Solar Panels On Half the World's Roofs Would Power the Planet (thedailybeast.com) 287
An anonymous reader quotes a report from The Conversation: Our new paper in Nature Communications presents a global assessment of how many rooftop solar panels we'd need to generate enough renewable energy for the whole world -- and where we'd need to put them. Our study is the first to provide such a detailed map of global rooftop solar potential, assessing rooftop area and sunlight cover at scales all the way from cities to continents. We found that we would only need 50 percent of the world's rooftops to be covered with solar panels in order to deliver enough electricity to meet the world's yearly needs.
We designed a program that incorporated data from over 300 million buildings and analyzed 130 million km of land -- almost the entire land surface area of the planet. This estimated how much energy could be produced from the 0.2 million km of rooftops present on that land, an area roughly the same size as the U.K. We then calculated electricity generation potentials from these rooftops by looking at their location. Generally, rooftops located in higher latitudes such as in northern Europe or Canada can vary by as much as 40% in their generation potential across the year, due to big differences in sunshine between winter and summer. Rooftops near the equator, however, usually only vary in generation potential by around 1% across the seasons, as sunshine is much more consistent. This is important because these large variations in monthly potential can have a significant impact on the reliability of solar-powered electricity in that region. That means places where sunlight is more irregular require energy storage solutions -- increasing electricity costs. Our results highlighted three potential hotspots for rooftop solar energy generation: Asia, Europe and North America.
Of these, Asia looks like the cheapest location to install panels, where -- in countries like India and China -- one kilowatt hour (kWh) of electricity, or approximately 48 hours of using your laptop, can be produced for just 0.05p. This is thanks to cheap panel manufacturing costs, as well as sunnier climates. Meanwhile, the costliest countries for implementing rooftop solar are the U.S., Japan and the U.K. Europe holds the middle ground, with average costs across the continent of around 0.096p per kWh. The report mentions this endeavor would be "extremely expensive," and won't be a solution for some industries that require very large currents and specialized electricity delivery. However, the report concludes by saying: "If the costs of solar power continue to decrease, rooftop panels could be one of the best tools yet to decarbonize our electricity supply."
We designed a program that incorporated data from over 300 million buildings and analyzed 130 million km of land -- almost the entire land surface area of the planet. This estimated how much energy could be produced from the 0.2 million km of rooftops present on that land, an area roughly the same size as the U.K. We then calculated electricity generation potentials from these rooftops by looking at their location. Generally, rooftops located in higher latitudes such as in northern Europe or Canada can vary by as much as 40% in their generation potential across the year, due to big differences in sunshine between winter and summer. Rooftops near the equator, however, usually only vary in generation potential by around 1% across the seasons, as sunshine is much more consistent. This is important because these large variations in monthly potential can have a significant impact on the reliability of solar-powered electricity in that region. That means places where sunlight is more irregular require energy storage solutions -- increasing electricity costs. Our results highlighted three potential hotspots for rooftop solar energy generation: Asia, Europe and North America.
Of these, Asia looks like the cheapest location to install panels, where -- in countries like India and China -- one kilowatt hour (kWh) of electricity, or approximately 48 hours of using your laptop, can be produced for just 0.05p. This is thanks to cheap panel manufacturing costs, as well as sunnier climates. Meanwhile, the costliest countries for implementing rooftop solar are the U.S., Japan and the U.K. Europe holds the middle ground, with average costs across the continent of around 0.096p per kWh. The report mentions this endeavor would be "extremely expensive," and won't be a solution for some industries that require very large currents and specialized electricity delivery. However, the report concludes by saying: "If the costs of solar power continue to decrease, rooftop panels could be one of the best tools yet to decarbonize our electricity supply."
One thing the solar industry needs to do... (Score:5, Interesting)
I love solar, but one thing the solar industry needs to do is make panels that interlock in a water proof fashion so that you can use panels AS YOUR ROOF instead of on top of your roof. The current crop of panels usually ends up causing roof leaks, which really sucks because now you've got all these heavy solar panels in the way when you inevitably need to do repairs.
If you've got the land and you've got non-interlocking panels, I'd say stay away from mounting them on your roof. Put them up in your yard instead.
Re:One thing the solar industry needs to do... (Score:5, Informative)
Re:One thing the solar industry needs to do... (Score:4, Informative)
Because it is at the early-adopter phase.
There is a lot more to making them into a roof than just interlocking the panels and hoping they stay waterproof. Right now, the quality of the tech is still pretty low, so they have to make for that with expensive materials and manufacturing methods. As more early-adopters buy it, the technology will slowly improve until eventually it will be mass-produced, and most roofs will be built with similar products.
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"There is a lot more to making them into a roof than just interlocking"
Interlocking tiles is ancient technology. Tiled roofs were being made thousands of years ago and the technology matured ever since. You need very little to make an acceptable tiled roof, and there's a huge field of science and technology about making said roof beyond excellent. Tell me, what's so hard about embedding solar panels in pretty regular roof tiles and connecting them up?
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Sounds like Tesla hired a slew of semiconductor experts, chemist, electronic designers, and not a single roofer.
Re:One thing the solar industry needs to do... (Score:5, Informative)
Because the "Tesla" roof is only viable for a climate like southern California. Any other climate with wind, will blow those tiles right off
If only technology had been developed to secure things so they didn't blow away! Some sort of anchor device... but I am dreaming. (/s)
Large areas of Southern California are regularly subjected to gale and hurricane force winds called "Santa Anas" due to the surrounding high deserts and mountains causing gravity enhanced down slope winds channeled through passes and canyons. Yet our roofs and solar panels stay put.
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A standard roof "in the north", aka Europe aka Scandinavia, can not crash from snow load. To make a roof crush you would need something like 100 yards or meters of snow on top of it.
The steepness is simply for letting the snow glide off if possible. Not to make the roof more robust. As usually - in our times - no one lives under the roof, the fact that snow is a superb insulator, is ofc unimportant. But in old times you had your cattle on the ground floor, your living rooms on first floor (or do you call th
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> the solar industry needs to do is make panels that interlock in a water proof fashion so that you can use panels AS YOUR ROOF instead of on top of your roof
You mean like this? https://www.tesla.com/solarroo... [tesla.com]
Re:One thing the solar industry needs to do... (Score:5, Insightful)
so that you can use panels AS YOUR ROOF instead of on top of your roof
Why? Having them separated from the actual roof improves building thermals and also cooling of the panels by the airflow. Why would you sacrifice these things?
Re: One thing the solar industry needs to do... (Score:2)
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Weight.
Have you ever lifted a solar panel?
They don't weigh much.
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The rugged ones, for installing outdoors? Yeah, about as much as ~30cm thickness equivalent surface layer of snow.
Re: One thing the solar industry needs to do... (Score:4, Informative)
For roof loading, solar panels add about 3 to 5 pounds per square foot. If it's a ballasted system on a flat roof that can be as high as 15 pounds per square foot. (A ballasted system is one where the panels are secured to the roof with racks held down with concrete blocks, rather than being physically attached to the building structure)
For 30cm (1 foot) the design load for snow is 16 pounds per square foot.
TL:DR; you're talkin' nonsense, bud.
=Smidge=
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For roof loading, solar panels add about 3 to 5 pounds per square foot. If it's a ballasted system on a flat roof that can be as high as 15 pounds per square foot. (A ballasted system is one where the panels are secured to the roof with racks held down with concrete blocks, rather than being physically attached to the building structure)
For 30cm (1 foot) the design load for snow is 16 pounds per square foot.
TL:DR; you're talkin' nonsense, bud. =Smidge=
Your calculations are based on a flat roof. With a flat roof, snow would accumulate on top of the panels. Thus, panel + snow could add significant weight.
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so that you can use panels AS YOUR ROOF instead of on top of your roof
Why? Having them separated from the actual roof improves building thermals and also cooling of the panels by the airflow. Why would you sacrifice these things?
It depends on how you build your roof. We have "in roof" solar cells. Our roof (and any modern roof in Europe) has an underlayer (on top of the insulation) that is waterproof. On top of that underlayer, you have the roof surface (shingles, or whatever). It's great, if that layer is also waterproof, but it is really just there to protect the real waterproof layer from weather. There is a gap between these layers, to allow air to circulate. The "in roof" solar panels are mounted in a framework, and provide th
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Re:One thing the solar industry needs to do... (Score:5, Insightful)
Is this opinion or fact?
We have roof top solar on over 20% of Australian homes. Nearly everyone I know does.
I've never heard one case of roof leaks caused by solar panel installs.
I'd like my panels to be simple and cheap to replace thanks, I don't want to have to replace my whole roof to take advantage of advancements in panel technology.
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I've never heard one case of roof leaks caused by solar panel installs.
The seppos use asphalt shingles for roofing, quite different to the steel panels or clay tiles used in Australia. Could that be relevant?
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Absolutely.
But it's not really an inherant issue with solar panels though. If one was willing to change their shingles roof for a solar roof I'd still opt for replacing it with a roof that can take panels.
Don't get me wrong, I'd like to have a workable solution for an "invisible" rooftop solar solution for aesthetics, but the practicality of removable panels is still winning.
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There are glass-glass panels but they are even more expensive than the Tesla solar roof. Making a waterproof roof is hard, and is usually done with multiple layers for resiliency.
Personally, my favorite solution was the peel-and-stick cells that could be used between the ribs of a standing seam roof. I’m unclear if their failure was in the need to walk on them or something else, but it was at least an elegant solution without getting overly complex.
Re: One thing the solar industry needs to do... (Score:2)
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I think you extremely missed the point of a solar panel then.
Yes, it would be nice for a solar panel to be "a roof" but the last thing you need is damage to your roof destroying an entire panel array. The ideal situation is that you have a metal, aluminum, roof (which lasts longer than most materials being used as roofing) for structural integrity, welded to a frame/foundation which then supports the solar panels itself. This way you can either have a typical home, or a trailer, RV, or whatever kind of thin
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I think they need to make different shapes too - too often homeowners have vast tracts of roof that they can't use because the panels can only go on horizontally and in block pattern. If they had some different sizes, triangles and such like, you could cover far more of the roof.
Oh, and get rid of the silver edges too ;-)
Cost (Score:3, Insightful)
Cost and viablibility (Score:3)
As it is, the US is still one of the most costly places in the world to use solar. So while lowering taxes on technology like this might help, it's far from enough.
You have to consider the limitations of the technology itself. First there is the storage and transmission. This is the same argument you also get with wind, wave and any other renewable energy source, it's not consistent in its delivery, and therefore you need to have large amounts stored, or supplemented from other sources when the production i
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Third, add in the geography of the US. While a large part of the country IS well suited for solar energy, Majority is not. Northern parts are too far north to produce much during winter
Except for Alaska, the northern parts of USA are on the latitude of Rome: south Italy. From there to Germany's north it is 3000km, or roughly 2000 miles.
Sorry, you are delusional.
transmission loss forces more local power then (Score:2)
transmission loss forces more local power then far far away power.
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HVDC loses 3.5% per 1000 km.
You gain more by putting the panels in sunny deserts than you lose in transmission.
Also, grid-scale panels are much cheaper to install than rooftop panels.
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In a big country that has its own deserts - sure.
But no matter how cheap the electricity would be, I would not like to depend on some other country for the electricity. Especially if the country is not stable. So, unless the area around the panels and the transmission lines is occupied by the EU (or the US) in order to guard them, I do not think it would be useful. It would provide a good target for terrorist attacks.
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I would not like to depend on some other country for the electricity
Good point.
It would provide a good target for terrorist attacks
Not really. Solar power needs coverage, spread out over large areas. Something spread out is a bad target, more centralized items like transmission lines and substations are better targets if we're going this route. Even better would be to just hit the SCADA running the panels. Less need for volatile chemicals and elaborate delivery of aforementioned chemicals.
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The transmission line or substations would be a great target. Yeah, panels themselves would be too spread out.
As for depending on another country, yeah, just look at how Russia uses gas as leverage. At least gas can be stored rather easily (compared to electricity) and can also be shipped from other places. Imagine Egypt or Libya being able to shut off (I mean, have an "accident" or a "terrorist attack" on the power plant or transmission lines) electricity to the EU...
Re:transmission loss forces more local power then (Score:4, Insightful)
Even within the EU, Spain has far more sunny days than Germany.
Another advantage of putting the panels in Spain (or Arizona and California for the US) is that it is west of most of the population.
Electricity use peaks between 4 and 7 pm, when the sun is higher in the sky further west.
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But no matter how cheap the electricity would be, I would not like to depend on some other country for the electricity.
Too bad. It's the only viable options for many countries. Even if they wanted nuclear power, they can't afford it.
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Depends on the countries in question. One EU country buying electricity (or fuel) from another should be OK.
The entire EU getting most of its power from some third world country that owns this particular spot in Sahara? No.
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The problem is at midnight the nearest place with last/first scraps of solar power is about 10,000km away.
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There may be a little less line loss but HDVC is less reliable, has lower availability, and the conversion stations are more expensive. And don't forget about the issues with arcing. In areas that are prone to, say, hurricanes(the entire southeast) or tornadoes(the entire central
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1000km? I have to assume you are European and have no clue about the shear size of the US. My state is nearly 1000km long. Your scheme might work for the part of the U.S. west of the Rockies but for the rest, it is iffy at best.
The furthest two points from each other in the entire contiguous US are 4,669 km apart. That would be a 17.5% power loss. That's not a very big deal. Also, from the southernmost tip of Portugal to the northernmost tip of Finland appears to be 5000+ km, so it looks like you have no idea about the shear size of Europe. That's just the EU of course. If you consider the "European" parts of Russia, I'm pretty sure that the furthest distance is even further.
There may be a little less line loss but HDVC is less reliable, has lower availability, and the conversion stations are more expensive. And don't forget about the issues with arcing. In areas that are prone to, say, hurricanes(the entire southeast) or tornadoes(the entire central part of the country), that would be a serious issue when trying to repair lines.
Despite all this, it still gets used. Including in US st
It is called "night" (Score:5, Insightful)
>"That means places where sunlight is more irregular require energy storage solutions"
No. Unless you are living on a different planet than I am, the sun doesn't shine 24 hours a day where people live. ALL solar installations will require storage, if there is no additional power source available. Where I live, we have had very little sun for the last 3 days due to poor weather.
>"The report mentions this endeavor would be "extremely expensive"
"Duh" comes to mind. If it weren't, it would already have been done.
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Interconnecting grids might help coving some parts of the gaps... It might mean inefficient transmission over huge distances though...
Solar power is ideal for some things. Air conditioning, water hearing - air cons are often needed to counter the heating of the sun and water heating can easily be done any time of the day if the storage is decently insulated.
Using it for everything is much harder, but it might deal decently with the increase in load during the day, which helps if some sources don't like chan
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(And with a global interconnected grid one of the issues are that some times during a day there is a lot less populated areas in sunlight than at other times)
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Not just inefficient. In the most remote parts of the world, the sun doesn't shine for 180 day in a row. In majority of the world 14 hours of night time is not uncommon during winter.
That means that given the earth circumference, grids would need to span at LEAST a third of the earths circumference, not accounting for earths irregular shape, that's about 15.000 km away you will need to get your energy from. While this is feasible (not to mention geopolitical issues), energy loss during transmission would be
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> Lots of defense contractors to keep happy.
And now we all know who determines the future of this country.
Could'a just listened to Eisenhower.
Re:It is called "night" (Score:5, Interesting)
The paper does mention the need for storage, but that's not what it is looking at. The paper presents a novel method using satellite imagery to estimate the amount of roof space available for solar PV in different countries, and breaks down cost on that basis.
As for "extremely expensive", they say about 40% of it can be realized at below $100/MWh, and most of it under $200/MWh. For comparison, new nuclear being built in the UK is currently at $127/MWh with a guaranteed yearly increase as part of the deal to built it.
Given that solar PV costs are falling, as are storage costs, solar is pretty competitive in some parts of the world and will continue to get more attractive.
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The paper does mention the need for storage, but that's not what it is looking at. The paper presents a novel method using satellite imagery to estimate the amount of roof space available for solar PV in different countries, and breaks down cost on that basis.
As for "extremely expensive", they say about 40% of it can be realized at below $100/MWh, and most of it under $200/MWh. For comparison, new nuclear being built in the UK is currently at $127/MWh with a guaranteed yearly increase as part of the deal to built it.
Given that solar PV costs are falling, as are storage costs, solar is pretty competitive in some parts of the world and will continue to get more attractive.
While I'm sure there are differences in the cost locally, how about comparing to wind power instead ? That's less than half the cost of solar ? And in the most modern of windmills, it's about 1/5 the cost of nuclear.
That said, a good mix of sources, including nuclear is still to be preferred, as each renewable energy source is not consistent in its output. That goes for wind, solar and even hydro. They all carry the instability drawback.
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Right, they aren't actually suggesting that the entire world uses only solar. They came up with a novel way of determining how much roof space for solar is available in a country and how viable it is to make use of it.
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The important point from this study is to show we could supply 100% with rooftop solar. So anyone who says solar can't supply all our energy is mistaken. It doesn't mean we actually want to do that. Even if we set a goal of 100% renewable, that will end up being a mix of grid scale solar, rooftop solar, wind, hydro, geothermal, biomass, and tidal. We'll choose the mix in each place that's cheapest and most reliable. Limiting ourselves to rooftop solar and nothing else would be crazy. But even if we di
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Will need some storage (Score:4, Insightful)
You can't just cost the solar panels like they are the hard or expensive part. You have to cost the storage too. They go hand in hand. Storage will be a lot more expensive than the solar. Past a certain point, solar is useless without storage.
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My point is that the cost of the batteries should be included when the ultimate goal is to "power the planet."
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Storage --- not batteries.
Molten Salt, Gravity, Flywheels, etc. etc.
Tho prices for batteries is expected to drop another 50% by 2025 and for capacity to increase as well.
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My roof design might accommodate some solar panels. I seriously doubt I can put any molten salt, gravity, flywheel storage up there, and I doubt if my local Zoning Bylaws will allow them in my backyard.
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WHAAAAT ? You aren't planning on installing 500 ft of cable pulling a 50 ton block to power Your own local generator ? I'm shocked. What kind of home improvement are you even thinking about ? :)
Re:Will need some storage (Score:5, Interesting)
Storage --- not batteries.
Molten Salt, Gravity, Flywheels, etc. etc.
Molten salt has about a 30% roundtrip efficiency.
Most locations don't have useful terrain for gravity storage.
Flywheels are prohibitively expensive for day-to-night storage.
For most people, batteries are the only viable option for storage.
But daytime electricity demand is higher, and wind turbines run at night, so in a well-designed system, not much storage is needed.
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There is a huge opportunity to recycle batteries for grid scale storage. As we transition to electric vehicles there will be more and more used battery packs that can be re-used for grid or home storage systems.
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Re:Will need some storage (Score:4, Insightful)
As is the case already, let the grid take care of the storage. It's far more efficient to do it at the grid level than per individual property.
Will need *a lot of* storage (Score:3)
Yes, grid-scale storage is more efficient. But it's still expensive. Particularly the long tail.
Easy: grid regulation (~minutes), like the Tesla battery in Australia.
Medium: load shifting (~hours), from peak solar into the evening and morning
Hard: sufficient storage to handle still (low wind) cloudy (low solar) weather (~days to a couple weeks, based on the logs from my solar panels).
Batteries for the hard case cost just as much per kWh as for the easy case, unless we shift to something like flow batterie
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Easy: grid regulation (~minutes), like the Tesla battery in Australia.
The Tesla battery wasn't even the biggest grid scale battery at the time it was installed. The Tesla one was also notable for it's short duration (1 hour). Many of the grid batteries have >=4 hours at full load.
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It's more efficient to generate the solar centrally too - but the economies work out well to distribute it (to a point).
Here in the UK, we get to sell our excess solar at the wholesale rate. If we need to suck some electricity from the grid, we pay the (much higher) retail rate*. As such, it's not economical to produce much more than your daily "base load". If you do generate more, then you're best off using it to heat water (for your taps, but ideally in a heat store for central heating too).
If I could gen
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It will all come down, but I suspect storage for utilities and homes is going to come down much faster than the cells. We'll see something like iron flow batteries take over the job with storage capacity only limited by the size of the tanks you bury in the back yard.
Personally, I don't like the plan this article presents. I'd very much like to see us just get rid of the grid. It's crazy that week long power outages in major metropolitan areas are still a thing today. Maybe neighborhood level sharing with b
VerizonMath? (Score:4, Informative)
That's pretty amazing, because solar typically costs over 100x that much, about 6-8p per kWh.
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Re:VerizonMath? (Score:5, Informative)
That's pretty amazing, because solar typically costs over 100x that much, about 6-8p per kWh.
It's obviously a mistake.
In the article and summary.
The paper...
Should be 0.068 dollars, 6.8 cents in China for example.
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they slowly lose the other 90% over a 20 year period.
Bullcrap.
My panels are warrantied to keep 80% of their capacity for 25 years.
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Make it part of the building code (Score:3, Insightful)
If it was part of new building code, then that that means that anyone doing roof work will need to have panels if they want it brought up to code. Bringing a place up to modern code standards happens a lot when a person is flipping a place because it increases sale value.
And of course, all new builds would have it as well.
Not that it would make any great difference anytime soon, but you know.... baby steps?
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Also, (particularly in the USA) make it illegal for HOA to object to/forbid solar panel installations.
We have such a law in the Netherlands and it makes solar panel installations a lot easier by removing a source of bullshit.
thermal effect of solar panels ? (Score:2)
One thing I've always wondered about solar (and wind) is:
Doesn't it affect the planet somehow? The energy we convert to electricity would have done other things otherwise. It would have warmed up the ground, or moved air around. I'm sure this has been studied, but it's just a tick in my mind so I don't really look for the science on it, but if someone can sum up in two sentences, that'd be great.
Maybe it's just a delay and move - anyway a lot of electricity is sooner or later converted to heat, just at a di
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Yeah good spotting. There is actually a serious issue here with the effect on ground albedo. Those things trap a lot of heat, I think there was a study done, maybe a decade ago, I think I read it on here, that basically worked out that if you took the US energy consumption and converted it entirely to solar you'd end up adding a few degrees to the climate from heat dissipated from the solar panels. That said , solar panels have come a *long* way since then, so maybe its not the issue it once was.
Re:thermal effect of solar panels ? (Score:4, Interesting)
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That's actually a good point. So putting these things as roofs over roads or walkways, as some people suggest, would actually be beneficial in multiple ways. Interesting.
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I didn't intend to push any agenda with my question. Anyone with two working brain cells realizes that burning fossil fuels will have a stronger impact on the climate. This isn't a pissing match, just a curious question.
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Yes, this has been studied and solar panels effectively reduce albedo because while their tops are dark, their backs are white. Therefore much of the collected energy is reradiated as IR, and specifically upwards (towards space.) Of course, the greenhouse effect still comes into play, but that's not solar's fault and is merely another argument for curbing CO2 emissions, and for fixing atmospheric CO2 as well.
From the Antipodes (Score:2)
I'll hold my breath until a rooftop in New Zealand will power my house in winter
Fine for the industrialized world (Score:2)
This would work fine for the industrialized world, if everyone could actually afford to install them. Not everyone makes tech worker salaries. And then there is the third world or whatever the politically correct want to call it now. Places like the majority of Africa, much of South and Central America, much of India and Southeast Asia. Solar panels don't grow on trees. If someone can come up with an economic and technical plan for implementing this in places where there isn't any money and there aren't man
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Not everyone makes tech worker salaries.
There are already plenty of companies willing to loan money to pay for solar panels.
You pay the finance company less than you were previously paying your utility and pocket the savings.
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Actually, that is what leaves are.
The problem is to get the power out of the leaves - I tried drinking palm wine, and its quite good on a small scale. What we need is to persuade politicians to drink it on a massive scale. It could only improve their sanity!
Why this fixation on solar? (Score:3)
Solar is not the only method of harnessing renewable energy. There are then additional sources of energy that do not use fossil fuels.
In the small set of islands off the north coast of Scotland (Orkney pop. 22k), they admit to generating 130% of their power usage from wind turbines. This figure could be a lot higher but the electricity company seems to be working hard to prevent it. Despite being around 59 north, people still find it useful to put solar panels on their roofs but I don't think that there are any commercial sites. Another source that is being investigated is tidal turbines - think of them like underwater wind turbines! As water is denser, you get a lot more power from a given sized set of blades and it is completely predictable.
If you live in what would naturally be a desert, solar panels are the right tool but for those of us in more habitable climates, there are better alternatives.
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Making a difference tomorrow is a good pitch for roof-top solar but that doesn't mean abandon every other idea, obviously.
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Yes even though places have cloudy days why not take advantage of free energy?
Fake (Score:2)
Only countries in the Middle-East and North Africa will be able to effectively and economically make use of solar power.
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It's much easier and far cheaper to just build dozens of nuclear fission reactors per U.S. state
What? No it is not. Even coal costs more than solar+storage and nuclear costs more than that.
It's basically energy storage and insurance premiums that will kill-off solar based power generation.
You have that ass-backwards, it's solar based power generation that will promote energy storage. Insurance is by far highest on nuclear, and The People always have to pay for it because no underwriter but a government will take the risk, so the free market can't assist with the cost. I for one am unwilling to underwrite nuclear plants that we don't need.
Energy != electricity (Score:2)
how many rooftop solar panels we'd need to generate enough renewable energy for the whole world
If I've read it correctly, the paper actually compares rooftop solar panels to the world's (2018) electricity demand. The world's total energy demand is considerably higher than this.
For 8-12 hours a day (Score:2)
How do we dispose/recycle/reuse? (Score:3)
Only question that matters.
Well also ... what is environmental cost of producing that many panels?
Not without Superconducting power cables (Score:2)
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Transmission losses are very low today, because of the high voltages involved. In the USA we lose less than 5% in transmission. But your analysis is way the fuck wrong anyway because we are talking about rooftop solar, which is to say it's installed at the point of consumption, and it takes load off the grid.
And if your aunt had balls... (Score:2)
...she'd be your uncle.
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Probably because it's not actually cheaper than solar. Your $1b estimate is at *least* an order of magnitude out. It's true that economies of scale would shrink that a fair bit, but it's irrelevant because 6000 nuclear plants are just not going to happen (nor are 50% of rooftops getting solar panels).
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Well, obviously, you put them on the other half, Duh