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Alex Simmons

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Alex Simmons last won the day on March 16 2018

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About Alex Simmons

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    Bellingen, NSW

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  1. 2000/7500 = 27% ROI Ain't many investments out there that are nearly as good. And consider this is saving you after tax expenditure, which makes it even more valuable.
  2. No, you generate and use your own power which means you use much less of the electricity the retailer would have sold you, and any excess production you sell to the retailer. Over the lifetime of a solar PV system the cost of the energy you generate is around 3 to 4 cents per kWh. So for each kWh you produce, you do two things: i. use some of it to power your home, instead of paying the retailer 20-35c/kWh, and/or ii. export the balance and get paid between 8 to 20c/kWh. Either way you are making a superb return. There are very few investments out there that can compete with the returns a domestic solar PV system can provide, especially if you are fortunate to have suitable roof space and orientation.
  3. As is my way, I've got this all charted: Chart shows the cumulative costs for electricity since the retailer's smart meter was installed. The top dark section is what we would have paid without the solar PV system. The next lighter section is what we pay now. Beneath that are two more lines. The dashed line is what we would pay if we were on a Time Of Use plan rather than out current flat rate plan. The bottom dotted line is what we would have paid if we also had a battery installed, with a Powerwall 2 specification. What this shows is the very big impact solar PV is having, the additional benefit of having the data to assess the best plan option (i.e. swapping over to TOU plan) and the lousy return provided by a battery. At that rate and current costs (NSW) a battery has a payback period of more than 50 years. The solar PV on the other hand is on track to be paid back in under 4 years. Gotta love power meters!
  4. The nature of my roof means I'm also able to get up there on occasions. Usually it's to blow out any leaf litter in the gutters. Cleaning panels I'm not so sure as once there is water about it gets a whole lot more dangerous. It may be OK as I can just stay on the flatter part of the roof over our eaves but with a prosthetic leg I have less chance to catch myself if I lose balance the wrong way or slip with the wrong foot. Where we live we get a reasonable frequency of rain. Something I'll keep an eye on.
  5. Just do the numbers. With general dust or grime (most of which rain deals with), panel output may be 1% lower. That's the typical impact reported in the scientific literature. So for a decent sized 6.6kW system you might lose 70-100kWh of production over a year. That's ~ $20-$30 worth of power. Or $10 worth of exports. So are you going to pay someone a couple of hundred bucks to clean them or risk your neck for a $20 gain?
  6. There are scientific tests done to assess the impact of cleaning v not cleaning - it's something solar farms do. When you have hundreds of thousands of solar panels, working out the cost-benefit of cleaning matters to the bottom line. Correctly installed, the benefits of cleaning domestic solar PV typically doesn't make up for the cost/risk. Obviously there can be one-off circumstances where that's not the case or if you happen to live somewhere grime accumulates more quickly (near major roads or other sources of pollution, have trees overhanging, bats or birds crapping, live in a dusty area) and rain is infrequent. Sometimes those with salt spray also might need to do the off extra clean but again rain usually does the job.
  7. Solar leasing is not all that popular in Australia. It really only emerged as an option in last couple of years but uptake is uncommon. Probably because installation costs here are typically far far lower than in the UK or USA and so people opt to purchase outright. Solar installation costs in the UK are about triple per kW than in Australia and in the USA they are about double that of Australia. It's one of the very few technologies where we don't pay the living in Australia tax. People here either pay up front from their own savings or they arrange their own finance. Some take up finance offers offered by installers but these are essentially straight out loans, not leases and are not tied to the property title. Interestingly, the rate of solar PV installation in Australia is highest in the poorer areas. If anyone is considering a lease, please be aware that come time to sell a home it is likely the lease will be considered a liability on the home. In Australia the payback times on Solar PV installations are so good that a lease is unnecessary. Leasing is more likely an option for a commercial operation to preserve working capital.
  8. They will self clean with rain, provided they are not flat. Sure there may be some stuff that sticks a bit more (e.g. bird shit) and might need a clean. If you really have had a bad dust storm or smoke, and it hasn't rained for a long time then perhaps a spray with the hose is worthwhile but that's about it. If you have tree sap or debris (or bird shit from a perch spot), get the tree lopped. Be careful about heading up onto a roof, especially if you intend to use water up there. It can get very slippery and dangerous. Also I would suggest turning both the inverter and the DC isolator switches off just in case (if you operate a DC string inverter). A check each year to make sure everything is safe 'n' sound is worth doing.
  9. Panels definitely have a decline in performance in the heat. They are designed to operate at an optimum temperature (usually around 25ᵒC - panel temp that is, not air temp), and then as the panel itself gets hotter the output declines. This temperature coefficient is typically in the order of 0.5% per ᵒC. It will be part of the specification of the panel. Panels on the roof in full sun can easily be 65ᵒC. Cooling the panel will see an increase in output and as you note it can be significant. This is why sunny cool days can result in higher peak outputs that hot summer days. I would be careful though in applying water to cause a sudden temperature changes to panels, there is the potential to cause micro cracking damage with rapid contraction of materials. This typically isn't an issue with rain because cloud cover already takes the heat out before rain does. That said, there are a few who have set up watering systems for their solar PV systems - usually via a misting application and a closed water system (tank water return via gutter) and pump. They figure that for some hours the increase in PV output far outweighs the cost of running the pump. It'd take a while though to recover the expense of set up and you'd want it to have some intelligence built in to assess when it's worthwhile running. If you have the roof space, it's far easier and cheaper just to put a few more panels on. That's the thing with solar PV, making up for inefficiencies with extra panels is typically the best way.
  10. This may indeed end up being a problem for those late to the party. As more solar is installed in a local area, the network service provider will likely begin to limit the size of new systems they will permit and reduce the export limit for new systems. In order to cater for the expansion of generation capacity in a local area, they may be required to invest in upgrades to transmission lines and especially to transformers. Something they may not want to spend money on. Easier to just cap the problem.
  11. It's why having the data on your energy flow patterns really helps. If you have a distributor's smart meter installed (common in some states, less so in others) then the data is available upon request from your retailer or from your network service distributor. They must provide it under law. If you don't have such a meter (it's pretty much a requirement if you have grid connected solar), then at least have the aggregate energy use data from your electricity bills over a year or two. That's at least sufficient to work out what the likely benefits are.
  12. If you have a reasonable amount of north-ish facing mostly unshaded roof space in Australia, and you expect to be in your home for many years to come, then the excellent financial benefit of installing solar PV is almost a lay down misère. Obviously every individual case on its merits but as an investment its ROI is very hard to beat. Of course doing the shopping around for a good deal on energy costs is also a worthwhile exercise. Use the comparison sites, find the options then talk with your current supplier. As a rule of thumb they will seek to keep you with a better offer. It may not match an offer you find, but you are still going to be paying less.
  13. It wasn't separately itemised price on the quote/invoice. In some cases the meters are part of the bundle. It's the 3-phase version of the Fronius meter so they are usually around $650 or so installed I think, but that's when done as separate install - whereas mine was done at same time as everything else so presumably that reduces the cost a bit (sparky already here, board wiring already being modified to suit, inverter settings adjusted etc). The single phase one is cheaper, about $350 I think. When I look at the data and modelling I'm doing, the decisions it enables means it will pay for itself in under 2 years.
  14. Much depends on what you are looking to achieve and your tolerance for the indoor trainer. Here's an oldie but a goodie, the Hour of Power: https://wattmatters.blog/home/2009/02/hop-to-it.html/ And a classic 2 x 20: https://wattmatters.blog/home/2007/01/two-by-twenty.html/ This one explains why we might choose to do such a workout: https://wattmatters.blog/home/2008/07/two-by-twenty-take-2.html/
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