I only now got around to watching the Technology Connections video on renewable energy, I wish I had seen it sooner. Almost feels like it should be required viewing. I definitely thought there were nastier chemicals/compounds in solar panels and hadn't updated my knowledge on them in decades.
I decarbonized my 125 year old home this summer. Cold winters here, using mini split heat pumps now for heat. Previously had oil, and 90 years ago it would have used coal. Love thinking this will be the first winter this house ever had where dirty exhaust wont be going up the chimney to keep it warm.
We have a wooden house from 1909, insulated, but not to modern standards and many windows. The heating and hot water is provided via a 10 kW (out) modern heat pump with a 100 meter borehole into the ground. This is a fairly standard installation in Sweden. It provides all the heat needed, except for extremely cold days (-20c or lower) when a 7 kW immersion heater can provide support. This is not needed more than a few days a year where we are.
We have added a small solar installation (7kWp) and a battery pack (18kWh). It provides 90% of power needed in the summer and allows for decent peak shaving in the winter, to lower network costs.
Additionally we are Co-owners in a windpower cooperative that provides more than our share of electricity into the network. So we are essentially operating our home on wind and solar, as well as powering the electric car.
Depends where you are, and what your start point is.
I've looked at improving old houses in Australia, and you would usually be better off putting the cash in the bank. (After heat pumps, and sometimes a battery).
Of course, but with a heat pump you get the combo of lower demand and much higher efficiency. In Germany for example due to high electricity prices you really need COP>3 or so to beat fossil fuel for heating economically.
I swapped my hvac for an electric heat pump. My energy usage went down. Because electricity is way too expensive and I’m okay sweating a bit in the summers and wearing jackets indoors in the winters.
Wearing jacket indoors is not a problem if your building is built like that.
I live in well insulated house. Big problem is moisture management if I don’t keep indoors fairly warm I will get walls wet especially in bathroom.
Heating up just bathroom is hard as outside is well insulated but then internal air flow cannot be blocked.
It is also not that great in the summer when it is hot outside. Cooking or any bigger screen will heat up inside of the house. But then opening windows might not help when it is high heat.
I got a CO2 monitor, and noticed that it often went over 1000 ppm CO2. So I started cracking the windows slightly, which resolved it. There are downsides to sealing the house too tight.
What kind of article shows you a newsletter pop-up as soon as you load the page? That virtually guarantees not a single person would ever enter their information because they haven't even had a single second's chance to make any sort of determination yet.
That's not quite what this is about. It is the Primary Energy Fallacy, that if you are to replace eg coal, you need to replicate its original energy content.
If 1kg of coal represents 1000 Wh, your generator loses 1/2 to waste heat, you only generate 500 Wh of usable electricity. Some analyses will state that renewable power has to replace the 1000 Wh of embedded energy within the coal, when it only needs to output 500 Wh.
If you use solar panels and generate 500 Wh directly, you have cut your energy use in half, even though the output has remained the same. An EV has a battery of ~80 kWh, equal to 2-3 gallons of gas, yet it can go a few hundred miles, a 3-4x ratio of efficiency, compared to an ICE.
Electric motors have gotten ridiculously efficient. In the right power curve you can hit 95%, which is why we have now moved onto power per unit weight and unit volume. You make the drivetrain lighter you reduce the power needed for 0-60 times, which gets you a few more percent of efficiency.
Same thing with battery power density - it’s the rocket equation. Heavy batteries don’t go far. To go farther you add battery, then more battery to carry enough power to carry the larger battery. Increase the specific energy rather than the mass, and all the extra power goes into going faster or farther.
I think your EV example is a better example than your coal one.
I’ve never seen anyone measure coal power by the amount of chemical energy stored inside, unless they are specifically referring to using it as a heating source. For electricity generated by coal it’s always measured as output.
A good visualisation for this I think are linked. Petrol/diesel use about 20% of the available energy and electric vehicles use about 80-90% for moving the vehicle.
> An EV has a battery of ~80 kWh, equal to 2-3 gallons of gas, yet it can go a few hundred miles, a 3-4x ratio of efficiency, compared to an ICE.
Now compare size and weight of the battery with 3 gallons of gas. I can carry hundreds of miles of travel on my person if it's gas, I can't carry much battery though.
Meanwhile, fossil fuels are only 'cheap' because the users are pushing the negative externalities off on everyone else in the world. Priced properly they'd be even more costly than they already are.
World energy production is increasing with solar coming to the forefront.
It is something overlooked by various reports of "In X amount of time, Y is projected to consume Z% of electricity" that the average increase in world electricity production is about 3% per year.
And the average increase in world population is about 1% per year, plus the bulk of the existing population is 'developing' i.e industrialization.
As fast as solar, wind, etc electricity production grows, the number of people requiring it grows along-side.
Also, 'renewable' is misleading, 'replaceable' is more accurate, all renewable energy generators wear out as everything does and need to be replaced using non-renewable energy mostly (you can't build solar panels from solar panel energy)
For the same reason there were no solar panels prior to 1800, there was not an excess of societal energy to invent and produce them. Solar panels are not trees.
And relying on trees is not a great idea either, look at Easter Island, lol.
(GPT has all the answers anyway, no need to ask me, I'm an old man with no issue and no stake in this stuff)
There were no solar panels because we didn’t know how to build them until the 20th century. Today you can run the factories that make them on renewable energy without a problem.
You can do the whole process from mining and recycling to installation using solar power. Trucks, furnaces, cargo ships can all be electrified. The only reason we're not doing that today is fossil fuels are still cheaper.
Why? I didn't start using more energy elsewhere when I switched to an EV or electric lawn maintenance tools. You think companies and people are using exactly as much power as available (or they can afford)?
It's a well-known "paradox" known as Jevons Paradox. Given enough efficient use of a resource, overall usage could actually far outpace the efficiency gains. E.g. use of coal got efficient enough that travel via trains using it became possible, which led to way more usage of coal.
Can confirm Jevons Paradox. But in a more environmentally friendly way.
Just took my house onto off-grid solar, yet my energy consumption now exceeds when I was on utility grid power.
Naturally we ration things when they're expensive. But now I don't feel the need to turn off the lights or appliances when I leave my home, and my EV driving has gone up knowing that "fuel" is essentially free from here on out. And to soak up excess solar, I run multiple computers and servers 24/7 with reckless abandon.
How far does it scale? Because I imagine there must be diminishing returns at some point. And even so, having a lot more renewable energy also means less cancer.
The crux of Jevon's paradox is that you’re lowering the cost of revenue below the sale price.
If I can generate $10 a sale then I’ll do no sales if it costs me $11 . If gas drops from $4 to $2 then I’ll do as many sales as I can as $9 is less than $10.
I mean, right now, supposedly, we don't have enough energy to run as many AI data centers as everyone wants to build, and so big tech is getting into the power plant business to scale up: they'd love it if you stopped using energy they want to buy!
It kinda depends on where the energy is coming from.
I was brought up to "save energy ". Lights switched off when not in thevroom, that sort of thing.
Now I gave solar on the roof. There's an excess production capability, so now, during most days it doesn't matter if stuff is on or off. That especially applies to AC which I'll happily turn on on hot summer days. In effect I use more "because it's there to be used".
My EV is coming soon and given I can charge it on solar I plan to do a lot more day-trips-out over weekends etc.
So you're right, availability and affordability- but electrifying is great (for me) for both those things.
The 'half' figure is mostly primary vs final energy accounting. A heat pump delivers 3-4 kWh of heat per kWh of electricity (COP 300-400%), and an EV turns ~80-90% of stored energy into motion vs ~25-35% for an ICE drivetrain. So electrifying heat and transport shrinks final energy demand even before counting upstream losses (refining, thermal generation - roughly 60% rejected energy in most Sankey diagrams of the current system).
The comment below about electricity prices is the real friction point though. Where time-of-use rates exist, running a heat pump with thermal pre-heating during cheap midday solar hours changes the math entirely - the building itself becomes the battery. I got into tracking my own load against TOU windows and ended up building a small tool for it (energy-iq.app); shifting ~40% of consumption off-peak ended up worth more than any single efficiency upgrade. Electrification halves the energy; rate-aware scheduling is what makes it halve the bill.
I only now got around to watching the Technology Connections video on renewable energy, I wish I had seen it sooner. Almost feels like it should be required viewing. I definitely thought there were nastier chemicals/compounds in solar panels and hadn't updated my knowledge on them in decades.
https://www.youtube.com/watch?v=KtQ9nt2ZeGM
I decarbonized my 125 year old home this summer. Cold winters here, using mini split heat pumps now for heat. Previously had oil, and 90 years ago it would have used coal. Love thinking this will be the first winter this house ever had where dirty exhaust wont be going up the chimney to keep it warm.
Did you have to improve insulation or do the heat pumps provide enough power?
We have a wooden house from 1909, insulated, but not to modern standards and many windows. The heating and hot water is provided via a 10 kW (out) modern heat pump with a 100 meter borehole into the ground. This is a fairly standard installation in Sweden. It provides all the heat needed, except for extremely cold days (-20c or lower) when a 7 kW immersion heater can provide support. This is not needed more than a few days a year where we are.
We have added a small solar installation (7kWp) and a battery pack (18kWh). It provides 90% of power needed in the summer and allows for decent peak shaving in the winter, to lower network costs.
Additionally we are Co-owners in a windpower cooperative that provides more than our share of electricity into the network. So we are essentially operating our home on wind and solar, as well as powering the electric car.
Better insulation makes cost savings sense regardless of what type of energy is used for heat
It does, but modern heat pumps are so efficient compared to an oil-based system from the 1900's it'll save more energy than new insulation.
Had the house been uninsulated it'd be another story, but such houses are very rare in the Nordics.
Depends where you are, and what your start point is.
I've looked at improving old houses in Australia, and you would usually be better off putting the cash in the bank. (After heat pumps, and sometimes a battery).
Of course, but with a heat pump you get the combo of lower demand and much higher efficiency. In Germany for example due to high electricity prices you really need COP>3 or so to beat fossil fuel for heating economically.
No more bitcoin cryptocurrency and will solve this issue. it has been wasting electric energy.
Or no more hot drinks. Ban kettles.
I swapped my hvac for an electric heat pump. My energy usage went down. Because electricity is way too expensive and I’m okay sweating a bit in the summers and wearing jackets indoors in the winters.
Wearing jacket indoors is not a problem if your building is built like that.
I live in well insulated house. Big problem is moisture management if I don’t keep indoors fairly warm I will get walls wet especially in bathroom.
Heating up just bathroom is hard as outside is well insulated but then internal air flow cannot be blocked.
It is also not that great in the summer when it is hot outside. Cooking or any bigger screen will heat up inside of the house. But then opening windows might not help when it is high heat.
Heat recovery ventilators are one possible solution. You can hook them up to home assistant humidity sensors and open a vent for example.
https://youtu.be/wJB3dyHDa-8
https://youtu.be/zSxyUFLwFbc
https://www.openerv.ca/
I got a CO2 monitor, and noticed that it often went over 1000 ppm CO2. So I started cracking the windows slightly, which resolved it. There are downsides to sealing the house too tight.
An electric dehumidifier in winter keeps moisture in check and you get the energy of evaporation back as heat.
We solved our humid air in the bathroom with an active extraction fan that starts when it registers humidity and light (I think) in the room.
What kind of article shows you a newsletter pop-up as soon as you load the page? That virtually guarantees not a single person would ever enter their information because they haven't even had a single second's chance to make any sort of determination yet.
Unlikely. We'd just use the leftover energy for new things.
That's not quite what this is about. It is the Primary Energy Fallacy, that if you are to replace eg coal, you need to replicate its original energy content.
If 1kg of coal represents 1000 Wh, your generator loses 1/2 to waste heat, you only generate 500 Wh of usable electricity. Some analyses will state that renewable power has to replace the 1000 Wh of embedded energy within the coal, when it only needs to output 500 Wh.
If you use solar panels and generate 500 Wh directly, you have cut your energy use in half, even though the output has remained the same. An EV has a battery of ~80 kWh, equal to 2-3 gallons of gas, yet it can go a few hundred miles, a 3-4x ratio of efficiency, compared to an ICE.
Electric motors have gotten ridiculously efficient. In the right power curve you can hit 95%, which is why we have now moved onto power per unit weight and unit volume. You make the drivetrain lighter you reduce the power needed for 0-60 times, which gets you a few more percent of efficiency.
Same thing with battery power density - it’s the rocket equation. Heavy batteries don’t go far. To go farther you add battery, then more battery to carry enough power to carry the larger battery. Increase the specific energy rather than the mass, and all the extra power goes into going faster or farther.
I think your EV example is a better example than your coal one.
I’ve never seen anyone measure coal power by the amount of chemical energy stored inside, unless they are specifically referring to using it as a heating source. For electricity generated by coal it’s always measured as output.
The battery loses 10% just by charging it.
I figured an EV is worth about 60mpg with a fair comparison to a gas car.
A litter of petrol is about 34MJ or about 9.5kWh
It propels a car about 10 miles. About 1 mile per kWh
Charging my electric car via AC at 7kW to replace the power used to drive 90 miles in autumn takes 26kWh according to the meter, so 3.5 miles per kWh.
A good visualisation for this I think are linked. Petrol/diesel use about 20% of the available energy and electric vehicles use about 80-90% for moving the vehicle.
https://yaleclimateconnections.org/2024/01/electric-vehicles...
Oil also loses quite a bit during refining and transport.
And more every year as the highest quality oil gets used up and we have to work harder to catalyze the rest.
> An EV has a battery of ~80 kWh, equal to 2-3 gallons of gas, yet it can go a few hundred miles, a 3-4x ratio of efficiency, compared to an ICE.
Now compare size and weight of the battery with 3 gallons of gas. I can carry hundreds of miles of travel on my person if it's gas, I can't carry much battery though.
> I can carry hundreds of miles of travel on my person if it's gas, I can't carry much battery though.
Particularly handy if heading off in a straight line, I to the wilderness.
Most of us are running errands around town.
That's true, we should clearly be powering our cars with uranium, or perhaps plutonium.
Have to wait for Mr Fusion l
How about antimatter?
It doesn't say it would cut energy costs in half.
Meanwhile, fossil fuels are only 'cheap' because the users are pushing the negative externalities off on everyone else in the world. Priced properly they'd be even more costly than they already are.
World energy production is increasing with solar coming to the forefront.
It is something overlooked by various reports of "In X amount of time, Y is projected to consume Z% of electricity" that the average increase in world electricity production is about 3% per year.
And the average increase in world population is about 1% per year, plus the bulk of the existing population is 'developing' i.e industrialization.
As fast as solar, wind, etc electricity production grows, the number of people requiring it grows along-side.
Also, 'renewable' is misleading, 'replaceable' is more accurate, all renewable energy generators wear out as everything does and need to be replaced using non-renewable energy mostly (you can't build solar panels from solar panel energy)
> you can't build solar panels from solar panel energy
... Why?
For the same reason there were no solar panels prior to 1800, there was not an excess of societal energy to invent and produce them. Solar panels are not trees.
And relying on trees is not a great idea either, look at Easter Island, lol.
(GPT has all the answers anyway, no need to ask me, I'm an old man with no issue and no stake in this stuff)
There were no solar panels because we didn’t know how to build them until the 20th century. Today you can run the factories that make them on renewable energy without a problem.
You can do the whole process from mining and recycling to installation using solar power. Trucks, furnaces, cargo ships can all be electrified. The only reason we're not doing that today is fossil fuels are still cheaper.
Why? I didn't start using more energy elsewhere when I switched to an EV or electric lawn maintenance tools. You think companies and people are using exactly as much power as available (or they can afford)?
It's a well-known "paradox" known as Jevons Paradox. Given enough efficient use of a resource, overall usage could actually far outpace the efficiency gains. E.g. use of coal got efficient enough that travel via trains using it became possible, which led to way more usage of coal.
Can confirm Jevons Paradox. But in a more environmentally friendly way.
Just took my house onto off-grid solar, yet my energy consumption now exceeds when I was on utility grid power.
Naturally we ration things when they're expensive. But now I don't feel the need to turn off the lights or appliances when I leave my home, and my EV driving has gone up knowing that "fuel" is essentially free from here on out. And to soak up excess solar, I run multiple computers and servers 24/7 with reckless abandon.
How far does it scale? Because I imagine there must be diminishing returns at some point. And even so, having a lot more renewable energy also means less cancer.
Really far.
The crux of Jevon's paradox is that you’re lowering the cost of revenue below the sale price.
If I can generate $10 a sale then I’ll do no sales if it costs me $11 . If gas drops from $4 to $2 then I’ll do as many sales as I can as $9 is less than $10.
I mean, right now, supposedly, we don't have enough energy to run as many AI data centers as everyone wants to build, and so big tech is getting into the power plant business to scale up: they'd love it if you stopped using energy they want to buy!
It kinda depends on where the energy is coming from.
I was brought up to "save energy ". Lights switched off when not in thevroom, that sort of thing.
Now I gave solar on the roof. There's an excess production capability, so now, during most days it doesn't matter if stuff is on or off. That especially applies to AC which I'll happily turn on on hot summer days. In effect I use more "because it's there to be used".
My EV is coming soon and given I can charge it on solar I plan to do a lot more day-trips-out over weekends etc.
So you're right, availability and affordability- but electrifying is great (for me) for both those things.
> Unlikely. We'd just use the leftover energy for new things.
You mean data centers. Can't ever have enough of those!
Discovered in https://www.bloomberg.com/news/newsletters/2026-10-31/europe...
https://www.youtube.com/watch?v=-jSqcwxpd14
The 'half' figure is mostly primary vs final energy accounting. A heat pump delivers 3-4 kWh of heat per kWh of electricity (COP 300-400%), and an EV turns ~80-90% of stored energy into motion vs ~25-35% for an ICE drivetrain. So electrifying heat and transport shrinks final energy demand even before counting upstream losses (refining, thermal generation - roughly 60% rejected energy in most Sankey diagrams of the current system).
The comment below about electricity prices is the real friction point though. Where time-of-use rates exist, running a heat pump with thermal pre-heating during cheap midday solar hours changes the math entirely - the building itself becomes the battery. I got into tracking my own load against TOU windows and ended up building a small tool for it (energy-iq.app); shifting ~40% of consumption off-peak ended up worth more than any single efficiency upgrade. Electrification halves the energy; rate-aware scheduling is what makes it halve the bill.
We got rid of our gas furnace and got a heat pump. We also got 7.3kw of solar on the roof. Our entire energy bill for a year for everything is $500.
In Canada I’m a deep valley where it snows a ton.