IIRC all the efficient solar cells we currently have contains some rare materials. Once a particular solar technology reaches grid parity, the demand for the relevant rare material will increase, placing a floor under the price of that solar cell.
In the case of Moore's Law, a transistor can be any size. By contrast, solar cells absorbs too little energy if they are too thin.
TL;DR: There are real physical limitations to solar cells.
1. The grams of rare earths required per watt of solar have been dropping steadily. And Solar PV panels with no rare earths at all have been developed, though they are not yet common.
2. "Rare earths" are not so rare. Their prices have tumbled substantially as new mines have opened up and substitutes have been found.
Can you quantify that? I'm seeing comments in this thread saying, over and over again, that manufacturing these things is an environmental disaster. But without numbers, the statement is meaningless. We are currently poisoning pretty much the entire planet for our energy needs. If we cut that down to, say, poisoning an area the size of Texas for our energy needs, that would be a massive win.
Solar is definitely far better than fossil. It's just not entirely clear that it's better than nuclear, especially with the advanced reactors that get a hundred times as much energy from the same fuel, and produce only a small amount of short-lived waste.
Humanity is an environmental disaster. The issue at stake is avoiding the worse evils right now so that we can continue to lead a somewhat prosperous existence which, with some hope, will eventually become sustainable.
>IIRC all the efficient solar cells we currently have contains some rare materials.
Yeah, but the super-efficient solar cells are not the cheap ones that everybody is putting on their roof. They're the ones going on the international space station.
>Once a particular solar technology reaches grid parity
It already did in about half of the continental US, about two years ago.
I mean that seriously. Right now, pretty much all that matters is cost per watt. For normal terrestrial uses, a 20% efficient cell loses out to a 5% efficient cell that's 10x cheaper. (Numbers made up on the fly with no particular basis.) We're not currently hurting for space for these things, and sunlight is free.
It's difficult to say. Solar thermal is not dropping in cost the way that solar PV is. For now, at low penetrations, solar PV is a far better bet.
But solar thermal has the advantage of integrated storage. When solar overall is at some reasonably high penetration (say, 10-15%) storage will become important. At that point, it depends on the cost curve of storage technologies.
If batteries or other energy storage technologies have gotten cheap enough, PV + storage will be cheaper than solar thermal. If batteries haven't dropped in price enough, solar thermal may see a resurgence.
My bet is on PV + storage, though there is no certainty here.
There's also, at least on a global-energy-system scale, the issue of efficiency. Solar thermal (I'm thinking of solar towers and the like) can heat a medium to about 300, maybe 400 C, and if I'm not mistaken using a conventional steam turbine that can give you a Carnot efficiency of ~25%, maybe 30%. Real generators engineered today are on the level of 90% efficiency, meaning that a solar thermal plant can - practically - convert ~20% of incident solar energy to electricity. Commercial PV will likely not reach that level of efficiency for years, and there are - probably - good ways to improve thermal efficiency beyond this 20%.
Of course, thermal generators required direct incidence (don't work well on diffuse light), but the long and short of it is that with thermal we (may) need about half the total area we would need for PV. (On the other hand, PV can practically uses space - rooftops - which is inaccessible for thermal.)
I know they're different technologies, but I wonder on the cross-over effects of the two. If people see a solar thermal plant going up near their town, will it encourage or discourage them from installing PVCs? Are nation states that encourage / subsidise large-scale solar thermal deployments more likely to encourage end-user scale (PVC-based) systems?
Entirely agree managing storage is increasingly the pain point - in both scales of systems (thermal just rides out cloudy / dark periods more smoothly, I believe).
Is it still true that the most $-effective large-scale power-storage mechanism is to pump water up a hill?
If people see a solar thermal plant going up near their town, will it encourage or discourage them from installing PV?
I don't think this will make much difference - individual PV installation is an investment decision (just like other big home improvements) based on cost of energy and subsidies. It makes some difference to how "green" people feel, but the cost matters more. It may have an effect in planning battles. Here in the UK (esp Scotland) it's all about the wind farms. European solar thermal is currently struggling against low natural gas prices: http://www.estif.org/statistics/st_markets_in_europe_2014/
Pumped storage requires naturally occuring suitable locations (not too many available) and incurs environmental damage of damming a river.
(Calling it "PVC" is really confusing me with the flexible polymer)
Understood, but I find solar too ambiguous. Like when people talk about nuclear. I like the idea of fusion reactors, but steadfastly oppose fission. Solar tech has two big branches, and conflating them is something we should stop doing any time now.
As to influence - I think HN types are more informed than the GP, so in our bubble it may be hard to speculate accurately on any such influence. By which I mean, if you're not informed about the technology or the trends, then any intrusion of these technologies into your life will be more significant. Perhaps I am wrong.
For Scotland I would think we're some way off a sufficiently efficient cell, given hours and angles of incidence of sunlight.
Disclaimer - I'm in Australia, about 35 degrees south, and to be candid don't really understand how even places like Germany have so much love for PVCs ;)
How do you think the fact that natural gas is guaranteed to decrease in availability / increase in cost (over the long term) compared to the guarantee solar will decrease in cost, will influence users? And how do you think the idea of users being able, or being primed, to think of themselves as producers as well as consumers will influence their decisions on power?
I have a 3.8kW rated system (cost about £5k) at about 56N, and it actually produces that much on clear summer days. Currently it's grey outside and outputting about 2kW (I can ssh into the computer looking at the meter). The high latitude does mean extended summer days. Admittedly it probably wouldn't be viable without subsidy today.
I don't think individuals are very good at adapting to the long term market. If I know gas will be more expensive in 5 years, I can't do very much with that today. There's also the old "the market can stay irrational longer than you stay solvent": if I invest too early I can just as easily lose money.
In the UK, I think the general public are ahead of the media and politicians on the issue. There's a noisy anti-environmentalist and anti-windfarm contingent, but most people recognise the tradeoffs. I don't think people want to be their own producer en masse, any more than grow their own food or be their own bank, but if they can make a capital investment that saves money and produces income then you're speaking the right language to the middle class.
People might start to get vocal when gas prices go up in the UK; complaints about fuel poverty and demands for more fracking. It'll require a long period of gas being more expensive than electricity for fuel and heating for people to switch their homes over.
The price of energy storage, an impact of energy storage technologies to environment, and costs of unpredictable energy distribution in the network does not seem to be calculated at all.
They are not trivial. Germany claims one trillion EUR direct costs on network upgrades to cope with renewable energy. They do not take into account energy storage costs. Even now (at least in my country) 75% of energy costs are distribution costs.
Germany gets roughly as much sunlight as Canada, and started installing solar when costs were 5-10x what they are today. They paved the way for future installations at lower costs, but their experience isn't directly applicable.
I do agree that Moore's Law generally holds true. However a better model is an approximation of multiple S-curves, where each S curve represents the beginning, growth, and maturation of each step in technology.
The smearing of S curves and integration of new lines of tech allow for what appears an exponential growth.
Also, I'd like your opinion on http://www.bioinspired.net/ -- Commercially available memristors, albeit high priced.
Assuming solar panels always require weather sealed sheets of glass, it would be interesting to look at graphs of cost of LCD displays per Sq Meter vs year compared to graphs for plain old house windows per sq meter over the years.
Its likely it'll never be cheaper to build traditional sealed glass panels cheaper than house windows, although per sq meter it might get cheaper than televisions.
Some of the more optimistic claims outside the article seem to have very unusual assumptions about the cost of glass.
If you could add the trendlines of conventional power sources (thermal, hydel, nuclear) it would give a better idea of when we can expect solar to emerge from the competition.
When we look at figure-1(levelized PPA), we see steady price reductions until mid-2013 , and than none. That is probably due to soft costs starting to dominate.
So since the cost drivers changing - why does it make sense to model future price on old cost drivers ?
The graph doesn't have an 2015 data on it, but the average in 2015 has dropped further.
I initially set out to model soft costs on their own, separate from module costs. However, that effort revealed other factors. Solar capacity factor is rising and operational costs (which are not included in soft costs are dropping. There are more variables at play. For some of those variables, there isn't robust data available over lon times.
All of those variables ultimately feed into electricity prices, in the end, which is why I chose that modeling approach.
The actual solar panels used are almost identical. Generally in the residential solar market you may use a slightly more expensive panel for aesthetic reasons, but the improvement in the underlying solar panel technology in terms of efficiency and cost are available in equal terms to both markets.
The inverters used in the residential market versus the solar plant market are usually quiet different and, IMHO, form two distinct markets. Reductions in the inverter cost for solar plant deployments would result in a reduction in the home market, but the relationship is not as direct as the relationship between the panels since you would rarely be able to use the same inverter in both markets.
So given the Fed 30% solar subsidy is set to expire at the end of 2016, have you modeled (or know of a model) that shows when the price of solar will crossover the loss of subsidy?
I.e. I'm trying to figure out if going solar now is better (in California) or just waiting a few more years. I'm in no particular hurry since my electric bill vs. sq/ft is already pretty good.
UBS has done some modeling on this for their clients. They believe utility-based solar will take a hit for a 2-3 years and then rebound. The Fed ITC will drop from 30% to 10%. Making up that 20% cost change will take a little over one doubling of solar scale.
Rooftop solar will probably also take 2-3 years to make up for the cost lost to the subsidy reduction. It may even be 4. So after 2016, I'd expect rooftop prices to rise before slowly dropping, and getting back to 2016 levels around 2019 or 2020.
If I could install solar today I would, regardless of cost (apartment living prevents it). That may sound crazy, but I theorize that when you consider externalities the cost of grid electricity already far exceeds the cost of solar. It's going to cost humanity a whole lot of money to both survive and fix the damage we're dealing to the environment today. I'd rather pay more now for solar, than pay through the nose later for the environmental equivalent of a triple bypass surgery.
I doubt others see it that way, so I guess I'll pay the cleanup cost later like everyone else regardless. Such is the human condition.
I used to think this way until I started dating a geologist. She brought down my optimism when she detailed the ways that the environment is ravaged to extract the materials necessary to create solar panels, wind turbines, and so on. Rare earths are great for handling high heat, but their resistance to reaction also means it takes a LOT of nasty chemicals to purify the ore. Not that we should keep on burning fossil fuels, but we shouldn't kid ourselves into thinking that renewables are a one-way street to environmental prosperity.
Not all PV panels, wind turbines or EV car designs use rare earths e.g. Tesla doesn't use any in their motors.
Also, lots of other things that aren't good for the environment use rare earths. Kind of weird and illogical that people only care about it when you're trying to do good.
People are terrible when dealing with large scale diffuse issues. Coal might be 30 times as bad as solar, but that's not zero and most of coal’s harm is spread over a large area.
In 2003, China had 4,143 coal related accidents that killed 6,434 people. But, installing rooftop solar also kills some people so it must be the great evil.
I would rather have 0.1% of the Earth be made toxic enough to kill me in 600 seconds than have 100% of the Earth be made toxic enough to kill me in 600 months.
The pollution from solar cell manufacture is mostly near the mines and chemical processors, and the effects are mitigated if you don't go near there or live downstream. Pollution from coal burning affects everyone who lives downwind of any furnace, and those are located near the users to cut down on transmission losses.
Natural sources of pollution, like volcanoes, are not much of a concern, because most of the biosphere chooses not to live near them. So an artificial zone made more inhospitable than the surface of Venus, confined somehow, and situated far from civilization, is a bit less of a concern than the air quality index of Beijing.
Would it help if the raw materials were mined from asteroids, the finished product manufactured in space, and then dropped to the surface by nontoxic ablative shields and parachutes? If the answer is yes, being able to confine the pollution to specific areas on Earth is almost as good. (But the confinement is the hard part.)
Are you sure about Tesla? What material do they use for the permanent magnets in their motors? I know the motor has to contain permanent magnets since Tesla cards have regenerative braking.
You need a magnet for regenerative braking, not a permanent magnet. An induction motor cannot regenerate without a source of electricity, but you can get a lot more out than you put in to generate the magnetic field.
The thing is, exactly the same is true of all the other methods of power generation and mineral extraction. You have to at least compare the size and nastiness of the tailings piles. Not to mention CO2 produces carbonic acid when dissolved in oceans; the least "nasty" acid, but still enough to very very slightly change the pH and damage a lot of ocean life.
A one-time dirty process for a future steady source of clean energy. Isn't it still much better than continually burning fossil fuels? And if we're counting extraction costs, don't discount the extraction cost to get fossil fuel and build fossil fuel processors (car engines, power plants, etc).
If only it was. Neither solar panels nor wind turbines last for a very long time, and the recycling processes don't exist on an efficient or clean scale for either yet.
Most panels have a rated life of 25 years and deteriorate slowly. That provides plenty of time for the recycling to be built. It's also comparable to the design lifetime of most types of non-renewable power plant.
But my grandfather worked at a coal fired plant. I've been to the strip mine. I've seen the trains that run continuously to truck it in.
From a layman's perspective it seems like an incredibly efficient process. Is there any chemical refinement going on at all? All that I saw looked mechanical (but I was very young).
I would guess that it would take many years of Solar before it broke even, in an environmental impact sense, with "cleaner" coal.
I think ultimately solar probably wins. But the initial cost seems like it must be orders of magnitude higher.
That said, I'd get solar if I could. Just not my highest home-improvement priority and I'd have to do something about the trees shading the south side of my roof. I like my trees. :-(
OTOH it would be nice if there were a high power (~2KV), affordable (<$2,000?), silent wind turbine solution to supplement our grid power.
There isn't chemical refinement in the same way as there is with oil. But there are mine tailings, ash, a surprising amount of radioactive thorium in the ash(1), sulphur (usually neutralised by trucking in limestone and out gypsum (2)), and of course vast quantities of carbon dioxide. "Clean" coal does not and cannot really address the CO2 even if it has been cleaned up in the other ways.
There are various estimates of the breakeven time, but even the most conservative ones put it under ten years.
You don't have to get your own solar if it's not convenient, that's what the grid is for.
Deciduous trees on the south side of your house are great for energy efficiency. The shade reduces summer cooling costs, and then the leaves drop so you get solar heat in the winter. You should definitely think about it carefully before cutting them down to install solar panels.
Unless you live in the southern hemisphere, in which case you want to plant them on the north side of your house.
On a somewhat related note, rooftop solar panels have also been shown to have good insulation benefits[1].
[1] http://www.sciencedirect.com/science/article/pii/S0038092X11...
True, you want the trees and panels on whichever side of the house is sunniest.
Since the GP was talking about "trees shading the south side of my roof" I'm guessing that he's in the northern hemisphere. Or maybe he's just really bad at siting solar panels, but I was giving him the benefit of the doubt. :)
Anything we do we have to undo, and undo always costs more. It's not a perfect solution (nothing ever is), but we really ought to be bridging the gap with nuclear.
You're right, we will have to bite the bullet to have enough renewable capacity in the future. All I'm arguing is that we know both the risks of action and inaction. It's hard to get a sense of environmental damage from inside a comfortable air-conditioned building.
It's funny how the current debate regarding sustainable energy is always about production, not consumption. Somehow consumption is always taken as a given, about which nothing can be done.
It's obvious modern societies are wasteful - energy, food, water, transportation - but everybody is talking about how to increase production efficiency, no one is talking about how to decrease over-consumption.
This is partly because modern societies are struggling to figure out how to enjoy prosperity without growth[1] (some would depressingly argue that prosperity is the growth of consumption).
> I'd rather pay more now for solar, than pay through the nose later for the environmental equivalent of a triple bypass surgery.
That's really generous, however I think it would be the government's duty to compensate for these externalities so you don't have to pay more for solar (or not much more) than for the grid. Otherwise the environment will just stay a huge "tragedy of the commons".
The very least the governments can do is eliminate all subsidies to coal, oil and natural gas. They've had them for decades. I don't think it's healthy for a society to prop up an industry that long with subsidies, especially when it's one of the most profitable.
A politician can make any kind of spending seem bad by just calling it a subsidy regardless of the social benefit. But when it benefits people they like it can just be quietly ignored.
The real test should be if it ensures that people pay a "fair price" for a product. Paying a little more for clean energy is perfectly reasonable.
> The real test should be if it ensures that people pay a "fair price" for a product. Paying a little more for clean energy is perfectly reasonable.
You could argue the other way and say that paying a little more for dirty energy is perfectly reasonable because someone has to come after them to clean things up. There is a cost to that.
This isn't what people normally mean when they refer to subsidies, but the fact that fossil fuel users are allowed to contaminate everyone's air is effectively a massive subsidy for their operations. If the cost of the CO2 and pollution were paid by those producing it, this stuff would be way more expensive.
The IMF recently published a working paper[1] on energy subsidies at global and regional levels that might be of interest. They do use an fairly broad definition of what counts as a subsidy (including cost of damages environmental damages and global warming effect of CO2 emissions).
Have you factored in the CO2 footprint of solar panels? Producing pure silicon is energy intensive, then there are various metals involved, so you've got mining, refinement, smelting, and bulk transport costs. The panels also have a limited lifetime so you need to think about the disposal or recycling cost in 15-20 years. Pretty sure I've missed a load of costs too.
The comparable number for fossil fuels (in this case, oil) is 'well to tank efficiency', which amounts to about 25% for oil, if i recall correctly. So 1/4th of energy contained in oil is already spent to bring it to market.
Notably, wind energy has a far more favorable EROI than solar does (currently), but wind power is a relatively limited resource.
To be clear, the article you link is arguing against the graph at the top.
> Solar panels, according to Weißbach, generate four times as much energy over their lifetimes as it takes to manufacture them. Unfortunately, Weißbach also claims that an EROI of 7 is required to support a society like Europe. [...] For solar, which I know better, this paper is an outlier.
> If we used only the estimates from 2010 on, we’d find an EROI for poly-Si solar of around 15. If we used only the 2013 estimate, we’d find an EROI of around 25.
> In summary: The Weißbach paper is, with respect to solar, an outlier. A more realistic estimate of poly-Si solar EROI, today, is somewhere above 10, and probably above 15. And it’s rising. Solar panels generate many times more energy over their lifetimes than is used to construct them and their associated hardware.
Wow. I suppose it should have been obvious, but it's still interesting to see nuclear's numbers so high, considering the enormous material requirements for reactors. Only makes me more sad that the world seems to be closing down nuclear rather than opening it up.
A large problem with current generation nuclear is that the easily obtainable uranium isotopes are in the process of running out (in no small part due to artificial limitations on e.g. reprocessing of fuel). We'll probably continue to have enough for some time to come, but a large-scale switch to nuclear energy is actually quite unlikely at this stage.
I don't mean to say that this is the primary reason for nuclear's demise - it isn't - but it is a real hurdle against increasing deployments.
Of course, there are very exciting new developments in nuclear technology that solve this - breeding, reprocessing, etc - but they are all (still) at an experimental stage. That's the catch-22 of nuclear: there's an existing, mature industry, which uses it's fuel unsustainably, and there are developments to sustainably use nuclear power, which is quite far from being an industry.
Wildly under-appreciated point. Many of those batteries die out quicker than you might think, and hold way less energy density than gasoline. Plus the environmental costs (much nastier stuff than CO2) of extracting rare earths and elements like lithium are huge. Since most of us on HN don't live in the global south or northwest China, we've never seen the breathtaking environmental devastation that brings us these "green" technologies.
breathtaking environmental devastation that brings us these "green" technologies
Again, this should be compared with the breathtaking environmental devastation of the non-green technologies. Most of us don't live in Appalachia (coal), Canada (tar sands) or Dakota (fracking) either. Or one of the two failed reactor exclusion zones in the world.
Seriously? For real? Lead acid batteries are extremely clean to recycle when done properly, and even though they have a short (~5-8 year life, depending on depth of discharge and cycle count) life, you simply drop into your local auto supply store to recycle them and pick up new ones.
We are literally pumping hundreds to thousands tons per day of CO2 in the atmosphere with coal, not to mention mercury and radium, and people are worried about batteries?
Could it be said that in order to gain the technology and production methods of a cleaner, more efficient energy source we must expend energy from dirty and inferior sources first? It seems to be the case; we go after the low hanging fruit or the fruit that we know we can do something with. If that is the case, then can that be seen as a optimistic outlook for human kind in regards to climate change? That in order for there to be a clean energy future we have to harness the energy sources available to us to get there.
One thing to remember though is that there is a reasonable level of CO2 extras around generating traditional non-renewable sources (mining, transportation, materials to build the plant, maintenance of machinery etc).
In many places you can pay extra to get your electricity from less carbon intensive generation sources without actually changing anything in your home, it may be worth looking into if you feel strongly about the issue.
In the UK Co-operative energy and Ecotricity are two that I'm aware of.
The other thing you can do is invest in a "community solar garden" project, which basically means you pay for the panels, and get the benefit of their generation, but they don't sit on your roof.
Avista Utilities, here in Washington state, is offering community solar in a nice, self-contained package. You lease a panel in their solar farm, they install and maintain it, and you get a credit on your electric bill for whatever it generates. At the end of the lease you will presumably have a positive ROI from it though that of course depends on actual power generated. It seems like a really nice way to "go solar" that's accessible to anyone with the cash to buy the lease. http://www.avistautilities.com/services/Pages/communitysolar...
Being a good citizen now doesn't reduce my obligations in the future, so I'll be avoiding a solar retrofit as long as possible.
Personally, it would take something like a decade to recapture the capital costs associated with a solar installation. I don't have a 10-year commitment to my home, and don't have a capital gain tax liability to offset. So with solar I save a few bucks a month, and pick up alot of risk that my electric utility bears right now.
Are you sure you can't? Apartment building rooftops in China are typically covered with solar water heating panels. Sure it's not PV, but it's solar and it serves tenants all the way down the building, not just those adjacent to the roof.
Perhaps you just need to check with your building owner.
If you own the apartment, you can formally present to the building board that solar panels should be built on the roof. They would be owned by you, some group of people living there or the housing association.
If you're a tenant looking for an apartment you can keep asking it from landlords. Hopefully they start seeing that it's something that can be a distinct factor.
If you're a company doing real estate software, you can incorporate info about solar panels (and things like energy efficiency metrics) to the software.
Even a few years ago, the amortized price per kWh of installing, operating, and maintaining a solar installation was lower for an end-user than the price they would be paying the utility for electricity, in most parts of the U.S.
In places where the regulatory regime and utilities are sane with regards to metering and feed-in tariffs putting in a solar installation is already a winning proposition.
Even in the UK with a massive government tax break our set of panels will take 8 or so years to break even - and we have an almost perfect south facing roof.
Makes sense if you own the property and have the spare cash to take the free money (8% yield tax free) - though the UK government is reducing the subsidy
For the north american audience, it's worth pointing out that the UK is as northerly as Canada, so its not ideal for solar, though it does have a part to play I think.
i live off grid inside of a 500w/h peak footprint.
i paid around $1000 for proper German (Schutten) panels, a charge controller suitable for them, 2 110ah "solar batteries" (lead acid usual cheapo old school stuff), and a Xantrex inverter.
After nearly 1 year running a fridge, lights, computer, router, & studio monitors, I'm ready to add more battery capacity before the winter (cloudy days) and a small wind turbine.
grid-tie systems are another story and a bigger investment. (need a proper electrician to wire it etc...)
feeding ignorant "city ways" in terms of people's silly habits fed by years of cluelessness (no a hairdryer will never ever be possible, as that's 2kw right there...)
that's where the biggest expenses come in...
if you don't try to keep up with the usual clueless electrical consumption, a well organized person can begin cutting their footprint down...
for example my alleged 85w macbook pro power supply consumes less than 20w typically... my inverter says so...
If you're up for it I still have my 2500 W windmill here and can't use it so you can have it, the base is damaged (slip rings, tower shaft and tower mount) and you'll need to put up a pretty solid tower. It's a 2.5 meter diameter machine.
It weighs about 100 Kg and it's currently in storage near the town of Beverwijk in NL. It cost a small fortune to make it and I'd rather see it being used than slowly rust away in storage.
Do you always use your MBP connected to a power outlet? If so, try running it until its battery is drained about 50%, then plug it into your inverter and see how much power it draws. My guess is it will draw about 50-60 W.
I've been using a pedal-powered generator to power my computer, phone, tablet, and LED lights for the last 5 years and have tested several laptops and other devices using it. I've found that most laptops draw from 12 W (11" Chromebook) to 25 W (older 15" Dell) when their battery is charged, but 40-60 W when charging.
The power supplies of most devices seem to have about a 50% safety factor, so a device that has a normal max power consumption of 50 W will use a 75 W power supply.
How much electricity can you generate? Just thinking off the top of my head, I'm a sucky cyclist so can only manage about 150W power output sustained, probably. I'm not sure I could handle more than an hour of stationary biking before I collapse in a puddle of sweat ;-) So that's about 150 WH...
Is that about right (ballpark), or have I missed something? It would probably power my laptop for the day, anyway... It's something to think about (since I love cycling, even stationary ;-) )
Most people seem to be able to comfortably produce 30 W over a sustained period of time.
If you're used to bicycling, dress appropriately, and work in a cool environment with a fan, you can produce 50-60 W.
Above that, it becomes difficult to maintain your concentration on your work while trying to pedal hard at the same time.
On most days, I maintain about 35-50 W, depending on the load.
So far this morning, I've ridden for 2 hrs, 5 minutes and produced 74 W-hr. The computer I'm using this morning is a Raspberry Pi2 with a 19" monitor. I'm also powering our DSL modem/router and a 12 V fan while recharging two tablets, four AA batteries, and my phone at the same time.
I wonder how much inefficiency there is due to the inverter and the computer's wall transformer. Would it be better to run DC from the generator to power a dc-dc converter (which might have its own losses)?
Yes, it's definitely better to power everything using DC if possible. The best, reasonably-priced inverter I've found still draws 2 W whether it's powering anything or not. But it's difficult to get the right voltage and connector for every electronic device you might want to power.
"no a hairdryer will never ever be possible, as that's 2kw right there"
You don't mention the model of Xantrex inverter but the 813-3000-UL is a 3 KW model.
I'm old enough that when I was young inverters and switching DC-DC and power supplies in general cost about a buck a watt, now its ten cents and dropping. That would have been $4000+ decades ago, now its about $300 delivered.
That's not the only cost, of course, 3 KW at 12 V is a non-trivial DC current, and two hundred aH isn't going to run that hair dryer for hours, but how much hair do you have to dry anyway?
My MSc is concerned with a model for simulating molecular photovoltaics. The work I do is a blend of physics, chemistry, maths and programming, in different proportions. I wouldn't say it was "easy to immerse", but complement your skills with physics/chemistry and you could be useful, yes.
A Grätzel or dye sensitized solar cell can be easily created in your garage. Look them up on Youtube.
Generally you can't grow silicon crystals in your garage, although you can create the photovoltaic effect with amorphous materials (see CIGS solar cells). A good start is to apprentice with a solar installation company to get a feel for what is the "current" situation.
As the article notes, module technology and module costs are no longer the most significant barrier to solar adoption---so if you're in software, the greatest opportunities to have significant impact are probably in tearing down the numerous _other_ barriers to widespread adoption.
To use the situation I'm most familiar with: there are hundreds of millions of people in emerging economies who live off-grid and spend tens of billions of dollars annually on expensive fuel-based energy. They'll switch to solar tomorrow if we [1] can solve the problem of upfront financing [2]. It's the same problem that SolarCity, Sunrun, et al. are tackling in the US. This problem is the kind that gets solved by, among other things, developing the same kind of enterprise-targeted mobile/web/backend/data systems familiar to any developer at a modern SaaS company (but targeting a different, unusually interesting and important market, with some unique challenges).
Does this make solar a great industry to invest in because of the growth potential, or a terrible industry to invest in because the prices are racing to the bottom?
Hi. I'm the author of the original post. The amount of solar installed in the world is going to scale by more than 10x in the coming decades. There will be more than a trillion spent.
If you pick the winners, investment will have huge return.
Most solar companies, however, will be casualties in the fierce competition to come.
The other area to look at is energy storage. More renewables will increase the demand for energy storage. And it's early days in that field. Again: Huge returns for the winners. But most companies will be shaken out of the field.
The race to the bottom is more applicable to the panel manufacturers. The lowest cost producers are mostly Chinese companies, and the financial performance for these companies (ReneSola, Yingli Green Energy, Trina Solar, etc.) has been pretty terrible so far. Probably the best way to invest in solar through the stock market is to invest in a developer of solar projects. The best of these in my opinion in terms of scale and expertise is SunEdison (ticker: SUNE), and incidentally, the stock has been in free fall for various reasons over the past couple weeks, so this is probably a reasonable entry point.
It's a commodity manufacturing industry. It's going to have big turnover and thin margins. There's scope for innovation-driven cost reduction, but not for SV-style "unicorns".
There are going to be some huge companies thanks to solar. Those companies are also going to have big valuations, at least until the market is much more mature and saturated, but we're decades away from that.
As Ramez said, you don't bet on an "emerging industry", you bet on the winners in that emerging industry, otherwise you may very well lose your money. When new industries are born there are usually hundreds of competitors in the beginning, but eventually only a few big ones remain, and it's usually those that started early and got big early.
I have a 1kW solar panel battery storage system which I use to power my computers and servers. I installed it a couple of years ago to help mitigate the $0.37 kWh top tier rate that SDG&E charges.
In California, a minimum charge was introduced and will be $10.00 starting in 2016. I suspect that this charge will be jacked up in increments till it is a significant fraction of the monthly bill.
If this does indeed play out, then the only option will be solar with localized energy storage, and disconnect completely from the grid.
California also will be flattening the rate curve at the Utility companies request to combat solar installations in the next 1-2 years. Users in the first tier will be paying more, the other tiers will be combined into one and be at a lower rate than the current top tier. In 2019 there is a plan to move everyone to time of use pricing. Once time of use is mandated, it may be too expensive to remain connected to the grid.
What you're saying does not make sense from the utilities point of view. Why, if they have superior competition, would they make themselves more uncompetitive?
Besides, centralized energy systems have certain advantages that household operations do not have. Maybe even better ones will arrive once solar becomes more accessible. SO it makes sense that they will stay at least as competitive as off-grid systems.
Can't keep customers? Then charge the ones you do have even more to make up for that shortfall.
Businesses trying to keep their outdated business models alive do that sort of thing all the time. Just look at the music and movie industry's continued flailing as they try to keep CDs/DVDs profitable while their customer base wants files that they can play on _any_ device they own, not a physical copy or some DRM-laden crap that forces them to use it on one system.
That's San Diego Graft and Extortion you're talking about, right?
This movement is going to put the skids under the home solar company's pitch that you'll be able to feed electricity back and sell it to the power companies.
I'm not happy with the diagrams. Example: the first one compares time to costs. That's really what we want. But why not add some lines for traditional ways to make electricity? That's what we want to compare to, or don't we?
The term "solar cell" refers to a wide variety of technologies[1]. Anything from common semiconductors, rare-earths or even fruit juice can be used to make solar cells. The impact will be highly dependent on the type of cell in question.
Fair enough. I think the most satisfying answer would be the released chemicals and other environmental effects normalized to kWh for various cell types, taking the designed lifetime and recycling into account maybe with some emphasis on cell types that are currently sold for households, or planned to be sold in the not too far future.
I'm interested in these questions:
- What cell types are currently bought, will be bought in large quantities?
The first of these links gives an overview of the risks, pointing out that it depends very much on the particular factory's safety record. I don't think normalising is even possible across so many different possibilities. All the risky chemicals can be recycled and non-CO2 emissions neutralised, but this is not always done. It also says the majority type sold is polycrystalline, so CdTe are rare. (Both cadmium and tellurium are quite nasty, but also bound in by the manufacturing process and not prone to leaking)
If solar is really that viable of an option, India should be investing a lot in this research. Power is a huge problem there. 24 hours of power supply is a luxury even in top cities. Small industries in rural parts operate around availability of power. There are a lot of wins here. And guess what, there is a lot of sunlight in major parts of the country throughout the year.
We all know that PV panels have a limited lifetime, and that building them has environmental cost. But I was wondering about recycling: does anybody know how much energy can be saved by creating new panels using materials from old ones?
Not really answering your question, but as far as I know panel lifetime is largely determined by cumulative damage from the environment. Scratches from trees, etc. reduce effectiveness, as does rain leaking into the panel through gaps created by the daily thermal cycle. There may be a lot of scope for extending their lifetime by improving packing, which would defer the environmental impact of recycling. There is some info on these factors in [1].
Also, panels may be declared end-of-life because they are not as effective as newer ones, even though they are still generating to original specification.
Power-company solar may matter more than rooftops, in the end. They have the economies of scale, choice of location and orientation, grid connection expertise.
Upcoming posts will look at the future of wind power, the future of energy storage, and what the missing pieces are.
If you don't want to wait, you can read my thoughts on energy storage here: http://rameznaam.com/2015/04/14/energy-storage-about-to-get-...