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<blockquote class="ipsBlockquote" data-author="NTA" data-cid="557614" data-time="1455016558">
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<p> :lol: I'll have to do it solo - wife says she's never leaving this house!</p>
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<p>If I <em>was</em> to go on something like Grand Designs, without shadow of a doubt it would be a earth-sheltered house. Energy efficient, basically fireproof, no need for air con or heating, and accessible for self-sustainability. Throw some panels on a couple of Powerwalls in there, and you're off-grid for life.</p>
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<p><a data-ipb='nomediaparse' href='http://www.baldwinobryan.com/'>http://www.baldwinobryan.com/</a></p>
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<p>I fricking love those.</p>
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<p>All you have to do is find a non earthquake area, so anywhere in NZ other than the North Island. Or South Island.</p> -
<p><a data-ipb='nomediaparse' href='http://www.vox.com/2016/2/5/10919082/solar-storage-economics'>http://www.vox.com/2016/2/5/10919082/solar-storage-economics</a></p>
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<p>Vox talking about Solar + Storage</p> -
<p>Will give that a listen at home.</p>
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<p>In other news: the battery has topped up as of 1:45PM local time (DST) today - 12:45 standard time.</p>
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<p>If the house is consuming around 0.5-1kW when we're home in the evening, I'll be able to run anywhere between 6-12 hours I reckon. Have to see how the Lithium will perform over time, and ensure minimums are set in regards to Depth of Drain.</p>
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<p>Never want to take a Lithium battery to 0% on a regular basis as it fucks the chemistry. But they recommendation of 20% minimum I reckon can be pushed a little. Will talk to the inverter guys about how to set that up.</p>
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<p>[attachment=1964:20160210_solaredge.png]</p> -
<p>A little test when I got home this afternoon - knowing it was in the mid 30s and the wife was just going to punch the air con when she got home, I decided to beat her to it.</p>
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<p>This is a before and after shot of things as they stand. Taken about ten minutes apart around 5PM:</p>
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<p>[attachment=1965:20160210_AirConComparison 5PM.png]</p>
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<p>Therefore, the ducted air con required about 6.15kW to operate, of which it pulled all the panel generation at that time of day (2.55kW), power from the battery (2.45kW, which would deplete it in under three hours), and still needed feed from the grid (1.48kW).</p>
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<p>Battery is now at around 57% because the panels at this time of day start to run out of puff, so it replenishes slower. And I think the thermostat on the air con is fucked, because I set the damn thing to 25 and its gotta be colder than that!</p>
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<p>Thing is, the west side of the house is where the kids rumpus and the garage is, so it cops a beating. I've floated the idea of putting up awnings on that side of the house, but Mrs TA is against it. She'd rather watch our money burn...</p> -
<p>Put the dishwasher on the shit list. FFS its like the fluffybunny who built this place bought the least efficient appliances just to piss me off... Next time we come around to replacing the kitchen stuff, the star rating for these fucking things is going to be a LOT higher.</p>
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<blockquote class="ipsBlockquote" data-author="gollum" data-cid="557627" data-time="1455026250">
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<p><a data-ipb='nomediaparse' href='http://www.vox.com/2016/2/5/10919082/solar-storage-economics'>http://www.vox.com/2016/2/5/10919082/solar-storage-economics</a></p>
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<p>Vox talking about Solar + Storage</p>
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<p>Addresses a point that a lot of analyses here are missing: selling back to the market. At present, I'd get 5-8 <em>cents</em> per kW I distribute off the panels. So, if I had a good day, maybe $1.00 / diem.</p>
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<p>That Reposit mob I was talking about are very enthusiastic, and the GridCredits scheme is looking at up to $1 / kWh - so on a good day I could sell the content of the battery (topping it up off the panels) for $7.00 / diem. Not that I probably would, because good days are not the majority.</p>
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<p>But with the algorithm they've developed to look at usage, weather, a grid requirements, anything above $85c that day will cover my daily connection fee, and everything after that offsets my import charges.</p>
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<p>The good news, this morning, is that the software I have is reporting enough battery to get us through breakfast and to work. Thanks to Mother Nature for providing us a cool afternoon where the wife didn't feel the need to scramble for the air con. The missing graphic is the solar panel, which is doing fuck all anyway, this time of morning.</p>
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<p>[attachment=1968:201602120625 - Copy.png]</p> -
<p>Been playing around with the web portal supplied by the inverter mob, and looking at how they do charts etc. I'm not convinced the data is 100% accurate - the installer said it may occasionally go a small percentage over or under because of electrons and shit - its pretty close. Occasionally I see the battery feeding the house AND the grid, but they said it could be a bit of feedback as the circuits switch direction. They'll check it out.</p>
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<p>Here is an example of one of the power graphs they provide which shows various click-on/off options in the GUI - some of this data I can actually use later to chart it on the blog I'll set up, in different layouts. Should be fun.</p>
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<p>You can see from this a graph of power ins and outs recorded for the last 24 hours or so. </p>
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<p>[attachment=1971:GraphExample.png]</p>
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<p>The first massive red spike (consumption - first arrow) is the air con going on around bedtime for the kids (bit stuffy in their rooms) last night (12th Feb) and the battery trying to keep up with it. The battery has a peak output of 3.3kW and did valiantly, but the ducted air pulls anywhere from 5kW upwards based on recent experience with this interface, so that is always going to hit the grid for some of its power.</p>
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<p>Then, during sleepy times shortly after that, the battery (blue) is keeping up easily with the power needs. Due to the bathroom light being on, and various other things like the alarm system, TVs on standby, devices charging, fridge etc. the house draws about 200W on average from the battery over the 6 hours from midnight.</p>
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<p>As we move toward 0800 hours, the NTA Clan are on the move, using power for breakfast activities and turning on the TV and stuff, and the solar generation also starts. Was a fucking mint day for it in terms of cloud, as you can see by the green curve. Just gunned up to 4kW by the middle of the day, then declined gracefully toward evening. Another 32kW day! But why didn't it really go over 4kW? The answer is in the panel efficiency: ideal temps are 25C, so anything about that and you start to lose a few watts here and there.</p>
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<p>But you can see around 2PM (second arrow), the air con went on again as the temp started to climb into the high 30s and even my sense of economics took a back seat to Mrs TA's need not to sweat (and no, I have NOT broached the topic of menopause - I want to live to see this system hit ROI! )</p>
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<p>As we tail off toward evening, everything is fairly stable, with another little spike (third arrow) showing where Mrs TA used the hair dryer after being in the pool. </p>
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<p>Right now the battery is supplying the house needs of of 0.47kW as the kids are in bed, one ceiling fan running, and this PC plus the fridge etc. I have 30% of the battery left to play with.</p>
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<p>Here is a zoomed in version of midnight to 6AM.</p>
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<p>[attachment=1972:graphzoom.png]</p>
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<p>Looking at it this way: if I go to sleep with about 30% of the battery available, keeping in mind it cuts out at 5% to preserve itself, the house can run for around 8 hours in "standby" mode without calling on the grid. That may shorten over time as we tweak battery settings, and as summer dies off and I don't need the air con and have more available in the battery for night time, sleep time, and breakfast.</p>
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<p>It looks a fairly good argument for a 95% reduction in grid usage alone.</p> -
<p>Also: its going to get to 39C here tomorrow, so we need to get the fuck out so I'm not burning my money in that fucking ducted system!</p>
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<p>And the polyphase (multi-directional) meter is installed on Monday apparently so I can start getting money for all the exporting I'm doing.</p> -
<blockquote class="ipsBlockquote" data-author="NTA" data-cid="558538" data-time="1455361367"><p>Also: its going to get to 39C here tomorrow, so we need to get the fuck out so I'm not burning my money in that fucking ducted system!<br>
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And the polyphase (multi-directional) meter is installed on Monday apparently so I can start getting money for all the exporting I'm doing.</p></blockquote>
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But you'll spend money driving, buying lunch, drinks etc -
<blockquote class="ipsBlockquote" data-author="taniwharugby" data-cid="558585" data-time="1455391578"><p>But you'll spend money driving, buying lunch, drinks etc ;)</p></blockquote>
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That was likely anyway - I have a wife. <br><br>
But at least THAT money is put to good use. -
<p>Do you know what the SEER rating (or Aussie equivalent) is for your AC unit? How many tons (or BTUs) is it? You can do the calculations to figure out how much it is costing you to have a less efficient unit. When I replaced my 20 yea old 10 SEER AC and furnace 2 years ago, to jump from the 13 SEER minimum to a 16 SEER unit involved a 15 year payoff before breaking even. Based on my usage, house size, current price of energy etc etc. It only got worse for the even more energy efficient units I looked at. I did spring for a wifi programmable thermostat though. Never touch it, it is programmed and has setbacks and schedules it follows to minimize AC and furnace usage. And I can access it remotely, say if I go out after work for a few hours. Why pay to heat or cool an empty house.</p>
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<p>Interesting - and the point about the ROI is well made. The unit in the house is only 4 years old. Unless the fluffybunny who built this joint bought it off eBay (like he did the pool) then I think any investment there is going to be too far a bridge for the ROI component, and the post-panels budget. So I just have to suck it up and offset it with as much power selling as I can manage.</p>
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<p>Not to mention the unit is mounted in the ceiling so you need to basically rip the roof apart to get it out.</p>
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<p>Here's the thing that shits me the most: we walked into the house this afternoon, and its a 40C day in Sydney. The house had been opened this morning and was a decent temperature - maybe low to mid-20s except for the west-facing room which always heats up in the afternoon because sun.</p>
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<p>Anyone sensible would just shut that room, let the rest of the house sit in dark coolness, and turn the ceiling fan on and sit in the east side of our house. But because the kids play in the west-facing room, she walks in there "Too hot!" and reaches for the air con, turned down to 24C - the thermostat is in the middle of the house so at least that will mitigate some damage.</p>
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<p>But its still on because SHE feels hot.</p>
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<p>And THEN SHE GETS A FUCKING CUP OF TEA FOR FUCK'S FUCKING SAKE! </p> -
<p>this is gonna put a strain on your marriage NTA!! </p>
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<p>Blinds and closed curtains for that west room? Does Aussie construction have insulation in the attic/crawl space above the living space? Might be worth doing a check and seeing if it would make financial sense to blow in some more, and see if that helps lower the house temp. </p>
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<p>Does anyone see NTA in the future ala Jack in the Shining, walking around mumbling about kW and air leakage.</p> -
I hate aircon. I guess it's necessary if it's 40 odd degrees and there's sauna like humidity, but overuse makes it almost impossible to go outside or even be able to tolerate relatively mild heat. I'll take a fan or a nice breeze any day. <br><br>
You have to be tougher Nick. I'm like farking Hitler with the aircon remote at my house. -
I hate aircon. I guess it's necessary if it's 40 odd degrees and there's sauna like humidity, but overuse makes it almost impossible to go outside or even be able to tolerate relatively mild heat. I'll take a fan or a nice breeze any day. <br><br>
You have to be tougher Nick. I'm like farking Hitler with the aircon remote at my house. -
<p>Rancid - exactly what I was saying to a mate: once you jam the aircon down to 23C, anything feels like its too fucking hot. Almost like drug addiction, and that is the wife's problem coming home from work - leaves an air conditioned office and hops in a hot car which she blasts the A/C into, then gets home into a hot garage. Walks in the door in work clothes, doesn't even take time to acclimatise or change into casual clothes, and she's setting things to "Arctic" while the rest of us are sitting there with a glass of cold water wondering what the fuck is going on.</p>
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<p>40 degrees sucks, but today when we got home it was tolerable and FUCKING POOL IN THE BACK YARD! She napped on the couch, turned up the AC and then had a cup of tea to "wake up" - again, female logic.</p>
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<blockquote class="ipsBlockquote" data-author="rustycruiser" data-cid="558682" data-time="1455428282">
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<p>Blinds and closed curtains for that west room? Does Aussie construction have insulation in the attic/crawl space above the living space? Might be worth doing a check and seeing if it would make financial sense to blow in some more, and see if that helps lower the house temp. </p>
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<p>We have batts (glasswool or fibreglass if you like) across the whole ceiling space. The only weak points are where the light mountings are around the kitchen, which have internal transformers. I had the blow-in recycled paper stuff in the last house, and while it was spectacular the first couple of years, long-term it was poo - air pressure or drafts and it all blows away or settles. The ceiling space is quite high, has a solar-power extractor fan to keep it below Ninth Level of Hell hot, and the sarking (against the corrugated steel roof) is top notch according to every tradie who has been up there.</p>
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<p>The problem with the west room is it only has venetian timber blinds on the inside. I'd get external blinds but that is another fight. Maybe heavy curtains in winter to help keep a better buffer zone, but here in Oz, the best idea is always to keep the heat as far from the house as you can manage.</p> -
<p>Look, to be fair, I have already made her change a couple of habits like running the dishwasher and washing machine during the day, and understanding that delaying one by 3 hours and one by 5 hours just works. Baby steps. She's a city girl, never really been disconnected like sometimes happened out on the farm I suppose. I think she has some complex from when she grew up in a small house, and how she went without things, and doesn't feel like she should now.</p>
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<p>When that first electricity bill comes in, it won't be full solar, because we've only had it three weeks and will be halfway through a billing cycle - plus the meters don't change over until next week (lazy fucking wholesaler) so the full effect won't hit this summer.</p>
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<p>But when that first bill for the March-June period hits, and we're using fuck all because we don't need the air con, or run the pool pump as much, she might begin to understand the extra changes we need to take the power bill reduction from 90% to 100%, or even 110% when we start selling power back to the grid.</p> -
If you're going to just use aircon all the time then a pool is pretty much pointless. I never had aircon when living in Brisbane, but always had a pool. That was the essential way of keeping cool back then. I remember a mate had aircon in one room and that was amazing. Everyone has it now.
Solar Power and Storage - a nerd's view