Stagger onward rejoicing

Tag: energy (page 1 of 1)

Metafoundry 75: Resilience, Abundance, Decentralization:

We mostly only close materials loops when it’s ‘economically viable’ to do so. By and large, what that means is that it takes less energy to recycle the material than it does to create it in the first place, which is true for aluminum, steel, and glass, but not for materials like plastics or concrete. But the promise of access to renewable energy is that it changes this equation, putting processes that are intrinsically energy-intensive, like recovering the carbon from plastics for reuse or desalinating seawater to make it potable, on the table. It doesn’t matter how much energy a process needs if it is inexpensive, doesn’t limit the energy available to others for their use, and is non-polluting. There’s a virtuous circle here too: the faster that renewable energy systems are up and running, and the closer we can get to achieving this potential, the more that we can apply that clean energy to repurposing the materials of our current technological systems to build out the physical infrastructures of our new ones. Not beating swords into plowshares, but recycling cars into electric trams. We live on a sun-drenched blue marble hanging in space, and for all that we persist in believing it’s the other way around, that means we have access to finite resources of matter but unlimited energy. We can learn to act accordingly. 

I don’t know anyone smarter than Deb Chachra. Please read the whole letter.  

Elon’s plan

Charlie Stross:

Musk owns Tesla Energy. And I think he’s going to turn a profit on Starship by using it to launch Space based solar power satellites. By my back of the envelope calculation, a Starship can put roughly 5-10MW of space-rate photovoltaic cells into orbit in one shot. ROSA—Roll Out Solar Arrays now installed on the ISS are ridiculously light by historic standards, and flexible: they can be rolled up for launch, then unrolled on orbit. Current ROSA panels have a mass of 325kg and three pairs provide 120kW of power to the ISS: 2 tonnes for 120KW suggests that a 100 tonne Starship payload could produce 6MW using current generation panels, and I suspect a lot of that weight is structural overhead. The PV material used in ROSA reportedly weighs a mere 50 grams per square metre, comparable to lightweight laser printer paper, so a payload of pure PV material could have an area of up to 20 million square metres. At 100 watts of usable sunlight per square metre at Earth’s orbit, that translates to 2GW. So Starship is definitely getting into the payload ball-park we’d need to make orbital SBSP stations practical. 1970s proposals foundered on the costs of the Space Shuttle, which was billed as offering $300/lb launch costs (a sad and pathetic joke), but Musk is selling Starship as a $2M/launch system, which works out at $20/kg.

So: disruptive launch system meets disruptive power technology, and if Tesla Energy isn’t currently brainstorming how to build lightweight space-rated PV sheeting in gigawatt-up quantities I’ll eat my hat.