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Where did the Carter White House's solar panels go? (2010) (scientificamerican.com)
79 points by rndmize 7 days ago | hide | past | favorite | 126 comments

> By 1986, the Reagan administration had gutted the research and development budgets for renewable energy at the then-fledgling U.S. Department of Energy (DoE) and eliminated tax breaks for the deployment of wind turbines and solar technologies—recommitting the nation to reliance on cheap but polluting fossil fuels, often from foreign suppliers.

Crazy. You see all these wind turbines all across the U.S. If not spread across the plains or along foothills, they're being shipped along the highways one blade at a time. I look at the transformation going on and figure we could have had this tech in the 80's. What happened in the last four decades? Talk about a lost generation.

It was so weird to grow up in the 70's when they were teaching us the Metric System in public schools, when National Parks were adding meters, kilometers to signage. Reusable spacecraft, renewable energy, (and nuclear energy), computers, micro-electronics....

To be sure there were warnings of an ominous, overcrowded, polluted future ("Soylent Green", "Silent Running", just to call out a couple films of the era) but as a kid I was infused with the optimism of the time. Buckminster Fuller, NASA ... even the hippies and their communes.

I think I still live in that world in my head. I hope maybe I have expressed a part of that optimism to my kids as I raised them.

"Hippy", "green", "woke": as time goes on, names change, but the battles of us vs them don't. There's a lot of partisan discussion around the idea of pushing back and "reopening" the spigot of oil and pushing back on EVs, for example.

Is woke really the modern version of hippie/green? I feel like a lot of people myself included can support and appreciate environmental issues but have no interest in this woke culture nonsense.

That’s largely because woke culture is not a real thing. It is vastly inflated by the same folks that said similar things about hippies. The extreme views that are given the most attention are fringe and not popular.

Hippies were much more about social inclusion than environmental issues though at the time. So I think yes the woke movement is definitely a descent of the hippy movement. Wokism has a stronger focus on racial elements, bit that was definitely present in the 60s too, just less militant in the hippy movement than it was in the black power movement. Possibly you could argue that wokism fuses black power and hippyism.

> Hippies were much more about social inclusion than environmental issues though at the time.

I would argue that they weren't, as a movement, about either, but more inward-directed self-discovery. They were contemporaries with both movements for social inclusion (the civil rights movement) and the beginnings of environmentalism as a mass social movement, and were distinct from both of those kinds of activist movements. They had more in common and probably more overlap with the environmentalist movement (like the hippies, a predominantly white, middle-class movement.)

“Wokism” isn’t an actual movement, its just a replacement name for “political correctness” used as a label for same right-wing general-purpose boogeyman that PC served as a label for from the late 1970s until the recent replacement with first and briefly “critical race theory” and, when that proved a bit cumbersome as a generic label, “wokism”.

Is "green" really the modern version of hippie? I can support free expression and tolerance, but forcing me to stop using my gas car is nonsense.

Except nobody is forcing you to stop using your ICE car.

It seems my point wasn't clear. Sorry for that.

It's always the battle of should someone who has access to something valuable but harmful have the ability to use it and have society clean up the consequences.

When phrased this way it sounds pretty darn easy of a choice, but reality never phrases it that way and that person had money to bribe politicians.

And so we struggle. Because those with wealth do not want to give up their wealth.

It's too bad, I hoped EVs were one thing everyone could agree on. Maybe because it's good for the environment. Or because it's good for energy independence.

There's a subset of the anti-EV crowd that's against EVs not because they're brodozer drivers, but because they realize individual vehicle ownership is the other half of the problem. EVs still cost resources that are harmful to harvest outsized relative to their use thanks to strip mining and the chemical process used to separate cobalt from manganese at a mass scale. Those people, myself included, believe that mass transit needs to make a resurgence instead of everyone switching to EVs. I even get annoyed seeing EV "bicycles" that weigh as much as the riders and cost as much as a scooter because I think they're wastes of resources used to dodge taxes and pedestrian right of way laws regarding motorcycles.

I'm very pro ebike. But some American classes of ebikes are just electric motorcycles with a set of crank arms for show. Pedelec bikes are ebikes. Everything else is with a throttle is a scooter

Cycling has more benefits than replacing cars. It connects us with joyful movement. And the infrastructure is cheaper to build and extend compared to railways.

I'm not against bicycles and electric bikes. I'm against "not" electric motorcycles. If your e-bike goes beyond 20MPH under power and goes beyond twenty miles in range then the primary mode of locomotion isn't supposed to be the pedals. The pedals at that point are a backup, like a reverse moped.

Ideally we'd return back to the 1890s-1910s with public transport consisting of fixed line trolleys or light rail covering distances larger than five or six blocks while walking or bicycling covers distances less than that. That's where EV technology would be ideal because you could run a combination of overhead, third rail, and battery power depending on available infrastructure and space, all using the same cars city or town wide.

I wish instead of the subsidies we shat out for EVs, we did them for ebikes instead.

>It connects us with joyful movement

This means nothing.

It meant something to me; I could certainly say that I felt connected with joyful movement when I test-rode an ebike last week. My partner and I were all smiles afterward.

> and the chemical process used to separate cobalt from manganese at a mass scale

Cobalt isn't necessary to build li-ion batteries, considering that there are mainstream chemistries like LFP which eschew cobalt entirely.

Individual vehicle ownership is not a "problem." The United States is not Europe, both from a cultural perspective and a geographical one. You can either propose unrealistic solutions like "push mass transit hard and increase density," or you can meet people where they are and realize America is a big, big country with a tradition of individual freedom.

People don't necessarily want to live in a big city, go only where the buses and trains go, and never have the chance to go on road trips or vacations to the mountains or the beach. Better for the climate to do this via battery power and not fossil fuels, because it's going to happen.

I work with a lot of relatively conservative folks. The F-150 Lightning is making huge waves in that crowd, in a positive way. One of them owns a landscaping company, and just swapped out their order of a half dozen regular trucks over to the electric ones. FWIW.

In the long run it will be fine, but likely they got a good deal to help clear out inventory.

Few Ford dealer workers I know have been Talking about the buildup of stock of f150 lightning and mache at dealerships.

People are turning down the purchases from preorder due to issues with battery or otherwise that is plaguing their full electric.

6 months ago you had to be on a long waiting list, now you can find one at alot of lots.

I wonder how much not needing a generator helps too.

It's a big deal to many of them. For the landscapers in particular, being able to fast charge the pro-level electric packs for leafblowers, weed whackers, etc in the frunk is a big part of it as well. From what I understand, there are contracts here in the Bay Area that pay more if the landscaping crew is electrified.

I’m really torn on EVs now because of all the freaking data collection (every new car, not just EVs). I want to do what I can to reduce how much I’m contributing to climate change, but I still might get another old car when this one goes because I don’t want to be spied on.

If you're into building things yourself you could convert an older ICE car to an electric by swapping out the engine for an electric motor plus the necessary electronics, removing the tank and replacing it with batteries and adding more batteries wherever they fit - you'll need them to get a reasonable range. Some companies make kits to do this, otherwise there are plenty of DIY forums where these types of activities are discussed.

> removing the tank and replacing it with batteries and adding more batteries wherever they fit - you'll need them to get a reasonable range

Is this actually doable? I thought in modern EVs, the battery takes up half the chassis. In a "retrofitted" EV, you'll have lots of space (and therefore battery capacity) taken up by mechanical systems which are essential for a central motor, but relatively useless if you could just use multiple electric motors.

Yes, it is doable [1] but these conversions for the most part do not get the range expected from factory-made EVs. From what I gather the range will vary from ~120km (small city car) to ~350 km.

[1] https://www.rac.co.uk/drive/electric-cars/choosing/electric-...

In addition to other objections, there's the people who think that EVs don't hit every use case yet, and they use a lot of rare earth metals, etc... and that you can get 90% of the benefit with a PHEV (and build/sell a lot more PHEVs with current resources).

IMO, we're going to need a lot of different approaches to solve climate. EVs, PHEVs, reduction of use of single-occupant vehicles, more transit, more biking, more e-bikes, blah blah blah.

Perhaps Elon can be the bridge there, since he's seen as a bit of a free speech messiah by the right.

If nothing else, I'd think the "red-blooded" crowd would love the speed that EVs give you.

That is his whole play - more than anything, US conservatives want liberals to be humiliated and angry, and Elon delivers, and that is the ONLY way owning an EV can be palatable to that crowd.

They will convert at precisely the moment it makes economic sense.

Yeah… because f350s make so much economic sense…

There are those who may not - those who see the EV subsidies as a symptom of the "woke mindvirus" and see fighting it as a matter of fighting for their overall way of life. They see the mandates some states are pushing as an assault on freedom, and a communist incursion, and the use of petroleum as a patriotic exercise.

Remove the partisan blather and you're on to something. It is the mandates, the top-down control based on incomplete and often false premises and the holier-than-thou attitude that drives people away from these "moon shot projects". Once EVs make economical and practical sense people will flock to them but that will take a while a while for many people, especially those with longer commutes and those who live in the more northerly/wintry areas. If you live in places where the sun always shines and have the space for a good-sized solar array it already makes sense, elsewhere - not so much.

Simple: remove all subsidies for ICE cars and everything they use.

Some will. My brother in law is a hardcore Trump supporter and he drives a Chevy Bolt. The TCO on that car beats every ICE vehicle. Every last one. If it were just economics, EVs are a winner for the majority of average folks already.

It's not that simple. Ideology is more important.

I think that is just what you’re being led to believe. I meet pretty hardcore conservatives all the time who have Teslas or other EVs. Hell, I can walk to the end of my street and there is a front door covered with a large Trump flag that has 2 EVs, a Model 3 and some Ford, in the garage.

No one has 'led' me to believe this because I've not heard anyone else say it. If you are trying to tell me that US conservatives have not politicized renewable energy in general and EV ownership in particular you are being naïve or dishonest. Musk is a salesman and has exploited this by doing what has worked for US conservatives since Rush Limbaugh- acting stupid and obnoxious.

I don't really believe it, but I wouldn't be entirely shocked if we learn MAGA Elon was just a persona who adopted to win over the relatively untapped market.

Metrification was also killed by Reagan.

Metrification was dying, and the plug was pulled by the Reagan Admin. Biggest blow was probably the abandonment of converting highway signs to km in 1977.


The biggest blow was the British privateers... yes, the British are why the US isn't on Metric.



> Thomas Jefferson, secretary of state in 1794, was eagerly awaiting a meeting with French physician and botanist Joseph Dombey. The Frenchman was supposed to meet Jefferson in Philadelphia to discuss a couple of critical international trade issues between their governments.

> He was also going to revolutionize the way Americans did business.

> But instead of meeting Jefferson in Philadelphia, Dombey found himself in the Caribbean, where his ship was being boarded by British privateers. Upon learning he was a Frenchman, and a famous scientist at that, he was captured and taken prisoner.


> The marauders now swarming Dombey’s ship were a particular breed of pirate: British privateers—the state-sponsored terrorists of the 18th century. These waterborne gangs had the tacit approval of the government in London to harass and plunder other countries’ maritime commerce and keep part of the spoils as their profit.

> After seizing control of the ship, the pirates came across a sailor speaking Spanish with a curiously French accent—Joseph Dombey. A French physician and botanist acting under orders from the French government, Dombey had left the port city of Le Havre, France, weeks earlier for Philadelphia and the meeting with Jefferson, the United States’ first secretary of state and future president. But storms had pushed Dombey’s ship off course and deep into pirate territory.

> ...

> Some historians view this event as a tragic missed opportunity whose consequences we are still living with today. When the U.S. became an independent nation, it inherited an inconsistent collection of traditional British weights and measures. Congress was aware of the flaws with its British measures, and a congressional committee was formed to recommend solutions. Thomas Jefferson, an admirer of French scientific ideas, lobbied for a measurement system similar to that of France. But Congress didn’t adopt it, and the British-influenced system took hold in the U.S. instead. However, If pirates hadn’t intercepted Dombey on his way to Philadelphia, the situation might be very different today. As historian Andro Linklater writes in his book Measuring America,

> “The sight [in Congress] of those two copper objects [Dombey’s meter and grave], so easily copied and sent out to every state in the Union, together with the weighty scientific arguments supporting them, might well have clarified the minds of senators and representatives alike. And today the U.S. might not be the last country in the world to resist the metric system.”

What, fundamentally, would be actually different if the US was "metric?" Why should a federal government enforce one particular standard or another?

Easier interactions around measurements when communicating with nearly the entire rest of the world for starters. Also, pretty much all of science is metric measurement these days, so there's that. We could also do away with the confusion of using two entirely different measurement systems here as we currently do. Milk often comes in gallon jugs but soda in 1 and 2 liter bottles for one example.

The Mars Climate Observer would have been observing the climate on Mars instead of becoming a crater [1] to be observed by future Mars satellites.

[1] https://en.wikipedia.org/wiki/Mars_Climate_Orbiter#Cause_of_...

It is literally in the constitution.

>To coin Money, regulate the Value thereof, and of foreign Coin, and fix the Standard of Weights and Measures;

"Congress shall have the power" was omitted, there. Congress is a representative body. Of course, representatives should have the power to recognize a national standard, the administration isn't entitled to just choose a standard and enforce it against the wishes of the people as represented by congress.

That was actually the point I was trying to get at. Thank you.

I really like that the US hasn’t adopted the metric system. I like the idea that humanity has some redundancy even in something like a system of weights and measures. It seems like the world would lose something intangible if we all went with the same one. Like if we all spoke the same language or had the same government.

The official US foot has been based on a metric measure for more than a century now though:

    The Mendenhall Order marked a decision to change the fundamental standards of length and mass of the United States from the customary standards based on those of England to metric standards.

    It was issued on April 5, 1893, by Thomas Corwin Mendenhall, superintendent of the United States Coast and Geodetic Survey, with the approval of the United States Secretary of the Treasury, John Griffin Carlisle.
At this point every US unit of measure (length, mass, volume, temp, second, etc) is defined in terms of a metric fundemental.

The US public are really just pretending that they don't use metric.

> The US public are really just pretending that they don't use metric.

I also like the fact that feet are are composed of inches in base 12. The promise that decimal brings some deep utility doesn't really materialize in most other contexts, and time is still base 60.

In my view, people who use metric pretend they like using metric. I mean, the unit of temperature is often expressed in divisions that are 0.1 apart, both because the basic units range and scale aren't particularly useful for human experience, and because "centidegree" is pretty difficult to actually "conjugate" in the system.

Neither system is particularly great, they're mostly just familiar, and outside of a few peculiar cases aren't very distinguished from each other.

It seems like it should be a priority to fix that.


Redundancy is normally a good thing, but being that weights and measures about communicating physical facts accurately and broadly, moving to metric seems like the most reasonable choice.

It's not clear how this "redundancy" your aiming for would benefit us.

I don’t think anyone not from that generation can understand how much we’re still living in Reagan’s world.

I like Reagan's world better than Carter's world of hour long gas lines and "Malaise Forever" stagflation.

Japan seems to be doing fine with decades of stagflation. Everyone is pretty much taken care of there. Meanwhile, the USA has people dying of diabetes because they cannot afford medicine. I also think if we used trains and other mass transit more, we would be in a better position, like Japan.

I would prefer the stagflation and trains, personally.

> people dying of diabetes because they cannot afford medicine

That's a problem stemming from government regulation that prevents competition in diabetes insulin.

> trains

I'd prefer trains, too. But the government makes it far too expensive to build lines and operate them.

> That's a problem stemming from government regulation that prevents competition in diabetes insulin.

It's amazing how neo-liberal see government the source of half of their problem. When generally speaking, the true source of their problems is just corporations trying to fuck them up and do business as usual.

We have insulin regulation in most of Europe and Japan.

And still insulin cost there less than 10$ and close to 100$ in USA.

Why ?

> Why

Taxes make up the difference.

I respect you for a lot of thing you say Walter but this is garbage.

Taxes are not 1000% higher in USA than they are in France or Germany.

The main reason are patents, lack of generics, lacks of leverage of insurers in the American health care system and lack of regulation.

One of the main insulin provider in the USA is currently Sanofi. Sanofi is a french company. And the same insulin in France is under 10$ and currently reimbursed at 100% by the government.

Why ? Because in France the health coverage is state managed. And when the state negotiates the prices (paid by tax payers), the industry shut up and accept them.

This is the same in most of Europe Switzerland excepted.

France has significantly higher taxes than the U.S. does.

Your train of replies reminds me of a canard I saw once on Twitter, can't remember by who: "Everything is monocausal and the cause the the thing I care most about." Your thing is regulation, apparently.

> Your thing is regulation

Regulation affects everybody a great deal, whether you're aware of it or not. In this case, insulin regulation has created a single supplier and prevented the market from working.

You seem to treat “regulation” as if it is some monolithic and controllable thing where the president could have a dial installed to their desk to turn it up and down.

Good thing Japan has no government.

oh wait...

The birth rate is cratering, people are eschewing dating, and many live meaker lifestyles than their own parents since they cannot afford to live as well as their parents did.

Rail, healthcare and rent prices might be bright spots in Japan, but I hardly would consider a regression in real wages and living standards to be "doing fine". Your not doing fine if you can't afford to support yourself and a dependent.


Japan per capita GDP was 44k in 1995 and 33k in 2022.

People die in of diabetes in the US because they eat too much bad food.

Thi is objectively and grossly wrong. Diabetes is genetic and most of those you hear about rationing got it as a child because of genetics(type-1), not because they over-ate. Also, elderly get type-2 diabetes without being overweight. It’s statements like you made the perpetuate the victom blaming of diabetes.

From the NIH:

"You are more likely to develop type 2 diabetes if you are not physically active and are overweight or have obesity. Extra weight sometimes causes insulin resistance and is common in people with type 2 diabetes. The location of body fat also makes a difference."


Obesity tends to run in families, and families often have similar eating and exercise habits.

Falsehoods like that are 100x worse than the price of insulin. 90-95% of diabetes in the US is Type 2, and it is crap diet that causes it.


And if you want cheap insulin, you can buy it for $25 at Walmart.

$75 for their Novolog analog. Almost no one should use NPH, it’s generally terrible and costs the same as we pay in Canada for the name brand Novo insulin aspart(It’s not subsidized).

The issue is people, generally, see diabetic and don’t ask, just assume. Millions are not type-2, many are due to pregnancies, old age too, or damage from disease. But even with obeisity/inactivity it is a risk factor and generally has a genetic component too. Plus, one the beta cells are gone, they are gone.

That’s an impressively reductive way to describe the 1979 oil crisis.

Want proof? The very first act Reagan did in office was to sign an Executive Order that repealed all the oil and gas price controls.

The gas lines disappeared literally overnight! And I mean literally in the literal sense of the word. It was amazing. Poof! I remember the next day well. I pulled into a gas station right up to a pump, filled up, and drove home. Aaaahhh! Gas lines never returned.

Reductive, true. Accurate, absolutely.

Carter just didn't have a clue.

Carter was running against traitorous Americans.


I let my subscription to the NYT lapse because of their unrelenting propaganda.

In any case, Carter's ineptness at foreign policy left an opening for his opponents. Not that that justifies his opponents, but it's still ineptness.

P.S. Carter is a nice guy and well-meaning, and I like him a lot. I'm glad he's been given a long life. He was just not a good President.

This is not news, and certainly is in character with that administrations.

The failure of your dialog here is further evidence that partisanship does not serve us well.

> What happened in the last four decades? Talk about a lost generation.

Neoliberalism and the Chicago school of economics happened.

> I still live in that world in my head. I hope maybe I have expressed a part of that optimism to my kids as I raised them.

You have been good to them, then. Those hopes were grown by a generation of survivors, thinkers, and humanists who expressed humanist principles in their work. They were agents of change. Knowledge, compassion, and fairness have been almost completely replaced in public discourse by cruel raving and demagoguery.

The thing I didn't know until I came across a similar article posted here on HN a few years ago (maybe it was the same one?) is that the White House panels weren't photovoltaic, they were solar-thermal for heating hot water.

Basically, Carter wasn't deploying some cutting edge and extravagantly expensive (at the time) technology that could be deployed as a high-profile technical demo but not actually economical to use, he was deploying a cheap, practical technology that could be used on most houses, during warm months at least.

i grew up in central florida in the 80s and we had solar-thermal water heating. we were not wealthy (dad was a construction worker and mom was an odd-job secretary) but my friends were all mystified by the things. i remember climbing up on our roof giving tours.

something really did a number on society and it politicized so many things that needn’t be politicized

So my grandfather turns 101 this year. He's kind of an ass in his old age, and wildly out of touch with the world. Like shockingly out of touch.

But he talks about politics from back in the day. Everything has always been super politicized. Everything. But our memories are short as a country.

There are polls, in the US at least, asking the same exact questions gong back I believe half a century or more. It is very clear from these polls that this is the most poltically polarized time in politics in decades.

It's not just recency bias - things are really screwed up.

Why (my opinion) one side started caring more about winning than any of their own positions. That then devolved into only caring if the other side loses regardless of what the policy is.

If a party's main focus is the other side loses rather than to successfully govern - you end up here. And the fact they more or less admit it, and people jump to justify it shows how far things have fallen.

Things have always been politicized heavily... But that doesn't mean that things aren't significantly worse than the recent past.

We actually had a political landscape from the 30's to the early 90's that was much less polarized than the rest of our history. We're returning back to where we were in the 1800's.

But what does he talk about though? There have always been super political things, certainly, but the scope of what was political vs common sense has had a huge shift.

Not really. Look at the New Deal. That makes a ton of sense, but was incredibly political. Also the war on poverty. Complete sense. Super political.

I guess maybe I don't know what you're talking about with common sense becoming politics. Do you have an example?

I didn't know they were solar water heating until right now. Barbados has been a cool case study of large scale adoption of solar water heating:


I was just on vacation in Greece, and solar water heaters are on every home and building there.

Everybody and their dog had a solar heater on their house in Cyprus, from 30 years ago. It was cheap deployable tech accessible to literally peasant farmers.

I visited Sardinia recently for the first time, and saw the exact same type of houses built there, with the same climate, but not a single solar heater on their roofs. I wondered aloud why, but got no answer.

My guess is that an energy company took an interest early on in Sardinia, and Cyprus was thankfully missed for a few decades.

In Canada it's not uncommon too see some homemade looking solar heating setups connected to people's pools. The coiled black tubing on shed roofs is very distinctive.

I'm well below Canada's latitude, and it costs me $250/mo to heat a relatively small swimming pool (about 10,000 gal) ... in the summer. If I keep it warm enough to swim in October, it'll be at least twice that. The capital cost of the heater is practically zero compared to the fuel. I can totally understand janky DIY setups to try and defray that cost.

There’s a bunch of YouTube videos showing how to make them. It’s really easy, actually, and you can get like 250-500W of heating from what seems to be a reasonably small device.

Sadly, I read often that at this point, PV is so good that it makes more sense to install PV panels and power a water heater via electricity. I don't want to believe it, but it's been said often enough that I am starting to do so.

I think electric solar heating makes sense for a lot of installations.

Wires are easier than pipes, we still need electricity, make the existing system larger rather than split between the two. Heat water during the midday when output is high. I use almost no hot water, so the system would have a long payback period. But I can heat water in a 15A kettle.

I love solar thermal, Trombe Walls should be integrated into the construction directly or added after the fact. They are for building heat, not water.


PV can beat solar thermal once a heat pump is used.

However that ignores the externalities of PV and heat pumps manufacture, replacement and disposal so I think the argument is BS.

Solar thermal is an aimed aluminum trough and a stainless steel pipe painted black on its focal point.

> Solar thermal is an aimed aluminum trough and a stainless steel pipe painted black on its focal point.

No, it's actually these fairly sophisticated phase-change evacuated tubes that have a heatsink at one end immersed in the water, from what I remember reading.

It sounds like you're talking about an "air to water" heat pump. Or some other source to water heat pump.

Phase changes, and pressurized tubes screams heat pump to me. This is different than solar thermal which is essentially leaving a bottle of water sitting in your car on a sunny day. Nothing more complex needed.

There are two kinds of water-heating systems based on heat-pump related ideas.

One circulates a non-water liquid between the panels and the hot water storage tank, and it exchanges heat obtained from the panel with the water in the tank. This has the downside of being complex (pumps, weird liquids etc.), but has the upside of keeping the fluid system associated with the panels distinct, which can reduce issues with freezing and can boost efficiency.

The other system doesn't use thermal panels at all, but just uses electricity to drive an air-source heat pump that exchanges with the storage tank.

It can be either. There's fancy thermosiphons, etc, but you can also just preheat water going into a water heater by pretty dumb means. You can run circulating pumps. You can have a separate working loop. Etc, etc, etc.

The Carter panels were pretty simple boxes with pipes and water circulated through them, I think.

Evacuated tube? Like the heat pipes on you CPU? Sure, but completely unnecessary unless you want to get rid of the pump [1]. And why get rid of the pump to substitute it with an evacuated tube?

[1] which you don't even need if you route the system well or use valves.

The best would be too use water-cooled PV panels with a heat pump to cool down the coolant and transform the heat. Cool panels produce quite a bit more electricity while the heat can be used elsewhere. Water-cooled panels are available commercially (with promises of far too high efficiencies, salesdroids gonna salesdroid) so this is not a pipe dream, especially not there where a water/water heat pump is available anyway - just install some valves to re-route the coolant through the panels.

I've had this notion too. The kicker is, as always, cost.

It's an easy intermittent power sink for supplemental hot water if you don't want to be grid tied or bother with a battery bank.

There were many books and how-to guides at the time to add solar water heaters. Anybody who wanted one could install one. I know people who did. They didn't need permission from Reagan.

Few wanted one.

They still can be installed today, the sun hasn't changed much.

And still they're rarely installed. I knew more people in the 90s who were ripping them out or leaving them dry (they were popular for pool heating in some areas) than installing them.

The people I know who had them complained about maintenance problems, and dealing with freezing weather.

I've considered it several times, and it came down to it being too much work.

Yeah, having large amounts of flowing and standing water on your roof is basically a recipe for maintenance headaches.

PV is much simpler, and if it stops working you can just ignore it.

Apparently Carter's solar heater leaked, too :-(

I once designed a solar swimming pool heater that had no moving parts and required no maintenance. I never built it because I didn't have a pool.

One fun thing about all this is learning that “no moving parts” is a polite fiction when you have water at various temperatures over long distances (and solar heaters are long if unwrapped).

Temperature changes can cause glued pipes to move enough that they become unglued. What fun!

Modern PEX offers significant advantages there (hundreds of feet with no joints).

A good design allows for expansion and contraction with temperature and stress, but those aren't usually considered moving parts.

I once had a car that had aluminum cylinder heads and bronze valve guides. The valve guides were a press fit with no keepers. Aluminum expands at twice the rate as bronze with temperature. So, when the engine got hot, the valve guides fell out.


We had solar-thermal panels on the roof of our house in Beirut in 1995... they're still going strong - just need to wipe them of dust every now and then. Hands down one of the best home appliance investments - especially in a country where electricity is sporadic.

The reason they haven't picked up in the US is because infrastructure is good - electricity delivery is reliable. It's much cheaper to install an electrical or gas water heater rather than the complicated plumbing needed to add solar-thermal.

IIUC investing in PV is actually more efficient for heating/cooling than solar-thermal, because you can use them to run a heat pump, and heat pumps have something like 400% efficiency (i.e. with 1 kWh of electricity they can pump 4 kWh of heat).

Here in the Netherlands government is now trying to ramp down PV subsidies, because PV has been so wildly successful that electricity spot prices are actually negative at peak sun (midday). (Even without subsidies I believe the panels are now cheap enough to be worth the investment, though.)

> Here in the Netherlands government is now trying to ramp down PV subsidies, because PV has been so wildly successful that electricity spot prices are actually negative at peak sun

Which means people should start buying batteries. Pull in power during midday at a profit, and then send it back out in the evening at a profit. I'm curious how long it'd take to pay back the price of a battery.

I just a few days ago watched a really good fairly deep dive video about the US' historical reasons behind this:


Pretty much. All in all they’ve been a very poor investment for home owners in America. At best you break even after ~20 years if they’re even still functional.

Could change as tech improves but as of today they are pointless for most people.

You’re talking about PV, not solar thermal. Break even for solar thermal can be one year.

Even for PV, most payback periods are under 10 years at this point. In sunnier areas payback periods can be just a few years.

> At best you break even after ~20 years if they’re even still functional.

This is misinformation.

I searched on google, bing and Yandex and all the results I found implied that breakeven would occur substantially before 20 years. The lowest breakeven time figure I found quoted was 5 years. The usual quoted breakeven ranges were, I'd say, 6-12.


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