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Comment by ronb1964 | Hacker News Reader

ronb1964

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 customers to right-size the system for their actual usage instead of what they think they'll use. People consistently underestimate idle draws and overestimate how much sun they'll get. Scale that mindset problem up to a national grid and I imagine the challenge is the same.

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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 parallel battery cell dis/charger to extent the LFP battery life to 20000 charges (one a day for 50 years).

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

15kWh 48V LFP battery around $1800 with low quality battery management system in metal box on wheels. Car batteries need more expensive inverters if you want to fast charge them (150kW-950kW) and super fast discharge them while driving fast (>100 kW). Thus my 600kW extender comes to almost $62000 for vans and small trucks. Cheaper if installed as house battery. The Mercedes eSprinter 56kW van costs around $80000 new but we sell 3 year old vans like this for $4000 without battery. So refurbished and converted to eCamper with 1800 mile range you pay $6700. You can drive 3000 km (almost 1860 miles) with this battery in the eSprinter and eCamper. A normal size car would go twice as far with this battery but it's big and heavy enough that you need to tow it in a trailer.

The crucial point though is the charging/discharging inverter (converter) that I purpose built (printed circuits boards) and a change to the car firmware. Without it the car will reject the battery, your acceleration would be less and it also would not last the same amount of discharge cycles. My battery electronics works fine for cars, trucks, boats, house and neighborhood batteries (up to 6mW per shipping container).

We build entire smart grids around the batteries, solar panels and tiny houses. https://www.researchgate.net/profile/Merik-Voswinkel/publica...

I love this! Thanks for the detailed response, super interesting

Thank you. I hardly get to explain the techology I 'invent' (power chips, power router, parallel battery charger, car firmware, charging (station) software, simulation software) because the investors customers only want to hear that its cheaper or sells better (then Tesla). Or that besides going from 4000 to 20000 dis/charge cycles you also prevent any li-ion fires and have fire alarm sensors on every battery cell. The main thing I would like to shout from the rooftops is: Not a single battery on the planet charges their battery cells in parallel as we do, they all shorten their cell lifetime by charging/discharging them to fast in series, what will damage all battery cell types but especially the li-ion.

It is the same with the article we are commenting on here: if people just listen to the statistics, the simulations and the actual market developments they would see that 100% solar+battery is the cheapest energy.

The simple message is Solar is by far the cheapest energy: below 1 dollar cent per kWh and that will fall a lot more in the next decade until we get to 'a squanderable abundance of free and clean energy' as Bob Metcalf puts it https://www.youtube.com/watch?v=axfsqdpHVFU Batteries still double the cost of that solar but these prices are falling rapidly too. It is already cheaper to have solar nearby than transmit it over a distance of a few miles.

More in my earlier comments weeks and months ago https://news.ycombinator.com/threads?id=morphle

Why are the prices in the USA so much higher?

Also: when we last spoke you were talking about energy storage solutions. How has that progressed recently?

$0,01 per kWh from solar, that is the price worldwide on the condition that they sell you the panels at a reasonable price and don't overcharge you on all the other parts like micro-inverters, field or rooftop installation, permitting and labour. That adds up to around 5 cent for rooftop solar in Australia for example (including everything). 1 cent is for solar panels lasting 50 years (with 20% degradation over decades), we refer to such prices as Levelised Cost Of Energy (LCOE) over lifetime. It halved in the last 10 years for solar and it will halve again (20% cost reduction on each doubling of manufactured capacity). Similar for batteries, they also go down around 20% each year.

1 kWh Wind, or Hydro, Thermal and other renewables do not go down as much in cost price because they have mechanical or chemical components that do not last as long as solar cells and need maintenance and repair.

We keep the cost low by group buying in bulk at wholesale prices (a shipping container with 770 panels for 20-30 houses) with our coop instead of premium installer prices by the electrotechnical or building companies. If you let our Fiberhood coöperative in the US install your solar, batteries, tiny house or eCamper you do not pay these high tariffs, we have enough panels pre-tariff. So you still can hit 1 cent per kWh but only if you get the decent installers and sellers.

Our energy storage solutions have widened. First you timeshift all electricity use of the car, house or neighborhood into daylight hours when the sun shines. This means a bunch of electronics and software changes. Next we build termal storage solutions, you can store heat much cheaper than electricity. You move heat around with a heat pump. Or you heat your water tank with a datacenter computer in your water tank (for free). In summer you store solar electricity in ice. Or you store it in iron, aluminum, glass or silicon by melting ore and purifying, You embodied the solar electricity into the purified ore. In northern and southern latitudes you need 10 to 50 times more solar panels to heat houses during cold winters. This means you have large overcapacity in summer that you can sell as embodied iron, etc. Batteries are only needed to store for the hours there is no sunlight during 24 hours, no need to store longer. The cheapest place is to store it in the electrical cars in your neighborhood. That is why we install our own brand ev car chargers in the neighborhood of the panels. In contrast, Tesla chargers overcharge you a factor of 34 to 76 and that's partially because its fossil energy and transmitted over hundreds of miles.

My message is that to reach 1 cent per kWh we need to solar electrify all our infrastructure https://www.youtube.com/watch?v=iEOPx2X-EtE

Also Trump doubling solar panel prices with tarifs and shutting down subsidies is wrong, it makes it much more expensive. Add an oil third world war however does help, we sold double solar, batteries and evs in the last month.

Wait, you put 600kWh of batteries on a sprinter van?!? I wanna know more...that's insane (base eSprinter is like ~115 kWh, right?)

eSprinter 2022 is 56kWh. In Europe I'm limited in the size of a battery by the total legal weight of van and it's trailer combined. So I can not tow more weight than 600KWh LFP batteries with this particular van. But with $0.01 cost per kWh it only cost $60 (52,08 Euro) for a full charge, good for 2000 km (Amsterdam to southern Spain). So even though I carry 5.5-6 times as much weight as a small city car around, it cost me a lot less than having a tiny battery and charging at commercial chargers with $0.40-$0.90 fees per kWh. And a lot less than gasoline (benzine) or diesel.

Also the larger battery means the individual cells can be pulse charged much slower and each cell individually at the rate where it doesn't damage that much. I measure the temperature, voltage and current of each cell so they never overheat. This is how I get many more cycles out of each cell so they last 50 years. It is also safer, with thousands of temperature measurements several times per second not a single sell gets warm, and if they ever do it is because it is damaged and we can immediately disconnect it and tell the driver where to locate it and remove it.

For a truck these thousands of battery cells discharging slowly in parallel becomes the reason all trucking companies will be forced to switch from diesel to electric, it is several times cheaper per mile or km. Lower energy cost, lower maintainace, lower downtime, longer life. The only thing you would want is that the maximum weight limit per truck goes up so you can ship more per trip. Right now you ship little kilo's if you carry a heavy battery. But charging with your own solar at home base is so much cheaper that it is worth to do two trips versus 1 trip with diesel.

The reason electric trucks are not yet everywhere is that the truck makers ask ridiculous amounts for battery cells that are still wired in series and discharged too fast to last long. Simply bad design. We need a disruptive electric truck startup and we need a disruptive battery startup. Investors welcome...

But 600 kWh is about ~4k kg, no? Isn't that like the max hauling a sprinter can do? So doesn't this just get you a bunch of range at the "cost" of not being able to haul anything or am I missing something?

7000 kg is the maximum a van and its trailer can way by law in Europe. It can haul a lot more.

No, my eSprinter camper is a small room with kitchen, bed and shower. The trailer ways 3500 kg, the eSprinter 2670. I could haul at least 889 kilo more. If I had the bigger motor I could haul twice as much.

I doubt that issue scales to the national grid at all... national grids tend to dictated in size by more or less market forces not careful pre-planning... and capacity planning for new projects tends to have actual data about energy demand and weather patterns and so on.

And what the market doesn’t solve the grid operator solves using ancillary markets.

Very nice. I have my eyes on Lithium-Titanate cells for my house, I can't wait until they go down in price enough. Weight and energy density are not an issue, but safety is and those cells are very good in that sense.

https://en.wikipedia.org/wiki/Lithium-titanate_battery

LFP is safe and is under $100/kwH.

> Scale that mindset problem up to a national grid and I imagine the challenge is the same.

Except that we have raw data there? The only question is how fast it grows, but since we're transitioning that's mostly a question of how fast you decommission fossil plants.

Yeah, agreed. It's a lot easier to be empirical when the scale of the requirements is quite literally unimaginable without just dealing with raw numbers.

Germany’s renewables rollout would like a word….

If you mean what they started in the 90s? That's not what this is about. The conversation was about not being able to rightsize today.

Germany did jumpstart their market successfully but that was in a wildly different time. Want to talk about what a typical KWp of installed solar cost at the time?

Hindsight....

Germany has only a tiny portion of their total energy needs on renewables - if we’re being honest about the definition of ‘total energy needs’.

Like in the camper van scenario, if we include winter heating and transportation? Oh boy.

It’s getting better, but if we’re really honest very far from the truth

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.

Thank you for sharing! that's an interesting project.

While I agree with underestimating capacity, the problem only really applies to off grid.

For regular homes, it just means less savings.

It means some other infrastructure (fossil fuels?) needs to take up the slack, and people underestimate actual costs at larger scales.

It’s the big issue in Germany for instance - it’s all fun and games until Winter.

And? Any coal not used in summer is coal not dug up.

Which is fine, since you're still reducing your reliance on the grid.

However, when you're off grid, underestimating capacity means your SOL and need to buy a generator and burn fuel on-site.

Germany has more wind in winter, so traditionally has more production of renewables in winter months.

It has dramatically higher thermal heat demands in winter - far higher than is compensated for by that. Even if everyone switched to heat pumps.

True, but higher demand for heating in winter is not specific to Germany. In the end, Germany will likely need to import energy anyway - just as it does today. But this means this question may not be the most relevant.

Huh? It highlights the relevance. It’s easy to handwave ‘imports’ away - but import from whom, and how do they make the energy?

One could import it as ammonia from locations that can produce a lot of it via solar.

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