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Post by technoish on Mar 22, 2022 9:51:58 GMT
Did they provide return on investment calculations?
Will you actually fill up the battery on an average day?
A key difference between Tesla Powerwall systems and other systems is that you should be able to use the stored energy in a powercut and I believe also continue to use the solar panels. For other systems, the system cuts out as to avoid any electricity going back into the grid (and risking electrocuting people fixing the grid).
So a Tesla system should allow you to actually be off grid. Other systems will not work without the grid functioning.
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Psiloc
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Post by Psiloc on Mar 22, 2022 12:06:26 GMT
Woohoo I think IFTTT is going to work.
Bit fucking random but I can do an IFTTT alert based on whether an Android device is charging or not. So I can get a junk old phone out of my drawer and plug it in to the plug socket permanently and IFTTT will tell me whether it's charging or not, i.e. whether there is spare solar. I can then control a smart plug based on that
Incidentally IFTTT is way easier to use than I thought it would be
I prefer the idea of this potentially wobbly power supply being used with a USB charger anyway now that I think about it.
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mrpon
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Post by mrpon on Mar 22, 2022 12:16:43 GMT
Great news! In other news, I'm looking at PHEV cars for a renewal in Oct. Had a test drive of the Kia Sportage HEV, which was nice, although distracting looking at the dash to see if/when it was charging!
Have you considered a PHEV Psi? I would love to have it charged up via solar, but that's another project.
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Psiloc
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Post by Psiloc on Mar 22, 2022 12:24:59 GMT
I strongly considered a PHEV for my new car actually but I went with a mild hybrid instead. I couldn't get the economics to work, for several years the price premium was considerably more than the money I'd save on fuel.
I reckon I'll be having something like that for my next car though
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Post by technoish on Mar 22, 2022 13:58:39 GMT
Net zero tho...
I plan to never own an ICE. Currently testing a Kia EV6. It's an ugly beast I guess, but lovely inside etc.
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Psiloc
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Post by Psiloc on Mar 22, 2022 15:16:26 GMT
It wouldn't surprise me at all if I regret my decision sooner rather than later on that score.
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mrpon
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Post by mrpon on Mar 22, 2022 15:56:16 GMT
Well my work commute is 1 mile, yes I know, I do walk somedays. The GFs is 30 mile turnaround, so figured the ~40 mile range could work for me. ymmv (no pun intended)  |
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Post by technoish on Mar 23, 2022 19:20:40 GMT
I've been quoted just under 4.5k for 7 panels of 390w, giving a total of 2.73kw which is the best quote I got out of 4. That's fitted, as well. The price of batteries is the setback. Company I'm using exclusively install Tesla, which is around 8 grand for a 13.5kw draw down. In theory, that gives you a day and a half of electricity. But I'd rather get a smaller battery (as they have a life of around 5-8 years) to see how it goes and then get a new one when the technology improves. That will save you a bunch |
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geefe
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Post by geefe on Mar 24, 2022 7:53:56 GMT
I saw that yesterday but am still somewhat on the fence about it. £4.5k (+ battery) is a lot to spend. I'm south facing and do get the sun a lot, though.
Is there anywhere to find real people's experiences?
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Post by technoish on Mar 24, 2022 9:12:30 GMT
I saw that yesterday but am still somewhat on the fence about it. £4.5k (+ battery) is a lot to spend. I'm south facing and do get the sun a lot, though. Is there anywhere to find real people's experiences? There are loads of websites and dedicated fora. YouTube pretty good also actually. The thing to base a decision on is the calculations on ROI - did you get any? |
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Psiloc
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Post by Psiloc on Mar 24, 2022 9:19:31 GMT
I saw that yesterday but am still somewhat on the fence about it. £4.5k (+ battery) is a lot to spend. I'm south facing and do get the sun a lot, though. Is there anywhere to find real people's experiences? I'd pull the trigger at £4.5k. You should be able to add the battery on at a later date if you wanted to stagger the cost / see how you feel about it down the line? Do you have a hot water tank + immersion heater by any chance? |
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geefe
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Post by geefe on Mar 24, 2022 10:49:30 GMT
Combi boiler.
The ROI calculations I got were a bit mixed. One said 6 years (lol sure) and one put it closer to 10.
I also gather that selling back to the grid is almost pointless, as you sell it to them for 6p and they sell it for 30p. Advice seems to be just get a battery and store it.
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dam
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Post by dam on Mar 24, 2022 10:59:38 GMT
The electrician I use is thinking about fitting a second Tesla battery to his house, so it's clearly working from him. He's got solar panels and electric cars/van.
If anyone is looking at this sort of thing in Scotland, I can recommend someone. We'll bite the bullet some day. Wish we had done it 15 years ago, but always assumed we would move house.
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Post by dfunked on Mar 24, 2022 11:10:15 GMT
Yeah, moving house is what's stopping me from doing it. Can't see us staying here more than a few years, so just doesn't seem worth looking into.
One day when we finally get that forever home...
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geefe
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Post by geefe on Mar 24, 2022 11:22:03 GMT
The electrician I use is thinking about fitting a second Tesla battery to his house, so it's clearly working from him. He's got solar panels and electric cars/van. If anyone is looking at this sort of thing in Scotland, I can recommend someone. We'll bite the bullet some day. Wish we had done it 15 years ago, but always assumed we would move house. Tesla battery I got quoted £8k, fitted. Can't afford that. It's why I'm looking at a smaller battery, especially as I'll be one person household for a reasonable portion of the next 18-24 months. |
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Psiloc
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Post by Psiloc on Mar 24, 2022 11:25:39 GMT
Combi boiler. The ROI calculations I got were a bit mixed. One said 6 years (lol sure) and one put it closer to 10. I also gather that selling back to the grid is almost pointless, as you sell it to them for 6p and they sell it for 30p. Advice seems to be just get a battery and store it. If you can't use the spare energy for hot water heating then yeah I'd strongly consider a battery. With a Tesla battery and the quoted panels on a south facing roof I doubt you'd pay for much electricity at all during the brighter months. Without any form of rudimentary energy storage a lot gets exported. Don't forget you there's nothing stopping you from selling excess back when the battery is full anyway so best of both worlds. I'd be slightly jealous tbh, you'd never have to think about it at all, it would just manage itself you'd just be saving money year in year out. Meanwhile I'm rigging Android phones up to my solar panels to get IFTTT notifications |
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Psiloc
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Post by Psiloc on Mar 24, 2022 11:28:04 GMT
Ah just so you know I think Tesla batteries only get sold with Tesla panel installations so you won't be able to mix and match
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zagibu
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Post by zagibu on Mar 24, 2022 12:40:44 GMT
Whether or not a battery is worth it right now depends on how much of the electricity you produce during peak hours you can actually use. If you can use it to heat/cool your home (heat pump) or boiler, for cooking over noon, maybe later do the laundry as well, then it might not yet be worth it. But if you have an electric car for example and it's sitting at your employer's place over the peak hours, then a battery can be worth it already, just to store the peak hours and later charge your car in the evening with it. Of course, electricity costs probably won't be going down anytime soon, so it might be worth it anyway if prices continue to go up. On the other hand, battery tech is improving at a quick pace, so maybe you can buy a battery for half the price in a few years with the same energy density. Lastly, there's also a political element. Currently, the electricity market is not very open, which is why providers can buy your electricity for peanuts and resell it for 5x the price, but that might change. There are already some changes in some countries that allow you to locally share self generated electricity, which can make it much more worthwhile to sell it to your neighbours in a local grid. In the future, I think batteries will only be placed where the consumer mix is very uniform, for example in residential areas where people aren't home over noon, and the generated electricity would have to flow off the local grid. But if you live in a heterogenous area with some commerce and industry, it will make more sense to just sell it in the local grid instead of storing it.
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Post by spacein_vader on Mar 24, 2022 13:47:03 GMT
Had a quote yesterday, and the ROI was better with a battery. Unfortunately for the battery to really pay off we need a smart meter and our area is currently unable to be fitted with them. No news on when the systems will be upgraded round to allow this but for our household it's not viable until its done.
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Post by technoish on Mar 24, 2022 14:17:31 GMT
What we are getting installed (I am assuming the VAT will come off and reduce the cost by a good deal!)  |
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geefe
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Post by geefe on Mar 24, 2022 14:21:37 GMT
Is that battery 4kwh for 2 grand?
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Post by TheSaint on Mar 24, 2022 14:37:32 GMT
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Post by technoish on Mar 24, 2022 15:02:08 GMT
Is that battery 4kwh for 2 grand? It's £2481 for the battery system, 4.6kwh. I think that's an inverter and two batteries, which are modular and can be added to later. So adding more storage would be cheaper. Again take off VAT now (I assume!) |
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Post by Dougs on Mar 24, 2022 15:14:49 GMT
That'll be the installer pocketing that 20% imo...
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Post by technoish on Mar 24, 2022 15:17:23 GMT
Looks like we spend about £100 a month on electricity, so £1200 a year. The estimates are that we will get 50% from the solar, so that is a £600 saving annually. So that makes it about a 12 year pay back. Mind that this is before the energy price increases (which are like 50%) and also doesn't take into account what we sell back to grid (estimated at about 17% of our own energy usage). I expect we will actually use more energy ourselves and not sell as much back due to home working, but this increases how much solar we use as a proportion of total. And of course, now I can take off the VAT, so that knocks a bit more off also. Above all though, this is also about reducing carbon emissions, which definitely makes it worthwhile! |
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zagibu
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Post by zagibu on Mar 24, 2022 15:23:34 GMT
I don't know, is a 10 or 12 year ROI bad? I mean the panels easily last longer than 25 years...
The battery should also last quite long, because it's working in a good temp range and on an easy load cycle, unlike the one in an electric car or in most mobile devices. But probably not 25 years.
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Post by technoish on Mar 24, 2022 15:49:47 GMT
I don't know, is a 10 or 12 year ROI bad? I mean the panels easily last longer than 25 years... The battery should also last quite long, because it's working in a good temp range and on an easy load cycle, unlike the one in an electric car or in most mobile devices. But probably not 25 years. Indeed it's pretty good. I think you have to replace the inverter more frequently, but that is easily done and a fraction of the cost. My contract gives a rating for the batteries of 20 years (IE how much they will lose in capacity over time, it's 12kwh/year, based on starting with 768kwh/year, so after 20 years it would be at 528kwh/year. Also, surveys show it adding a fraction to the house price, so that probably immediately pays it off. |
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Psiloc
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Post by Psiloc on Mar 24, 2022 16:10:18 GMT
I think predicting anything about energy prices ten years in the future is a bit foolish tbh |
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Post by dfunked on Mar 24, 2022 16:47:13 GMT
*chuckles*
We're all doomed
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zagibu
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Post by zagibu on Mar 24, 2022 23:03:24 GMT
My contract gives a rating for the batteries of 20 years (IE how much they will lose in capacity over time, it's 12kwh/year, based on starting with 768kwh/year, so after 20 years it would be at 528kwh/year 768 kWh / year is only around 2 kWh per day, though. Isn't that a pretty small battery? Or is that estimated use per day and the battery capacity is way higher? 2 kWh is really nothing, that's an electric heater running for 1 hour. |
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