Browse Forums Heating, Cooling & Insulation 1 Jul 23, 2011 8:25 pm Am looking to add solar panels to my house - 23 square house, no swimming pool, 2 occupants. West coast of SA, low rainfall area - aprox 7in / year in old money. Am hoping system with 3.6k inverter and 15 panels will cover or almost cover our usage - average daily use according to our summer bill was 24 kw/day - would be less in other quarters and less now son has moved out but unfortunately havent kept back pages of those bills. Quoted cost of $17,800 with Combined Solar - does this sound reasonable? What have others paid and how many panels have you gone for and how happy are you with outcome? Re: Solar system questions 2Jul 23, 2011 8:29 pm sound a bit dear,I have had quotes 4 kw sonnyboy inverter 14000 with rebate Re: Solar system questions 3Jul 23, 2011 8:31 pm The inverter is 3.6kW, but what is the output from the solar panels. This is what matters. For instance, if the panels are 180W each then 15 panels would be 2.7 kW. To cover 24 kW.hrs per day, you would need a 4.4 kW system (you get lots in summer, less in winter and the average is about 5.5 hours of "equivalent full sunlight" per day). Demolition August 2009, Construction Started September 2009, Completed December 2010 Re: Solar system questions 4Jul 24, 2011 11:09 am Thinking this through a bit more - the 24kw/day quarter = a $621 bill, the other 3/4 of that year were bills of $ 411, 391 and 289 - extrapolating from this, our average usage over the year was probably around 15kw day and will be less now son has moved out - is my logic right so far? So, Casa, are you saying the output from the panels would only be 2.7kw/day - that is less than a fifth of our estimated usage???? Is this taking into account our climate and location? According to the sales rep we would average 6 - 8 hours of direct sunlight here a day. Hardly seems worth the capital outlay - such a small dent in elec usage and cost resulting?? I should add that the price is all inclusive - installtion, the smart meter from ETSA etc. ETA: Pattycake, which state are you in - I wonder if the rebates are different from state to state - also I think the feed in tarrifs are - in SA it is 44c for another 16 years if you sign a contract before Sept 30th , plus each elec company adds their own few cents on top of this. Re: Solar system questions 5Jul 24, 2011 12:31 pm In Vic,I think our feed in is 60 cents or there abouts Re: Solar system questions 6Jul 24, 2011 12:45 pm Helyn So, Casa, are you saying the output from the panels would only be 2.7kw/day - that is less than a fifth of our estimated usage???? Is this taking into account our climate and location? Basically what i think casa is saying is the inverter capacity won't tell you how much power you get. You need to find out the rating of the panels and multiply by it by the panel rating to get a total kw panel rating. You then multiply the panel rating by around 3.5 (that's the figure I use for Melbourne) to get the amount of power you will get on an average day. Here is how I worked out whether solar power added up for me. http://www.anewhouse.com.au/?p=820 The Harder You Try - the Luckier You Get ! Web site http://www.anewhouse.com.au Informative, Amusing, and Opinionated Blog - Over 600 posts on all aspects of building a new house. Re: Solar system questions 7Jul 24, 2011 6:39 pm The equivalent peak hours of sunlight can be found in tables like http://www.gtmall.com.au/guides/solarpanel/. I see Sydney averages 5.1 hours per day, while from the top of my head I used a figure of 5.5. Close enough. Helyn, to work out how much you wil produce you need to look at the rating of the solar panels. They are typically around 180 W, but depend alot of what type of panel they are and how big they are. You should be able to look up the solar panels you plan to use on the web and see their rating. Yes, it looks like your usage averaged over a year is 15 kW.hr per day. So, you would need a 15 kW.hr / 5.1 hrs worth of panels = 2.94 kW. So a 3 kW system would be the way for you to go. Remember, that's the rating of the solar panels not the inverter. The inverter just has to have a greater rating than the solar panels. Adelaide has about the same latitude as Sydney, so I would expect the same hours of sunlight. You may get 6 to 8 hours of sunlight per day, but the strongest hours are around midday. Therefoe the 6 to 8 hours of sunlight reduces to about 5.1 hours of equivalent peak sunlight, if you know what I mean. Just as bashworth said. Take the rating of each panel and multiply by the number of panels then multiply by the average equivalent peak hours of sunlight. There's no need to match usage exactly with generation, particularly if you get generous feed in tarrifs like 60 cents per kW.hr. The equivalent peak sunlight hours in Melbounre is 4.6. Hope this all makes sense. My kids are tugging at me to play games with them so if it doesn't make sense or you want more clarification, just let me know. Demolition August 2009, Construction Started September 2009, Completed December 2010 Re: Solar system questions 8Jul 25, 2011 9:25 am Quote: You may get 6 to 8 hours of sunlight per day, but the strongest hours are around midday. Therefoe the 6 to 8 hours of sunlight reduces to about 5.1 hours of equivalent peak sunlight, if you know what I mean. No, I dont really get that - but will look up table in link and see if our area is covered - we live in Whyalla, 350k west of Adelaide, because it is dryer here, more sunny days (a third of Adelaide rainfall) we should get better returns than Adelaide, even if we are on same latitude. . Will check in the sales brochure which panels we would have and check them out - just google something like solar panel comparisons? Thank you for your assistance, everyone. Re: Solar system questions 9Jul 25, 2011 11:07 pm In simple terms (and please, anyone correct me if I'm wrong) what casa is saying is that solar panels do not produce their max output for every hour the sun is up. My 1.9 kw system ramps up and ramps down in power generation as the sun rises and sets each day. In the early morning when the sun is at a low angle my entire system of panels is only producing 200-300watts at best (0.2-0.3kw). The hour after daybreak is classed as a "daylight hour" but my system has nowhere near produced 1 KwHour of power in that first hour of daylight. Given it's Winter and the Sun's angle in relation to my panels is not at it's absolute optimum, it takes me about 2.5 hours of actual sunlight in the morning to make 1 KwHour of power. The same applies in the afternoon. The best part of the day to produce power is obviously in the middle of the day when the sun is high in the sky and my system produces more power as the sunlight angle is at it's best in relation to my panels which at this time of year my panels are peaking at about 1500-1600 watts (1.5 - 1.6kw) at the best part of the day. For my system, facing due North, no shade, in the middle of winter, in Sydney, it's making about 5.0 - 5.1 KwHours of power a day. This is except for last week when it rained everyday and I made bugger all power but my rainwater tank is full Hope this helps. Re: Solar system questions 11Jul 26, 2011 11:16 pm Helyn ETA: Pattycake, which state are you in - I wonder if the rebates are different from state to state - also I think the feed in tarrifs are - in SA it is 44c for another 16 years if you sign a contract before Sept 30th , plus each elec company adds their own few cents on top of this. My understanding is that in SA the system must be installed and you must have the certificate of compliance by 30th September to get the 44c feed in tariff (signing the contract by 30th September is not enough). You then have an additional 4 months to get the import/export meter to finalise the installation and confirm qualification for the 44c feed in tariff. You need the feed in tariff and to change your habits to eliminate your bills. eg try to use as little power during the day so you can sell it back to the grid at 44c and do the washing, dishwasher etc at night so you are buying at 24c. Then you don't need a system that produces all the daily KWH that you use, only part of it. Slab Down: 2/6/11 Moved in 13/3/2012 Current Status : Waiting for the garden to grow. My build thread : viewtopic.php?f=31&t=47031 Re: Solar system questions 12Jul 27, 2011 9:47 am Crow, we were told you only have to have contract signed by 30th September, not neccesarily have system installed by then. Will double check on this as they have told us 6 - 8 weeks from signing until installation (it may be less than this in metropolitan areas but takes longer in country) so plausible will not be installed by Sept 30th. Have decided to go for 18 panels which according to sales rep will produce on average 13kw/day in our area - if we are using on average 15 kw and dropping (as only 2 people in household where there were 3 for 9 of last 12 months) this should cover us nicely. Yes, I get the advantages of using more electricty at night - as we are mostly out at work during the day this would be the case anyway - but will remember to charge phones, laptops, and do other such things overnight. Re: Solar system questions 13Jul 27, 2011 9:59 am (The deadline for approved application of permission to connect in order to take advantage of the generous 44c/kWh feed in tariff rate is 29 September, 2011.) This is from this site here: http://www.solarchoice.net.au/blog/sa-f ... ry-debate/ and reads to me that one only has to have contract signed and application approved. Hope that is correct. Re: Solar system questions 14Aug 23, 2011 1:05 am Typical annual solar output is about 1600 kWh/kW system. In Adelaide it is about 2/3rds of this in winter and 1/3rd higher in summer. i.e. for a 1 kW system - 4.4 kWh/day (average). 2.7 kWhr/day (winter), 5.7 kWhr/day (summer). Check out typical monthly outputs in Adelaide from this site. pvoutput.org I looked into it a few years ago and my conclusion was to just build a carport that will support panels and get a system installed separately. The company I looked at had… 1 5421 Once you know the basics, the rest is easy. Read my post in the thread linked below. viewtopic.php?p=1919271#p1919271 2 15419 It's all about wireless, self install now. The cost/benefit of wired setups for the house are no longer what they used to be. Lots of wireless options. Eufy, Arlo and… 2 6798 |