Solar and batteries can power the world • Hacker News Board

Re: Solar and batteries can power the world

#301

Post by RobinL » Fri, Apr 03, 2026, 5:53 PM UTC

morphle wrote: post #286

ronb1964 wrote: post #130

I build off-grid camper vans for a living and install solar + lithium battery systems regularly. The technology has matured a lot in the last few years. What used to take a massive roof array and a bank of heavy lead-acid or AGM batteries to run basic appliances now fits in a fraction of the space with lithium. The limiting factor in real-world installs isn't the panels or the batteries anymore, it's getting customer…

I build off-grid electrical campers (Mercedes eSprinter) with extended 600kWh batteries (11 times more battery capacity than the default model) and charge them from solar panels at home. I disagree with your negative mindset, people who ride in my eCamper quickly learn you can go 100% solar and use you camper at home to store all neighborhood solar and even charge other EVs from our eCamper battery. We make our own p…

Wow, that's big! I'm curious, how much does the 600kWh battery cost nowadays? Amazing that the tech has got to a point this is even possible

Re: Solar and batteries can power the world

#302

Post by chongli » Fri, Apr 03, 2026, 5:53 PM UTC

sillyfluke wrote: post #137

chongli wrote: post #60

Earlier quoted context omitted.

66F is ridiculously cold to me, and I live in Canada where it can reach -40(F or C) in the winter. I would find that very uncomfortable and elderly people would be shivering constantly and highly susceptible to respiratory illness. I have a modern cold climate air source heat pump which essentially needs to run 24 hours a day to maintain a stable 20C when the outdoor temperatures reach -15C. Below that, the heat pump…

>66F is ridiculously cold to me...I would find that very uncomfortable and elderly people would be shivering constantly and highly susceptible to respiratory illness. I know people who live in the Mediterranean and get by with no heating during the winter with indoor and outdoor tempuratures this low or lower, so it seems that one can be conditioned into doing so. Perhaps it's the presence of more sunlight on average…

You’re forgetting about humidity. Mediterranean climate has comfortable humidity year-round. Where I live, winter relative humidity is 0% because outdoor humidity is nonexistent from freezing temperatures.

Re: Solar and batteries can power the world

#303

Post by FuriouslyAdrift » Fri, Apr 03, 2026, 5:54 PM UTC

declan_roberts wrote: post #5

The article is just wrong. And only mentions energy used for heating in passing. Heating requires MASSIVE amounts of energy. I should know bc I have a whole house battery and solar system (almost 30 kWh battery and 24kW solar). It keeps the lights on, but not heating. I live in a mild climate. The reality is that battery/solar requires major quality of life and activity time shifting trade-offs.

Heating is mostly affected by the roof insulation and really should not be done with electricity alone. It's just not efficient.

Cooling, on the other hand, is brutally expensive without living in basically an air tight Styrofoam box (or underground).

Re: Solar and batteries can power the world

#304

Post by jabl » Fri, Apr 03, 2026, 5:57 PM UTC

ryzvonusef wrote: post #230

ronb1964 wrote: post #130

I build off-grid camper vans for a living and install solar + lithium battery systems regularly. The technology has matured a lot in the last few years. What used to take a massive roof array and a bank of heavy lead-acid or AGM batteries to run basic appliances now fits in a fraction of the space with lithium. The limiting factor in real-world installs isn't the panels or the batteries anymore, it's getting customer…

there is a youtube video I watched where an RV guy converted as many appliances and gadgets on his vehicle to Direct DC as he could, saved a lot on wastage from DC-AC-DC conversions. We need mundane home DC solutions.

There's https://currentos.org/ working on it.

Re: Solar and batteries can power the world

#305

Post by chongli » Fri, Apr 03, 2026, 5:58 PM UTC

PyWoody wrote: post #95

chongli wrote: post #60

Earlier quoted context omitted.

66F is ridiculously cold to me, and I live in Canada where it can reach -40(F or C) in the winter. I would find that very uncomfortable and elderly people would be shivering constantly and highly susceptible to respiratory illness. I have a modern cold climate air source heat pump which essentially needs to run 24 hours a day to maintain a stable 20C when the outdoor temperatures reach -15C. Below that, the heat pump…

I actually live on the same latitude as Ontario so -40F/C is not unusual. Add in windchill, and it gets even more common, given my windy location. Yeah, I understand I'm probably an outlier at 66F. I was using the numbers more to point out how little a house temperature will drop with good windows and insulation.

What year was your house built? Do you have a whole-house humidifier?

My house was built in the late 1980s. It has decent insulation but not amazing. It still needs a lot of heating when temperatures plunge below -15C. I do not have a whole-house humidifier. I had one with my previous furnace but it had issues with mold in the filter and clogging of the condensate pump.

Re: Solar and batteries can power the world

#306

Post by jillesvangurp » Fri, Apr 03, 2026, 5:59 PM UTC

KaiserPro wrote: post #209

brianwawok wrote: post #65

Earlier quoted context omitted.

In the short term the math is usually bad. Can be a 20, 30, 40 year payback on insulation. For the builder? It’s almost for sure a loss unless he can play the green card. For any individual owner? They are likely to leave before they recoup a project like this. Appraisals on houses are price per square foot with a bedroom and bathroom modifier. Until people start pricing in energy efficiency in homes, say a price mul…

> Can be a 20, 30, 40 year payback on insulation. For the builder? In the UK, houses have energy ratings, which are largely not that useful, but they do allow estimated annual running charge. The house that I live in we moved in and were spending ~1.7k on gas a year. We needed to re-render the place, because it has a few missing pieces. we spent the extra £4 to put in 90mm of external wall insulation. We also had to…

There's also the simple reality that houses with better energy ratings are worth more when they are sold. If you own a house, it's a good way to lower your bills and increase the value of your house. The only thing you know for sure when you pay hundreds per month for gas is that it goes out of the chimney. Over ten years, that adds up. Most houses you can probably do some sensible things that definitely earn themselves back in that kind of period while also increasing the value of your property. The inconvenience and financing tend to be the big obstacle. Add incentives to the mix and it becomes an easy choice in a lot of places.

Re: Solar and batteries can power the world

#307

Post by eldaisfish » Fri, Apr 03, 2026, 5:59 PM UTC

orthecreedence wrote: post #222

dv_dt wrote: post #56

Earlier quoted context omitted.

Beyond the other better insulation comments, pairing electric with heat pumps that are SEER 10+ goes a long way to improve heating efficiency. Old resistive heaters are 1:1 on energy to heat, while newer heat pumps operate to much lower temperatures, and give you 1:10 or 1:15 electric:heat energy ratios.

> 1:10 or 1:15 electric:heat energy ratios Under what circumstances? I've seen higher-end units that do maybe 1:5 in ideal conditions (heating to 68F when the ambient temp is 55F), but never seen units that do 1:10 or 1:15. This was about 2-3 years ago I did this research. Have things improved that drastically in the last few years?

things have not improved.

Too many folks here do not understand or care to appreciate the constraints of the real world. Heat pumps are excellent and relatively cheap but have limitations. One of the biggest limitations is that a heat pump's efficiency drops as ambient temperature drops. This is the worst possible situation for heating as the conditions when the risks of losing heat are the highest, are precisely the conditions when these devices are least efficient.

Re: Solar and batteries can power the world

#308

Post by daneel_w » Fri, Apr 03, 2026, 6:00 PM UTC

declan_roberts wrote: post #5

The article is just wrong. And only mentions energy used for heating in passing. Heating requires MASSIVE amounts of energy. I should know bc I have a whole house battery and solar system (almost 30 kWh battery and 24kW solar). It keeps the lights on, but not heating. I live in a mild climate. The reality is that battery/solar requires major quality of life and activity time shifting trade-offs.

Gonna go off on a limb and guess that you live in North America where the state of the art in single-family homes is double-pane windows and thin outer walls made of cardboard and pressboard, clad with "luxurious" vinyl siding. I mean no offense to you guys. It is what it is.

Re: Solar and batteries can power the world

#309

Post by pjc50 » Fri, Apr 03, 2026, 6:06 PM UTC

germandiago wrote: post #165

Retric wrote: post #108

Earlier quoted context omitted.

The economics only changed recently and infrastructure lasts a long time. It’s the same reason EV’s make up a far larger share of new car sales than a percentage of overall cars, EV’s sucked 20+ years ago yet there are a lot of 20+ year old cars on the road. The US stopped building coal power plants over a decade ago but we still have a lot of them. Meanwhile we’ve mostly been building solar, which eventually means w…

> The economics only changed recently and infrastructure lasts a long time This needs investment also. An investment poorer people cannot or do not want to do. It is reasonable that when someone gives up a couple of things because that person is rich (rich as in a person in the developed world) the sacrifice is more or less acceptable. Now change environment and think that these sacrifices are way worse. Even worse t…

The transition is happening rapidly in Pakistan: https://www.theguardian.com/environment/2026/mar/17/pakistan...

Re: Solar and batteries can power the world

#310

Post by maxerickson » Fri, Apr 03, 2026, 6:10 PM UTC

gamblor956 wrote: post #287

tencentshill wrote: post #190

Earlier quoted context omitted.

That's why it will require a functional government who can use taxes responsibly to make the technology affordable to everyone. The US had a pretty good start until one man decided to stop and try to reverse any progress made.

But why should American taxpayers be responsible for making the technology affordable for everyone? Why shouldn't Europe or China be expected to shoulder this financial burden? EDIT: I think people are misunderstanding my response. I fully support local subsidies for solar and renewables. My question is why my tax dollars should go toward making it affordable for everyone, including non-Americans. Either market dynam…

Look at it this way: Benefiting everyone is a side effect of benefiting American taxpayers.

Or do you think that US federal investment in solar and battery technology would be bad for the American taxpayer?