The previous post got thousands of views and Twitter comments, inspiring me to write a thread on the related topic of solar-Powerwall-Tesla car as an ideal of independence for green consumers. It’s compressed and minus the usual citations, but it explains why the dream Elon Musk is selling isn’t anywhere close to realization. The thread:
1) Experts also know $TSLA fantasy setup of solar/Powerwall/Tesla car doesn’t work without grid connection to net metering utility. The battery capacity is too low, it can’t supply surge startup for AC units and the like, and grid power down means no power for anything.
2) Special circuits supplying only a subset of the house’s critical appliances have to be installed to allow use while grid is down. Big AC units can’t be included. Cost for the gridless setup in the extra $10,000s as a retrofit.
3) Year-long net metering, required to make solar ROI reasonable in most locales, is a huge subsidy to wealthy rooftop solar owners and is rapidly disappearing as it impacts rates for poor people.
4) Electric utility rates are set by law to guarantee profit to the utility, so a subsidy to solar users raises the rates for everyone else. CA already generates so much solar electricity around noon in spring that the state has to pay other states to take some of it.
5) Rooftop solar can only be a small portion of generation without distorting management of the other forms of generation, turning them into peak-nighttime plants only and raising costs further.
6) Big battery storage installations can help a lot in special cases (islands, “over-solared” states like Germany) but cost far too much to compete with conventional or existing nuclear plants for base power needs.
7) Tesla’s fantasy world is at least decades away. Utility-scale solar farms are cheaper and more easily maintained. The public sentiment supporting home rooftop solar will melt away when people understand they are paying twice as much so others can escape paying for the grid.
8) Tesla’s only real success was the Model S, which caught the imagination of wealthy Silicon Valley types who wanted to show their virtue and have the shiny thing few people had. But that market is small and fickle.
9) As governments around the world discover they have subsidized and required alternative energy too much (every pol seemed to love raising the percentage required), those subsidies are being rolled back or removed. Deadly for Tesla car and solar sales. /end
Tesla and its impresario Elon Musk are in the news this week. One aspect of his hype machine, the ballyhooed solar roof tiles, looked suspect to most of us who follow solar developments when it was introduced. Like many of his supposedly visionary ideas, there was nothing new about it and others who have worked on it gave up because it was not yet practical or cost-effective. But when Elon is selling blue sky dreams to attract more investors, his PR machine can flood the media universe with hundreds of articles uncritically rewriting Tesla’s press releases before even one skeptic is interviewed.
The solar roof tile scam is one of many schemes Musk has employed to keep his hype machine going. The increasing frequency of new business ventures he’s promoted over the past few years are a sign of desperation; his narrative must keep expanding to bring in more cash to keep the Tesla dream alive. Everything from new models (long-haul semi trucks, a pickup truck…) to solar roof tiles and batteries to stabilize the grid. Each one of these ideas has merit, but the shotgun promotions came as the company lost $billions and is years behind schedule in getting Model 3’s out to customers who placed $1000 deposits on the promise of a $35K base model. There is no longer any prospect of a $35K base model, and no money to fund new GigaFactories hyped for China and Europe.
Today we’ll focus on the solar roof tiles and the NY GigaFactory to produce them.
The context of the fraud is Tesla’s takeover of his cousins’ failing business, Solar City, which was nearing bankruptcy when Elon swooped in to offer Tesla stock for it. The motivation was to avoid a failure in his family of businesses which might have damaged his reputation and hurt his much bigger bubble company, Tesla. Musk owns about 20% of Tesla shares and has borrowed against about half of that, so declines in TSLA stock price directly threaten his net worth; it is likely he used the proceeds of these loans to fund his other companies, notably SpaceX, the Boring Company (small-bore tunneling), and the Hyperloop efforts. A margin call that might result if his stock value declines enough to no longer cover the loan amounts would trigger large forced sales and a complete collapse of the stock price and his empire.
In order to induce the stockholders of Tesla to approve the purchase of Solar City, Musk emphasized its importance to Tesla’s long-term strategic plans of promoting solar as part of a mix including utility-scale batteries for load balancing and solar to replace fossil fuels and nuclear. This vision is premature since even in most favored areas for solar, solar plus battery for daily load balancing is impractically costly compared to gas-fired plants and a mixed strategy, and even that doesn’t address the yearly load balancing required.
The solar roof tile product was promoted to make buying Solar City seem a reasonable use of Tesla’s cash and equity. The fraudulent nature of the unveiling, presented as a product ready for customer deposits and installs, has been reported on but ignored amid the raft of glowing stories from credulous media. For example, this Fast Company story from 6-19-2017, “Inside “Steel Pulse,” The Project That Became Elon Musk’s Solar Roof”:
Tesla’s sleek new product helped clinch the company’s merger with SolarCity. We investigate its mysterious origin.
In late August 2016, Elon Musk went to check out the first iteration of his new “solar roof” product on a customer’s home. Musk has famously high product standards, but he needed this one in particular to be a stunner. The Tesla CEO was in the middle of pushing through a controversial, multi-billion-dollar acquisition of SolarCity, the company his cousins Lyndon and Peter Rive cofounded. This new offering would be key to selling Tesla and SolarCity shareholders on the merger. In fact, just weeks earlier, on an August 9 SolarCity earnings call, Musk hinted that a “beautiful” roof product would soon be unveiled, telling analysts that it would create a “huge market” for the combined companies. “What if we can offer you a roof that looks way better than a normal roof? That lasts far longer than a normal roof?” he teased. “Different ballgame.”
Yet internally at SolarCity, the solar roof product was far from what he would consider market-ready, let alone beautiful, according to nearly a dozen sources familiar with the project. In recent months, SolarCity had focused on developing a standing-seam metal roof with solar integration, code-named “Steel Pulse.” Whereas traditional solar panels are usually mounted on top of existing shingles, the basic goal of Steel Pulse was to make the roof itself solar powered, so it looked like a normal roof, yet generated electricity through embedded solar cells. Some employees felt Steel Pulse was unattractive, but the project’s leaders, including then-CTO Peter Rive, seemed keen on its aesthetics, and pushed ahead. The company found customers who were open to having the latest prototype installed on their Bay Area home, and when it was ready, Peter invited his cousin to see the metal solar roof in the wild.
Musk hated the implementation. According to two sources, after he arrived, he told Peter and other team members that they were wasting his time with this “piece of shit.” He demanded more “stunning” concepts and soon directed the team to pivot their focus toward a different style of solar roof—and fast. After all, Tesla and SolarCity shareholders would be voting soon on whether or not to approve the merger. Musk needed this new product to live up to the expectations he had set on the earnings call weeks ago.
…considering the timeline of Steel Pulse’s development with the SolarCity acquisition, some insiders have wondered if Musk sold shareholders on a product that didn’t exist. “It’s all about the narrative for Elon,” says a source close to Musk. “Solar Roof was as ‘real’ as anything he’s ever shown [off to the public]. Was it a finished product? By no means.”
The demo Musk introduced last October at a splashy presentation was a glass-tile solar roof, much different from the metal prototype he’d seen before. How did he pull off this transformation in just weeks? More to the point, who executed the idea and when? Leaders at Tesla and SolarCity, including Lyndon and Peter Rive, gave a variety of different answers on the timeline of its origin and development. At first, the companies said Solar Roof was a Tesla product, and then, later, a SolarCity product. Public statements are similarly contradictory. Some involved with the product’s development suggest that the mixed messages are a result of the combined companies’ wish not to appear as if they rushed out the glass-tile prototype in order to be able announce a high-profile product before the shareholder vote on the acquisition, which some critics viewed as Tesla bailing out SolarCity.
[Musk rejects a standing-seam metal solar roof developed by Solar City and demands a replacement that looks like conventional roofing tiles]
…Somehow, over the next few months, teams at SolarCity, Tesla, and 3M (which makes solar films that can be used for solar glass tiles) managed to put together a glass-tile solar roof demo, which Musk unveiled on October 28 at an event at Universal Studios’ back lot in Los Angeles, on an old residential set used in Desperate Housewives. Shortly before sunset, Musk appeared onstage in front of a crowd of several hundred to make his big reveal. “The houses you see around you are all solar houses. Did you notice?” he said, gesturing toward the homes with a grin. They appeared to have regular shingled rooftops, but Musk said they’d actually been retrofitted with a new product called the Solar Roof, a potentially transformative system that’s nearly indistinguishable from a traditional rooftop—and one, he promised, that lasts longer and costs less, all while generating electricity. “Why would you buy anything else?” he said. The crowd cheered.
Some people aware of Steel Pulse’s development at SolarCity were shocked by what Musk revealed. “Where the hell did that come from?” says one source, describing a common sentiment among certain teams at the time. Considering how different it looked from the standing-seam metal roof prototype, many sources concluded the demo was simply not real–it was merely vaporware. (As one jokes, “There’s a reason that they announced the idea on a fake block in a fake neighborhood with fake houses!”) A well-connected source explains, “Basically, from August to October, it was more about getting the thing to look right, and then from October until now, it’s really about getting the thing to work. This is just how Tesla does things. Their first car demo [for the Model S] was held together by magnets.”
…the company does acknowledge that the demos Musk unveiled at Universal Studios were not functional. …No matter how the Solar Roof came to be, it seems to have worked: Three weeks after Musk’s presentation, 85% of shareholders approved the Tesla-SolarCity merger.
The slick promotional material featured “photos” of a modern house with glossy solar roof tiles and a Tesla car in the garage — in a vision of a completely solar-powered yet stylish way of life for those wealthy and virtuous enough to choose it.
The photo above has now been traced back to its source, a slightly-modified model of a modern house licensed and augmented with the Tesla features. There was no such house, and it seems unlikely any will be built anytime soon. The rendering is based on a Mascord software model modified and re-rendered; I assume Tesla licensed the model from Mascord, but I recognized the photo from its common use in Portland to market new homes. In other words, it was slapped together on short notice to market what didn’t exist.
[The Mascord “Norcutt” house plan is pretty — see the source here.]
User “Justin” on Twitter found an ad for replan/rerender on some service like Fiverr, and commented: “Wow they bought the CAD file flipped, added some height to the entrance, and re-rendered it.”
So we now know Tesla’s solar roof tiles aren’t going to be going out to people who placed deposits on them this year, if ever, with a total of 12 installs (apparently 11 to Tesla execs.) The one install in public view took a large crew two weeks and the customer was charged about twice the cost of a standard solar setup. Tesla lost much more than that. The NY Gigafactory for producing them is mostly idle, and owes the state $100s of millions in penalties if it doesn’t employ 1500 people by deadline. The 8-7-2018 Reuters story, “Inside Tesla’s troubled New York solar factory”:
…Repeated hold-ups since the Buffalo, New York plant opened last year have forced Tesla’s partner in the joint venture, Panasonic, to seek other buyers for the components it had built to sell to Tesla, according to a Panasonic employee, a former Panasonic employee and a former Tesla employee. The issues have also rattled the faith of state officials in Tesla’s ability to deliver on investment and employment promises it made in exchange for $750 million in state subsidies.
The production challenges add to doubts over Tesla’s cash-strapped solar operations as it focuses on boosting production of its better-known electric vehicles, which have also seen repeated production delays. Tesla acquired the solar business in 2016 in a controversial $2.6 billion purchase of SolarCity – a sales and installation company founded by two of Musk’s cousins – but the business has been shrinking ever since.
…In a call with Tesla investors last week, Musk said “hundreds” of homes already had solar roofs, but the company clarified the estimate in its statement to Reuters, saying it included systems that had been partially installed or were “being scheduled for install.”
In California, the nation’s leading solar market, there were twelve Tesla roof systems connected to the grid as of May 31, all in Northern California, according to records from the state’s three investor-owned utilities. The cost per watt for those systems was listed at nearly $6, according to the records. That’s about double the national average for solar systems. [Ed. note: and the cost to Tesla of that install, which required a large crew working for two weeks, is likely many times what the customer was officially charged — see below.]
Tesla began accepting $1,000 deposits from customers for the Solar Roofs in May 2017, seven months after it unveiled a prototype.
Tesla confirmed in a statement to Reuters that it has been seeking to improve on its production process for the solar roof at the New York plant. “We are steadily ramping up Solar Roof production in Buffalo and are also continuing to iterate on the product design and production process,” the company said in the statement. “We plan to ramp production more toward the end of 2018.”
…Some New York state lawmakers worry Tesla may fail to hold up its end of the bargain. The state provided $350 million to build the factory, along with $274.7 million for equipment and $125.3 million “for additional specified scope costs,” according to a Tesla filing with the Securities and Exchange Commission.
The subsidy package requires Tesla to employ 1,460 people in Buffalo, including 500 at the plant, within two years of the facility’s completion, and to spend $5 billion in the state over a decade.
Empire State Development, the state’s economic development arm, is overseeing the agreement. The agency believes Tesla is currently meeting its obligations, said spokeswoman Pamm Lent, adding that the company would face penalties of $41.2 million a year if it falters.
Republican New York state Assemblyman Ray Walter, who represents a district near the factory, said it concerned him that only a small portion of the plant appeared functional when he toured it in March. “After investing $750 million of taxpayer money, we want it to work out,” he said. “It just does not look like it’s heading down that path.”
Tesla said in its statement that the facility now employs about 600 people and is on track to meet all of its commitments. None of the Tesla sources could provide a production figure for the solar roof, saying only that output was low and frequently interrupted. They said only the textured black version of the solar roof had been produced so far, one of four varieties Tesla is marketing.
EQUIPMENT IN BOXES
Panasonic recently produced about 1,900 conventional 325-watt solar panels per day at the plant, meant to be sold under the Tesla brand, and about 2,000 5.5-watt photovoltaic cells per day that were intended for the solar roof, according to two Panasonic sources, one who recently left the company.
That would put annualized production at about a quarter of Tesla’s target for the plant, which is 1 gigawatt per year by 2019. And Tesla isn’t buying most of the cells being produced, according to the Panasonic employee. … For now, wooden crates filled with unused equipment are sitting around the factory, according to the Panasonic employee and three other employees with knowledge of the plant operations. Some of that equipment has become obsolete over the past couple of years as technology has changed, two of the workers said.
One of the few customers that has taken delivery of the Solar Roof is Tri Huynh, 39, who works in business development in Silicon Valley. Huynh said he paid about $100,000 for the system, which included three Tesla Powerwall home batteries to store the power produced. It took two weeks and a dozen workers to install, compared to a day for most traditional panel systems. “It’s fantastic. I love it,” he said, adding he was saving hundreds of dollars a month in power costs. “I’m a tech guy, so I kind of wanted the latest technology.”
Warren Jason, a retired technology entrepreneur who is building an 11,000-square-foot house in the Hollywood Hills, is not so pleased. He put down $1,000 to reserve a roof in early 2017 but it has not yet arrived, and he has been unable to get details to give to his architect and engineers. “We’ve been begging Tesla for information,” he said. “It’s been extremely frustrating.”
The solar roof tiles were a fraud, part of a scheme to defraud the market and Tesla shareholders by inducing them to commit resources to a dying company run by Elon’s family and friends. Musk is in big trouble now as the SEC examines his more recent Twitter claim of an offer to take the company private at $420 a share, but that has also focused attention on the smaller-scale frauds he has used to keep a narrative of constant innovation and disruptive products growing. As people who know the market areas for each of his supposed innovations compare notes, they are just starting to realize they all knew he was a fraud in the area they understood, but so long as he was apparently successful at promoting the dream no one had a reason to look more deeply at all the claimed new products. But now they do.
In coming days and weeks, the truth of his claims will come out. And it may signal the top of the most recent tech bubble which has tech giants’ stock prices inflated beyond reason. Most of these are real growth businesses that can actually make a profit without needing massive new cash infusions, but their stocks have been inflated by the prevailing atmosphere of easy credit and a steadily rising market. Being reminded to check sources and listen to contrary voices by a high-profile failure like Tesla’s can change sentiment for the whole market.
Granola Shotgun has an excellent post on his approach to solar. Because his building is in a somewhat less favorable zone for generation and in a much less intensive use zone (AC is rarely needed, so electric bills are modest) he discovers a large standard photovoltaic system will not be worth the cost or (just as importantly) the complications.
I asked my tenants to look at their electric bills. $47 per month was the average with the highest month being $65. Service fees, taxes, and other administrative costs made up a significant chunk of those bills so $25 was owned even before any power was used….
If I assume an electricity bill of $60 a month a standard grid-tied solar package will cost $9,000 up front after government subsidies. There’s a thirteen year pay back period. And after twenty years there will be $6,000 in savings. Financially, it makes no sense to spent $9,000 to save $6,000. There are lease and loan programs for solar equipment that don’t require any money up front, but I don’t like debt or complex transactions with binding long term contracts and legal fine print…. The problem with my property is that it simply doesn’t use enough power for solar to work given the established industry parameters.
He checks into a system that would use battery backup and allow independent use (many people don’t realize standard solar tie-ins are useless in the event of power failure; a lot of effort in splitting circuits and expensive batteries is required.) It would be great if you could throw a big switch and go gridless, but for most people that day is far away. Mr. Shotgun discovers completely independent small systems which use a few panels to charge batteries and run small electronics are cheap and readily available, and don’t require the expensive overhead of government inspections and teams of workers as in standard solar installs. By keeping his needs and expectations minimal, he can get to some disaster-proof independence.
Read the whole thing. This blog focuses mostly on how to make the larger home more efficient, but minimalism and living small are valid solutions as well.
Mike Shellenberger is a maverick environmentalist and activist who ran for the Democratic nomination for governor of California. He stirred up some good conversation by his willingness to address the myths coastal Californians cling to to avoid recognizing their votes have gradually strangled the rest of the state and led to a crisis of high cost and low availability of housing for younger and poorer people.
This is the story about a real-world “Elysium” — a state which has the highest levels of poverty & inequality in the country but whose residents have convinced themselves that they are behaving ethically, protecting the environment, and fighting racism. California seems to be a progressive paradise, but it is number one in poverty and inequality in America. How can this be? And how does California maintain its reputation as a progressive leader…
Everyone believes California is our most progressive state. And why not? It imposes the highest tax on the richest one percent. It is aggressively implementing Obamacare. And it is standing up to President Donald Trump on everything from immigration to the environment. And yet the Golden State is also number one in poverty & inequality. How can this be? Around the world, progressive nations like Sweden and France, which redistribute wealth through high taxes and generous social welfare policies, boast of less inequality than other nations.
What gives? And how does California maintain its reputation as a progressive leader given the reality on the ground? To answer those questions, let’s take a closer look at what might be considered a present-day Elysium. In the 2013 science fiction film “Elysium,” the rich have fled to a luxury satellite orbiting Earth while the poor toil in dangerous conditions below. Life in California today differs in degree, not in kind, from that dystopian vision.
Homeless encampments with hundreds of people have cropped up in the last two years. Occasionally, they are ravaged by hepatitis A, which in 2017 killed 20 people. In Silicon Valley, 132 people died — up from 85. In San Diego, 117 people died, up from 56. Last year, San Diego city workers nearly killed a homeless person after accidentally throwing her and the tent she was sleeping in into the back of garbage truck. She escaped just seconds before being crushed by the trash compactor.
Meanwhile, inside comfortable homes perched atop Berkeley and Beverly Hills, affluent progressives condemn the cruelty of the Trump administration toward the poor. It’s true that workers in California earn 11 percent more than their counterparts nationally. But that amount is not enough to make up for mortgage payments and rents that are 44 percent and 37 percent higher (respectively) than the national average. Where 56 percent of Californians could afford a middle-class home in 2012, in the third quarter of 2017, just 28 percent could.
This matters. Homeownership has been the traditional route for the working class to join the middle-class, notes Chapman University demographer Joel Kotkin, who has been ringing the alarm about the crisis for years. One fact says it all: homeowners have a net worth that is whopping 36 to 45 times higher than that of renters.
California’s elected officials make serious-sounding pronouncements about the problem but back them up with only symbolic actions. Last September, Gov. Jerry Brown signed housing legislation that will raise $250 million per year to subsidize housing. But that’s just enough to subsidize 1,824 units annually at a time when 100,000 to 200,000 new units are needed.
Is the problem too few progressive policies — or too many?
A political machine based on an alliance between the ultra-rich and the powerless must be fueled by hypocrisy. By feigning great concern for the poor and homeless while quietly strangling new housing and industrial development via downzoning and environmental lawfare, the neo-feudal lords of California have preserved their comfortable life in the wealthy coastal cities and gated communities while driving out the middle class. The black population of San Francisco has fallen from 13.4% in the 1970 census to less than 6% in 2010. Wealthy communities make the construction of modest homes and apartments for poor people illegal but rely on service workers who pack rented homes two to a bedroom or commute long distances from poor towns.
Starting in the 1970s, housing prices began to rise dramatically as new housing was restricted by anti-growth policies, couched in terms of preserving the environment but really designed to pull up the drawbridge to preserve a privileged lifestyle for those who had already bought houses. Because motivations had to be disguised as environmental concerns to appear less selfish, communities contrived to keep water supplies limited and opposed new roads and transit. The propaganda took hold and is now so entrenched that “all right-thinking people” accept that no new supplies of fresh water should be built, new highways only allow more sprawl, and even local roads should have European “traffic calming” design applied, removing traffic lanes and parking. Meanwhile, the state government is wasting billions on a boondoggle high-speed rail project, aka “train to nowhere.” The fantasy of renewable energy and mass transit for everyone is coming into conflict with the development of driverless car services, which may strand those expensive transit investments in the next few decades. The political machine continues to promote higher energy costs for suburban and interior populations and has demonstrated it cannot build new infrastructure at a reasonable cost or on time, but its control over the state is unchallenged.
A few green shoots of rebellion, like Shellenberger’s candidacy, are no threat so far — he received a bare 0.5% of the primary vote. Yet discontent is rising, and nearly half the Bay Area residents polled recently said they’d like to move away. For the well-off in booming industries, the wonderful coastal climate and groomed upper-class population of wealthier enclaves continue to make life sweet. Street crime, poverty, and homelessness are creeping into even some of the most favored areas, though, and the election of Donald Trump as president shattered the technocratic fantasy of rule by the “best people” like themselves.
Some good reading on how this fantasy of environmental and social justice grew to enable the wealthiest to keep control of the state and most local governments while actively harming lower and middle classes:
Good book by MIT Prof. B.J. Frieden, who saw the syndrome’s beginnings in 1979 after only a few years of antigrowth “I’ve Got Mine, Jack” policies in the richest suburbs, notably Marin County:
Abstract: A powerful, ideologically driven crusade to keep the average citizen from homeownership and the good life in the suburbs is exposed as a warning signal to environmentalists, whose concerns may backfire, and to homebuilders and the general public in other parts of the country where projects for urban growth may soon run up against the protectionist’s blockade. Frieden asserts that the connections between housing and serious environmental issues such as pollution, use of toxic substances, nuclear-testing hazards, and the conservation of natural resources are few and minor. The attack on home-building does not follow from the central concerns of the Sierra Club and other environmental groups, he feels, but stretches the environmental agenda to phony issues designed to keep the average citizen from using the land, while preserving the social and fiscal advantages of the influential few. He documents environmental controversies that have already discouraged large, planned-unit developments with community open space, driven up the cost of housing, and promoted a return to the 1950s-style building practices of expensive freestanding single-family homes, each on its own lot in small, exclusive developments at the urban fringe.
In the 1970s, unprecedented peacetime inflation, touched off by the oil cartel OPEC, combined with long-standing federal tax privileges to transform owner-occupied homes into growth stocks in the eyes of their owners. The inability to insure their homes’ newfound value converted homeowners into “homevoters,” whose local political behavior focused on preventing development that might hinder the rise in their home values. Homevoters seized on the nascent national environmental movement, epitomized by Earth Day, and modified its agenda to serve local demands. The coalition of homeowners and environmentalists thereby eroded the power of the pro-development coalition called the “growth machine,” which had formerly moderated zoning. As this chapter shows, these changes in the meaning of homeownership and in the political behavior of homeowners explain why local zoning has become so restrictive.
In hindsight, a state government with foresight might have headed off this slow-motion disaster by preventing local governments from acting against the larger interests of the state and the future citizens who might have chosen to live there had a good supply of housing been available. Curbing the use of environmental lawsuits and zoning to stop or delay new housing and continuing investment in infrastructure projects like highways and water supplies would have led to a larger population in more desirable coastal areas with lower housing prices and rents, and a healthier growth economy not deprived of middle-class labor. The only people not better off under that scenario are the already-wealthy whose spacious estates in Atherton and Beverly Hills are in effect subsidized at the expense of lesser citizens.
A watered-down bill to address the problem recently died in the legislature. It would have lifted some height and density limits statewide in areas served by transit. Without a groundswell of voter support, nothing will be done.
Whether rooftop solar is a sensible investment depends on:
• Details of grid power tariffs in your locale — in progressive jurisdictions, you may be paying very high rates as part of a conservation/soak-the-rich scheme to charge much more for higher use, and subsidize lifeline use (very small houses, no AC, few appliances.)
• Site characteristics, including local shading by nearby trees or buildings, the practical tilt your roof allows. Few roofs are optimally aligned with the correct E-W roofline and angle so an optimal array of panels can collect maximum solar energy. Closely-spaced panels on flatter roofs will shade each other unless tilt is decreased and spacing between panels increased.
• Weather: clouds and fog, dust and rain cut down insolation (amount of solar energy hitting the surface), and dust or snow on the surface of solar panels either must be cleaned off or lower production accepted.
Online calculators that take solar angles and local climate records into account can give you a rough idea of how much power a rooftop solar installation will produce. One of the best is the National Renewable Energy Lab’s PVWatts Calculator. First look up the approximate latitude of your site, then look up the optimal tilt of panels for that latitude here. If your roof is ideally aligned and angled, you can use the optimum fixed tilt for your location, or substitute an angle required by your roof or siting issues. I’ll go through using the calculator for the site we used near Palm Springs, which has almost ideal solar conditions, then repeat for the same house in Seattle, which has fewer cloud-free hours and lower solar intensity even under clear conditions since at higher latitudes the sun is lower in the sky and solar radiation has to travel through more atmosphere to reach the panels. Not to spoil the surprise, but the combination of lower grid rates and much less power production from panels due to much less sun will demonstrate that rooftop solar is not cost-effective in Seattle now, and won’t be until grid rates rise and panel prices fall substantially from here.
The Palm Springs Case
First, enter the site address so the calculator can pick up the nearest climate and solar data:
Then you enter some details of the planned installation — in this case, 66 panels generating 360W each for about 24KW total power, “Premium” type (we used the current industry-leading Sunpower X-Series panels.) “Azimuth” is set to 180° for exact south-facing alignment, “Tilt” at 15° as installed, and “Average Cost of Electricity” (from the grid) at 20c/KWh — as we’ll see later, utilities in progressive areas have complex tariff schedules that make this number hard to calculate, and even more complex ToU (Time of Use) and moment-by-moment charging schemes are on the way. Since we’re simplifying this just to get an idea if solar comes close to being cost-effective, I’ve selected 20c as an average cost for high users in Palm Springs — actual peak rates are much higher.
For our own project, a flat roof with limited area meant keeping the tilt angle of the panels less than the optimal 28° — higher angles would have rows of panels shading the next row, so a lower angle (15°) was chosen.
The outcome is shown below: about 40,000 KWh/Year generated, saving about $8,000 a year in grid power bills. Since this installation cost about $65,000 after subtracting the Federal tax credit, it is expected to return about 12% of its cost yearly and pay for itself in about 8 years — neglecting some minor cleaning and maintenance costs and assuming little degradation in production as the panels age, which is close to correct for these premium panels, which are guaranteed for 25 years. This is one of the highest-return investments you can make, under these almost-ideal conditions. Note less costly thin-film panels cost less but also degrade faster.
The Seattle Case
Now we set the calculator up for a similar installation in Seattle:
Now to give the Seattle case the optimal tilt angle of 39° is entered — this works well if the Seattle house has a south-facing roof at a 39° angle to start. Few real Seattle houses will be so ideal for rooftop solar., and most will have local obstacles like trees and nearby obstacles like hills and other roofs cutting down on insolation. But we’re supposing the best imaginable house:
Results: only 27,000 KWh/year generated, and because local power averages out to 12c/KWh (on the low end of costs in the US), grid power costs saved is only $3,200/year. Ignoring other costs, the rate of return on investment is 4.9%, and payback period 20 years — but the maintenance costs and cost of money invested, with loans for 20-year periods in the 4% range, means the panels will be nearing the end of their guarantee and producing less than we assumed. The investment is marginal at best, close to break-even even after the 30% tax credit.
Large areas of the US have unsuitable weather, lower grid costs, or a limited supply of houses with appropriately aligned roofs for solar installation. So when you see solar installs in those areas, it’s a result of government spending foolishly on trophy installations that make no sense, or the desire by a few consumers to sport a trendy symbol. If you look around at your neighborhood and see few or no solar panels on roofs, that means you are likely to be disappointed in the return on your investment in solar. Designing in future solar during homebuilding, on the other hand, can make sense in much larger areas of the country — having the right roof and house orientation may well be a wise choice for when panels are even cheaper and electric rates have risen further in your area.
The widespread hype for solar, including the large number of scams and fly-by-night, high-pressure solar sales companies active recently, has victimized some consumers. “Aspirational” solar purchased by wealthy homeowners because they want to signal their enlightened attitudes is just another conspicuous consumption good, like Teslas. Rooftop solar is another complicated system to maintain and is a bad investment unless it returns its costs quickly.
This begins a series of posts on solar power, mostly about solar photovoltaic (PV) installations on residential rooftops. I’ll explain why it pays to install solar PV in some areas of the US and not others, with factors to consider including local utility tariffs, government and utility subsidies, resale value, and maintenance costs, as well as the total amount of solar radiation available in a locale considering clouds and latitude. As we will see, it’s a very complex subject and the cost-effectiveness of solar can depend on the whims of state utility regulators as much as technology and cost of panels. Most of the online information about solar is promotional material from advocates, installers, or manufacturers. These sources tend to oversell and underexplain the costs and benefits, which are so locality-dependent as to make general advice almost useless.
We just did a large solar install on our test mansion in Palm Springs, wiping out almost all electric bills but shelling out almost $100,000 ($70,000 after the 30% Federal tax rebate.) California’s Public Utilities Commission (PUC) has been applying textbook Progressive policy ideals to regulation of electric utilities for decades, resulting in very high rates (topping out over 30c/kwh) for inland users that need much more AC than the mass of voters who control state government, who live on or near the cooler coasts. The cost calculus that results almost compels rooftop solar for large inland houses, which otherwise would pay some of the highest electric rates in the mainland US. Our calculated payback period is around 8 years, while in many parts of the country with more reasonable rates (12c/kwh) solar payback periods are more like 30 years, or never if maintenance and total lifecycle costs are fully accounted for.
So we’re in the position of committing to solar for large Palm Springs homes while warning most others to avoid it unless they are wedded to the status symbol of having solar panels on their roof. In the longer run, utility-scale solar PV farms in the desert are likely more practical and cost-effective than rooftop, but as rooftop solar has grown to become a significant percentage of generation in California, electric utilities are correctly warning that grid stability and economics require more stable sources or a greater commitment to storage to hold intermittently-generated power for later use — and that is still a very expensive prospect.
Other forms of solar power, like passive solar for home heating, solar pool heaters, and solar hot water pre-heating, have completely different cost calculations and alternate fuels (notably cheap natural gas), so we won’t address them here.
[next: Solar Potential by regions — Climate vs Utility Rates]
Further topics to be addressed:
Net Metering (NM) vs Time of Use (ToU)
Types of Solar Panels – AC/DC, microinverters, amorphous vs crystal silicon, Perovskites…
Elon Musk’s Solar Roofs: Hyped?
Local Storage and Going Off the Grid: Practical?
Electric Cars as Local Storage
In the early 2000s, most large new houses came with a doorbell system that connected to the house wired telephone network — you rang the doorbell and all the wired phones inside rang with a distinctive shortened ring. Answering the phone, you’d be connected to the intercom speaker by the doorbell to talk with the visitor. Often you could then press ‘9’ or some other special key on your phone to activate a relay unlatching the door so the visitor could enter.
House wired telephone networks are obsolete now, and many features (like security system calls to central monitoring) no longer work with VoiP-based phone systems. The latest thing is video entry systems, which let you see the visitor as well as talk with them. This is overkill for a small house, but since video entry systems are now cheap and easy to install, you may want to upgrade to one.
For this project, there was already a cat5 wire running from the central communications closet to the outside doorbell’s electrical box — only two wires were being used by the intercom for phone protocols, but the cat5 cable was easily repurposed for Ethernet and PoE (Power over Ethernet), so we chose a brand which could use a cat5 hookup, since this promised to be more reliable than the wifi and battery combination used by others. Battery-based wifi systems are very easy to install since no connections are required, but the need to change batteries and the occasional loss of wifi are negatives.
All of the above have apps for iPhone and Android phones which allow you to use your phone to answer the door. All support (or will soon support) Apple’s Homekit or the equivalent Android home automation interface. The Doorbirds also have circuits for unlatching doors if you have an electric latch installed. We chose the cheaper Doorbird because the flushmount version, which is superior in appearance and solidity, would have required installing a custom inwall box to hold it, whereas the surface-mount D101S could be attached directly to the old doorbell-intercom beveled steel faceplate, avoiding additional carpentry and stucco work. (The wifi-battery units are easiest of all, of course, because you can mount them anywhere.)
The Doorbird people have borrowed a lot of their design and packaging aesthetic from Apple. As with Apple, you’ve paid a premium price and are rewarded with well-thought-out, sleek design. The printed manual is suitably German, minimalist but informative enough for anyone who’s installed networked appliances.
I also purchased a PoE (Power over Erhernet) injector to feed power into the Ethernet cable. This is installed at the cable source in the wiring closet, since normal Ethernet has no power-supplying function. The relatively new PoE standards are intended to cut down on cabling in video surveillance and other situations where network appliances are to be installed in isolated areas. Switches and injectors supplying PoE are easy to find — I chose this one: TP-LINK TL-PoE150S PoE Injector Adapter, IEEE 802.3af compliant.
The Doorbird wiring is accessed through a back panel, and the box has several adapters to plug whatever wires you are using into the circuit board sockets. the color coding made this fairly easy to figure out.
I pulled the wiring through the old doorbell-intercom speaker grille to hook up the Doorbird, then screwed the Doorbird mounting screws into it so the Doorbird was centered and covered the speaker grille.
This install went well and returned doorbell functionality. A a side benefit, when the doorbell is rung I get a chirp on my phone wherever I am in the world and can chat up any visitors even while I’m on the road, which is handy. The Doorbird servers keep photos from the last 90 days of visitors, so you can go retrieve them as needed.