I often see posted about how covering a relatively small area in a desert with solar panels could power the world – but transferring that energy is too difficult. Why can’t we just use that to charge batteries and ship them places/ everywhere?
In: Physics
You would spend more energy transporting those batteries than you would obtain from your theoretical solar farm, and most of that spent energy would be from fossil fuels.
Because everything uses energy.
Moving energy requires energy. Batteries are heavy. Heavy things need trucks. Trucks need fuel, roads, maintenance, drivers, etc. And at some point you spend more energy moving the batteries than the batteries store.
Batteries are heavy. I think you miss the scale of things at work here. You might be able to chargee car and house with a battery thats the size of a smal shed and you need to rechatge that every day.
So a cargo ship of batteries per street or village per day would be my rough estimate.
You can compare that with an oil tanker, thats full of oil that you can burn to generate energy too. Even thats not woth it for electricity production.
You can! Mostly.
Many green power installations also use large scale power storage like enormous ranks of batteries (or other options like pumped water storage or flywheels.). However, this is not a flawless solution. Batteries require special materials to be built, such as Lithium, which is not a very abundant element world wide, making it expensive. Mining Lithium can have negative environmental impacts, and we need an incredibly large amount. Like, it’s hard to really articulate how much electricity we use to power everything. Batteries, even our very best designs, just aren’t that efficient at storing electricity, not when it comes to the scales of powering a whole home or city. If we wanted to power everything off of solar and batteries, we would need *millions* of huge batteries. On top of that, rechargeable batteries degrade over time. Many are only rated for ~1,000 discharge cycles, or in other words, about 3 years of lifetime before they need to be refurbished or replaced, and hopefully recycled. And, batteries, even if they aren’t terribly efficient, are still storing a lot of power, which means that if they fail or break they can be dangerous and start fires.
The problem isn’t really about moving the electricity from place to place, but in the immense expense and environmental impact of building huge numbers of batteries or other power storage options. This means that an ideal power grid would probably use a mixture of options, like solar, wind, tidal, and nuclear power generation alongside substantial batteries in order to provide a consistent stable supply of power all day long.
Because we do not have enough batteries. The global consumption of electricity each day is kind of insane when you think about it. In 2022 the world used 25,500 tera-watt hours. That’s almost 70 tera-watt hours per day. A brand new Tesla Powerwall holds 13.5 kilo-watt hours. You’d need nearly 5.2 billion Powerwalls to store a single day’s power supply, assuming they are all operating at peak capacity.
Batteries also wear out, go bad, and lose capacity over time. It also takes time to ship items across the world. You’d be looking at probably needing 100+ billion Powerwall equivalent batteries to implement your idea, and that’s a conservative number. Taking into account needing batteries in use, in transit to/from, and being charged. You also need back up storages in each location in case a shipment is lost/damaged/delayed. And you need to be making more batteries to expand capacity, not just to replace ones that are no longer useable.
Any environmental benefit you gained from going solar would be offset from the massive mining operations needed to build all the batteries you are using to store the power. And all of the shipping efforts to transport them non-stop globally to feed the world’s power needs.
Say you want to transport batteries from A to B. B requires 10 batteries/day. Transporting them requires 10 batteries one way (assuming you don’t want to use fossil fuel). So you need to construct a vehicle that carries 30 batteries – 10 for the outbound trip, 10 for the return trip and 10 to deliver. On the way back that vehicle carries 10 empty batteries back to A. Meanwhile A has to charge 30 batteries so that it can fuel the return vehicle and resupply B.
The total batteries you’ll need 30 for the truck, 10 at B and 30 at A. A total of 70 batteries just to keep B supplied continuously. And A has to have the ability to charge 30 batteries at a time.
Think about this in global scales. The solar power needs to be 3x of that needed for B and the number of batteries is 7x that B consumes. This is a made up example but is representative of your idea. You can understand why this would likely not work.
It’s worth noting that this is a thing, though it only makes any sense to do locally. Nomad Power basically rents out battery trailers, meant for supplemental power for stadiums and the like. No idea how economical it is, but they definitely aren’t sending th m long distances.
Shipping batteries is far more expensive and loses much energy than transmission lines.
The global electricity consumption is about 3 billion kW, that means we need 3 billion kWh per hour. A typical laptop battery might store something like 0.05 kWh. That means every hour we need to ship 60 billion batteries. If the shipping takes 10 days = 240 hours for a round-trip then we need an inventory of 60 billion * 240 = 14400 billion batteries. Worldwide production is maybe 1 billion per year. You can use other battery types but the problem doesn’t go away. We can’t produce that many batteries, and even if we could it would be far too expensive.
Even if we ignore how to get the batteries: At 50 grams per battery, our batteries have a total weight of 720 million tonnes. We need ~3000 of the largest oil tankers repurposed for battery transport. To match the energy carried by a single oil tanker we need ~40 battery tankers.
With what? Battery powered cargo ships?
Tranfer that energy is not difficult, just expensive. The world works with money and moving around solar energy TODAY is more expensive than a thermal power station using coal for example. Because of infraestructure, logistics and so on. Moving a battery would be even more expensive because of reasons other people already said here.
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