Welcome to r/science! This is a heavily moderated subreddit in order to keep the discussion on science. However, we recognize that many people want to discuss how they feel the research relates to their own personal lives, so to give people a space to do that, **personal anecdotes are now allowed as responses to this comment**. Any anecdotal comments elsewhere in the discussion will continue to be removed and our [normal comment rules]( https://www.reddit.com/r/science/wiki/rules#wiki_comment_rules) still apply to other comments. *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/science) if you have any questions or concerns.*


uh, the "or heat" feels like it's doing some heavy lifting here.


Yah, if more waste heat is being recovered and then turned back into electricity it would be something. But that should just be a higher total Electricity efficiency, since a boatload would be lost to the various (more traditional) heat-to-Electricity conversion methods you'd need to capitalize on that heat. Unless it's specifically targeting cold environments where a lot of the electricity usage is in heating. But then you need the user physically close to the solar farm setup.


Actually, this looks like it is designed for industrial applications, so the heat will probably just be used directly. It will replace giant gas furnaces used to generate "process heat" that is used in manufacturing and chemical plants. Some industries spend 80% of their energy budget just making heat. This is a potential replacement for that. Also, as you say this is great for solarization in more northern latitudes where heat is the primary need for environment control system.


This is also a good development for non-fuel-using desalination. Passive desal, and thermal solar in general, is critically underused at the moment, which needs to change given the fuel-scarce future we are quickly heading into.


Yep. This + desalination + a satellite up-link is basically civilization in a box. I especially like this as the individual cells are small enough to provide great versatility while avoiding essentially all of the pitfalls of more classic thermal solar generation designs.


>fuel-scarce future If we can get climate change policy that we really need, there will just be no market for fuel, and petroleum companies will just shut down and decommission oil wells etc. Green tech is almost always cheaper to run, quieter, cleaner, takes less capital investment, more reliable Lots of gas station property to convert to electric charge stations, and any petrol cars will have to seek specialty sources for the fuel, like how cars that require leaded gasoline must go to airports, or for methanol from hobby stores for small qualities There is more than enough oil that we can extract from the ground, with enough money. But it quickly becomes not worth the cost to extract it. Electrification will win


The energy still needs to come from somewhere, which is why solar hybrid concepts like this are a good one. I have independent solar PV and solar thermal on my house, getting both in one unit would be a great benefit. Unfortunately we'll likely always be burning some fuel for heat on days like today. Raining, dark clouds and 5°C means none of my solar is bringing in any energy, and as such my NG boiler is firing even though it's May. Luckily at least it provides both space heating and DHW. There's also no point in decommissioning the entire fossil fuel infrastructure if we can instead just cut back usage to minimal/backup applications. Otherwise we need nuclear for base load and everyone is needlessly terrified of it.


I want more molten salt reactors


Don't we all! (well we should, thorium (etc) reactors are the ACTUAL energy panacea that we've been looking for)


What about fusion? Should be working great in about 20 years... Joking aside, the recent developments at MIT using high temperature superconductors actually have given me hope for a fusion powered future. Much stronger fields and cheaper magnets could have a huge effect. https://www.psfc.mit.edu/sparc Would be pretty funny if this unit is generating power before ITER can get their first plasma lit. Fusion development suffers from the interstellar travel paradox, where it doesn't make sense to launch a lengthy mission since it's almost guaranteed that a future mission with better tech will pass you by and get there first.


Why would you want that? The one outside of Vegas failed miserably.


I believe that was due to wild mismanagement more than it was due to a failure of technology.


Molten salt minus corrosion plus durability. Not a problem we've overcome


> Unless it's specifically targeting cold environments where a lot of the electricity usage is in heating. In which case, it's basically just saying "paint your roof super black and keep it exposed to the sun" or so.


I was more picturing a more standard liquid heat exchange system to feed the HVAC needs, so mildly useful but certainly not revolutionary


It feels like we have a lot of road to go before we are able to emulate the quantum processes that make plants so efficient at turning photons into energy.


Massively. Asphalt does a good job of collecting heat also.


Asphalt converts 90% of the Sun's energy it receives into electricity or heat. Some black paint reaches over 99%.


I came here to make this exact comment. Pulling heat off panels is a good way to bump up the efficiency of you need the heat, but it's not exactly pushing the laws of thermodynamics


Given that a large part of energy usage is for heating, that might not be too bad. You'd just have to be really smart about how you'd set it up to utilize the heat energy in winter, and not in summers.


Yeah. Because we already have devices that convert nearly 100% of the sun's energy into electricity and heat. Called solar panels.


I built a device that turns almost 100% of the sunlight it receives into heat. It’s a black rock.


i added pipes to my black rock and used gravity to effect a system of moving that heat around to other places


NAWWWWWWWWW, that'll never work


add a trompe and flywheel if necessary, and with all this heat and stored energy moving around we can just throw in a sterling engine for fun by adding in a geothermal cooling closed loop and another energy pipe on that black rock


I carried my black rock to a shady area, and transferred the heat. Pretty soon I'll have to carry my black rock back into the sunlight. 3 or 4 more cycles and the shady area will be just as warm as the sunny area.


Damn, this is a great comment.


"Or heat". What is this? Is this the next go-fund-me scam material? "While our competitors can only provide 20% efficiency in sunlight to electricity conversion, we can provide 65% efficiency in sunlight to electricity ^(or heat) conversion!" Yeah. Just paint a steel plate with Vantablack and claim 99.96% efficiency.


/Sigh..... Tell me you haven't read the article without telling me that you haven't read the article. It is called "cogeneration" and is also commonly used with turbine diesel and gas generators. Building heat or industrial process heat is a major source of energy consumption and it is common to harvest waste heat from other generation types to provide for that. Upwards of 10% of the US **total** energy consumption is industrial process heating. Being able to provide for that along with electrical energy is a big win.


Somehow I doubt a lack of heat is a large issue in places with an abundance of solar energy. If anything, a good deal of this electrical energy will be put towards running AC systems to cool interiors.


Actually, you don't even need the middle step of converting it to electricity. If you have heat, you can make cooling using the absorber cycle like propane refrigerators in RVs do. This is referred to as trigeneration and is deployed similarly to cogeneration, especially in remote facilities with out grid hookups, in places that both need cooling and generate more heat energy than they are using. Additionally, concentrator systems like this have advantages in places where solar would not normally be deployed (e.g. the far north).


I am not as knowledgeable about the topic of energy generation, so I will take you up on your word. I have tried to skim through at least the abstract(or summary in this case). However, the problem with the the statement still stands. They purposefully made the title as it is to confuse the less knowledgeable reader. This was also the case in the summary. They purposefully did not separate the total electricity and heat generation. Heat generation is good, but there will be yet more energy loss when we try to turn the heat into useable energy. What they are using is concentrated sunlight. We could make an apparatus that is more efficient in heat production, we could definitely get over 65% when it comes to pure heat generation. The problem would then be to harvest this heat energy into useable energy. This is why I had a problem with this article. Not separating the heat production from the electricity was disingenuous. It can easily mislead the public, and should be condemned for what it is.


> This is why I had a problem with this article. Not separating the heat production from the electricity was disingenuous. It can easily mislead the public This is a scientific paper published in Cell Reports Physical Science, not a blog post. It's not written for the lay public. For the technical audience that might be expected to read this journal paper, [combined heat and power aka cogeneration](https://en.wikipedia.org/wiki/Cogeneration) is likely a familiar topic.


I was under the impression this was already an option. I remember reading like a decade ago about home solar panel options that included water cooling systems that allowed you to use the heat generated to mitigate the need of a dedicated boiler system. I find it odd that it's readily being compared to conventional solar panel efficiency and not other *similar* thermal-solar panel efficiency. The main purpose of this tech seems to be the expected versatility of a high-heat producing panel (others produce lower heats), not the efficiency itself. Though at the moment the design suffers from significant part degradation at normal sun conditions.


Yea, the prototype they have here is definitely targeted at Industrial installations. Replacing gas furnaces for process heat would be a big win. The prevalence of gas process heat in industrial applications is problematic in multiple ways. In addition to the climate change implications, it is also the reason Germany is so dependent on Russian natural gas.


Except this heat is at 245C, which means it can be used to generate steam for power generation.


Even then, 60% heat efficiency is not something amazing for concentrated solar / vacuum tubes. Just more expensive materials.


Perhaps. But if it allows more energy production in a smaller space, the higher cost might be worth it for some people.


... why can't we do that? use the sun to heat things, harvest the heat energy.


We can, that is not the problem. There are more efficient method to just collect heat. The study is lumping the electricity production (which is the current bottle neck in solar energy) and heat collection(which even kids have used to burn holes in paper with a magnifying glass) into one basket. It is easy to collect heat energy from the sun. The problem is the conversion of said heat into useable energy. There is a loss of energy associated with this conversion as well. The article ignored this and clumped both of these into one. This is disingenuous.


That would be the basis for agriculture, food is chemical energy after all


Sounds like they are simply using the heat for replacing additional heating needs. _Hybrid concentrator photovoltaic-thermal (CPV/T) systems generate both electricity and process heat by splitting concentrated sunlight onto CPV cells and a thermal receiver utilizing a heat-transfer fluid. Such energy co-generation increases total conversion efficiency and reduces system costs to compete with more widely used electricity and heat-generation methods in target markets. _


Exactly, it is great for more industrial settings that consume a lot of heat directly for their processes.


The pure electrical efficiency appears to be between 7% and 9.3%. So, lots of heat, much less electrical power than the current state of the art.


That "or heat" at the end really changes the thing huh


No, it doesn't. >>n the same receiver, thermal output >245°C may be generated from both waste heat from the CPV cells and a spatially separated fraction of the incoming concentrated light illuminating a heat-exchanger coil.


>US average [levelized cost of heat](https://www.sciencedirect.com/topics/engineering/levelized-cost-of-heat) of 2.5 ¢/kWth. Devil would be in those details.


Theres been other designs like this that use prisms to split the wavelengths out, and I have a number of such concepts in my notebooks. The temperature of the output high grade heat here is quite good, in the future this temperature range can also get reasonable efficiency out of a CO2 supercritical turbine (closed loop) so that the electrical efficiency could be higher also. Higher temperatures are possible and can assist with thermo-chemical processes such as reduction of CO2 and H2O to synfuels or carbon. Those ideas were published some years ago, let me get the link; [https://onlinelibrary.wiley.com/doi/10.1002/adma.201103198](https://onlinelibrary.wiley.com/doi/10.1002/adma.201103198) [https://pubs.acs.org/doi/10.1021/acs.accounts.9b00405](https://pubs.acs.org/doi/10.1021/acs.accounts.9b00405) https://www.semanticscholar.org/paper/Recent-Advances-in-Solar-Thermal-Electrochemical-Ren-Yu/95974b1ec806a25e22c2e0d3524817888049ed8c/figure/0 The researchers on that envisaged prismatic beam splitting to get the required temperatures and P.V. electricity.


So does my left boot. It's black leather.


What color is your right boot? You keep it white for when you're overheating and need to cool off?


So instead of burning a lot of stuff in the air we breathe, we should use that giant ball of nuclear fire . Brilliant !


"...or heat" - thats useless unless captured. Even then its only a \~30% conversion into electricity at best from the heat


> useless unless captured. Except for the fact that it being captured and concentrated to a level useful in industrial applications is the whole point of this research paper. Also, plenty of industrial applications consume heat directly so no need for conversion.


Didn't they built that thing and then the mirrors kept going blind with dust?


What was the previous best?


Is this meant for solar farms where you don't need to have a central concentration tower?


Amazing! Many are no more than 22% effective. This gives me excitement & hope.


Unfortunately this method is much less efficient: less then 10% into electricity. It just generates a lot of heat too. So this isn't very exciting for most applications.


How many square miles of panels are required to use up enough of the suns energy to cause a planet wide temperature drop? Is it even feasible?


Energy can't be created or destroyed. Harvested energy from the sun will eventually come out as waste heat. If you want a temperature drop you need to reflect the sunlight back into space, not absorb it.


True, but energy can be converted. For example from heat energy to mechanical energy or to chemical energy.


It all just goes back to heat eventually, and the first and second laws of thermodynamics ensure you'll always have a conversion efficiency of below 100%. Using that mechanical or chemical energy will produce waste heat as a result of friction or reaction byproducts.


Exactly on the conversion. In theory, you could capture enough sun energy to and turn it into mechanical energy some of which converts back to heat energy to reduce the temperature of a system. Considering the sun puts enough energy on the planet in a day for all of the energy humans have ever used is problematic.


Does it also convert it to light as well?


Put that on your roof


where will my cat sit?