Why roof-top solar panels really don't make sense

Davis Swan | Jan 06, 2014

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In many parts of the world there are significant financial incentives for homeowners to install roof-top solar panels.  This can include capital grants for the equipment, tax write-offs and/or Feed-In-Tariffs that guarantee that electricity produced by the solar panel will be purchased by the local utility at above-market prices.  In Hawaii the annual cost of these incentives is at least $200 million.  In Germany it is now in the $billions.

As I pointed out in an earlier blog posting there is inherent unfairness in these subsidies which are only available to relatively wealthy single-family home owners.  People living in multi-family dwellings, renters, and those on low or fixed incomes that cannot afford the capital costs of the installation cannot share in these programs.  They can, however, contribute through taxes and electricity bill payments to the cost of the subsidies.  They can also disproportionately help pay for the added complexities of a grid that can incorporate distributed power generation.

The incentive programs in many areas are also vulnerable to abuse. One couple in Ohio have installed over $180,000 worth of solar panels in order to provide year-round heating for their large indoor swimming pool and indoor tennis court. I'm sure they are most grateful to the taxpayers of Ohio and in fact the entire U.S. for the more than $55,000 they will receive in various tax breaks. And by the way, their solar panels do not help anyone become independent of Middle Eastern Oil.  Electricity in Ohio is generated primarily by coal-fired plants with a small amount from natural gas-fired and nuclear plants.

Putting aside the fairness issue there is also a very strong argument against residential roof-top solar panels based upon basic economics.

If you live in the suburbs your street probably has dozens of single family homes of different sizes and shapes with various configurations of roofs covered by a variety of materials.  Imagine if you will a veritable army of roofers crawling over these houses, attaching frames and mounting solar panels.  If you think about that for a moment you will have to come to the conclusion that it is not an overly efficient operation.  Lots of up and down ladders time and safety setup time and not so much install solar panel time.  Now imagine that same scenario when it is raining or snowing - more than a little scary for everyone involved.

Compare that to utility-scale solar where uniform racks can be laid out and solar panels mounted from the ground in a matter of minutes.  The two scenarios are illustrated by the photographs.

Recognizing that the public and electrical utility customers are footing a large part of this installation bill which configuration would seem to provide the best return on investment? It would be hard to argue against the utility-scale solar panels.

What about efficiency in terms of making the best use of the solar resource?

In the case of residential roof-top solar there are likely to be plenty of other buildings, trees, and hills nearby so that the solar panels are often in the shade.  Almost all of these solar panels will also be mounted rigidly, most commonly at the angle that is the roof pitch.  This will not be the optimal angle for most sites and latitudes.

Utility-scale solar panels can easily be equipped with single or dual-axis tracking which very significantly increases the power generated under all circumstances.  They will also be located in large open areas where they will be in direct sunlight for most of the day.

Battery backup?

Having small, deep-cycle batteries as backup for the solar panels might be an expensive necessity at Possum Lodge but in suburban North America that type of installation doesn't make a lot of sense - which is probably why almost nobody does it.  Instead, through the magic of net metering, the surplus solar at mid-day is pushed out onto the grid whether  it is needed or not.  The home-owner effectively gets to use this mid-day electricity as a credit against the much more expensive evening and night electricity that would otherwise have to be purchased from the local utility at peak demand prices.

For the local utility the end result is a significant reduction in revenues from the owners of the roof-top solar panels even though they are making the grid more expensive to build and maintain.  Who picks up the slack?  Everyone that does not have roof-top solar panels.

Regular maintenance?

The home owner that installs the roof-top solar panels will probably be pretty excited about them and will maintain them to some degree.  But as houses change hands that commitment could fade;  as leaves, moss, and dirt accumulate through the years who is going up on the roof-top to polish up those solar panels.  Nobody is my guess.  So the overall efficiency of the panels is bound to decline over time.  The same with local battery storage if it has been installed.

Finally, the presence of roof-top solar panels has been identified as a significant danger to fire fighters.

All in all, looking at roof-top solar panels perfectly objectively they just don't make sense.  There are better ways to spend those dollars as we transition away from a hydro-carbon economy.  Some other ideas are described in my Sustainable Energy Manifesto.

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Comments

Now for the question of the year: at the present time does it make sense to replace coal by utility scale solar in the great state of Ohio, or for that matter in Germany?

By the way, this is an important article.

Fred,
Nope. Makes virtually no economic sense. Ditto from the environmental "save-the-planet" standpoint. Just another exercise in driving the middle class into poverty with stunningly stupid wastes of money promulgated by the government and left-wing elitist.

The article is spot-on. Well done Davis!

Wait a minute now Michael, wait a minute. As I understand the position of Davis Swan, he Thinks that rooftoop installations are nutty, but not necessarily utility scale installations. Say in Yankee Stadium.

The observations on the wildly uneconomical roof-top installations are accurate.

As far as utility scale applications, rather doubt they make much economic sense. However, if the solar cells ever reach a few cents per Kw, might work. Vaguely recall semi-conductors/transistors were pretty expensive at first. Not any more.

With currently available technology roof top solar electricity generation is an entirely foolish idea from apublic policy standpoint.

1. It does not get anyone off oil, or coal or gas. Some studies say that it actually increases the burning of these fuels because generators must be on spinning reserve to take up the slack when the sun does not cooperate. Generally spinning reserve - that is the generator is fired up and synchronized to the grid - takes about 2% of output so for a 1000 MW coal plant you are using 2% x 1000 = 20 MW just to keep the machine running when it would otherwise not be. That basically wipes out all your solar output.
2. It increases the amount of CO2 because the panels are almost all made in China whose primary energy source is coal and making these panels is VERY energy intensive.
3. It snows in Ohio (solar panels covered in snow produce nothing)
4. It is dark at night (solar panels produce nothing when it is dark).
5. Only a few people have access to it (those with roof tops) - apartment or multi-unit residential buildings generally occupied by the less well off members of our society do not.
6. Massive power swings occur when clouds roll over and intercept the light.

I could make a much longer list but all we are doing by subsidising these things is make the installers wealthy and the manufacturers (mainly Chinese companies).

So a bit stupid if you ask me.

Utility installed systems are even worse. They occupy vast areas of land that could be put to productive use. A common target for installation is those who have land - farmers. So we use the sunlight to make electricity instead of grow stuff for a hungry world to eat. That is a really far sighted idea.

Now I did say with current technology. New developments based on graphene could make solar electricity generation 10 to 100 times more efficient per unit area. Secondly graphene based super capacitors may allow the storage of large amounts of electricity in a small space. But with what we have now - it is not economically viable or viable from an energy standpoint.

But that is what you get by elelcting people with degrees in law and economics instead of folks that understand why.

A sad world we live in.

Malcolm

First comment, long time reader. Many of your viewpoints in the above article are not valid and below I will go into depth on why:

1. With new financing mechanisms that pay the up-front costs of solar installations, such as those offered by Sungevity and Solar City, low income homeowners can install solar on their rooftop for no up front fee and reap the benefits of cheaper electricity. These offerings are expanding to many states as we speak.

2. The solar modules installed to heat the indoor swimming pool and tennis court actually do decrease our consumption of fossil fuels with the assumption that the family would be heating their pool and tennis court to the same temperatures without solar. Whether it is ethical is another story. Personally, I would focus more on whether the significant tax loopholes for the 1% and large corporations are ethical rather than the few homeowners that 'take advantage' of solar incentives to heat their pools and tennis courts.

3. There are many rooftop installations that are the size of small scale utility installations, totaling 200 kW to 1 MW or more of solar on one roof. These installations can be installed with a ballasted racking system that decreases installation time significantly and minimizes transmission losses. These installations can also be installed on a major power consuming entity (e.g., a factory) thereby saving costs for the business directly.

4. Electricity in the middle of the day is typically much more expensive than electricity in the evening. That is because there is more demand in the middle of the day when offices and factories are operating. Therefore, theoretically, it is beneficial for the grid to have additional power generated from solar during peak, day time hours because it supplements the traditional fossil fuel based generators. Practically though, there is currently too little solar in most US grids for it to matter. All that said, there is no real time demand-based pricing for solar energy that I know of in the US, which means that your argument about daytime output being used to subsidize evening consumption is not valid.

5. Maintenance of small solar installations is extremely minimal and in most areas, the dirt will wash off by rain. In utility installations, you have to worry more about maintenance.

6. Most municipalities have fire codes to guide the installation of solar modules on a roof that create safe working conditions for firefighters so that they can easily move around or under solar modules. Therefore, solar modules are similar to other HVAC equipment and plumbing vent lines on a roof that firefighters have to dodge.

In summary, distributed generation is going to happen and rather than avoiding it and pointing towards insignificant hurdles that we can overcome, the U.S. should adopt it by creating a competitive market for the manufacturing and consumption of clean, distributed energy.

A more proper criticism of the United States solar energy incentive policy would be its link to the tax system. This enables large banks such as JP Morgan and Goldman Sachs to profit at IRRs of up to 15% just from investing in the tax equity of utility scale and small scale solar energy systems. If we decouple the tax system from solar energy incentives, prices will drop significantly.

-Dan

To cut to the basics, roof-top solar cells are a pain-in-the-butt to deal with while being extremely expensive and impractical for large swaths of the country. Far easier and cheaper to rely on power from the grid.

@Daniel - I appreciate all the points you make - they provide a different perspective which helps readers evaluate the many aspects of a complex issue. I will provide a bit of the rationale behind my arguments as you have addressed them.

1. Inability of low income residents to install solar panels - I would refer you to the recently published Hawaii Electric Company Integrated Resource Plan (and bearing in mind that Hawaii is ahead of most parts of the world in solar adoption)

"As the amount of installed rooftop PV grows within Hawaii, it is creating significant economic cost transfers between groups of Hawaii's citizens. These include the fact that Hawaii taxpayers are providing tax credit subsidies for new PV that do not accrue to non-PV owners; the feeder upgrade and operational requirements that increasing levels of PV impose upon utility customers; and as more PV owners (often more affluent citizens) generate their own energy, they leave fewer customers remaining on the utility system to pay for the fixed capital and operational non-energy costs of system operations."

It is only common sense that renters and seniors are not going to be able to take advantage of roof-top solar panels. I applaud the existence of low interest loans to help people reduce energy usage. But I don't think the fact that some people take advantage of those programs negates my comment.

2. I found it annoying that the couple tried to tie their installation of solar panels to a political "hot button" issue - import of Middle East oil. No amount of solar panels, particularly in Ohio, will reduce the import of oil.

3. Large scale solar panel installations on commercial/industrial rooftops or parking lot canopies make sense as far as I am concerned so I agree with you at least at latitudes less than about 30-35 degrees. North of that the difference between summer and winter generation is quite extreme (3-5 times more in summer than winter). If we want to actually replace thermal generation assets with solar this is really problematic because we would have to overbuild the solar to supply enough in the winter and then have a huge surplus in the summer. So I am not convinced that is the best investment option at higher latitudes.

4. Electricity Time-Of-Use pricing is very inconsistent but does not match solar power production in any meaningful way.

I would refer you to Ontario where peak pricing in summer is from 11:00 am to 5:00 pm but in winter is 7:00 am-11:00 am and 5:00 pm to 7:00 pm (http://www.hydroone.com/TOU/Pages/Default.aspx). In Oklahoma peak prices run from 2:00 pm to 7:00 pm in the summer (http://www.oge.com/residential-customers/products-and-services/Pages/SmartHoursQA.aspx). No TOU scheme I have seen matches peak solar production which reliably occurs between 10:00 am and 2:00 pm local time. So on this point we disagree. Feed-in-tariffs typically are equal to or higher than peak retail rates - therefore there is some subsidization of solar power going on in jurisdictions with TOU pricing. I believe we are headed for an Availability-Of-Supply pricing structure at some point in the future when mid-day solar power will be worth very little because there will be too much of it. Germany is already exporting large amounts of electricity at low prices mid-day in the spring.

5. Maintenance of solar panels. The panels degrade by about 1% per year and as new technologies develop they could be replaced by more efficient panels. But I won't quibble about that. Maintenance is probably not a big issue (but expensive if necessary).

6. Danger to firefighters: There is a difference between rooftop appliances which can have the power cut off and solar panels which cannot be prevented from producing electricity. The article I reference describes a situation where the building was allowed to burn to the ground because of the perceived danger. So I can't agree on that point either.

The idea that distributed generation is inevitable is highly suspect in my opinion. Every jurisdiction where solar (the only viable distributed generation) has started to become significant is having real problems. These problems will translate ultimately into monthly access charges and/or reduced/eliminated feed-in-tariffs which will make installation of solar panels uneconomic. If homeowners can't save money by installing solar panels they won't. And that is what I see as a more likely outcome. Installations in Hawaii and Germany are already slowing down.

This article is complete nonsense and another example of the recent increase of attacks on clean energy technologies. Written by a biased oil and gas person consisting of anecdotes, exaggerated suppositions and the promotion of an outdated business model that would continue the monopolistic centralization of power generation. It only serves the interests of utility company greed and right wing vitriol. But of course the reality that is completely ignored by the writer and his supporters are the billions of tax payer dollars that are given to the fossil fuel industry every year. For the last three decades these annual subsidies have ranged between $13 and $20 billion, far more than all the clean energy technologies combined. Tax payer handouts have been given to oil companies for more than 100 years, so if the writer and his fans are truly concerned about the unfairness of solar incentive programs and question their economic viability, why are they not promoting a level playing field to eliminate all energy subsidies?

@Griffin - your comments are both mean-spirited and dead wrong. I did work in the oil & gas industry and I am absolutely aware of the many financial incentives that industry has enjoyed. I have also been a vocal and unshakeable advocate of alternative energy development for more than 30 years. If you care to read some of the postings at the Black Swan Blog that will become obvious.

What I am nervous about and why I started writing the Black Swan Blog is because I truly believe that we are on the wrong path when it comes to renewable development. The goal must not be a reduction in the burning of hydrocarbons. The goal must be the elimination of the burning of hydrocarbons. That is a very different engineering challenge. It requires that we somehow make renewable energy available when we need it at any time of the day or night, in windy or calm conditions. That requires energy storage, transmission system upgrades, demand response, more development of Concentrated Solar Power - all the things I have identified in my Sustainable Energy Manifesto (http://www.theblackswanblog.com/blog1/?p=152) and probably a lot more.

My postings and comments are always supported by factual data and references. If you have factual evidence that refutes my statements please provide it. Characterizing my comments as "anecdotes" or "exaggerated suppositions" in the absence of rational logic or data does not support an objective assessment of the options that we need to consider.

Hi Davis,

I appreciate the productive conversation and agree with some of your points but not all. Therefore, I'd like to respond for the benefit of readers.

1. Hawaii is a unique market in that electricity is extremely expensive, last time I checked $0.42 per kWh, which is 3-4 times the price of typical electricity prices in the continental US. I would encourage you to look at other states such as New York, New Jersey, Massachusetts and California. These states have robust solar energy incentive systems and comparable pricing of electricity. Offerings by Sungevity and Solar City are not low interest loans, they are PPAs for small households and are popular in these states. I would make the guess that their customers are expanding to lower and middle class households because they literally require no money or credit down and realize instant savings on energy. I would agree that renters are not going to take advantage of solar incentives but in many cases their landlords do thus increasing the property value of homes and in some circumstances minimizing rent by decreasing the cost common area electricity. Many seniors do install solar as it increases the value of a house.

2. Agree

3. This makes a lot of sense and I completely agree. We need to think more strategically about renewable energy incentives. This would entail regional customization based on available natural resources rather than just pushing solar or wind.

4. I understand now and I think the meta-point is that different markets have different peak prices at different times. Therefore, none will match solar production consistently -- although in NYC where I used to work it was relatively consistent. That makes sense to me. That said, from my understanding the price of Feed-in-tariffs are determined primarily to stimulate demand (not based on TOU peak prices) and typically decrease on a year over year basis as supplier and installers become more efficient and cost decreases.

I think TOU pricing would be great for the industry once the cost of solar installations reach grid parity. We need to get competitive.

5. Agree.

6. Firefighters need to understand solar modules and other distributed generation rather than just be scared of it and let a building burn to the ground. Once you turn off the power to the house from the street or the main panel in the basement (which they are instructed to do before entry), the solar panels don’t produce power at all and are therefore not a danger. Educating our firefighters is the answer here not disincentivizing rooftop solar.

I think that distributed generation is inevitable and once smart grid solutions become adopted, utilities will be able to better predict and control it, making it an asset to the grid, not a problem. If you add cheap distributed storage to the equation, you are talking about a more reliable grid with decreasing blackouts. I think that this is the future of the first world utility.

The fundamental problem not addressed is that solar electrical panels do not operate for at least 50% of the time. Without large scale storage distributed systems cannot and will not work for an industrial economy. If you live in the Northern parts of the continent as I do and have just endured a massive cold spell - a polar vortex as it is called - followed by snow dumps of several feet you will see first hand the futility of solar panels in these regions. Many are beneath several feet of snow and ice as I speak and are producing nothing. If there was no grid to rely upon we would all be in very serious trouble.

Like Davis I am a great supporter of clean energy - the very reason I joined the nuclear industry which produces large amounts of electricity with zero emissions. The distinction of course is that nuclear can do that day or night rain or shine snow or no snow. Solar cannot.

And of course you must face the reality that not everyone lives in a house with a roof. How does the average condominium dweller put solar panels on a condo roof? The roof area is nowhere near enough to supply buildings of this size and number of occupants. The tendency is for more and more of us to dwell in cities which means bigger buildings and less roof per person.

The only reason that solar panels can possibly work is if there is a grid to back it up. But the conundrum is if distributed energy systems are successful there will be no grid.

You can't have it both ways.

Malcolm

The solar panels like anything else will have to be maintained in good conditions to work at their best like the standard heaters need to be checked annually to avoid explosions due to rust or scale. In hot countries the solar panels should be the best solution for hot water heating still this would go in competition with the electricity/gas companies due to the lower cost of solar energy. Here in Italy you might install the solar panels on your house roof or in your garden but you still have to pay the basic tax to the local electricity company to which, though, you can sell the exceeding energy produced to them.
Like anything you own and produce, you will have to take care of it and this brings us down to people’s own sense of duty and responsibility.
We need to see the reality of things and not just our own convenience.
Regards,
Marie

Generally, other than that of the writer, I am pretty unimpressed with conjecture in this thread. I'll be signing off and not checking after the below responses.

@Malcom

You can have it both ways and we will have it both ways. There are also hybrid structures such as microgrids that will likely be popular in emerging markets and that heavily leverage distributed generation. In the first world, we'll have the grid with distributed generation, just like we do now...

@Marie-christiane rollo

Maintenance of solar panels is very minimal compared to other appliances. Most of the time for small installations, you don't have to do much of anything for maintenance other than replace the inverters every seven years and dust off the panels once in a long while (e.g., less than once a year due to weird weather conditions)

@Daniel - thanks for your respectful and thoughtful comments. I encourage you to stay engaged with these conversations. There can be a lot of nonsense but there are enough gems that come to light occasionally to make the effort worthwhile. Puclic awareness is the goal after all.

Cheers
Davis

I am unimpressed with the failure of solar panel enthusiasts to face reality.

There is and continues to be a large disconnect between the amounts of electricity that can be produced by solar panels and the enormous needs of industrialised societies.

It simply cannot be met by putting solar panels on household roof tops. Furthermore the demand cannot be met without large scale energy storage.

I find it incredible that intelligent people such as Daniel Fink really and truly consider that running aluminium smelters or steel plants consuming hundreds of megawatts of power round the clock using rooftop solar panels is feasible. It is not conjecture Mr.Fink it is cold hard reality and as yet you have been unable to tell me how you [propose to do that without a large grid and very large power plants.

In the first world (there is only one world I would add) you run the serious risk of making the grid uneconomic to operate by forcing utilities to buy power from solar panels at ridiculously inflated prices and further forcing them to accept that power whenever it happens to be available. None of those make any economic or practical sense and the result will be (and is) higher cost power to all.

My argument is exactly that you will not have a grid to depend on if you pursue such misguided policies.

Malcolm

The post by Griffin Carrison highlights what makes the energy debate so interminable and volatile. We will get nowhere in the discussion while there is "subsidy envy" and an avoidance of data, both technical and economic. The topic is more complex than the picture many paint who simply want to resolve it to a political essence - either right or left. As a prime example, those who offer the subsidizing of the existing mining and energy generation as a justification for renewable subsidy or increasing renewable subsidies rarely go deeper into the analysis than the politics of it. For example, I rarely see discussion of the traditional energy subsidies' benefit or impact on end pricing versus the that of renewable subsidies. A point was made in David Swan's post about a negative cost impact to the poorest energy users. Does the same apply to "dirty" energy subsidies? I've seen the opposite proven in many an analysis. That's just one point. And to be clear, I'm not making an argument in support of subsidies in general. They distort in ways expected and in ways unwanted.

But my comment on the article content itself is this:
The value of renewable energy in a distributed network is affected by a wide range of factors. Time of generation, time of demand, demand topography (making rooftops more practical), utility pricing constructs, capital costs (including installation and the 'convenience' of the location), utility avoided costs, survivability (catastrophic weather), distribution network resilience, etc. And the most bypassed part of all of these factors is how they vary and especially how they are influenced by location. So for Arizona and New Jersey to seek the same targets and utilize similar economic models and incentives completely oversimplifies the situation. But to take Arizona as an example, building new structures to include solar facilities isn't unreasonable. Already construction designs (and costs) include approaches and materials specific to the region. Since the insolarity is good, including electricity generation in the build can have a fair payback. Likewise, when other conditions from the many are suitable, retrofitting can make sense. In areas where industrial and/or population growth is steady and predictable, a utility can offset both generation and T&D costs by supporting an increase in distributed generation. But all scenarios rely on the continuing decline of capital costs and improvement in lifetime efficiency, among other things.


But as long as people take a purely political, all or nothing position the debate will not only continue, but it will not lead to meaningful actions. The path to the future cannot be forced by politics unless we are willing to accept the higher costs and inefficiency that come with political solutions, and maybe the increased chaos. There is a natural path for increasing distributed energy generation. It can be accelerated best through research rather than subsidizing the end stages (sales). There is another natural path for transitioning the existing generation and T&D infrastructure for reasons beyond their elimination, such as resilience and survivability. But as long as solutions are mostly political I guess we'll see more fool's errands. Such as solar subsidies in places like Nova Scotia or Vermont.

Thursday January 16, 2014 11:29

Hello Ms Laney,

You wrote

We reviewed your request for expedited processing and
determined that it does not meet the requirements for compelling need under the
FOIA.
but you apparently did not follow FOIA rules which requires
(6)

(A) Each agency, upon any request for records
made under paragraph (1), (2), or (3) of this subsection, shall—


(i) determine within 20 days (excepting Saturdays, Sundays, and legal
public holidays) after the receipt of any such request whether to comply with
such request and shall immediately notify the person making such request of
such determination and the reasons therefor, and of the right
of such person to appeal to the head of the agency any adverse
determination
; and


http://www.law.cornell.edu/uscode/text/5/552

Please tell me the name, address, phone number and email address of the 'head of the agency' so that I can file an appeal.

Please do this by the close of business Friday January 17, 2014.

Regards,
bill
Liberal arts 'educated' journalists protect their
breathern.


Where do journalists come from? They are manufactured
in America's universities in a liberal arts curriculum.

Mark
Mathis

http://www.prosefights.org/irp2014/irp2014.htm#laney2

One of the better altenergy posts?

Fraud/scam wind generation of electricty photos.
Electrlcity equivalent of a sewer system?

I would like to add that in places like the Midwest were housing prices are much more affordable, if there were a FIT in place, it would only encourage people to buy a home rather than rent. That steady additional income from the utility would greatly help offset household costs.

I'm a little surprised that the author mentions anything about safety, Lord knows that the oil and gas industry is far more hazardous and has similar, and additional safety concerns. Ladders can easily be replaced with scaffolding for example.

oilman2 right?

Knowing that Shale gas and oil entail “drill or die”
programs
due to the nature of their depletion
curves
,





http://www.prosefights.org/irp2014/irp2014.htm#laney3

I have a few objections to some of your arguments. Specifically that low income people can't benefit from solar incentives so they are not fair.
That argument ignores the fact that energy (in California) is sold in tiers according to how much you use. Lower income people don't use as much electricity so they get a discount, and the only simple way to discriminate against upper income people is to charge more as you use more. If you have a lot of gadgets, you will use more and pay more. Not fair but accomplishes the goal to provide lower cost energy to lower income people.
If the tax breaks are not in place, no one will purchase solar. If no one purchases them the prices will remain forever high because of no economies of scale. New technology is always too expensive for the low income people.. like Television. My family could not afford a TV set for some years when I was little. Then we finally bought one because the price dropped... because the higher income people paid huge amounts to get the industry up and running. Now the poorest person in the US can afford multiple tv's.
The tax incentives (which are paid mostly by middle income people) allow people with forsight to save some money. That's the purpose of the incentive. and arguing that the money doesn't help low income people "RIGHT NOW" is surely short sighted.
Another point you misrepresent is the generation of electricity only in the daytime is a waste because if never helps to heat homes at night. That argument is unrealistic because most places in the US have power shortages "IN THE DAYTIME" due to high AC usage. I live in California (not the hottest state) and the electricity usage during the daytime is a big problem You don't have to worry about electricity generators spinning idly during the daytime because every watt of electricity is critically needed. And since we don't have enough then we import it from other electrical grids (like yours) and we pay top dollar for it. In fact most of our electricity rate hikes are justified by the eternal need to power AC's in our "not very hot" state. The solar spike in the hottest part of the day is a perfect match for the highest solar power generation. There is even talk of raising cost of electricity "IN THE DAYTIME" to forstall need for additional generation plants. If lots of people install Solar and the cost per purchased watt keeps dropping, we may never need to build those plants. I think that will be a good thing.
And finally, your mention of safety makes me scratch my head.... "What?" is all I could think. Those roofs on those houses are installed by guys on ladders. They are repaired by guys on ladders. Electricity from the grid is installed into your house by guys on ladders. Why do you single out solar cells as being unsafe for guys on ladders? You imply we should setup solar on the ground? Do you know how many would be stolen routinely on the ground? a $1000 solar panel sitting on the ground will be way more temptation then your average thief can stand. He will just have to drive by in his pickup someday, take that panel and drive home to put it on his own house. You can bet he won't install it on the ground either! Not to mention it would be ugly and a little unsafe due to reflected sunlight.. If you drive by a house and the sun reflects of a big shiny black solar panel in the front of the house and you crash or run over someone.. how unsafe was it for you or that person?

" The home-owner effectively gets to use this mid-day electricity as a credit against the much more expensive evening and night electricity that would otherwise have to be purchased from the local utility at peak demand prices."

I have read the above 10 times! I am trying to figure out what planet you live on!! Here in California we have four tiers for the electric company. I don't remember them all but 1 is for the first 386 KWH @ .14 Tier 2 is I think .19 for the next couple of 100 KWH to 501 Tier 3 is .28 for the next 269 KWH tier 4 is then .32 until the end of the billing cycle. They have the nerve to say 1/4 of there customers never get out of that first tier. On top of these charges they now have smart meters and charge more for high use times when most people need it or die because they need to turn it off. If some does not get past tier 1 it is because most people can't afford the price gouging and need to turn off air and suffer most of the day if not all. In July we got a surprise of $269.00 With a friendly note saying we saved $100.00 because of being low income. I can tell you we don't run Air all day and night. You can't turn on the air and pretty soon if not right now you will not be able to cool off in a sprinkler.
You mention peak demand I wonder if they are still closing down plants during these times of peak demand like Enron did to get as much as they can. As far I am concerned I will try to get a system that just 0 out my use because I am fairly sure they will figure out how to get it for almost free if not free. They cry about what they will lose but in reality they will lose nothing as the higher demand will be turned of anyway.
The poor Electric Company they will make a little less so more people can have a little more comfort not to mention a little more money in there pocket!!!