Seret

The point is that there's not enough money in the pot to replace the current roads, so there certainly wouldn't be enough to replace them and pony up for a whole lot of gucci PV arrays on top. The problem seems to be that America is big, and Americans have paved over more of it than they can now afford to maintain. But yes, if you could just take the road budget and instead spend it on sensibly sited and emplaced solar arrays you would indeed generate more power than a solar roadway. That's not really the point though. Presumably only when weather conditions demand. There's no intention to power this from solar energy, insolation during winter is too low for that anyway as you correctly point out. I'm inclined to agree, I think the integrated lighting is somewhat superfluous. But the idea is worth investigating even without it. The practicality of a solar roadway will depend on whether they can solve the materials and integration challenges at the right price. The integrated lighting feature is just a sideshow IMO. If it works, great. If not, who cares? Dropping it would just make the panels simpler and cheaper.

I wouldn't take what's written there as gospel. The section about stealth in particular seems rather flawed due to the fact that it assumes (without any justification) that the vehicles would be manned.

Some of his points are perfectly correct, but some of it is also nonsense. His initial point about the LEDs is particularly silly, as is his "experiment" where he uses an ordinary glass bottle to prove that glass couldn't be engineered to the required spec. It's like using the fact that you can bend a teaspoon to prove that steel is unsuitable for building skyscrapers. I'm still not convinced that the idea will result in a practical product, but the backlash against it has been somewhat shrill and incoherent too. That probably not helped by the shrill and incoherent tone of the viral "Solar freakin roadways" video produced by a fan of the technology.

Yes, but the whole point of the project is that the roads need replacing anyway. In the US there seems to be a bit of a funding crisis to get this done, so the idea is to resurface them with something that generates income, instead of just being a cost. Conventional roads are surprisingly expensive. Yes. The best performance comes from tracking the sun directly, although fixed panels inclined at an angle are generally more cost-effective. Shading is bad for solar arrays, although less of a problem if you use microinverters. The roads have to be kept clear anyway. Heating is a solution used in some places already (some of the Nordic states use it IMO, presumably tied into their district heating systems and using waste heat from power plants). Tbh it just seems like bling to me, although it could be handy to have road markings that could be controlled externally. Variable speed limits could be shown, weather and traffic warnings, etc. In short all the stuff you'd normally use a separate sign at the side of the road. Too early to say, it's still in R&D. The inventor doesn't even have a unit cost yet, let alone the lifecycle costs. Indeed. It needs multi-year test under real road conditions to get an idea of output over time. They're engineered to give good traction, this isn't a biggy IMO. If they didn't provide a tractive surface at least equal to current roads they wouldn't be fit for purpose. Obviously they'd have to pass the kind of safety tests regulators would impose on any new road surface material.

Somewhat less, ideally you want to incline them towards the horizon.

Pros: Microgeneration of clean electricity at a local level. Already co-located with support infrastructure. Generates an income. Integrates heating for cold climates. Integrates signalling or marking into road surface. Cons: High upfront cost. Reliability is unproven. Safety under real traffic conditions is unproven. Many roads are not ideally oriented for solar generation, especially in city centres with shading issues. Not clear if they'll be available from more than one supplier (what parts of the design are protected?). The panels are flat, which could be an issue for drainage and camber. I'm sure there's more of both, but those are the ones that leap to my mind.

Ah, that'll be because of the conspiracy. *TV infomercial mode* Got no proof of your crackpot idea? Just invent a conspiracy and the need for proof vanishes like magic! And as a bonus, if anything comes up that actually disproves your beliefs, just expand the conspiracy to include the source of the information!

It's from their FAQ. They're not entirely wrong. Over short distances and low current DC would be fine. If we really did have a shedload of DC microgeneration down at local level in the grid it would be worth looking at. Somewhat putting the cart before the horse for them to suggest it though. Classic suggestion from an engineer looking at things from a purely efficiency-based optimisation perspective and missing the big picture. Not only would we have to replace the whole grid after the last transformer, people would have to replace all their devices. No thanks. This solar roadways thing is just one guy's personal project, so a bit of idiosyncrasy is to be expected.

It may well have been, but the effectiveness of any integrated LED lighting doesn't either invalidate or validate the idea of solar a roadway. What isn't clear from their promotional material is what type of inverters they're using. Do the panels have microinverters or are they wired into strings with inverters at the roadside? They're suggesting on their site that we should be using more DC loads, but that's somewhat beside the point. If existing grids are AC their roadway will need to be an AC output.

Thereabouts. Night vision is affected more than day vision, you'll lose some even well under that altitude without oxygen.

It's a bit of a misrepresentation to use the Turing test for this. Chatbots aren't a good candidate for genuine intelligence, they're just a big database that's picking what to say based on previous experience holding conversations. They're essentially designed to game the Turing Test. It's an example of a good chatbot, not good AI.

Whether the solar road panels include LED lighting or not isn't really relevant to their main role. There job is to do two things: provide a safe and reliable driving surface and generate electricity. Integrated lighting is a "nice to have", but not essential. Not including them would in fact simplify the panels a fair bit, as you wouldn't need to be able to control them remotely. Personally I think it's too early to say whether it's a good idea. It's worth testing so that we can get some numbers on how much it would cost both up-front and ongoing, and to find out how practical they are. Personally I suspect that the high up-front costs would put a lot of people off, even if they turned out to be easier to maintain than current roads. I wish them luck, but they've got an uphill battle.

IIRC BMW switched directly from making aircraft to motorcycles after the Treaty of Versailles. Their logo is an aircraft propeller seen from the front.

All-electric is actually a pretty orthodox vision for our future energy systems, and doesn't necessitate space-based power stations.

At first I thought this was a dumb thread, but it's not a bad discipline to reality-check your ideas with a real experiment even if you're confident how it'll turn out.

ALM would be difficult in zero-g, but definitely worth investigating. You need to use a lot of things that would be troublesome without gravity, such as powdered metals. Obviously you don't want a powdered conductor loose in your environment. However the ability to manufacture non-critical parts out of ali or steel would be very useful. Even one of the nasty plastic extruders could be handy. People do seem to forget that you can only make a subset of parts using ALM. It's not a magic box that can produce anything, and it's often not the best way to make things.

Do you play Dwarf Fortress? That lot seem to have a similarly cheerful attitude to failure.

Sure, is that a problem? Indeed, you've identified the main risk I think. Large multi-national organisations like the UN are indeed difficult to govern, but I think we have to admit that step-change in space exploration is an endeavour that is simply too large and expensive to be pursued effectively by individual states. Only the very richest have the resources to do anything effective. By pooling resources from a wider group we'd end up with more in the pot. I'm sure relatively affluent countries like Australia and Korea would love to be able to take part in a well-funded space programme, and they'd be able to compete for lucrative high-tech contracts.

Probably not from the thermal energy of humans stored in tanks.

I think no. The idea that a private company with no space experience and no governmental backing can fund and operate a space mission more expensive, complicated and longer than anything ever attempted is ludicrous. The 2020s will be here before you know it, and things will look very much the same as they do now.

There are plenty of examples of effective multi-national cooperation in spaceflight. I actually think a permanent international space agency would be a great idea.

Contemporary man can do without computers, but contemporary society, no. And tbh, why would we want to? They make everything work better. Sure, big computer systems crashing can be inconvenient, but things like non-computerised traffic light systems can fail too, and on balance it's worth it.

Trams used to be a lot more common in the mid-20th century, but they're making something of a comeback. Modern ones are able to function as light rail too, where they run at good speed between towns (often on elevated tracks) then enter the towns and travel on the streets.

What's the big deal with a manned mission to Mars anyway? We're doing a fine job exploring robotically, and there's little payoff from going there and planting a flag until we're able to start a permanent settlement. That requires numerous intermediate hurdles we've yet to clear. We need to be focussed on cheaper access orbit, better propulsion and closed loop life support before manned missions to Mars become practical or desirable. If I was in charge the manned exploration programme would be focussed on successor stations to the ISS and a base on the moon as a test-bed. We could go to Mars within a couple of decades if we wanted, but we'd get a lot more from it if we put it off until we had more suitable technologies. It's just too soon for boots on Mars, and it shows in the pricetag.

Directors of large companies do have a responsibility to show a return on investment for their shareholders or investors. That's their business model. The amount of non-productive work they engage in is going to be very limited, unless they can spin it as having significant PR value. Private companies do engage in exploration and science work, but only because they're contracted to. You're not going to see private enterprises launching their own exploration missions unless they see a commercial reason to do so. There's no reason science packages can't piggyback on commercial missions though. Big organisations like NASA are already a hybrid of public and private. NASA couldn't get anything done without all the contractors that actually build their hardware.