To name a couple, you enable mass desalination and cracking of water. Solve humanity's access to clean water, enable replacement of fossil fuels for vehicles, solve anthropogenic climate change. Just those two are huge.

Isn't it the promise of renewables already? Prices dropping by double digits every year, exponential growth in every market.

Coupled with emerging energy storage it seems like cheap energy is due to come long before fusion

Renewables are expensive to set up and scale (you're gathering smallish amounts of energy from large areas!), but cheap to pull power out of.

Fusion could potentially be extremely compact, extremely energetic, and not _that_ expensive to set up relative to how much power you get out of it. Renewables could make energy _cheap_, but fusion could make it practically _free_.

> Renewables are expensive to set up and scale

They are cheaper to set up at scale, but also work very well in a micro production / distributed environment (albeit slightly more expensive)

I understand your argument about space, you need a lot of space to harness energy, but we're now starting to see deep sea wind turbines, and Earth happen to have quite a bit of windy areas above deep sea.

Just the North sea itself could cover a massive portion of Europe's energy production (double digit)

Right, I'm absolutely not suggesting renewables aren't a great idea, nor that we shouldn't do them, nor that they aren't vastly superior to fossil fuels along basically every access except space (which, as you say, isn't as much of a problem as it might sound)

Just, fusion could be better _still_, if it gets off the ground. That's not a reason to not focus on what we _can _do now, though.

Fair enough!

Renewable energy doesn't have the same amount of energy density.

Fission already beats renewable by a good margin and Fusion puts some on top of that.

The fuel for fusion is incredibly cheap; hydrogen and helium, the most common elements in the universe. Easily obtained from solar wind if we find the amount on earth is lacking.

Additionally, Fusion does not produce any dangerous waste. Any byproducts that are radioactive decay quickly.

Fusion is also a lot safer than Fission since the reaction cannot exist outside reactor conditions while a uranium rod will happily go prompt critical if it gets the chance.

Fusion is cheap energy.

>Fission already beats renewable by a good margin and Fusion puts some on top of that.

This is not true, I don't think people realise how much the renewable prices are currently dropping: https://www.theguardian.com/environment/nils-pratley-on-fina...

I can see the benefit of fusion though I'm not very convinced by the density argument (we do have space to put solar on our roofs, wind on our shores, batteries in our basements and distribution points, and plenty of spots to pump geothermal)

Uranium produces 80,620,000 MJ/kg [Wikipedia], Deuterium produces about 10% more.

I'm not seeing any Solar Panels or Wind Turbines on the market that can output 80 TJ per Kilogram of Weight over their lifetime.

The article you linked talks about Energy Cost, which is another issue. Though considering Hydrogen and Helium are the most abundant resources in the universe, I'm not holding my breath for any renewable resources consistently beating that.

Cost =/= Density, otherwise we'd be powering electric cars with AAA batteries.

>(we do have space to put solar on our roofs, wind on our shores, batteries in our basements and distribution points, and plenty of spots to pump geothermal)

Yes but the point is that fusion requires a lot less space for a lot more power, doesn't depend on the weather or surrounding geology and is 100% clean.

Almost every application cares more about energy cost than energy density. I think only shipping (ocean, air, and space) care about energy density in any significant way, and the first two can fairly trivially use renewable-electrolysed hydrogen. (Space can also use it, but I wouldn’t say it is trivial because nothing about current space access is trivial).

I'm confident that given time Fusion can outpace renewables in energy cost too.

Uranium is somewhat difficult to obtain; you have to mine it from deep under (using what amounts to slave labor), clean the ore and then carefully and thoroughly enrich it (238 is almost unusuable in reactors, you need 235, which is only present in a small fraction of the ore).

On the other hand, getting hydrogen can be achieved with electrolysis (electrolysis requires less energy than the fusion reaction produces), various other chemical processes or simply solar wind.

Hydrogen is the most common material in the universe, it will and can outpace any other energy source.

Renewables are simply different methods for capturing energy from the fusion happening in the sun with some efficiency.

which renewables are truly clean? Wind turbines require so much material and energy to manufacture that they will compensate this only over their whole lifetime. No clue about solar panels.

China is building tons of new coal plants to cover its current needs. It doesn't seem that renewables are that great, when not subsidized (which is the only true measure of effectivity)

I think your numbers may be off for wind turbines. Random googling gives

>for an offshore wind turbine 0.57 years of expected average energy production are necessary to recover all the energy consumed for manufacturing, operation, transport, dismantling and disposal https://www.wind-energy-the-facts.org/energy-balance-analysi...

>China is building tons of new coal plants to cover its current needs

Not so sure about this one: https://www.theguardian.com/environment/2017/mar/22/coal-pow...

Sure they are still building but at a rate that has been drastically shaken up by both the price of renewables and their own environmental policies.

Now regarding the environmental impact of producing solar panels and wind turbines, they clearly are carbon negatives

http://www.drawdown.org/solutions/electricity-generation/roo...

http://www.drawdown.org/solutions/electricity-generation/win...

Though I'm sure they can't have no-impact, you will get some other form of pollution, but at the moment what matters most if reducing our greenhouse effect. It's cheap, it's already there so there's no reason to delay it I think.

If energy is basically free, how will it impact crypto prices?

I believe the proof-of-work calculations automatically become more difficult as more computing power is dedicated to solving them. The net result is that the amount of energy consumed will probably increase inversely proportionally to any reduction in power prices.

Will the concept of money still mater as much if at all if all energy is free?

Let me rephrase - “will anything be scarce if electrity is free?”

The answer to that is obvious: yes. So why wouldn’t we need money?

Agreed, hence "as much". My thoughts were that the main cost of 'stuff' is the energy used in mining or preparing it. If you have free (cheaper) electricity, you don't need oil, metal production has it's biggest cost removed, etc.

Variable costs are eliminated so the amortized fixed cost of hardware is the only ingredient for price.

Basically the price (demand) for hardware goes up and should equilibriate when it reaches the previous cost of energy.