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US solar plant costs fall another 30 per cent in one year (reneweconomy.com.au)
460 points by doener on Sept 19, 2017 | hide | past | web | favorite | 167 comments

The non-decline in the associated costs for individual installs has to be thought about. If this is a true reflection of unavoidable costs, home installs are unlikely to break a cost barrier, and won't make substantive differences in centralized generation. If on the other hand they are mutable costs, and can be brought down, then microgrids and local power has more chance of becoming something of substance.

The bigger "win" in this is the transmission loss. Consumption close to generation has lower transmission loss so it's innately higher efficiency in that one regard.

PHES and Battery technology probably matter more now than PV as a the cost problem in generation: we need time shifting for solar power to replace other forms of generation, to get to serving demand outside of the sun.

Inflation-adjusted residential costs according to nrel.gov are shown in the chart on page vi of https://www.nrel.gov/docs/fy17osti/68925.pdf

The raw costs, not adjusted for inflation:

Q1 2014: $4.52/W total for $1.03/W modules [0]

Q1 2015: $3.09/Wdc total for $0.70/Wdc modules [1]

Q1 2016: $2.93/Wdc total for $0.63/Wdc modules [2]

Q1 2017: $2.80/Wdc total for $0.35/Wdc modules [3]

Conclusion: Even if the modules cost $0.0000001, the total price could not fall much more unless the rest of the business model gets updated. Probably some solar installer companies will drop out of the market, and the survivors will adapt to lower profits.

[0] Page 12, https://www.nrel.gov/docs/fy14osti/60401.pdf

[1] 5.2kW system. See page 7, https://www.nrel.gov/docs/fy15osti/64746.pdf

[2] 5.6kW system. See page 16, https://www.nrel.gov/docs/fy16osti/66532.pdf

[3] 5.7kW system. See page 21, https://www.nrel.gov/docs/fy17osti/68925.pdf

Based on the Australian experience, the next wave of price declines for residential solar will indeed come from balance-of-system cost declines, increased installation efficiency and lower profits.

Current costs in Australia are about A$ 1.70 /pk-W (~US$1.35), pre-subsidies, split roughly into 35% modules, 10% inverter, 10% mounting system, 10% other hardware (cabling, switchboard etc), 10% installation and 25% "vendor's margin", including marketing, sales and profits.

The household has also to pay for a bi-directional meter to allow for energy sales. IIRC that was around A$350.

It's a mystery why the US costs are so high - maybe not enough competition?

It's worth noting that in Queensland, we saw a big decline in cost after the feed-in tariff was dropped substantially in 2012, reducing demand. I paid AU$8500 for a 3kW system when I could lock in a 44c feed-in tariff, but everyone knew there was a deadline looming that wasn't changing. Once that deadline hit and it dropped to 6c, demand for installs dropped and the subsequent price dropped towards where we are now. Essnetially, panel and other equipment supply (as well as labour supply) overcame demand and the price fell as a result.

We also had the renewable energy credits scheme which made the price float about a bit since they were a traded commodity and the installer would take them off you for a price reduction proportional to their market value (if you elected to not instead keep them for yourself and pay 'full' price, but then have to sell them yourself too).

Basically what I'm saying is that there were multiple levers causing the price to float around a lot over the last 5-8 years and it's not strictly just because gradually supply/competition grew.

Based on that, shouldn't it be possible to get close to a 35% price decline, as long as the government allows you to buy wholesale and self install?

It would be great to see a DIY community around this, making widespread adoption even cheaper.

Maybe... but in Australia, the system must, by law, be installed by an accredited installer to be eligible for the "small scale technology certificates", a form of subsidy. This is currently worth about 45% of the pre-incentive cost. The accreditation itself is fairly straightforward, but costly.

> The accreditation itself is fairly straightforward, but costly.

As is typical in Australia, to do almost any job you need to purchase that right. Even construction labourers (guys carrying out the bins and sweeping floors) and waitresses who serve alcohol, need an accredidation.

You can definitely get a monetary price decline from DIY. But most people's time has value, too.

Yes, it does. But outside regular work hours, it's hard to get a meaningful return on those hours - something as costly, yet relatively easy (if laborious & monotonous) as installing solar panels/shingles, makes for an attractive DIY.

> But outside regular work hours, it's hard to get a meaningful return on those hours - [...]

I mostly agree. Of the top of my head, installing solar panels mostly competes with leisure and other DIY projects.

Perhaps also with commuting, but for most people the decision on how long to commute can't be altered in the short term.

Not sure what your lifestyle is like, but I think you would be surprised by how many people are willing to do weekend DIY projects on their homes, especially if they will save them money.

A properly done and code-compliant residential rooftop solar install is non-trivial for many DIYers. I do lots of things around my house but a rooftop solar install is something I'd definitely hire an experienced and insured contractor for.

Your typical DIYer is unable to penetrate an asphalt shingle or metal roof and properly waterproof those penetrations for the panel frame supports, voiding your roof warranty and possibly negating any ability to make a claim for water damage from your homeowner's insurance.

Also, any electrical work in most sane jurisdictions is going to require signoff from both the local code department and the utility (if grid tie).

The labor of a professional is cheaper than possible poor outcomes.

Ok, I can appreciate those concerns, but if someone wants to do this, I think that's their right. What if they have a cabin that they want to wire with solar? What if they just want to setup some panels on top of an awning, or in their backyard, and hook them up to a beer cooler?

To be fair I installed a solar+2nd battery+inverter that can also charge or be charged from the primary battery in an RV. I waterproof'd the roof, did the wiring, there's lots of guides on how to do it and it is not rocket science. Should you or my local gov have stopped me from this?

> Should you or my local gov have stopped me from this?

The government isn't stopping you from putting solar panels on the top of your RV, and it's regulation of structures through building codes is usually reasonable.

You might be interested in reading about the Tiny House movement. I think you would be surprised by how many people Rdisagree with you, and are upset with draconian housing laws and building codes.

Again, I don't see an enormous difference b/w putting solar panels on an RV, and a backyard, shed, cabin or house, particularly for off-grid power.

You are absolutely entitled to state your opinion though. I just think if other people want to do something that doesn't bother you in any way, it can be nice to warn of the risks, but why tell them they are wrong?

> I just think if other people want to do something that doesn't bother you in any way, it can be nice to warn of the risks, but why tell them they are wrong?

Because if you're breaking building code, you're breaking the law. That's the entire reason the Tiny Home movement has to build their structures on RV trailers; to be compliant with building code (which doesn't apply to RV trailers).

Ok no one is saying you should break the law, and that also wasn't even your concern in the previous comment, either, which was about the reasonableness of building code. Before that you were primarily concerned about time and risk of cost.

Bringing the goal posts back to the original aim of my comment: that a DIY community would simply increase adoption, let's look at the Tiny House movement. It grew as a DIY community. People sharing info on all parts of the process, incl. building code, helps many people who would have been told by someone that it can't be done, just as you are doing now, to build their own house. And we are talking about building an entire house, not a minor solar panel install.

As that community grows, you have more people that are able to even shape laws for the better, which is what that community is doing.

And you are incorrect about there being no laws governing auto work and customization.

No one is saying you should do this. To be frank, the "hire a qualified contractor" advice is pervasive at HN, but it's also this groupthink attitude of negativity that can grow around a subject that I don't think is necessary, or helpful.

Yes. Though of course, solar panel installation still has opportunity costs.

Eg even if you don't want to get a second job, you could still be lazing about, spend time with family, do another DIY project, or even commute to a job in that time.

(Commuting decisions usually can't be changed in the short term, but in the long term it's up for grabs just as anything else as people contemplate moving or changing jobs.)

Probably not enough interest.

It'd be interesting to see the costs split out based on available sun. I would guess they are lower in Phoenix than in Connecticut.

Energy costs are significantly lower in the US.

Most of the northern states don't have much sunlight and have cheap enough power to make it not worth it.

A common misconception. Even in northern Sweden, which is above the arctic circle, you can still generate ~80% of the energy that Southern Europe generates.

This is fascinating if true. Do you gave any sources, I'd be really interested in reading more on the matter.

This gives a good overview. What people miss is that during the summer the sun is up all the time. (In the winter, not so much.) And average cloud cover is also accounted for.


That diagram suggests Northern Sweden to Southern Europe is 50%, not 80%, which sounds more plausible.

Thanks! That is quite surprising, and very encouraging.

It seems that solar is a very good overall fit for even most of the world, and once the tech is good enough to be used in huge numbers the differences can probably be compensated with other, local power sources (like hydro in Scandinavia, which is huge there).

> What people miss is that during the summer the sun is up all the time. (In the winter, not so much.)

It sounds like these two effects should cancel each other out. Are you saying that people take winter into account but not summer?

Depends on what you're using it for. A common use-case is cottages that run off the grid, which are only used in the summer half of the year anyway.

But cold panels produce more power.

PVGIS is an excellent tool and I have been using it for years!

Do I understand correctly that the wishful thinking value of 75% photovoltaic conversion efficiency is plotted in the diagram?

It means the conversion factor of yearly yield in kWh to installed PV in kWp. "Yearly sum of solar electricity generated by 1 kWp system". It's not about the physical PV efficiency.

The 75% performance ratio represents system losses not module efficiency. So a system rated at 1kW(peak) which may be 5-6 square meters in size, and which is exposed to annual sunlight of 1200 kWh/m2 might only produce 900 kWh of usable power.

So efficiency has to do with the rated power per surface area and the performance ratio reflects all the system electrical and environmental factors that reduce the amount of usable power below what would be expected based upon module ratings and annual sunlight exposure.

One factor that helps is that solar cells become less efficient if temperature goes up (https://www.thegreenage.co.uk/article/the-impact-of-temperat...)

See the comment from bjelkeman! I don't have any "hard" sources but reserarching solar panels for myself by hanging around Swedish solar forums and noticed people way up north still get a good yield from their panels.

Most of the energy comes from ambient light, direct light is best of course but not strictly needed

Nitpick: Only the northern tip of Sweden is north of the polar circle. But yeah, Sweden is pretty dark anyway.

This is a good introduction & has excellent maps. http://solarinsolation.org/tag/map/page/2/

Here in Maine your solar panels are going to be covered with snow 5 months of the year, so the power production in the winter can't be very significant.. It's one thing to store energy between night and day and it's another thing to store energy between summer and winter. Don't get me wrong, I think solar is the future, but not sure how to make it work up north.

I live in Massachusetts, and have 37 250 watt panels. Snow isn't an issue. The panels generate a little bit of resistive heat, which means snow typically doesn't stick. If it's snowing so heavy, and is so cold that the panels do get covered with snow, the snow melts and slides off within an hour or so.

In July my panels make 1300 kwh and in December and January they make 300 kwh, mostly because of the angle of the sun and the length of the time above the horizon. I also have significant southern tree cover, so my production is not optimal for my area.

In curious about this, does it snow so heavily for 5 months there would be no way to clear the panels?

I mean they're installed at an angle to start with so how does the snow build up? Could panels not be designed with inbuilt defrosters?

The snow could be cleared off with a shovel, but then you have to either pay someone to do it in the case of industrial solar, or in the case of home solar, go up on your roof when it's covered with ice and snow, not the safest maneuver. Defrosters might be possible but that might use more power than the panels generate. You'd have to raise the temperature of the panels to above the freezing point of water, which might be a change of 20 or 30 degrees F on really cold days. Some years are worse than others- 2014 was really bad, I didn't see bare ground until late April.

It's a combination of the 80% output and the cheap local hydro power which makes it not attractive.

It's true that power here is cheap (~0.1€ per kWh). However, since most electric companies buy back what you overproduce you can get an installation that covers your whole years supply and have it paid of in 7-10 years.

What about some place like California?

It has sunlight almost all year round, it has a pretty progressive government, and a leading tech sector. With house prices being so high, so the cost of solar panels would be relatively lower too.

They also have a crazy amount of NIMBYs. Though they might not have figured out how to object to solar panels, yet?

in Los Angeles, solar panels are becoming increasingly common on single family dwellings.

as more and more existing trees die off because of higher water costs and a general theme of reduced water usage, there's a little bit less shade, too.

> Conclusion: Even if the modules cost $0.0000001, the total price could not fall much more unless the rest of the business model gets updated.

Which is where solar roofing comes in, taking up the cost of installation almost completely and dropping price almost to grid scale. Of course, the only solar roofing available forces you to get it installed by their technicians, but hey. Baby steps.

The discussion in your first link is interesting. Smaller installers can end up having lower costs because they spend less on customer acquisition. They pay somewhat higher prices for material, but plummeting panel costs and not holding panels in inventory have worked out well for them.

This sounds like inverse economies of scale. Interesting.

Thanks to your comment I looked this up. There is actually a term for this. https://en.wikipedia.org/wiki/Diseconomies_of_scale

Tesla's approach of taking the solar installation and "baking it into" changing the roof is very interesting in this regard, long-term. A labor-intensive job is done in parallel with another labor-intensive job, with a good amount of overlap.

>>Conclusion: Even if the modules cost $0.0000001, the total price could not fall much more unless the rest of the business model gets updated.

Sure, when building the roof, it is installed as a solar one, saves on roofing materials and installation, since you only pay for solar and for solar installers. Granted not 100% substitution since not all the roof can be covered but a nice chunk.

Or make the panels more DIY...a few cases of beer, a few friends and be done. (plug it in after 24 hour, to make sure that the beer is gone from system)

not to dispute the concept of an easy solar install, in theory, but i note add that, in Los Angeles at least, it's hard to imagine a quick, low-cost, DIY solution.

to the LA Department of Water and Power, home solar is basically competition. and the DWP is an important cash cow for city workers and the city budget. they will find ways to add customer fees and reduce the customer's energy bill savings. (e.g. limiting the amount of electricity a home is allowed to feed back into the grid.)

the agency and the city simply need that cash.

So from 16 to 17, the total cost aside from modules went up?

I haven't collected the hard numbers for what is presented on page vi of https://www.nrel.gov/docs/fy17osti/68925.pdf, but soft costs appear to have swollen to take up most of the cost savings from reduced module prices.

In other words, yep.

Here are the exact numbers that went into the figure you reference, the key costs findings by category for 2010-2017: https://catalog.data.gov/dataset/nrel-u-s-solar-photovoltaic...

Soft costs decreased appreciably from 2016-2017 in both "utility-scale" categories (Fixed-Tilt, and One-Axis Tracker), and have increased slightly at the smaller "commercial" and "residential" scales. Across all scales, soft costs claim a larger portion because other costs are falling more quickly.

Only at residential scale has soft cost growth consumed much of the savings in other costs: $-0.18/(watt installed) total cost, $+0.16/(watt installed) soft costs.

At commercial scale: $-0.32/(watt installed) total cost, $+0.05/(watt installed) soft costs.

While this direction of change is certainly suboptimal, I don't think the magnitude is worrisome yet.

EDIT: paragraph/line breaks for clarity of presentation.

Which from an outsider perspective could have been companies recouping on bets made (discounts offered) in 2016 to grow their brand recognition, etc. It's hard to draw too strong a conclusion from data for for so few years, where costs change so much, and the outlier is the most recent year (which is also incomplete). It's also possible that the actual business costs from year-over-year operation are finally becoming well known, and the installation costs are finally reflecting items that weren't correctly priced in earlier (botched installation fixed, warranty repairs, etc).

6% isn't really a non decline, it just isn't a huge decline.

The major component of residential cost is non-labor soft costs. The NREL pdf is easier to read (https://www.nrel.gov/docs/fy17osti/68925.pdf) and lists them: permitting, inspection, and interconnection, land acquisition, sales tax, overhead and profit.

According to their modeling, it's mostly profit, overhead and sales and marketing costs.

Emphatically, this. 21 is the page with the breakdown: only 10.7% of the cost is in installation labor!

Percentage-wise, not counting the module itself, the biggest culprits are profit(14% vs 7%), supply chain adding 17%, and sales adding 14%. Installation is actually lower as a percent of overall cost. Profit and sales are usually higher for direct to consumer, but supply chain is the biggest single cost at 42 cents out of 280 per watt. Scale will bring that down drastically but it will always be cheaper to centralize.

Sales should become cheaper as volume goes up and the market becomes more mature. But supply chain with 17% looks very high for non-perishable goods. They need to be handled with care but this could surely be brought down? Or anyone here who knows why they make up that much of the cost?

Part of this cost is the rapid panel depreciation which increases complexity or causes loss when inventory drops in value.

In the US at least, a huge fraction of costs for residential solar are in customer acquisition. Something like 20%-30% of the cost of a residential install goes to paying for lists of potential customers and marketing to them! This makes US residential solar much more expensive than in many other countries.

After that cost is reduced, there may be room for innovation in reducing install costs by bundling solar with roof replacement, or something similar.

I'm not so sure that transmission losses themselves are a huge win, since only about 5% of power goes to transmission and distribution.

However, if storage + solar allows the utilities to avoid transmission and distribution capital upgrades, that's a much larger chunk of the cost of electricity, about 36% according to the latest numbers and rising every year.

When I got solar several years ago I watched as the various installers wasted a ton of time selling to me. It was clear that all the steps between when I was interested and when I gave the go ahead to start the install were extremely expensive in the big picture and in the long term the winners of residential installation would be those that will be able to drive that cost down and or spread that cost out to as many customers as possible.

They visited my house when I was just looking for a quote. The quotes were these large custom contracts with all the information which we would iterate a few times on.

I can imaging these days just going to a website, finding my roof, selection my option and getting a quote in real time. Maybe they would even let different installers all bid for the job, who knows. The website would have detailed information and information if I want it. Only if I did an initial downpayment would someone come out to confirm it could be installed. Someone like this could be able to drive the install cost down.

Or maybe "groupon deals" where if you and 4 other neighbors on your block all buy solar it is 15% cheaper or something. That would be one way to shift the marketing and sales to the consumer and not the installer.

That website exists, to some degree: https://www.google.com/get/sunroof

Here in SoCal, I have to fight off door to door solar salesman at least once per month. It's really annoying.

For what it is worth I do to. It is amusing to get to tell them I already have solar at which point they look up and then walk away. But think about it... What kind of margin pays to have someone walk door to door? That is the kind of waste that the system has not yet rung out and why residential costs don't seem to be going down as much as they should. As long as all of the installers don't drive their costs down they all get to enjoy growing profits!

> What kind of margin pays to have someone walk door to door?

If I had to guess, the door-to-door folks are probably lead gen companies that sell leads to solar installers. The economics work out largely because solar installations are such a big ticket item that good leads can demand a nice sum. As a thought exercise, Amazon will pay in the range of 5% to affiliates. If you buy a $100 pair of shoes on Amazon, that will net the affiliate $5. If a solar lead gen gets the same rate, then a single $30k system will earn them $1500. So that salesman only needs to sell a few systems per month to cover salary. Hence the door-to-door.

Also, it's worth mentioning that the residential solar market is pretty cutthroat. Quite a few companies have recently filed for bankruptcy. Part of the reason lead gen and marketing costs are so high is because these companies are fighting tooth and nail for customers. I am pretty sure most installers would love to cut back on that spending, but without it their business would collapse.

That's it! I just need to install fake panels on my roof!

The numbers bandied around make it look like fake panels wouldn't be appreciably cheaper than real ones.

Is there an attempt to go after multi unit residentials? Any incentives for builders to implement?

Asking this as a layman.

> In the US at least, a huge fraction of costs for residential solar are in customer acquisition. Something like 20%-30% of the cost of a residential install goes to paying for lists of potential customers and marketing to them!

Page 22 of the report[1] estimates sales and marketing/customer acquisition for residential solar to be 12% of the price, and says Vivint and Sunrun report it as 17% and 22%, so I think your numbers are a bit high. I also doubt that cost will actually fall- if anything it might rise, since advertising pays for itself. As costs drop it becomes more important to advertise the low costs!

[1]: https://www.nrel.gov/docs/fy17osti/68925.pdf

Ah yes, 30% was too high. But 19% is what's reported by other analysts, such as GreenTechMedia [1]. Like you, GTM also expects customer acquisition costs to remain high, which I find to be unfortunate. As pointed out above [2], Australia manages to have an industry with less money spent on marketing.

[1] https://www.greentechmedia.com/articles/read/costs-to-acquir...

[2] https://news.ycombinator.com/item?id=15290269

Retrofits may be expensive, but think about what low costs mean for new builds, especially multi-unit dwellings - well, not highrises that lack enough rooftop space, but lowrises and townhomes.

Beyond some height wind makes total sense.

You need pretty big rotors to generate enough electricity to pay for the embedded energy: http://www.lowtechmagazine.com/2008/09/urban-windmills.html

Output scales with design, size, location and height. With "beyond some height" I mean really tall buildings would need just a tiny propeller. Micro turbines are nice for a very different reason. -- "Unfortunately, micro wind turbines deliver hardly enough energy to power a light bulb." The benefit from not siting in complete darkness starts at about 1 Watt, the example produces considerably more. -- "Payback time: 50 to 750 years" The interesting bit here is the static world assumption. No one can tell how manufacturing, wages/income, the economy, geopolitics, climate, migration, food, etc will change. There is lots of room for the grid to go down and it kinda already regularly does in the best of locations one time every 10 years. (atm the entire grid in Puerto Rico is down) -- While it would be nice to have a heater or a cooker small devices like led bulbs and radios are valuable when the power is out.

Do solar roof tiles help this out at all, under the assumption that you'd be replacing your roof anyway? Is the labor cost of replacing with solar tiles in line with the price to replace a shingle roof?

Even if so, installation costs are minor when solar is included in the initial construction of the house. So I expect a much bigger emphasis on that soon...

Germany has much lower soft costs than the US so there is still room for the price to fall. Particularly, customer acquisition costs are comparitively higher in the US because there is much less environmental awareness.

Flying recently from Phoenix to San Jose I was amazed by the size of the solar arrays I saw in the desert. I wasn't sure that that was what they were; but I found some of them on Google maps satellite after and confirmed it (cool time we live it). Good news is that there's so much more room to build more!!!

Edit here if anyone's curious: https://goo.gl/maps/SjzWw9b2dSH2

Edit 2 - as an aside, when I first saw, I couldn't tell if it was solar or ag (e.g. here's what ag looks like - https://goo.gl/maps/AGvAxJ61BwB2 if you zoom out they look very similar!)

Sadly, there appears to be many environmentalists and conservation people against large desert solar arrays claiming it threatens habitat of whatever lives there. It probably does have an impact but at this point unless population declines or energy use dramatically decreases I think we need to focus on minimizing human impact on the environment and not stopping everything that isn't completely harmless.

> Sadly, there appears to be many environmentalists and conservation people against large desert solar arrays claiming it threatens habitat of whatever lives there.

Can you cite a significant environmental group that completely opposes all large desert solar projects for this reason? Otherwise this reads like a rather unfair characterization.

In a recent case [1], the Sierra Club successfully argued that a planned solar array outside Hollister should be made smaller (by about either one half or two thirds, it's not clear why each successive cut was made), due to the potential threat to a handful of endangered species in the area. They also indicated unequivocal support for a similarly sized solar array in Imperial County.

Given how much undeveloped desert land exists in the US Southwest, it seems reasonable to build solar arrays first in areas that won't threaten the habitat of endangered species.

[1]: http://www.mercurynews.com/2017/07/21/giant-solar-project-re...

Endangered species need to go extinct. We are committing a high level universal crime by intervening in life's natural hygiene process.

That's just as unbalanced a view as "endangered species may never go extinct". The difference is whether they go extinct because of maladaptation to the natural environment or because of maladaptation to human influence on the natural environment. No reasonable person would argue against the first thing, but many argue against the second thing.

Are humans not part of the natural environment?

It's a bit disingenuous to call extinction caused by human activity "nature's hygiene process".

Do those same people get sad when they see arable land being used for food production or large cities from space? They probably need a reality check on their understanding of humanity. We have always been modifying the environment to suit our needs, every species does this.

>We have always been modifying the environment to suit our needs, every species does this.

Humans have only been farming for the past 11,500ish years, while Homo sapiens have been around for more than 200,000 years. Humans modifying the environment to a significant extent is rather new in our timeline.

I don't know about that. There's at least speculation that some percentage of animals that went extinct in North America were due to humans. Also in North America there was a lot of impact to ground cover by people before agriculure - i.e. burning down forests to make it easier to hunt game. It's hard to imagine those things only occurred in the Americas.

Yeah, but we are the first species to start modifying 100% of it in such a way that only corn and cows will be left.

Why is that sad? Are you more knowledgeable than said environmentalists, or do you simply assume that they are wrong?

Environmentalism is often just a stated preference. Like humans shouldn't disturb some thing.

So it isn't necessarily the case that you need to be more knowledgeable to challenge them. Availability of inexpensive energy without burning coal is another preference.

I certainly have reached the point where I think popular environmentalism is waaaaay too focused on static conservation.

That's a generic view which I might actually be inclined to agree with you on. I'm personally skeptical of the current climate change politics, for example.

But OP made a more specific claim about solar arrays in the desert. Seems like we should be able to debate that on its merits.

That alternative to putting them in the desert is putting them in some non-desert area or putting them nowhere. If these people are objecting to putting them in a desert, they'll object to putting them in a non-desert area too.

Making better use og roof-tops generally is a win as far as environmentalists are concerned; NIMBYs/BANANAs may complain however.

Not that I see any intrinsic beauty in concrete titles or roofing felt. Even clay tiles and slates I suspect are just something we have gotten used to.

In all cases they are a financial and embodied energy and financial cost as-is, and PV can turn them into something positive.

Ignorant people look at a desert and see lifeless desolation. When they educate themselves they come to see the desert as an very active environment with limited resources, and cut-throat competition for same, that makes human impact more pronounced. Better to put solar panels over scrubland or even farmland than into deserts.

Generally, it isn't really environmentalists exactly fighting these projects. Instead it's folks who don't want them near where they live or other powerful interests in the vicinity, who utilize existing environmental regulations to put these projects into analysis limbo for years on end. So there is a relationship in that the environmental laws are able to be abused to stop NIMBY projects. The same laws are now being used to stop High-Speed Rail.

I'm guessing theyre sad because they don't value desert habitats highly nor appreciate them and are probably raised to think deserts are "empty" when thats far from the truth.

I think some reference is useful, here.

Agriculture is and will be much more land-intensive than solar.

I once calculated that the US could switch entirely to solar just on a fraction of the land that is currently used for ethanol production alone.

And what is a better place to put solar panels? In the desert or fertile arable land? Deserts contain life, of course, but the density of life and biodiversity per unit area is much smaller. Additionally, solar panels provide shade and, unlike agriculture, don't require intensive tilling, harvesting, irrigation, spreading of pesticides (natural or otherwise) or fertilizer and the runoff that causes. They mostly just sit there, maybe getting a cleaning every once in a while (but unlike concentrating/thermal solar, don't need to be cleaned super often).

Once the panels are placed, your desert tortoise can nestle in the convenient shade they provide.

We'll destroy habitats anyway. But stopping/slowing down climate change by reducing the habitat of some species will still be beneficial for global diversity of species. I find it hard to believe that warming oceans would kill less species than solar panels in the desert. And even for 100% renewable energies, only small parts would have to be used for production.

There are circular-ish arrays of mirrors which reflect light to a tower with a water tank. The water turns to steam which turns a generator. There's at least one of these on the flight path from phoenix to SF somewhere.

Anyway, I read that this instantly incinerates any birds flying near the focal volume and you get these little puffs of vaporized bird every few minutes.


The incinerated birds are called streamers. Here's a reference. [0]

[0] https://www.sciencealert.com/this-solar-plant-accidentally-i...

And then it was adjusted and no birds have died since https://cleantechnica.com/2015/04/16/one-weird-trick-prevent...

The fix described in that article was for the standby position. It doesn't explain why there would be zero bird mortality when power is being generated.

Very interesting, but it'd be nice if they'd mention that many thousands of times more are killed each year by building windows, and pet cats, to put things in perspective for people.

The bird deaths are mostly used by people who are against solar power (or this particular implementation of it) to begin with. Even if the article mentioned it but it would not change many minds.


I would replace "many" with "some". The problem we have is that there are many types of environmentalists, each with their own agenda. Just because a faction of environmentalists consider the desert solar array bad, doesn't mean that all do. In fact I would wager a guess that most think that it's worth it, considering how much pollution it's saving.

Very true, but this tends to be an issue mostly in California. That's why it's quite surprising that states like Arizona, Nevada, Utah, NM and Texas haven't started getting into this in a big way. I think it's just a matter of time. Especially since they can sell their power to California for a big profit.

We (Arizona) are getting "into this in a big way."

Existing AZ Solar:

- Agua Caliente (~400MW)

- Arlington Valley (300MW)

- Solana (280MW)

- Mesquite (150MW)

Future AZ Solar:

- Sterling (1200MW)

- Hualapai (340MW)

- Hyder Valley (325MW)

- Sonoran Solar (300MW)

- Crossroads (215MW)

- Quartzsite (100MW) [1]

[1] https://en.wikipedia.org/wiki/Solar_power_in_Arizona#Large_p...

Deserts are abandunt- in fact they are the default ecology on all planets.


If solar panels could be modified to create substained microclimates below that would be awesome. After all, there is still enough straylight getting below, to allow for a average forrestplant to exist.

Speaking of which, they also could be used to condense the (low) air humidity and channel it into the ground, so the possibility to create a micro ecology system is even more higher. Water immediately attracts life.

There was a small project where somebody used a hygroscopic substance (Silicagel) to collect water in the atmosphere in the desert and freed it with concentrated sunlight, and then condensed it.


There are studies that have found that the net carbon impact of such desert solar arrays can actually be detrimental -- that is, installing the solar arrays in the desert causes an imbalance in desert soil ecology causing a release of soil carbon that exceeds the carbon benefit of the solar array. Here's one article on it, but I'm sure you can find others:


That article has all the standard petroleum industry claims: bird deaths (cats kill more birds by a factor of 100x), Native American tribal opposition, and whole lot of data meant to fit a narrative.

The US can't quit coal/oil - because the alternatives along with advanced batteries would sideline petroleum. And we certainly can't have that.

ag = agriculture ... took me an embarrassingly long time to figure out it wasn't a technical term for something.

On the one hand it's great to get Solar below cost _at someone else's_ expense (Chinese over producing manufacturers), on the other hand I'd prefer that some of our own PV mfgs remain afloat.

Ultimately the goal is to wean off of fossil fuels, but if all our R&D is unprofitable we may miss some breakthroughs.

"Over-producing" isn't really a thing. You're complaining about supply outstripping demand causing prices to fall - that's always going to happen with any mass produced goods.

It sounds like the real issue is that doing R&D in the U.S. is uncompetitively expensive compared to doing the same work in China.

Germany was once (ten years ago) the top PV panel producer. All it's MFGs, including SolarWorld[1] have gone under because of dumping and flooding the market with cheap PVs. This subverts R&D in panel technology both in Germany and in the US. In addition, some German PVs were hacked[2] and had their IP end up in the hands of CN MFGs, again, that subverts German (and any other MFG) R&D efforts in PV tech. So we may end up with retardation in PV R&D which is not a good outcome.



Isn't this a good thing when it comes to renewables? If the Chinese state pays for the world to become less dependent on coal that should be good? Solar installations are still labour intensive, probably more so than coal plants.

This is one of the very few cases where I don't mind states subsidising. The technology is still well understood by others so that European/US companies could start producing again if China decides to raise prices.

Not really because they cannot sell below cost in perpetuity --that's just a temporary race to the bottom to see who can survive the bloodbath. In the meantime no one is innovating because there is no money to be made and also there is no money to invest by the subsidized companies since they are bleeding money anyway. So the result is innovation gets retarded.

No, what he is complaining about is the fact that a solar install is a durable good--it has a lifetime and must be amortized.

If the install is cheap crap and only lasts 5 years when you need 10 to amortize it, that's a problem. If the cheap crap drives good manufacturers out of business, that's even worse since now you can't recover once you discover it.

Err ... not according to Econ 101. A rational producer in a perfectly competitive market supplies just enough to clear the market. When people distort markets with subsidies, etc. the amount produced is more. This can also be in industries with barriers to entry as a large producer might supply more on purpose to drive existing competitors out of business.

Always gotta be careful applying 101 knowledge to a real world problem.

Also, this is an unfortunate misinterpretation of even econ 101. Econ 101 says that there is not a fixed demand for most goods. Demand (and supply) have elasticity, which is a measure of their responsiveness to price changes. A rational producer with perfect information does not "clear the market" if that means "supply enough to meet all demand for the good." (If that's not what it means, I really don't know what it does mean.) They supply just to the point where marginal cost of production is equal to the price the next consumer is willing to pay.

And, subsidies are not definitionally distortionary. Sometimes they can be used to correct uncaptured positive externalities.

> rational producer

With perfect information.


It's a problem when market prices drop below the cost of manufacture. That can lead to a financial collapse for individual producers, lack of investment in maintaining capacity and a lack of investment in new technology and manufacturing processes. That can lead to sudden reductions in supply and unpredictable price surges which make it very difficult to control the costs of long term projects.

Extreme price swing for panels aren't guaranteeed to happen, it depends on how governments respond in financial support for producers and changes to subsidies, but that's just shifting the costs of all of this on to tax payers.

There is a thing called dumping though, when a country or company intentionally produces more than is optimal in order to decrease prices and drive their competition out of business.

Over-producing isn't a thing in a pure free market, but it's absolutely a thing when government subsidies get involved.

Sounds like we need to boost demand then!

If panels keep getting cheaper and cheaper I wonder if installing them vertically on south-facing walls will start to make sense. This won't ever be optimally efficient, but installs will be much cheaper since it won't involve roof work.

If you want to take the idea to an absurd level, garage doors could be designed with integral panels and then installed anywhere somebody has a south-facing garage door. In most cases the garage door will also be unshaded since there will be a driveway in front of it rather than a tree.

One serious concept that sounds a bit silly at first is to put solar panels on the back of solar panels used for grid scale arrays.

Obviously not optimal since these are literally turning to continually face away from the sun yet apparently get you a 1% improvement and you're spending the rest of the money for installation, wiring anyway so at a certain price point it makes sense.

Here in Rio, one building retrofit added panels vertically to the whole visible part of the north-facing blind façade (the neighboring building is smaller).

We forget Feds fund American roads and local congressional districts like it that way. Our people grid is a road grid accessing an energy grid. Every single story suburban home is a waste of space and HVAC. Rationalizing costs will penalize cheaply built homes along roads built with federal funding. Our TFR's have peaked and Sante Fe Institute folks do not predict happy sprawl. Look at DC or Boston Building town homes and condos more densely on shared public transport with Uber fill in. Quite successful medium enterprises spread out by Eisenhower cannot find employees. Various locales like Columbus, OH and Pittsburgh are slated for gathering that slack into ecosystem. The economic concerns of remote Americans playing fake prairie homesteader are not especially relevant to long term planning. Plan for yourself last to see the big plans in motion. There are business opportunities skating to where large pluralities of pucks are going. Levis made jeans for rushing gold rushers and lived to tell the tale.

TFR = total fertility rate?

When will prices drop below $20k for a full install? I get so frustrated when I hear that the price keeps dropping, but the price for a consumer install hasn't dropped below $20k in years.

If I do the installation myself, will that make it cheaper?

I suspect a lot of it has to do with housing prices where you live. It's a pretty easy upgrade to a house, and adding $20K to the mortgage for most houses these days is trivial. If you are selling, then you can probably even make a pretty decent return on investment because people are willing to tack on such "small" amounts when they buy the home. So until solar panels become a standard that everyone expects in a home, or until the next big market crash, I suspect solar installations will have inflated price tags.

20K turns into roughly 33k in 30 years. I think trivial is a relative term.

Trust me, I'm with you on that on :-) But I think most people who are plonking down $1 million on a house will not notice an extra $20K on the price tag, but will notice solar panels.

Somewhere else in this thread people posted the cost. Labour is only 10%. Most is marketing and supply chain, so if you buy them directly from the manufacturer and hire people to install them it should be much cheaper (~30-40%). Not sure if that's possible though.

If you have an interest in investing in solar, this Friday the ITC will decide if US solar manufacturers were harmed by too cheap imports. If they rule yes, most likely the manufacturers will drop.

If the ITC finds that manufacturers were harmed and allows some sort of benefit for them to compensate, surely their share price would increase?

They tried that that for Japanese TV imports in the 80s under Reagan, guess how many US Manufacturers survived.

Our local solar panel plant shut down a few months ago - Suniva. They just mysteriously closed up shop.

It's no mystery to those in the industry. They simply made some bad bets, and decided to meet high local demand by importing panels rather than being able to manufacture on their own. This is from the US solar industry's trade association in response to Suniva's requests for price floors and tariffs:

>Listen later today to our witnesses who will tell you about:

• how Suniva’s ion implant cell technology was a commercial failure;

• how Suniva shipped its cells to other countries to assemble into modules because its own module assembling facility in Michigan was poorly designed;

• how Suniva and SolarWorld both failed to take advantage of opportunities to sell to some of the largest residential solar developers in the country;

• how both companies failed to meet basic delivery and product quality standards, leading to a loss of repeat business; and

• how SolarWorld had the opportunity to sell American-made 72-cell modules to utility-scale developers but filled those orders with imports instead, because they clearly don’t have the capacity to meet U.S. demand for these products.


Basically they tried and failed, where others are succeeding. Now they are trying to play into a political narrative that doesn't apply to them in order to prop up their business, at the expense of all the downstream solar installers in the industry.

I understand this is trivial, but I have a serious bias against that company just because the name really bothered me.

It sounds too much like a crappy Iced Tea.

No warning at all?

Suniva has been under financial stress for years.

Suniva was in the news this week, and not necessarily in a good way: https://www.bloomberg.com/news/articles/2017-09-18/little-kn...

they probably just went in for the government subsidies

Many of the comments seem to be focusing on the initial install costs and missing a big point here. Solar can save a lot of money and even make a nontrivial amount of money for the owner.

As you would expect, there a lot of factors that go into how much an array would save/produce (generation, storage, etc.), but a regulatory factor that changes everything is rate structures. Rate structures are far from a standard thing, pretty much wherever you go, there's something different, it varies by state and even at a smaller, city level for municipally-owned utilities (about 15% of the US is served by these, including parts of Bay Area, LA area, Phoenix, Seattle, etc.).

For consuming energy, there is usually a flat-rate or a time-of-use rate (many varieties) but there are more and more capacity fees and fixed charges taking over. For producing energy, it gets much stranger. Many cities and states use versions net metering [0], some will pay you the wholesale power rate and others will pay you the retail rate (retail is ~3x wholesale), some will use a Feed-In Tariff [1], some will factor in a more time-based rate (like time-of-use above), and some others too. If you want to know more about rate structures in general, check this out [2]. [0] https://en.m.wikipedia.org/wiki/Net_metering [1] https://en.m.wikipedia.org/wiki/Feed-in_tariff [2] https://www.google.com/url?sa=t&source=web&rct=j&url=https:/...

Rate structures are heavily regulated, for good reason. Their design is a very difficult task and is pretty murky. On one hand are the consumers and their desire to connect solar and other DERs [3] like storage to lower costs. On the other hand are utilities, usually not acting malevolent, wanting to maintain reliability, and, at all costs, avoiding the death spiral [4], which basically means that more people connecting solar and even leaving the grid will skyrocket costs and tank reliability. Though sometimes, the generators will desperately lobby against them. Depending on where you are, the utilities can be the generators too, another matter. [3] http://www2.epri.com/Our-Work/Pages/Distributed-Electricity-... [4] https://www.greentechmedia.com/articles/read/this-is-what-th...

Rate structures are arguably the largest factor in installing solar. Initial costs are important, but the rate structures will affect them over their 30+ year life. In some places, like North Carolina, it can lead to solar flourishing. In other places, hostile rate structures and other regulations can severely harm solar's adoption, like Florida which should be the best place in the US for photovoltaics.

Even more complicating is the ability of the grid to handle a lot of solar, let alone other DERs. The energy grid in the near future can be highly distributed, 100% renewable, and even more reliable than it is today, but there are some big system levels problems to solve before than (these rarely get any attention, most attention goes to node-level problems like sheer generation). I am fully engulfed in this field and am working on these things now. I thought I would present an important point and give y'all some information on this field that I find absolutely riveting. :)

What's the best way for an interested prospective solar customer to get informed so as to not get ripped off? This seems to be a situation with significant information asymmetry between the consumer and the seller.

Solar can save a lot of money over 30 years, but current homeowners have to pay the initial cost. Solar initial costs are much more than composite and homeowners may not stay long enough to make it worthwhile. Also, they may not recoup their investment when they sell the home.

> "I am fully engulfed in this field and am working on these things now."

What aspect of the field are you working in currently?

So mining bitcoin is 30% cheaper!

Imagine if we could do solar in space.. infinite area- no soil wasted, the power transmitted as a ray of death... oh, so this is why we do not do solar in space.

Technically it's not infinite. The sun emits about 10^26 Watts of solar radiation energy produced from the nuclear fusion of about 4*10^6 tonnes of hydrogen per sec, i.e. a 100% efficient dyson sphere would capture that much energy at most.

How about building something similar to a space power station that loads huge batteries, then gravitationally launches them towards ground, while on the other side an automated system launches rockets with empty batteries that docks to the power station?

Guaranteed to be hugely net energy negative in the energy required to launch the batteries. Think about payload fractions and the huge amount of energy in rocket fuel.

Step 1: Build a space elevator

Step 2: ...

Step 3: Profit!

Launch Loop or Space Fountain are superior. Even the Laser Transmitted Energy solution is. Why? Because they do not have such tremendous costs to install and do not rely on hypothetical yet to develop substances.

Solar panels are a semiconductor technology, and as such follow Moore's Law, and have been for decades.


No. Moore's law talks about miniaturization that leads to better performance and about the fact that when it was first pronounced, no significant roadblocks seemed to exist for 20 years.

The improvements in solar panel tech do not depend on such a straightforward route. There is no process that you can simply iterate through to reproduce the last performance gain.

Yes, it's very much about miniaturization, not processing exponential amounts of surface area per dollar. Cost per wafer has been steadily increasing. http://techreport.com/r.x/broadwell-14nm/transistor-costs.jp...

Moore's law is about improvements in cost-benefits that occur at a steady rate, and CPUs have not simply been shrinking transistors, but adding instructions, reorganizing the architectures, moving motherboard components on-die, etc.

PV panels have had certain types of regular process improvements. My understanding is that they try to add layers that use more of the energy of the light spectrum.

Conversion efficiency improvements are responsible for more of the cost-benefit improvements than taylorist improvements via economies of scale. And those improvements have been occurring at a remarkably steady rate for five decades.

Moore's law simply says that the density of transistors in CPUs doubles ever two years. It was an observation over the past, and M.Moore (who is still alive and often criticizes Moore's law) famously said in 1965 that he did not see a reason for it to stop for another decade.

Later Intel said that performances (not just transistor density) would double every 18 months, which is different.

Moore's law talks about transistors and we arguably have finally reached a point where it slowed, after having outlived its initial prediction for several decades.

Moore's law, though, was more than an extrapolation of the past: it was an understanding of the causes for the speed of the trend and an examination of what the future may provide by someone who understood the manufacturing process behind CPUs.

Moore knew about CPUs, he was talking about CPUs and transistors. His "law" holds no predictive power whatsoever for PV. You will have to find a specialist about the processes to know if there are any predictable roadbloacks ahead.

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