

    • bozzabear on 18/12/2023 - 09:35

      Ah perfect, good to know. Thanks.

      Winter days here are generally pretty sunny being in QLD, but can still be pretty cold. That said we rarely use heat in the house so that should help during winter months to not go beyond our solar supply during solar hours.

    • ESEMCE on 18/12/2023 - 10:07
      +1

      High temp causes a loss in efficiency, not low temp (at least not Australian Low Temps)
      Winter efficiency is more likely impacted by cloud cover which is obviously variable from year to year.

  • saltypete on 18/12/2023 - 09:38

    Have you done the demand management side of the equation yet? Adding solar to a property that squanders energy is likely to disappoint.

  • freefall101 on 18/12/2023 - 10:29
    +2

    The solar proposals show huge amounts of money I'll save, however after doing some online research on energy comparison sites (wattever, energymadeeasy, etc), punching in my details, trying to estimate my future usage and considering solar, it still comes out crazy expensive! Cheapest was $1800/year so either I'm not doing something right or maybe these solar proposals are misleading?

    They are absolutely misleading, every solar place I talked to talked about how I'd never have an electricity bill again (and seemingly ignored daily tariffs) and based it on power generated vs power used (while ignoring the time that happened and using some very generous calculations for power generated).

    Best bet is to look at your own power usage and break out a spreadsheet. If you have a smart meter you should be able to get hourly usage, I just assume anything during the day goes to zero and anything after 6pm I keep using (which is relatively accurate). But last bill I exported more than double what I used and don't use much peak power and we still had a net cost for electricity alone (then tariff on top).

  • megaclix on 30/12/2023 - 22:59

    This thread is a bit aged, but given you got the Sungrow Inverter, do you use the App/iCloud to check your usage.

    Hopefully at the price point, your install included a consumption meter so you get the full set of data.

    With the live data and historic charts, you can see your actual usage, and make decisions on how to better match your usage with solar generation. There is some basic changes that you can make e.g run pool pumps, washing machines etc when the solar system is at max generation. Next, you can timers for such things as hot water systems, PV charging. Then better, there are smart controllers that can match excess solar generation to such things as PV charging.

    Overall, in the original quotes, they have an arbitrary percentage figure of how much of your solar generation gets utilised. For most people, me included, this is guess work. What you can do is calculate yourself what a typical monthly bill will be with your average monthly consumption, with all the solar going to FIT (0% utilisation). On the other end, calculate the same with with 100% utilisation (using all your solar generation offset against your typical consumption). This will give both extremes of potential savings/payback. Then your job becomes maximising the utilisation.

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