EEVblog #938 - Tesla Solar Roofs - Are They Viable? - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: October 31, 2016, 02:29:55 am
content: Solar Freakin' Roofs!How viable is Tesla's Solar Roof concept?What did Elon Musk not mention at the product launch?How efficient are they?Who much energy is required to manufacture them?What about optimum angle to the sun?https://www.tesla.com/solarEnergy required for existing roof construction:http://buildforliving.com.au/wp-content/uploads/2014/01/BR-Roof-Tiles-For-Living.pdfInternational Energy Agency on Efficiency:http://www.iea.org/publications/freepublications/publication/tracking_emissions.pdfUS Government on PV Energy Payback:http://www.nrel.gov/docs/fy05osti/37322.pdfList of solar single companies that have gone bust:https://www.greentechmedia.com/articles/read/A-Note-to-Elon-Musk-And-The-Brothers-Rive-on-The-Integrated-Solar-RoofDow Chemical Solar shingles goes out of business:https://www.greentechmedia.com/articles/read/dow-chemical-sheds-solar-shingle-businessSolar shingle efficiency:http://sunpowerbyinfinitysolar.com/solar-shingles-efficiency/Sun position and angle/elevation calculator:http://www.sunearthtools.com/dp/tools/pos_sun.php

author: boffin
author_rank: Unknown
timestamp: October 31, 2016, 02:45:32 am
content: Powerwall II ? Really? Why wouldn't you just do it with existing technology (Lead-Acid & electronics) all of which is available off the shelf right now? The advantages of Lithium batteries for cars make a lot less sense in houses, where the lower weight and size really don't make as much difference.As for the roofs, if they can make non-solar version, that looks the same, but without the solar (for a lot less money) for the off-side of your house they might have something.

author: riyadh144
author_rank: Unknown
timestamp: October 31, 2016, 02:48:53 am
content: We should wait for the datasheets, and prices to judge.

author: optoisolated
author_rank: Unknown
timestamp: October 31, 2016, 02:56:42 am
content: Aesthetically very much up to Tesla's usual standards. Gorgeous! At the end of the day though, if the cost of production plus the efficiency of the panels means they are still significantly below standard modular panels, I don't see this being more than a fad.The case for the Powerwall though; no-brainer if you can afford the initial outlay.

author: EEVblog
author_rank: Unknown
timestamp: October 31, 2016, 03:10:55 am
content: Quote from: boffin on October 31, 2016, 02:45:32 amI mentioned this in the video.

author: nuclearcat
author_rank: Unknown
timestamp: October 31, 2016, 03:12:44 am
content: Quote from: boffin on October 31, 2016, 02:45:32 amOne of benefits of lithium is that it might charge much faster. It might be beneficial for winter, if you are getting just few hours of sun, because on topping stage lead-acid charging is really slow, and if you have only 4 hours of sun, it is basically not enough to refill your batteries to full. So you might keep cycling between let's say 40-70% depth of discharge, which is not good at all for batteries health.Sure if i understand lead-acid charging process correct and my info might be outdated.

author: boffin
author_rank: Unknown
timestamp: October 31, 2016, 03:21:18 am
content: Quote from: EEVblog on October 31, 2016, 03:10:55 amOK, I admit I hadn't got that far into the video when I wrote this. But you're definitely on point, might make sense for one part of your roof (half of mine for instance that faces SW), but not for other parts, and putting something to optimally use it makes sense. I really don't understand why sunny climates don't have ordinances requiring solar panels on roofs, plenty of places in Aus or the SW United States are perfect for solar, yet I don't see that many panels when I visit the states.One application I did see and thought "Wow, that makes sense" is a company called Rio Grande (interestingly owned by Berkshire Hathaway aka Warren Buffet), in New Mexico USA, who used solar panels as car port roofing, and power their warehouse from it.https://www.riogrande.com/ad/responsibility

author: Someone
author_rank: Super Contributor
timestamp: October 31, 2016, 03:26:38 am
content: The orientation east/west away from ideal doesnt reduce the power generation as much as you might think.Through the seasons a flat panel (extreme vertical alignment) is not as bad as you make out.You could tile your wall in Melbourne Australia with a fully vertical alignment and get 60% of the optimal 30 something degree alignment, a flat install is over 80% of the annualised generation compared to the ideal fixed orientation.So,assuming you aren't shadedLess than ideal insulation angles would lose less than 50% overall, which will still payoff in many installations. The loss of generation factor from misalignment needs annualised numbers to back it up, not just single examples at one time of the year/day. Shadowing will be the killer not alignments and you can put cheaper but matching tiles on the sides facing away from the sun.

author: nuclearcat
author_rank: Unknown
timestamp: October 31, 2016, 03:43:34 am
content: Few questions of such roof might be interesting:1)Electrical hazard safety. While they claim their tiles are really strong, they don't go pieces, but they might still break. Adding that it is mentioned this shingles mostly are connected in series, if it will have similar micrometeorite impact as Dave has, it is possible that this shingle will be open circuit, and this part of roof, especially if it is wet will be under high voltage. And if such thing wont be noticed, stepping on such wet roof might be quite dangerous. Also, seeing how connector is done, and how many of them will be on roof, there is some risk of bad insulation/bad connection, which leads to same issue, especially it might happen after few years of operation, and due design it is really hard to check that connections. I am not talking that stepping on such shingles may cause disconnection and open circuit as well.As i read before, firefighters might not use some part of their strategy during extinguishing fire, because solar installations might be serious risk factor for them. With solar shingles it might get much worse.2)Solar cell efficiency drops when they heated, while regular solar panels design help them to cool down by free cooling, regular shingles according statistics can get up to 70C, and on this temperature efficiency drops quite significantly (30-40%? not able to get precise numbers).

author: GeekGirl
author_rank: Newbie
timestamp: October 31, 2016, 04:15:29 am
content: Hi all,My $0.02 (Inc GST)#1 People are saying no to whole roof as it will have a very low efficiency as an entire system. BUT I think we are looking at the problem the wrong way, these solar roof times are designed for when you build a new house / modify a house etc ie when you do the roof from scratch. So why not say we want 100% coverage. We want a good efficiency, So we will design the new roof to accommodate this ie like the old warehouse roofs where they were a saw tooth pattern. Then we can have BANKS of panels all pointing at the optimum angle at the best orientation we can achieve (the roof would still need to be square to the building or the builder would go nuts trying to construct it.#2 I think that it would be cheaper and easier to install if the "Tile" was a bigger size, as this would lessen the amounts of interconnects. If you use the idea above then you do not need to cut "tiles" as you can start from the centre of each row and have an overhang each side to take up the remaining width of the "tile"#3 As nuclearcat has mentioned interconnection is a major problem if the tiles are connected in a vertical column with the pins you can see at the top of the tile in the video, As the roof expands and contracts if will twist which will make connections go open circuit (even if they have a spring that is 100% of the thickness of the tile). This is not so much of a problem in the US and Europe where they tend to put sheets of plywood down before the tiles but here in Au where we have battens straight on the roofing timbers the roofs do move. They will also (as pointed out by nuclearcat) move and go open circuit as weight changes on the roof ie a human walking on the roof. This will lead to arcing (as this is DC after all) which over time will damage the contact..... Suddenly your roof is on fire. Also how are these tiles going to stand up to other trades opening up the roof ? (eg plumbers, electricians, security techs .....) Generally they just work out where they want to go in or above a cavity and kick a few tiles up ? What ever the interconnect system it needs to be able to withstand the abuse a roof gets !#4 I know fire fighters do not like anything that is live while they are trying to put out a fire. If they can safely reach the fusebox (at least around here) they will throw all the breakers and pull the supply authority fuses that way they know the only thing live is the overhead / undergound cable to the house and then to the fusebox. There have been designs I have seen for roof top solar isolators that are remote controlled and fail safe (if the house looses incoming power the inverter shouts down and the device opens the solar DC bus in both legs up on the roof before any cables go into the roof cavity)Regards,Kat." I am an Engineer, Not an English teacher, God Damn it" Moi 1999

author: station240
author_rank: Unknown
timestamp: October 31, 2016, 04:26:05 am
content: My understanding is Tesla/Solar City's solar roof is designed to solved a particular problem with US houses.That is where the home owner wants solar, but needs a new roof to mount it on.It's no accident the four roof tile types are those most difficult to mount normal solar panels to:a) Ashfelt sheeting roof mounted over plywood.... yeah lolb) Slate roofc) Tuscan tile roofd) Modern flat tile roof (actually not that difficult)I'm just not seeing this product selling well outside the US. Does Solar City even have a presence in Australia ?

author: ziggyfish
author_rank: Regular Contributor
timestamp: October 31, 2016, 04:50:53 am
content: When will the Left realise that there is no such thing as a one size fits all solution.Solar sounds great in theory, but in practice, it simply won't work on a large scale. This and Solar Freaking Roadways is the perfect example of this.Even those who say their state or country 100% relies on renewable energy are often using non-renewable energy to supplement it.Take South Australia. A fair bit of its energy comes from Victoria (it's the reason why South Australia had a statewide power outage this year), and soon to be NSW. However, the government argues that the state runs on 100% renewable energy.This same thing can be said for Germany and many other countries that claim to be 100%.-----We simply don't have the technology to make solar or wind a sustainable, efficient and scalable energy source.

author: boffin
author_rank: Unknown
timestamp: October 31, 2016, 04:59:39 am
content: Quote from: blueskull on October 31, 2016, 04:50:39 amIt's a good question, my parents had solar hot water on their house 25 years ago, and it's not like we have the most ideal weather for solar here in Canada. It was just a pre-heat tank for water going into the hot-water tank.

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: October 31, 2016, 05:15:01 am
content: Quote from: blueskull on October 31, 2016, 04:50:39 amThat's a thermosyphon system, which works well as long as the outdoor air temperature doesn't fall below freezing (tubes would burst otherwise). In freezing climates, one can use a dual-loop system that circulates water+antifreeze into a collector, and runs this through a heat exchanger to heat up water. Lots of info here:http://www.builditsolar.com/Projects/WaterHeating/water_heating.htm

author: ziggyfish
author_rank: Regular Contributor
timestamp: October 31, 2016, 05:31:53 am
content: Quote from: wilfred on October 31, 2016, 05:16:16 amWhat I am saying is that we don't have the advances in technology to make solar sustainable. Whether we will be able is yet to be known.Anyway hers the German reference.http://reneweconomy.com.au/germany-nearly-reached-100-percent-renewable-power-on-sunday-32091/

author: nuclearcat
author_rank: Unknown
timestamp: October 31, 2016, 05:36:18 am
content: Electrical supply has multiple challenges.1)Most of renewable energy are not stable in term of electricity generation. Exception - hydropower, it is plainly perfect. Solar has issues at cloudy weather, winter, night. Wind - depends.(Battery storage of energy economics/longevity/environmental impact are terrible, molten salt for solar/hydro storage is much more promising)2)Some supplies has drawbacks, for example some nuclear power cannot change output enough fast for fluctuating power consumption during the day. (not load following) Some are load following, but cannot compensate enough fast events such as "TV pickup".This means you need some very quick "maneuvering" capacity, and if you don't have hydropower, this means thermal plants (gas/coal), just to supply enough energy to provide sufficient power.It is serious problem, and very interesting indeed, i suggest read about TV pickup in wikipedia.Supplying energy from other areas has it's costs as well, because of transmission efficiency, line cost, fault tolerance questions and etc.So i believe it will be bad choice for current moment to be 100% renewable in countries who doesn't have enough hydropower, without having alternative ways to store energy. So only they can brag, when they have enough output at day from solar, that "waw, at current minute we are 100% renewable", but at evening, while demand much higher and there is no solar, they are burning coal like hell.I believe proper smart grid will help a lot optimizing consumption at low supply periods.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 31, 2016, 05:37:45 am
content: Video is showing as private

author: jonovid
author_rank: Super Contributor
timestamp: October 31, 2016, 05:47:46 am
content: Quotelike diesel vehicle emission claims. its all relative. even al gore has his own central air conditioning , but tells others not to have them.http://oilprice.com/Energy/Energy-General/Al-Gores-Hipocrisy-The-Climate-Crusader-Profits-from-Fossil-Fuels.htmlthe video is gonskiQuoteno one asks about fuel consumption if you own a Rolls Royce. its just about the most expensive things money can buy.however I find no fault in the idea even with no change in the weather whatsoever, whether you have this or not IMO . viability rests in the sales of the product.EV Rollshttp://www.caradvice.com.au/42211/rolls-royce-phantom-ev-in-the-pipeline/

author: nuclearcat
author_rank: Unknown
timestamp: October 31, 2016, 05:50:02 am
content: I dont want start conspiracy theories, but always they come up in mind.But let's hope they called Dave and offered him completely free installation for test, including Tesla car, in exchange for detailed review

author: jonovid
author_rank: Super Contributor
timestamp: October 31, 2016, 05:57:18 am
content: new video

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 31, 2016, 05:57:34 am
content: It's back - maybe just a YT glitch

author: nuclearcat
author_rank: Unknown
timestamp: October 31, 2016, 06:01:10 am
content: I think Dave just added "UPDATE: Yes, the press kit mentions they all have identical looking solar and non-solar tiles to chose from for shaded/inefficent areas." in description, and maybe to video.

author: zapta
author_rank: Super Contributor
timestamp: October 31, 2016, 06:15:14 am
content: Quote from: riyadh144 on October 31, 2016, 02:48:53 am... and subsidies and incentives. A key component in Tesla's business model.

author: Someone
author_rank: Super Contributor
timestamp: October 31, 2016, 06:31:43 am
content: Quote from: ziggyfish on October 31, 2016, 05:31:53 amStorage solutions exist and are already profitable, Tesla is pushing their batteries (which are not profitable for the owner in most circumstances) as one way to provide energy storage but pumped water is already able to store excess electricity generation economically. Chapter 26 of "Sustainable Energy – without the hot air" covers it well:https://www.withouthotair.com/c26/page_186.shtmlWhen you have zero cost (or negative cost) energy coming from the solar panels people will find uses for it.

author: coppice
author_rank: Super Contributor
timestamp: October 31, 2016, 06:41:39 am
content: Quote from: radar_macgyver on October 31, 2016, 05:15:01 amI haven't seen a thermosyphon system which is not dual circuit. I imagine there are a number of amateur systems like that, but do commercial single circuit systems exist?

author: jancumps
author_rank: Unknown
timestamp: October 31, 2016, 09:24:22 am
content: Quote from: mikeselectricstuff on October 31, 2016, 05:57:34 amMmmm. Not for me. Still shows "The video is private"

author: EEVblog
author_rank: Unknown
timestamp: October 31, 2016, 09:32:13 am
content: Quote from: mikeselectricstuff on October 31, 2016, 05:37:45 amNew version has been uploaded.

author: Artlav
author_rank: Frequent Contributor
timestamp: October 31, 2016, 09:58:14 am
content: A bit lower efficiency is equivalent to us aren't being in 2016, but are in 2010, for example. It's not a huge factor.A huge factor engineering people tend to overlook is public appeal.The solar installation being turned from some nerdy-hippy stuff into nice, sexy, pretty everyone-does-that stuff.That is the key value and selling point of this, i think.

author: neotesla
author_rank: Unknown
timestamp: October 31, 2016, 10:52:49 am
content: Good video, thanks, Dave.Sadly, the comments on YouTube videos, particularly this one, are becoming unreadable for unhinged swearing and aggressive stupidity. It's a good thing that they can't shoot guns in there, as there would be dead and injured. I suppose it goes with the territory of being massively popular. Note to self, avoid in the future.

author: nctnico
author_rank: Super Contributor
timestamp: October 31, 2016, 11:01:17 am
content: IMHO the concept isn't bad but what will break it are the many interconnects between the tiles which will make installation and maintenance costly (90% of problems with electricity have to do with interconnects). It does make sense to use bigger ('normal sized') solar panels to make a roof water tight because the original roof tiling underneath it is kind of redundant with solar panels on top. Then again solar panels over a roof should provide extra cooling to the house so less need to run the AC.

author: EEVblog
author_rank: Unknown
timestamp: October 31, 2016, 11:02:24 am
content: Quote from: neotesla on October 31, 2016, 10:52:49 amI just had to ban a troll. Don't have to do that too often. I suspect it was a previously banned troll with a new account.

author: nuclearcat
author_rank: Unknown
timestamp: October 31, 2016, 11:06:20 am
content: While cars are often premium product, as a watch or other luxury accessory, and frequently used to show off "social status" of owner, people in such cases doesn't really calculate efficiency that much and don't go in details. Especially because Tesla cars on road is clearly different, has very nice exterior and interior. Plus, driving Tesla across the city still draw attention.Energy product i believe a bit different. First, they took approach of making roof looking similar to existing slates, so you need to come to your neighbours, and tell look, dude, despite the usual look, actually i have fancy pancy expensive Tesla roof (and funny that Musk appealing exactly to that). But, well, not so impressive. You can't wear your powerwall or roof as backpack for some event.So they will come down to ground, calculating what does they spent and what they got back in return. It doesn't look so impressive:https://electrek.co/2016/07/27/tesla-powerwall-6-months-customer-review/, or even sometimes worse:https://bryanalexander.org/2016/05/29/the-tesla-powerwall-fails-life-as-an-early-adopter/Datasheets of Powerwall looks very rudimentary to compare with similar products in the market, no power factor info, no warranty for capacity for cycles/time, requirement to have constant internet connection (otherwise warranty void) and etc. And for now, regular AGM lead acid still looks attractive. I hope someone has done "real life" tests and calculations of efficiency, real capacity and etc.P.S. I'm living in a country where electrical supply are BIG deal. But still, economics of solar power sucks, and even here feasibility is questionable.

author: StuUK
author_rank: Frequent Contributor
timestamp: October 31, 2016, 11:07:00 am
content: Quote from: EEVblog on October 31, 2016, 11:02:24 amjust read the past posts, total troll...

author: digsys
author_rank: Unknown
timestamp: October 31, 2016, 11:19:49 am
content: Quote from: boffinThen you missed the key point :-)He's building a gigafactory. Sales to cars will take eons to make it worthwhile, LET ALONE provide R+D money to keep expanding technology.There are 100+ millions houses in USA alone, just sitting there, doing nothing :-)So, that already gives him an absolute unlimited market, which boosts R+D, plus making a cute panel 1/4 the size of Lead-acid, and no possibility of H2 or other smells.It's like Hybrids, a pretty much waste of time (all things taken into account), BUT they progress electric technology. Otherwise we'd still be twiddling our thumbs.Edit: Plus - who wants all that lead out there ! It's had it time.

author: rrinker
author_rank: Super Contributor
timestamp: October 31, 2016, 12:18:26 pm
content: I really wouldn't even need the 'fake' ones on my house, the way it is oriented, the sun rises on the right front corner and sets on the left rear so throughout the day, the entire roof gets some solar exposure - exactly where depends on the season.

author: Jeff_Birt
author_rank: Regular Contributor
timestamp: October 31, 2016, 01:01:43 pm
content: If you want to put a solar roof on your house I have no issue with that. If Musk want to spend millions of his own and his investors money to make them that is fine too. The only thing that will make it viable is government handouts to the factories and the rich people who have the money to blow on a solar roof. If the technology was actually viable on its own then it could stand on its own without tax breaks. This is just a slightly more practical version of solar roadways.The best PV cells made are less than 30% efficient, and those are the high dollar ones used on satellites. The rectangular silicone cell PV modules you see on roof tops are about 15% efficient. The solar roofing materials are typically in the 5%~8% efficient range. Some PV materials produce usable power in lower light than typical silicon panels, thinking specially of the Uni-Solar flexible panels, which can mean that you can get more usable power in low light conditions. Still the amount of power that you get from 'solar roofs' is really low.Back in 2004 I advised our university's solar house team on the construction of a small, very efficient house using a custom hybrid roof made of copper seamed roofing with heat collection attached to the bottom and uni-solar panels on the top. With 80% of the roof south facing and the ENTIRE roof covered with Uni-Solar panels the house could not produce enough power to be self sufficient. We were one of the first homes in the state of Missouri to be grid tied, the first in our city, and the process of getting it approved was expensive and time consuming. The city credits the wholesale rate when net metering so the payback just for the grid tie expense would be on the order of 10 years.Notice also that in the entire length of time Musk is blathering on there are NO technical details given. There was however a lot of BS about the different tiles ascetic appeal and other marketing wank.The solar heating of water is very efficient and even in colder climates you can use the evacuated tube type collectors. A solar water heater is by far the most efficient and cost effective way to harness solar energy but it is not sexy.

author: DH2ID
author_rank: Newbie
timestamp: October 31, 2016, 01:23:45 pm
content: I see this more from a technical/engineering/experimental point of view:Hey, we've got the technology, we should just find some guys who want a new roof on theirregular houses (not especially built, and in various cities and in the countryside, in sayPennsylvania/Oregon/Texas/California) and give it to them for free in exchange formeasurement equipment and internet access to their roof output.Then watch what happens in summer/winter/heat/freezing cold, inspect the tiles andimprove them.My main concern at this moment isa) interconnection of the tiles (in salty air/dust)b) efficiency (in cold/heat/low sun angle)c) durability (ice/hail/fire/storm/micrometeorites)d) safety (electrical current should be shorted to ground in a fire or while walking on the roof)e) cleaning the roof (California/water supply)

author: lpickup
author_rank: Regular Contributor
timestamp: October 31, 2016, 01:59:52 pm
content: Thanks for the video Dave.I get the desire to achieve the best possible solution when it comes to efficiency, and agree that a conventional rooftop solar would be more efficient & cost-effective WHERE a conventional rooftop solar could be installed. But consider the situation I was in in my last house, and will be in my future house: I'm in the northern hemisphere and the FRONT of my house faces south, meaning I'd have to install solar panels on the front of the house. I can forget about getting homeowners association approval to do such a thing, much less get my wife's approval. Plus the style of my house has a more vertical layout in the front--the best sloped roof is in the back (north facing) side of the house. So effectively the efficiency we are comparing it to is 0. The idea of solar shingles is very compelling to me (provided it meets the HOA/wife approval).My primary concerns would be how all those tiles/shingles are actually connected together, and what is the installation cost? I know Elon made the statement that the price point he was aiming for was to be cost competitive with a traditional roof + the cost of electricity. I don't imagine he took installation costs into place, and I also suspect he was comparing the material cost to more high end roofing materials (i.e. those slate tiles he was so proud of). Plus, electricity is actually very cheap in my area, so meeting that cost goal would be a pretty tall order.

author: coppice
author_rank: Super Contributor
timestamp: October 31, 2016, 02:58:58 pm
content: Quote from: DH2ID on October 31, 2016, 01:23:45 pmIt might be interesting to match that list up with the long list of failed solar roofing tile ventures, and try to identify the most common cause of their failures. Elon Musk showed nothing more than their ability to make glass roofing tiles that look OK, and I'm not even sure if that was genuine. The tile he held seemed to have no electronics (there are two nail holes at the top, and apparently no other features) and looked like they had sprayed a dark rectangle on a conventional tile.

author: lpickup
author_rank: Regular Contributor
timestamp: October 31, 2016, 03:25:18 pm
content: Quote from: Jeff_Birt on October 31, 2016, 01:01:43 pmIt probably could stand on its own no problem if we properly accounted for the "hidden" costs that the incumbent solutions (i.e. fossil fuels) incur (i.e. damage to the environment, GHG emissions and the resultant damage caused by climate change, health care costs due to airborne and water-borne pollutants) not to mention the very generous subsidies and tax breaks that oil, gas and coal companies receive for their exploration costs.Even so, I don't necessarily have a problem with offering incentives to change behavior and help advance a technology that we need to get to to create a sustainable energy source that significantly reduces our impact on climate change. Almost by definition it won't be the cheapest solution, and I can tell you that most people will not be willing to put the greater interest of society and the planet first without some kind of incentive. Unfortunately I feel it is a very selfish attitude to take that our generation should be entitled to consume a finite source of energy at a very rapid pace and meanwhile destroying the environment, leaving nothing but problems for our descendants.

author: nixfu
author_rank: Unknown
timestamp: October 31, 2016, 03:34:12 pm
content: Of course.... if they actually also provided a superior, stronger, and longer lasting ROOFING material than traditional materials that could offset some of the costs of using them even on shaded parts of the roof compared to traditional materials.Prediction, Coming in 2017- Solar freaking FLOOR TILES! Tile your entire house in solar, great for the bathroom/shower too!- Solar freaking DRIVEWAYS!- Solar freaking POOLS! Put solar panels at the bottom of your pool, after all it has a built in lens effect to magnify the solar radiation! Hmm that might not be a terrible idea on first thought. I should patent that.

author: Jeff_Birt
author_rank: Regular Contributor
timestamp: October 31, 2016, 04:01:39 pm
content: Quote from: lpickup on October 31, 2016, 03:25:18 pmYou mean oil companies get to deduct their business expenses? How is that different than any other company/industry on the planet? On the other hand billions of dollars are handed out to companies worldwide to fund this 'renewable' mania. These billions of dollars are of course taxes. Spain really jumped off the deep end and wasted precious money and resources (taxes again) to fund these boondoggles.If private companies and individuals want to invest their own money in this stuff then I'm all for it. If it really is a winning proposition then investors would be lining up.I'll give you a prime example of government logic. The university I work for had a central steam generating plant, it has been in operation for decades burning coal and waste products from local wood processing. New EPA regulations made it too costly up refit the plant so the university has spent millions and millions installing a ground source system and touting how green it is. Meanwhile all of the old buildings on campus have leaking windows and doors wasting a tremendous amount of energy. In addition a few perfectly functional dormitories had to be torn down as there was no practical way to add a local steam generation source to them. Two more had a temporary boiler installed but they too will be torn down in a few years after new buildings are constructed.The average person spending their worn money would first say, "lets fix the doors and windows and maybe add some more insulation". That would reduce energy consumption and reduce cost. The amount of pollution from the steam plant would also be reduced. The 'green' government funded solution mandated tearing down a perfectly functioning steam plant, and a tearing down a total of four dormitories, spending millions of dollars on a new ground source system and doing nothing about the crappy doors and windows. What is the total 'environmental footprint' of these two options? Tearing down large structures and building new ones is very costly and uses a LOT of resources and energy. But those hidden costs are not factored in.

author: jonovid
author_rank: Super Contributor
timestamp: October 31, 2016, 04:02:01 pm
content: Quoteone idea maybe the use ozy colorbond corrugated roof sheets and conductive printed paint. the idea is you cut-off the length you need.steel roof sheets with layers of laminated solar cell material, with conductive strip cut gaps on the roofing tin. think corrugated pcb with a steel back.http://www.abc.net.au/tv/newinventors/txt/s3008638.htmalso the idea of printed solar cell material as roof sheets came from here-

author: MisterDiodes
author_rank: Frequent Contributor
timestamp: October 31, 2016, 04:04:25 pm
content: Every time I see these big fashionable Tesla galas about how great solar is - I cringe.Being involved in the critical production processes of the business end of a silicon wafer - mono or amorphous - I can tell you those government reports of a payback time of 2 to 3 years is far too low. When you count in the cost of hazardous waste generated, toxic water and the cost of the production of precious metals and acids: Several of us engineers at a production plant calculated that a solar panel connected to the grid would have to run 10 to 15 years before it comes close to offset the impact of energy and hazardous waste it took to build the module.IN short: Solar power is not quite as "green" as people think - and generates quite a lot of waste. Take a look at the tanker trucks carrying away spent acid and various other junk leaving the production plant. Take a look at the power required to run the silicon furnaces 24/7... The power required to process the aluminum frames, glass, the cost of fuel shipping the heavy & fragile panels around, etc.And NOW look at the cost of recycling spent solar panels. The ones built in the 80's are becoming useless now, and will create even more waste - and is a looming problem you don't hear a lot of discussion about:http://news.nationalgeographic.com/news/energy/2014/11/141111-solar-panel-manufacturing-sustainability-ranking/Does it make sense to put a solar array for electricity on every roof? Not here in the Pacific Northwest USA for instance - typically in winter you're looking at 3 or 4 usable hours / day for PV production, maybe less. If you're near a power grid, it is far less expensive and far more efficient to just connect to the grid for juice. IT DOES make a LOT of sense to use a hot water heating system - especially with vacuum glass collectors - because heating water directly with a standard electric heating element is not the most efficient - and most energy used in a home is for hot water. Depending n the cost of propane for a gas water heater, a rooftop heat collector can be a real increase in efficiency and quick payback on the energy used to produce the collectors - much more so than a PV array. It just depends on where you live, and cost of various fuels. Where I live, we have very cheap electricity in the first place, and very cold water from the well - so solar hot water makes a lot of sense on payback time. A house in a sunny location will make better use of a PV array.Also - be careful of the cost of lead-acid batteries for storing energy - they have a very limited lifetime and create waste hazards of their own - and use up a lot of fuel shipping back and forth from China. If you live where it's not TOO cold during the winter, nickle-iron and related old battery technologies are a good choice: They are not space efficient but are cheap to build and last virtually forever. They have to be kept warm though during the cold months.There is no one perfect answer for every house - and solar PV arrays will not be the answer for all energy needs. Every location needs to make the best use of power sources that are appropriate to that locale.

author: cavac
author_rank: Contributor
timestamp: October 31, 2016, 07:15:34 pm
content: Quote from: EEVblog on October 31, 2016, 02:29:55 amDave, maybe you could do a video on a DIY solar system with those slightly damaged but functional reject solar cells from Ebay. Something like a 12 Volt/5 Volt system thats not connected to the grid.Not the "mounting in a frame" part, which there are lots of youtube videos. But the wiring stuff, the maths, how to select the correct wire gauge and things like that. For example, how to wire a single panel, but also how to correctly wire up multiple panels to a single charge controller? How does one calculate the values for the protection diode? That kind of video.

author: f4eru
author_rank: Super Contributor
timestamp: October 31, 2016, 07:23:13 pm
content: Quote from: MisterDiodes on October 31, 2016, 04:04:25 pmJust give us numbers.The EROI of solar PV panels is generally shown to be around 5, but if you have better numbers, just give them to us.Concerning hte recycling : let's assume panels will be recycled in 30 Years, on average.The copper, aluminium is straightforward and easy to retrieve. The glass, silicium, interlink ( probably also mainly copper) will probably be wasted, which is not a big deal, silicium is cheap and very low relative weight, glass also. Interlink copper is a small portion of the total copper.

author: f4eru
author_rank: Super Contributor
timestamp: October 31, 2016, 08:08:09 pm
content: Concerning the solar shingles, this will probably be a fad.Conventional panels are just easier to manufacture, sturdier, easier to mount, more efficient, and cheaper.Concerning efficiency, regarding the sole change in linking technology:Warning : these are ballpark calculations.let's assume they have a single cell that outputs 0.6V @ 5A in one of these shingles.let's assume the resistance of the interconnection to the next cell is 10 mOhm, (a 25cm wire @60°C 1mm² is 4.8mohm, plus 5.2mohm for a connector). Cable loss : 0.01*5 = 50mVNow you already have aloss of 8.3%of the generated electricity only in the shingle to shingle link.......le's see on a small traditional glass panel : 24V @ 5AThe cells are very close together, there's only a few mm from cell to cell, the end of the string is looped back to the start of the panel.The same 1mm² wire with 1m length @60°C -> 19.3mOhmThe same connector @5.2mohmthe interconnects drom cell to cell can be estimated at nearly zero (the loss of the cell to edge interconnect and the few mm from cell to cell are the same than in the shingle solution )cable loss : 0.0245*5 = 0.1225V -->0.5% lossNow that's much better !!Now let's consider the ressource "copper" in this link :40 shingles(24V) : 40*0.25m = 10m of copper wire@8.9g/m, 40 connector pairs @ 2gtotal : 169g of coppersingle 24V panel : 1*1m of copper wire, 1 connector @2gtotal : 10.9g of copperSo you have roughly 15x the power loss in the link despite investing 15x more in the copper, just because you want to space the cells for aesthetic reasons.

author: kevyk
author_rank: Contributor
timestamp: October 31, 2016, 09:45:20 pm
content: Everyone is forgetting a most critical limitation to the engineering for ANY solar panel including the Tesla / Solar City ones. This issue alone makes almost all rooftop solar panels completely unviable once you do the actual calculations. And no one ever talks about this.The issue is, for at least on one evening every year, the weight of Santa's sleigh would obviously crush any solar tiles placed upon the roof. This makes rooftop solar panels impractical.Now, when Santa finally implements anti-grav, then we can talk about solar again, but until then don't waste your money on an obviously flawed technology.

author: f4eru
author_rank: Super Contributor
timestamp: October 31, 2016, 10:07:22 pm
content: The problem is, there are people also in nuclear power stations, so sometimes the roof collapses at nuke power stations when santa passes :http://media.gettyimages.com/photos/snow-storm-in-isere-the-roof-of-in-warehouse-at-the-nuclear-plant-of-picture-id162568841?k=6&m=162568841&s=594x594&w=0&h=iWRnFUXLd9WwgoukcN4GTfR1DL2YIZ_rtI1ana_33Xo=

author: f4eru
author_rank: Super Contributor
timestamp: October 31, 2016, 10:37:33 pm
content: Strange! BBcode strips the final "=" sign in the URL. Some bug in the parser probably..Here's the picture :

author: rrinker
author_rank: Super Contributor
timestamp: October 31, 2016, 11:12:22 pm
content: Quote from: nixfu on October 31, 2016, 03:34:12 pmThat's it, when I repaint my pool, I'm painting it black instead of blue.

author: boffin
author_rank: Unknown
timestamp: November 01, 2016, 02:55:14 am
content: Quote from: kevyk on October 31, 2016, 09:45:20 pmOMG and that's today OCT(31) = DEC(25) !

author: CatalinaWOW
author_rank: Super Contributor
timestamp: November 01, 2016, 03:40:02 am
content: Almost all of the replies here give comments on the engineering viability of these panels. They are mostly correct, and largely irrelevant.If you look at US homes (and I suspect homes in much of the developed world) engineering evaluations are very far down the list of what makes them sell. Just as an example there are few engineering reasons to differentiate between granite counter tops and tile counter tops. But the vastly more expensive granite counter tops are greatly desired and widely sold here. Since most US owners actually don't own their homes for more than a decade, even the lowly melamine coated counter top competes well on a technical basis.So the appeal of these solar tiles will be for style, green points, feel good reasons. Not anything related to efficiency, payback time, or even real impact on global warming. They will have to be fairly reliable and repairable, but that is about all from the engineering side. And as many have already pointed out, this baseline design may not meet that need, but I wouldn't bet against the product that actually reaches the market.

author: Bud
author_rank: Super Contributor
timestamp: November 01, 2016, 04:29:21 am
content: I think after all there may be a problem with installers workforce. This looks delicate technology, and seeing those Chinese roofing crews in my neighborhood coming a dozen people on the roof and doing boom boom boom shooting their nail guns, finishing the roof in no time (with their usual quality issues of course), I cant possibly picture how they can repeat that with solar shingles. Job quality may become an issue, installation may require qualification, maybe even licensing and may be expensive and take longer, this alone will drive average house owners away.

author: nuclearcat
author_rank: Unknown
timestamp: November 01, 2016, 04:34:38 am
content: Probably as Powerwall, they void warranty, as soon as unit are not installed/maintained by certified installer. (at least according TESLA POWERWALL LIMITED WARRANTY (AUSTRALIA AND NEW ZEALAND), Jun 21 2016)I guess same will be for solar roof, it will be pricey (but because of that highly profitable for installer), and logically - well done.

author: Brumby
author_rank: Unknown
timestamp: November 01, 2016, 05:16:05 am
content: Quote from: boffin on November 01, 2016, 02:55:14 amHow long have you been waiting to roll that one out?

author: dansan
author_rank: Contributor
timestamp: November 01, 2016, 07:30:24 am
content: I didn't see Elon Musk taking any questions from the audience after his solar roofs announcement. If so, that's probably a good thing, considering the cringeworthy audience questions he got after his recent mars announcement.

author: f4eru
author_rank: Super Contributor
timestamp: November 01, 2016, 08:07:47 am
content: Quote from: CatalinaWOW on November 01, 2016, 03:40:02 amA kitchen typically is a style driven buy which is sold by a guy getting a big comission.A roof typically is a cost and performance driven item which is proposed by your architect, or builder, which is budget constrained, and tries to get the best performance out of cheaper materials.Very very very very different things.The market of styly overpriced solar tiles is a very small one compared to the market of efficient cheap panel solar.That'S where the marketing of Tesla will fail.and where others failed :http://client.dow.com/dowpowerhouse

author: jonovid
author_rank: Super Contributor
timestamp: November 01, 2016, 08:26:37 am
content: QuoteTesla Solar Tiles, the solar you have, when you want everyone to think you do Not have solar. gosh that's not hard to do.

author: nuclearcat
author_rank: Unknown
timestamp: November 01, 2016, 08:34:40 am
content: Just because there is plenty of fanboys, he might succeed. They already bought car (but it is really good), powerwall(v1 was not so good, feasibility questionable, but still good sales as they say), why not "solar roof" as well?Only difference with Apple - world was waiting for proper handheld device, phones were moving to this direction, and Apple iphone has significant innovation in UI.But, IMHO, solar power not in favor right now, due low oil prices, and he is not much different from solar shingles.I hope someone do real innovation, rather than just repacking existing technologies in shiny envelope, for example improve nickel-iron batteries with their insane lifetime (30-50 years and almost unlimited cycles), which also much less hazardous to environment and dont need lithium (limited supply and lithium mines are really terrible for environment).

author: dekra54
author_rank: Unknown
timestamp: November 01, 2016, 09:55:02 am
content: As someone who install Photovoltaik Systems nearly every day i think the most important thing is the final cost per Watt and cost per kW installed. Right now in germany it is between 39 to 60 Cents per watt. And about 800 to 1200 Euro for 1 kW installed depending on the type of roof.But aside from the financial aspect i'm interested what technical solutions they come up with. Especially with the interconnects because apart from a broken inverter a defective connector is the most common reason why i have to climb on to a roof. And i dont Like having hundreds or maybe thousands of connections that are connected on a construction side where are a amount of reasons why such a simple thing can go wrong. Would also be interesting how they tie it to groundGesendet von meinem SM-G900F mit Tapatalk

author: dekra54
author_rank: Unknown
timestamp: November 01, 2016, 10:38:17 am
content: Quote from: wilfred on November 01, 2016, 10:10:38 amSure one depends from the other. At the moment the fixed feed in tarif for self energy use systems is 8.5 to 12.5ct (depending on size) per kWh and for complete feed insystems its much lower. About ten years ago it was abou 50ct ! but the price for the system installed was obviously much higher.And in germany there is actually no direct public sponsorship for installation, just the fixed feed in tarif for 20 years (at least that i'm aware of).

author: b_force
author_rank: Super Contributor
timestamp: November 01, 2016, 11:15:04 am
content: Maybe the following is a bit of a party pooper.But every time I see something about 'reliable energy solutions' I can't help thinking about one thing.We are simple with WAY to many people on earth.Even if magically we nail all the problems, reduce the total power consumption AND garbage waste with 50% (which is heaps!)Currently the world population is growing with a whopping 83 million each year.If we don't don't anything against it, this means that in 2050 the world population will be around 9.7 billion pooing, farting, wasting, drinking, eating super apes.Or 11.2 billion in 2100.The population at this moment is 7.4 billion people.In other words, we need to cut at least 30% of all waste (in any form) to be even as we are today in 2050.That also means, we haven't gained anything extra, to 'safe' our asses (not the world, the world will be fine eventually)There are some ideas and predictions that the growth will go down eventually and even get lower.Anyway, realistically I don't see how on earth (no pun) we are going to fix 50% of the total waste.Another thing I don't get is, why the focus is only on this subject, and not the extremely high growth?I guess because from an ethical point of view it's a difficult subject.Does this mean all of this is b*llsh*t?No! As many great scientists already pointed out, there is nothing wrong with making things better, more efficient, more reliable.On top of that it creates new exciting jobs.It's only not going to help us in the end......

author: f4eru
author_rank: Super Contributor
timestamp: November 01, 2016, 11:38:20 am
content: Quote from: jonovid on November 01, 2016, 08:26:37 amhmm. So, if i understood you correctly, Tesla tiles are about bragging about a thing that is nearly invisible ?That's kind of a very very niche market to me.

author: f4eru
author_rank: Super Contributor
timestamp: November 01, 2016, 02:04:03 pm
content: Quote from: b_force on November 01, 2016, 11:15:04 amYes, completely true. The world is overpopulated. Ressources are not lasting. We need to reduce drastically the population, that is the "easiest" measure.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: November 01, 2016, 07:01:38 pm
content: Lets be clear. Solar roof tiles are nearly invisible. Unless you are a car nut, Tesla roadsters are also nearly invisible. I can't tell you how many times one of my sons has said "There goes a Tesla" and I look around without spotting it. They are smallish, rounded vehicles not greatly different than dozens of others on the road. I need to see the Tesla logo to know what the car is. So bragging rights aren't firmly tied to a flamboyantly obvious product.The same thing applies in a variety of other fields. Have you ever tried bragging about your new piece of test gear to your significant other or to friends who do not share your avocation?So I am going to pile on with others and say that the primary market barrier for these is the interconnect problem. If these have magic in this area it isn't obvious.Those arguing that efficiency or cost is the primary factor are totally ignoring the fact that the best engineering solution to those problems is to make the house smaller. But except for certain fad markets (the tiny house movement, for example) that direction has met little success in most of the developed world. None at all in the US.

author: Don Hills
author_rank: Regular Contributor
timestamp: November 01, 2016, 11:38:02 pm
content: Quote from: f4eru on November 01, 2016, 02:04:03 pmWhich method do you have in mind to achieve this? Plague? War?

author: retrolefty
author_rank: Super Contributor
timestamp: November 01, 2016, 11:50:23 pm
content: Quote from: Don Hills on November 01, 2016, 11:38:02 pmWell we could always try the "tax what you want less off and remove tax from what you want more of".I recall from my service days that married Airmen were allowed extra income allotment for each child up to five. Not many had more then 5 but most had more then 2.

author: Alexei.Polkhanov
author_rank: Frequent Contributor
timestamp: November 02, 2016, 03:39:25 am
content: Quote from: Don Hills on November 01, 2016, 11:38:02 pmWe, humans, will have to do something about overpopulation eventually, why not start now? I would hope that people that did not want to do anything about it, due to some stupid political or religious agendas, got eaten first when we end up on this planet like a bunch of hungry rats in a metal barrel.

author: Marco
author_rank: Super Contributor
timestamp: November 02, 2016, 04:21:55 am
content: Quote from: CatalinaWOW on November 01, 2016, 07:01:38 pmYou could do it inductively.

author: Marco
author_rank: Super Contributor
timestamp: November 02, 2016, 04:56:55 am
content: One of the times humans experimented with overpopulation and resource depletion on an island they killed themselves, the earth is a large island.

author: nuclearcat
author_rank: Unknown
timestamp: November 02, 2016, 06:12:45 am
content: And thats where Elon Musk "Mars colonization" step in.Maybe worth to forgive all his mistakes and marketing nonsense, just because he is pushing civilization to right direction.

author: Red Squirrel
author_rank: Super Contributor
timestamp: November 02, 2016, 07:13:15 am
content: Neat idea but every time I hear of this concept I can't help but think of the logistics of installing these. When you setup solar you want each string to be equal number, when you have regular solar panels you might have like 4 or so in a string, so you can group them in groups of 4 in parallel and they'll physically be laid out so wiring them is fairly easy. Basically you look at the whole roof as a blank slate and find the most effective way to place them. There will be dead spaces or what not but you just look at covering the most you can.With shingles, you NEED to cover the whole roof, including corners where you have to CUT them so they line up with the other side of roof (ex: the peak or the edges of a cottage style roof etc). When you install shingles you start from the bottom and work your way up, and cut any as required. Having to also think of the logistics of which ones are in series with which ones and making sure it's the right number etc... then combining the strings to thicker wires.. just sounds like a logistical nightmare. And what do you do with the ones that you have to cut, these don't look like they're made of materials that are easy to cut, like standard asphalt shingles. Even the ones that don't have the solar cells.Everyone keeps trying to revolutionize solar but standard setups with regular panels is still the best way imo. For people who have big property having them on the ground is even better as you're not adding extra penetrations(giggity) to your roof and it also makes them easier to access for maintenance such as daily snow removal in winter.

author: Marco
author_rank: Super Contributor
timestamp: November 02, 2016, 08:20:23 am
content: It wouldn't be too hard to integrate electronics which can combine power from rows of differing number of tiles automagically. Since inductive power transfer is the only reasonable way to transfer power between them you already need electronics any way.The only raison d'etre of these things is to please home owner associations, hardly a mass market outside of the US.

author: tszaboo
author_rank: Super Contributor
timestamp: November 02, 2016, 12:38:35 pm
content: It does not really matter how much it costs. Or how much extra effort it takes to make. Or how much the efficiency is. Just does not matter.Regular solar panels work this way: You buy a house. You got extra money later, you buy a solar panel from your pocket money, so you save 50 bucks a month.Solar rooftop works like this: You go around shopping for a newly built house. After all, you live in the US. There are two houses next to each other. One is with solar roof, the other is without it. You can buy the one without it, you pay x to the bank. Or you buy the other one, and you pay x+10 to the bank, and save 50 a month. Or you put an "ugly" solar panel on your roof, but keep in mind, you are a not one of the cool people anymore.Solar roof makes sense. You are not going to replace your roof, and install this. Construction companies will adopt, and sell it, because it makes sense, because that is what the people will want. You are not the customer, who has to make the decision. The construction company is. And for them, solar will make more sense.

author: sibeen
author_rank: Frequent Contributor
timestamp: November 02, 2016, 01:10:45 pm
content: Quote from: NANDBlog on November 02, 2016, 12:38:35 pmConstruction companies have had many years to adopt this technology. They haven't. It puts up the price of construction; they ain't going to touch it with a bargepole.Just because the Tesla name has been attached to this won't change that economics.

author: StuUK
author_rank: Frequent Contributor
timestamp: November 02, 2016, 01:28:29 pm
content: Construction companies only adopt things that make the build cheaper (for them)/easier or are mandated by building codes....

author: Brumby
author_rank: Unknown
timestamp: November 02, 2016, 03:23:30 pm
content: I've often said building underground is one of the most energy efficient concepts. Just put a solar freaking roadway over the top - and we're done!

author: Fungus
author_rank: Super Contributor
timestamp: November 02, 2016, 03:53:25 pm
content: Quote from: StuUK on November 02, 2016, 01:28:29 pmIf that was true then they'd only ever build windowless concrete bunkers.Construction companies want to maximize profit, not to build the cheapest house possible. They'll happily add expensive things that increase the perceived value of a house.Tesla (and Toyota) have already done this with their electric cars: Buying a Prius Or Tesla makes no sense economically, you're never going to recover the purchase cost in saved fuel. Those cars still sell by the bucketload. They sell more Teslas in Norway than all of Ford's models combined and Teslas cost over $100,000 in Norway.Similarly iPhones, MacBooks, etc. At's much more about image than economics or the actual product.If Tesla does a good sales this right then having a Tesla roof will be fashionable among rich people and they'll sell loads, there's no doubt about that.

author: tszaboo
author_rank: Super Contributor
timestamp: November 02, 2016, 04:01:47 pm
content: Quote from: sibeen on November 02, 2016, 01:10:45 pmTablet was introduced by Microsoft, with windows xp. Nobody cares.Table introduced by Apple, with iOS. "revolutionary". We know the story.There have been electric cars ~ hundred year ago. I've seen it in the museum. Now, tell me who made the electric car story a success?

author: Fungus
author_rank: Super Contributor
timestamp: November 02, 2016, 04:15:49 pm
content: Quote from: NANDBlog on November 02, 2016, 04:01:47 pmThey even had the exact same name. Remember the "iPaq"? That was produced long before Apple decided to make anything pocketable.And Microsoft still can't manage to sell their stuff today. There's (probably) nothing wrong with Microsoft tablets except they're not 'cool' enough for the hipsters.The same goes for laptops. If you're prepared to pay $1500+ for a laptop then there's non-Apple laptops that make the Apple offerings look like pieces of junk. Apple laptops sell like hot cakes though. Go to any classroom and count how many Apple machines you see compared to all the others. Makes no sense, but there it is.

author: cavac
author_rank: Contributor
timestamp: November 02, 2016, 04:53:25 pm
content: Quote from: nixfu on October 31, 2016, 03:34:12 pmOk, let's add a bunch of batterizers and make them work at 800% efficieny!!!

author: b_force
author_rank: Super Contributor
timestamp: November 02, 2016, 07:05:59 pm
content: Quote from: Alexei.Polkhanov on November 02, 2016, 03:39:25 amThat IS exactly my point.We can build solar roofs, super uber sustainable other resources and many more things.All absolutely great and awesome from engineering, artistic and scientific point of views.However, it's is very far from a proper argument to safe 'the planet' (aka, saving our own asses), because that's not gonna happen this way.Next point is that we can safe a bit on energy here and there, if there are still a handful of big countries who consume and waste over 1/3 of the total amount, it's still not doing anything.Big deal that some countries have to safe a few percent on freaking little plastic bags. Compared to the general waste of these other countries and factories it's absolutely microscopic.

author: aw_ful
author_rank: Newbie
timestamp: November 02, 2016, 10:07:54 pm
content: So many comments, on the pre-existence of solar roofing, on the efficiency of the tiles, of the issue with installation, that there better ways to capture energy by using water, of the issues of costs, that it is not fully green. The thing he announced is not related to any of those comments. What he announced is a fully integrated system that (mostly) becomes self-sustaining personal supply of energy. It has nothing to do with low cost as he is appealing, like Tesla (for now), to deep pocketed people, and to whom aesthetics is a major concern. He is not concerned with tile efficiencies, because he has their mammoth roofs to work with. He is not concerned with material or installation costs because a premium roof already is expensive. What I hear is the ability to never waste time going to a gas station, using a car with less complexity and therefore better reliability that refills itself, making driving an almost inconsequential electrical cost that doesn't degrade the environment (as much), making solar broadly available to a multitude of home uses so that it becomes personally economically feasible, and maybe the ability to stop subsidizing electrical infrastructure and nuclear power plants for heavy users like heavy industry and commercial, and just maybe then reducing the human energy footprint on the earth. Ultimately, he closed the day/night/storage loop with these tiles AND Powerwall (not possible separately), making it economically possible, meaning maybe someday never having to attach or having to have a grid at all.

author: Someone
author_rank: Super Contributor
timestamp: November 02, 2016, 11:42:08 pm
content: Quote from: Fungus on November 02, 2016, 03:53:25 pmThe cost effectiveness of electric or hybrid cars varies wildly around the world, Norway has some of the worlds most expensive fuel (petrol/diesel) costs and cheap electricity. But to further convince the public to purchase plug in electric vehicles they also piled on huge monetary incentives:https://en.wikipedia.org/wiki/Plug-in_electric_vehicles_in_NorwaySo its cheaper to own an electric car in that case and everyone is rushing to do so.While in other markets the incremental cost of a Prius C over the Yaris its derived from is roughly the savings in fuel use over the lifespan of the vehicle, priced to match the market and not the obvious failing you suggest. They have their markets and uses, but they're not solutions for everyone worldwide.

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 03, 2016, 03:07:32 am
content: Quote from: nuclearcat on October 31, 2016, 05:36:18 amThe underdeveloped (part of) the solution is to try to adapt demand to supply. The technology for it has been available and affordable for many years, there's just a lack of development and standards that keeps it from being widely deployed.The "TV pickup" problem is becoming a problem of the past now that on demand content (Netflix, Youtube, etc.) is the norm.Quote from: Fungus on November 02, 2016, 03:53:25 pmWhile the current Teslas are indeed unlikely to pay back (that's not the point of owning one), good hybrids most certainly can. That's particularly true for those who drive a lot, especially commercial usage.

author: b_force
author_rank: Super Contributor
timestamp: November 03, 2016, 08:31:33 am
content: Quote from: aw_ful on November 02, 2016, 10:07:54 pmTesla aims for a very niche market, yes.Isn't that EXTREMELY obvious?That's also the whole problem. Because they kind of pretend they have solved a world problem.Even today there are still people who could never ever afford something like this.In fact, they even struggle to survive on a daily basis. Do you think they even care about how they get their energy, from solar, wind-turbines or the filthiest way of burning something?They are glad they have at least something.If you look at the numbers, that is at least roughly 30% of the world population (if not (much) more)

author: Fungus
author_rank: Super Contributor
timestamp: November 03, 2016, 08:53:07 am
content: Quote from: b_force on November 03, 2016, 08:31:33 amHopefully.Quote from: b_force on November 03, 2016, 08:31:33 amNo they don't. They act like they're showing the first generation of a nice new product that they're proud of (rightly so - it's a beautiful product with some really good engineering underneath, some real hard work has gone into it).How the press is reporting it? Well, that's the press for you. Look at the press Batteroo got even though they're a pair of suits with no working product.

author: tszaboo
author_rank: Super Contributor
timestamp: November 03, 2016, 09:21:37 am
content: Quote from: b_force on November 03, 2016, 08:31:33 amMusk said, that the technology he is developing is for the mass market. But you cannot just enter the mass market, because that doesn't work. He is entering the top market, sell stuff, mature the technology, drives down the cost. After that you enter mass market. Take the Tesla model 3 for example. It is priced 35000 dollar, almost the same than the new price of the car I own. It is not a car for CEOs, not 70.000 like the mode s. It is not the roadster's 100.000 dollar price tag.The business model seems to work. Probably in a decade, solar roof price will be brought down 1/3. Just let the technology mature. This is for the premium segment, the statement is more important than price or efficiency. This is the roadster. Wait for the S and the 3.

author: zapta
author_rank: Super Contributor
timestamp: November 03, 2016, 01:57:40 pm
content: Quote from: Brumby on November 02, 2016, 03:23:30 pmThe cost of the periscopes can be significant though.

author: XynxNet
author_rank: Regular Contributor
timestamp: November 03, 2016, 08:41:12 pm
content: From a home owners perspective:Will I get a replacement shingle in 20 years?Good traditional shingles have a lifetime up to 80 years here.

author: Brumby
author_rank: Unknown
timestamp: November 04, 2016, 12:52:20 am
content: Quote from: zapta on November 03, 2016, 01:57:40 pmI'd go for a WiFi Camera (with PTZ) up a pole, powered by a solar panel and battery.

author: lpickup
author_rank: Regular Contributor
timestamp: November 04, 2016, 11:16:50 am
content: Quote from: XynxNet on November 03, 2016, 08:41:12 pmWhat type of shingles are "traditional" in your area?Here, the standard is asphalt shingles that are labeled as "30 year", but you'd be lucky to get 20 out of them. You can buy premium "40 year" shingles. I have never heard of 80 years, so you must be talking about some kind of slate tile shingle or something like that?At any rate, other than physical damage from micrometeorites or a stray fly ball from a neighbor's baseball game, the durability of these shingles is something I wold expect to far EXCEED the standard shingles installed in my area.

author: coppice
author_rank: Super Contributor
timestamp: November 04, 2016, 11:34:48 am
content: Quote from: lpickup on November 04, 2016, 11:16:50 amMusk was showing off replacements for slate and ceramic tiles. These, and other rigid tiles - e.g. concrete, are usually good for at least 50 years, and 80 is not unusual.Continued supply of compatible tiles is an important factor. Many people need to undertake small localised repairs to their roof during its life. At the end of the life of the tiles compatibility is much less important. In most cases you can easily use completely different tiles for a fresh new roof.

author: tszaboo
author_rank: Super Contributor
timestamp: November 04, 2016, 11:50:54 am
content: Quote from: lpickup on November 04, 2016, 11:16:50 amWell, in Europe, houses usually built with ceramic roof tiles, bricks and they last lifetime.You are supposed to order some excess, so it can be repaired.

author: KM6XZ
author_rank: Newbie
timestamp: November 16, 2016, 09:49:22 am
content: The whole discussion based on a tech version of traditional anything undermines the opportunities by getting away from tradition. Traditional methods were used based on the technology limitations if 300 years ago. When cars first became available regulations stifled development because they were assumed to be horse drawn carts without the horse so required some of the same policies that carriages were covered by in the late 1800s in US and European cities.Obviously Musk was thinking of North America as the first target audience, lower volume at high price as the while the production technology ramps up to mass production and evolutionary changes. Just as he did with the Tesla cars, starting with the roadster for rich early adopters who were a small enough number they could produce enough to satisfy demand. The Model S is a much higher production vehicle but still small compared to the established auto companies. But ramping up to a couple hundred thousand luxury sedans paved the way to a mass produced affordable $35000 model.Using the same plan, a replacement for slate and tile roofs with something that might even cost less is a good target audience. In California, a slate roof can easily cost $80-150k and a ceramic tile one can cost $50k. It becomes viable option with less sales resistance for the smaller number of potential customers that a start up can produce for.After driving a P85s Model S Tesla I have no doubt that Musk knows his audience better than any car company executive. The US auto industry in the 1960s employed 1 in 7 people in the US and was the largest car industry in the world. In 2015, the total US output of cars was a little over 4 million, a fraction of just 10 years ago, while China produced 24 million up from almost zero 15 years ago.Musk's approach of gaining experience before ramping up to lower cost products will likely result in Tesla being the largest car producer in the US in 6-7 years. The same would not be out of the question for the solar roof tiles. Forget about initial cost efficiency, or mass production trying to compete with a mature, stagnant industry, he does not have to have a product that replaces current traditional products...yet, wait for the 3-4 generation of these and see where the volume is. I would bet on Musk in the long term.

author: Brumby
author_rank: Unknown
timestamp: November 16, 2016, 12:39:58 pm
content: Quote from: KM6XZ on November 16, 2016, 09:49:22 amWhile I agree that it is not wise to condemn an emerging technology on production cost, the fact is that the concept has been out in the field for a number of years - and no-one has made a go of it. Do we think Elon Musk will do any better? If so, why?

author: Fungus
author_rank: Super Contributor
timestamp: November 16, 2016, 02:26:22 pm
content: Quote from: Brumby on November 16, 2016, 12:39:58 pmBecause he made pretty ones and aimed them at rich people.(just like the Tesla Roadster)

author: Fungus
author_rank: Super Contributor
timestamp: November 18, 2016, 01:43:55 pm
content: Elon Musk has announced that his roof will be cheaper than a traditional roof.https://electrek.co/2016/11/17/tesla-solar-roof-cost-less-than-regular-roof-even-before-energy-production-elon-musk/(I guess it will depend on what he classes as a "traditional" roof - not everybody installs fancy slate roofs)

author: lpickup
author_rank: Regular Contributor
timestamp: November 18, 2016, 01:50:18 pm
content: Yeah, he has GOT to be comparing this to tile/slate roofs. There is no way this statement is true for asphalt shingles.

author: coppice
author_rank: Super Contributor
timestamp: November 18, 2016, 02:43:14 pm
content: Quote from: lpickup on November 18, 2016, 01:50:18 pmHe was showing tiled roofs. On the other hand he was showing fake homes in a Universal Studios movie set. I don't know how much a movie set roof costs.

author: Fungus
author_rank: Super Contributor
timestamp: November 18, 2016, 02:44:44 pm
content: Quote from: lpickup on November 18, 2016, 01:50:18 pmI guess it doesn't matter. So long as it's cheaper thansometypes of roof thatsomepeople are installing then he's got a sales pitch.

author: Marco
author_rank: Super Contributor
timestamp: January 01, 2017, 09:22:32 pm
content: I don't think you can make the glass for the tile even as cheap as an entire traditional tile.Unless they use induction connecting everything electrically will make installation take a hell of a lot longer too.

author: coppice
author_rank: Super Contributor
timestamp: May 12, 2017, 07:41:00 am
content: Tesla appears to have put their solar roof system on sale. There is no new technical information, beyond the original vague presentation, as far as I have seen. They have talked prices, but again in a pretty vague way. They are taking $1000 deposits, though.Telsa say regulations prevent more than 50% of the roof being solar. Does anyone know what those regulations might be, or their rationale?

author: djos
author_rank: Unknown
timestamp: May 12, 2017, 07:59:53 am
content: We are certainly getting to the pointy end of this saga!It'll be interesting to see what the efficiencies are like and how it actually hangs together.Personally I'd rather have solar tiles than Solar panels - my roof is only good for a few more years as the concrete tiles are not in the best shape. I'd either go solar tiles or Colourbond Steel with panels but would prefer the terracotta tiles when available (current tiles are orange too).

author: thm_w
author_rank: Super Contributor
timestamp: May 12, 2017, 07:25:40 pm
content: Quote from: coppice on May 12, 2017, 07:41:00 amI found this: "Residential Systems—Single and Two-Unit Residential Dwellings: Plan review is required if a system is to be installed that will occupy more than 50% of the roof area of a residential building."http://osfm.fire.ca.gov/pdf/reports/solarphotovoltaicguideline.pdfI can see some reasoning, you need to be able to access the roof and if the whole thing is covered with panels you can't walk on that would be difficult. But, of course these are more tiles than traditional panels, so its probably straddling some weird mix of regulations.

author: james_s
author_rank: Super Contributor
timestamp: May 12, 2017, 07:31:16 pm
content: Well it certainly seems more viable than a solar roadway at least.I didn't watch the video so I don't know how much the cost will be but from what I have seen it looks nice, a lot nicer than conventional panels mounted on a roof. Also if you need a new roof anyway it seems like this might make sense, it's a nice looking and durable roof that also happens to generate electricity.

author: james_s
author_rank: Super Contributor
timestamp: May 12, 2017, 07:33:53 pm
content: Quote from: XynxNet on November 03, 2016, 08:41:12 pmWow, 80 years? One is lucky to get 25 years out of a roof out here, even one claimed to be a "50 year" roof and well maintained. Tree leaves/needles cover it and keep it moist, moss gross and the roots deteriorate the roof. Snow/rain/ice, freeze/thaw cycles, it all ends up being really brutal.

author: tronde
author_rank: Frequent Contributor
timestamp: May 13, 2017, 05:45:42 pm
content: Quote from: james_s on May 12, 2017, 07:33:53 pm

author: james_s
author_rank: Super Contributor
timestamp: May 13, 2017, 07:35:14 pm
content: Quote from: tronde on May 13, 2017, 05:45:42 pm

author: coppice
author_rank: Super Contributor
timestamp: August 14, 2018, 12:08:14 pm
content: I wonder how realistic this article is being?https://stockboardasset.com/insights-and-research/elon-musk-tesla-and-the-solar-roof-tile-fraud/

author: Koen
author_rank: Frequent Contributor
timestamp: August 14, 2018, 12:52:07 pm
content: According to nearly a dozen sources familiar with the factory wooden crates, including one who recently left the company, mildly.

author: b_force
author_rank: Super Contributor
timestamp: August 15, 2018, 12:52:39 pm
content: Quote from: NANDBlog on November 04, 2016, 11:50:54 amA lifetime?Let's make it many generations

author: Fungus
author_rank: Super Contributor
timestamp: August 15, 2018, 05:29:51 pm
content: Quote from: NANDBlog on November 04, 2016, 11:50:54 amI've been in ordinary-person European houses that were built in the 15th century.(and in quite a few pubs from the 16th/17th century)I bet there's houses older than that if you look hard enough.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 15, 2018, 06:37:31 pm
content: Quote from: Fungus on August 15, 2018, 05:29:51 pmAnd I'll bet you find that they have all had numerous repairs over the years. In addition to the modifications to bring them into usability by modern standards. Things like heat, plumbing and electricity. At least here in the new world where there is a significant stock of 300 year old houses and buildings that is the case. Those repair jobs include such things as taking chimneys apart and re-setting the stones.

author: nctnico
author_rank: Super Contributor
timestamp: August 15, 2018, 07:24:03 pm
content: 15th century homes are a bit over the top but there are many older building with ceramic roof tiles which are over a century old. Over here concrete roof tiles came into use since around 1910 and these don't need mass replacement even after 50 years. Needing to redo a roof with ceramic or concrete tiles is unheard of in the NL.

author: james_s
author_rank: Super Contributor
timestamp: August 15, 2018, 09:08:45 pm
content: In some parts of the US, ceramic and tile roofs are common, but out here cedar shakes are the traditional material with asphalt composite shingles becoming a lot more common. The house across the street from me actually has a tile roof but that's very unusual here, I think the much higher cost puts a lot of people off, even if it does last longer people are notoriously short sighted. That and with all the trees it's not uncommon for a tree to fall or drop a heavy branch that would cause considerable damage to brittle tiles. That may be why they're less common. The places that do have a lot of roofs tend to be the more desert-like regions where >100' tall evergreen trees are not everywhere.

author: Fungus
author_rank: Super Contributor
timestamp: August 15, 2018, 11:59:52 pm
content: Quote from: nctnico on August 15, 2018, 07:24:03 pmA good slate roof can last alotlonger than that.

author: coppice
author_rank: Super Contributor
timestamp: August 16, 2018, 02:03:45 am
content: Quote from: Fungus on August 15, 2018, 11:59:52 pmA good slate roof can last a long time, but most sources of good slate have been exhausted. Much of what is available now starts to delaminate after 20 or 30 years as a roof tile.

author: EEVblog
author_rank: Unknown
timestamp: August 16, 2018, 04:57:25 am
content: Quote from: coppice on August 16, 2018, 02:03:45 amMy terracotta roof tiles have lasted 30 years and are still fantastic. And I'm still able to buy the same original matching tiles now.If you can buy those Tesla tiles in 30 years time I'll eat my hat.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 16, 2018, 03:46:18 pm
content: Terra Cotta tiles are virtually permanent in the southern tier of the US. In my current location they last less than five years. A wet climate with regular freeze/thaw cycles turns the to powder rapidly. In Colorado, where I grew up the drier climate allows them to last until the next hail storm with golf ball or larger size hail. Mean is about thirty years, but it is just three luck of the draw. The lifetime of all roofing materials is heavily dependent on the match to local conditions.

author: rrinker
author_rank: Super Contributor
timestamp: August 16, 2018, 06:27:40 pm
content: Interesting, my Uncle had terracotta tiles on his house in New Jersey, which would definitely subject them to frequent freeze/thaw cycles - North Jersey, not near the ocean or down in South Jersey. No idea how long they were on the house before he bought it in the 70's, but he never had his roof replaces and they sold the house int he late 90's. House was built in the 1920's.

author: SeanB
author_rank: Super Contributor
timestamp: August 16, 2018, 07:10:55 pm
content: Yes, depends on the tile and how it is fired, and the clay base used for it. Fire for a long time, and then glaze it, and it will last virtually forever, or till it is hit by large hail. Make it cheap and cut the firing time down and it will be softer, slightly more hail resistant but will turn back to clay with time and rain. However here there is almost universal tile roofs along with having some of the heaviest hail around in the high country, and there you might have a tile every few years to change, at $1 per tile if you are unlucky, and have the discontinued types that are sold as demolition recoveries. Otherwise you have a choice of ceramic, brick, concrete and even composite.There are also a lot of houses with steel corrugated roofs, and they vary in age from brand new, made from the thinnest steel you can think of ( thinner than a regular spray can for the cheapest ones) to 3 century old ones, made from 1/16inch hot zinc dipped corrugated steel, still in service on listed monuments. Slate is rare, and wooden shingles even more so, as the insurers like them even less than they do thatch, which is common enough, though most of them are getting corrugated outer layers, to reduce insurance rates from stray embers.Common to have a thatch roof in rural areas, as it is both low cost, as literally you get the entire roof structure locally grown, aside from steel strapping, steel wire for binding and nails, and the number of people who can lay them, and maintain them, is quite large.

author: james_s
author_rank: Super Contributor
timestamp: August 16, 2018, 07:27:19 pm
content: Wow, thatch, that certainly isn't something you see in these parts. Maybe 150 years ago.

author: SeanB
author_rank: Super Contributor
timestamp: August 16, 2018, 07:42:53 pm
content: Quote from: james_s on August 16, 2018, 07:27:19 pmPretty good material though, just have to do the modification that Benjamin Franklin discovered, and put in a good lightning earth on it.but then i still remember watching CNN during Gulf War 1, and them popping to a US segment of a California wildfire, with the usual vista of lots of empty burnt out lots, sporting burnt out cars, piles of bricks that were chimneys, and in the middle of it a single house standing proud and white walled. Cut to the talking head speaking to the owner, an immigrant to the US of A from Korea, and an engineer. They ask him why his house is still there, when all around are mere heaps, and he explained " I though everbody know wood BURN", as his house was built from brick, had a tile roof and protected eaves, so the fire risk to it was minimal. He also had trimmed his yard, to keep flammable brush clear of the house.

author: coppice
author_rank: Super Contributor
timestamp: August 16, 2018, 08:36:55 pm
content: Quote from: james_s on August 16, 2018, 07:27:19 pmThatch is such a big deal in the British countryside that we elevated a Thatcher to run the country in the 80s.

author: james_s
author_rank: Super Contributor
timestamp: August 16, 2018, 09:21:05 pm
content: Wood does certainly have disadvantages, but when you live in an earthquake zone like the west coast of the US, the flexibility of wood structures is an advantage. Brick buildings collapse, wood buildings sway. Also wood is abundant in this region so it's a lot less expensive than building out of brick or concrete.Everything is a compromise though.