'Pavement power' - The bad idea that never seems to die

We've said it before, but because “walk on this pavement for renewable energy” remains a recurrent news story, it's worth saying again. You can't get a useful amount of energy that way: it's a gimmick. The latest iteration comes from Las Vegas, which according to the Las Vegas Review-Journal is installing street lights from …

[Anonymous Coward]

To be fair, wind and solar are gimmicks too.

[wolfetone]

Be quiet Mr.Trump!

[RIBrsiq]

>> To be fair, wind and solar are gimmicks too.

It's not possible to run an economy based solely on them, yes. But that's a far cry from it not being possible to run anything useful based on them.

So, no; you're not being fair.

[Anonymous Coward]

I would say he was absolutely fair for two reasons.

1) as you said they are incapable of supplying base load.

2) they all require government subsidies to even look as if they are economically viable.

[Olius]

Have you ever looked in to how much govt subsidy the fossil fuel energy sector gets?

[Anonymous Coward]

Yes. They get none. Stop reading the Graun.

[Olius]

They get plenty.

Here, enjoy: http://priceofoil.org/content/uploads/2014/07/OCI_US_FF_Subsidies_Final_Screen.pdf

[RIBrsiq]

>> they all require government subsidies to even look as if they are economically viable.

I was not talking theory, you know.

We have a PV system running, at work. No subsidies whatsoever. It cut down the electricity bill by about 90%, so accounting are purring like kittens. And it's very economically viable, considering that a system with a projected lifespan of 25 years should have paid for itself in 3, even taking into account expected drops in efficiency.

I guess it all depends on who is trying to achieve what and where they're doing it.

That said, it is important to be sane and conservative about things and not promise undeliverable miracles to people who do not know, nor care about the details.

It's clear that a sustainable overall solution would have to be based primarily on nuclear and augmented, where possible, with renewables as the specific environment where the deployment is taking place allows -- I live in a place that's much sunnier than the UK and most of the EU, for example; hence, PV works great, here. So selling a dream of a system that's primarily based on renewable energy while simultaneously feeding the unreasonable fear of nuclear is, IMO, almost criminal.

[CustardGannet]

"It's clear that a sustainable overall solution would have to be based primarily on nuclear"

I keep telling people that the *only* solution is to take off and nuke the entire planet from space, but do they listen to me ? "Take your meds", they say. "Stop struggling or I'll call the doctor." Pfffft.

[Anonymous Coward]

I live in a place that's much sunnier than the UK and most of the EU

And that's dandy. In parts of the world where sunshine is plentiful and reliable, then PV's a great idea. Even more so when peak solar output is closely correlated with peak demand. Throw in some battery storage and you can really be cooking on sun.

But in the context of the UK energy system that doesn't help. Our peak demand is the coldest winter days after dark. During winter capacity factor on solar is about 5% (less on cloudy days or if there's snow). So for the UK government to subsidise PV at the ridiculous rates that it did in recent years was madness. All that it achieved was to take demand away from thermal plant, without obviating the need for the thermal plant for those cold. windless winter days and nights. As a consequence the utilisation of thermal plant fell, efficiency fell as well (so offsetting a fair bit of the claimed benefits of the PV) and government had to introduce subsidies to keep thermal plant available.

UK energy policy has left nothing to chance in ensuring that the end user pays the highest possible price for energy. Networks have been required to spend billions on connecting new "renewable" plant with a guaranteed return, wind turbines have been subsidised and mandated, solar PV has been heavily subsidised, new nuclear is getting a big fat subsidy, new interconnectors will be subsidised by regulated returns, biomass plants have had big fat subsidies under various schemes, thermal plant, nuclear and interconnectors all get "capacity market" payments. To make up for a broken and disfunctional welfare system, government throw a £1.5bn at Winter Fuel Bribes for pensioners, energy companies are required to throw in about £500m to a similar scheme (Warm Homes Discount), and then a further £700m to energy efficiency measures for customers. And even that list is only the big ticket stuff - below that there's vast amounts of subsidies and transfers on all manner of other rubbish.

It is a huge, huge mess.

[ma1010]

Which goes to show..

That there's no situation that's so bad on its own that government intervention can't make it much worse.

[Alan Brown]

"In parts of the world where sunshine is plentiful and reliable, then PV's a great idea. "

In parts of the world where sunshine is plentiful and reliable, solar hot water systems are a much better idea. You can use them to drive Solarfrost cycle cooling systems (modified low-temperature ammonia pumps) and as it gets hotter you get more cooling.

It can even drive freezing systems (solarfrost will go to -30C for 60C input) and stirling motors for water pumping or circulating fans.

Low tech, low maintenance, more efficient overall than converting to electricity and then driving AC with it - the PV systems can be downsized enough to provide for lighting/entertainment systems.

Suitable building desig, solar chimneys and awnings are also a lot better than trying to bruteforce the cooling using AC.

[Anonymous Coward]

In parts of the world where sunshine is plentiful and reliable, solar hot water systems are a much better idea. You can use them to drive Solarfrost cycle cooling systems (modified low-temperature ammonia pumps) and as it gets hotter you get more cooling.

Maybe, but I'm sceptical that these can be made economic. Technologically, little or no problem that can't be overcome. But I work for an energy company with world class expertise in power-to-gas, methanation, CAES, pumped storage, district heating, district cooling, battery storage, heat storage, power-to-heat on district heating systems, solar thermal assisted district heat etc. And the one thing we've learned is that multi-stage systems are resolvable technology problems, and usually unresolvable economic problems.

Throw more subsidies and we'll build anything, but half the problem is that these are trying to address the system problems of ineffectual renewables. At the core of that is idiot politicians failure to understand that for an energy system to work, capacity must be despatchable - which should have meant renewables having to buy the capacity to back up any down time ideally against an average system load profile.

However, we are where we are. And in the case of UK or European energy policies, our location on the map is some place called "Screwed".

[RIBrsiq]

>> But in the context of the UK energy system that doesn't help.

Well, that's not a failure of solar technology, is it? It's a failure of whoever is trying to implement it.

Nothing is a one-size-fits-all.

I mean, if we tried to use, say, tidal generation in this practically-land-locked-desert right here, how well would you expect it to work? And would it not working be at all an indication of how well it would work if properly implemented off of the shores of an island?

[JDX]

re: for the UK government to subsidise PV at the ridiculous rates ... was madness

I don't think you understand. New technology is more expensive so it requires backing to get people to bother - companies will invest seeing the long-term profits but individual people don't have that resource.

The government uses taxes and subsidies as a kind of crude steering because ultimately the market responds to what makes money. Tax things you don't like, subsidise things you do.

[Alan Brown]

"We have a PV system running, at work. No subsidies whatsoever. It cut down the electricity bill by about 90%, so accounting are purring like kittens. And it's very economically viable, considering that a system with a projected lifespan of 25 years should have paid for itself in 3, even taking into account expected drops in efficiency."

How big was the grant (subsidy) you got to install it?

What value is the feedin tarriff you're getting?

I've seen feedin rates up to 45p/kWh being bandied about. As my electricity costs 14p/kWh, it's clear that your feedin is being paid for by consumers.

And if you honestly expect to get 25 years out of a solar PV installation I have a couple of bridges I'd like to sell you. It'll be down to 50% capacity in 8-9 and half that again by year 16, if the inverters haven't blown by then or some other silicon failure knocked it out.

[RIBrsiq]

>> How big was the grant (subsidy) you got to install it?

Nothing. Fully funded by a bank loan that's being paid back by the savings on the electricity bills.

>> What value is the feedin tarriff you're getting?

About half of what we pay. But that's practically irrelevant as it's an on-grid setup such that the theoretical maximum we can get is to pay nothing, averaged over a year. As they say; in theory, there's no difference between theory and practice. But in practice, we still pay!

>> And if you honestly expect to get 25 years out of a solar PV installation I have a couple of bridges I'd like to sell you. It'll be down to 50% capacity in 8-9 and half that again by year 16, if the inverters haven't blown by then or some other silicon failure knocked it out.

Well, I'm a simple physics major who does IT for a living, so what do I know...? But the contractual warranty on the inverters and panels is 10 years. And the warranty on the panels includes an efficiency of 80% after 10 years; so I guess we get new panels, if what you're saying is true! In any case, everything breaks down, and I cannot see the fundamental difference that will make solar tech fail more than fossil fuel; or nuclear, for that matter. If anything, I would think that having fewer moving parts will make solar last longer, all things being equal.

[Alan Brown]

"It's clear that a sustainable overall solution would have to be based primarily on nuclear and augmented, where possible, with renewables as the specific environment where the deployment is taking place allows"

LFTRs and other molten salt nukes can load follow and are _much_ cheaper than renewables once deployed. They can provide "peaking capacity" when renewables drop out, but that's also knowin as load following and because they're way cheaper than wind/solar, renewables are an expensive pain in the ass that will rapidly be kicked off the grid.

Conventional nukes can't load follow, so you need fast "peaking capacity" - inefficient open cycle generation - to fill the gaps when solar or wind drop out. Renewables suppliers get preferential power rates and are not required to pay for the upkeep or operation of these backup systems, or the grid overlays required to handle large unpredictable power flows that weren't in the original designs.

Either way, greenwashs system will end up as monuments to folly. They can't provide anywhere near close to enough electricity to allow us to replace carbon emissions (demand will rise by a factor of 6-8 over current baseload. Renewables - at best - could just match current baseload.)

[Anonymous Coward]

Don't worry, the Chinese are hoping to have LFTR commercialized by 2040. At least it'll be ready before fusion.

[Anonymous Coward]

I recall a story on here several years ago where the current head of greenpeace said that even if humanity finally cracks safe usable nuclear fusion, then we can't use it because mumble mumble nuclear!

So presumably, if all forms of power generation from a fusion reaction are a no go, then we have to rip down all the solar panels.

[Anonymous Coward]

Mumble Mumble Nuclear

"if all forms of power generation from a fusion reaction are a no go, then we have to rip down all the solar panels."

And outlaw photosynthesis. Hell, lets just build that wall a little higher and block the sun.

[Pompous Git]

And it's very economically viable, considering that a system with a projected lifespan of 25 years should have paid for itself in 3, even taking into account expected drops in efficiency.

I'd love to see the numbers. When the Australian government were heavily subsidising solar PV I came up with 18 years to pay for the investment. Australian consumer magazine Choice came up with 16 years, but didn't specify the exact location. Where I live there's lots of sunshine hours. Only Perth in Western Australia have more. Likely Choice were basing their figures on Melbourne, or Sydney.

The seller's estimated cost savings required the array to supply 140% of its rated output. They never responded to my questions. The estimated costings were based on excess energy being paid for at better than retail price per KW/hr. Feed-in tariff is now at wholesale electricity prices so I wouldn't be surprised if the time to repay the investment now exceeds the anticipated life of the installation.

[Lotaresco]

"We have a PV system running, at work. No subsidies whatsoever."

I find that very difficult to believe. Are you claiming that the company has forgone the FIT and is selling the electricity generated at the current unsubsidised wholesale price of 3.8p/kWH? I can't see your bean counters being very happy with that.

[Anonymous Coward]

Well, fair and fair.

Green power is at the moment generating 11.4% of our (the UK's) electricity, which sounds great, Until you look closely.

We have 8GW of wind generating capacity installed in the UK. It's has never, ever actually generated that amount of power. It's currently generating 2.88GW, which is a weekly high. This out of a total demand of 42.36GW. The next largest "green" supply of power is Biomass, which is currently generating 2GW minus a fraction of a decimal point. Biomass is Drax 2 & Ironbridge 1 & 2 which are coal plants converted to burn wood. These then gain access to "green" subsidies payments, despite being the single largest CO2 sources in Europe. Green subsidies literally go to chop down trees to burn.

Green energy excluding EVIL (CO2 free) nuclear = 4.8GW. (Wind, 2.8GW, Biomass/Timber burning releasing tons of CO2, 2GW.)

Nuclear (not Green energy because OMG CHERNOBYL!!! despite no CO2 emissions) = 8.4GW, (or 10.4GW, if we count the 2GW of French imports which come from their nuclear program.)

Gas (the non green CO2 belching "backup" to wind power) = 20.3GW.

* All figures correct at time of writing, and viewable live at "gridwatch.templar.co.uk"

So, the green drive to reduce emissions has reduced emissions by under 5% (unless we are going to argue burning trees is green/zero emissions) and resulted in green taxes of 15%, plus the additional costs from the national grid to upgrade their systems to deal with unpredictable surges and shortfalls from wind, plus additional costs from feed in payments to the rich who can afford their own houses and solar panels to go on the roofs.

Since there is not and is unlikely to ever be enough power fed in from home solar panels to shut down a gas plant, home feed in tariffs simply means that the electricity company has to pay for electricity twice. When somebody with the solar panels on their roof gets paid and their bills go down, what then happens to everybody elses bills? Yeah, they go up to compensate.

Current green policy literally taxes the poor to pay the rich, while delivering virtually no additional usable electricity we didn't have before these policies came along, and is actively paying to chop down trees to burn. These anti progressive and anti environmental policies are morally, logically and environmentally unjustifiable.

That said, the typical way of defending the indefensible is to label anybody who points out the hypocrisy as being a thought criminal (sorry, flat earther, ignorant or something similar) which admittedly has worked in a fashion, but now that middle ground opposition is in hiding or radicalised the opposition largely is from Trump et al who really, really don't care what you call them.

Contrary comments welcome. If you don't have any coherent argument against this yet want to vent your rage then consider a downvote. ;)

[Jez Burns]

Don't forget that the 6 million+ tonnes of soil nutrient-depleting chomped up trees (2014 figures) need to be shipped over from the US to feed Drax alone. Assuming a load of 45,000 tonnes per shipment, that's 133 transatlantic trips, burning ~200,000 gallons of heavy oil each way: 1675342 tonnes of oil burned to feed one power station in a year. Of course, coal ships will burn the same fuel, but as you'd need to ferry almost double the quantity of woodchip to achieve the same energy output as coal, it seems likely that transport of the stuff alone negates any benefits of burning it in terms of emissions - not just the widely hyped gaseous plant fertilizer, but the nasty particulate stuff that clogs up your lungs.

Obviously the people running this scheme will know perfectly well how wasteful and environmentally damaging it is. So what's the point in doing it? Renewable subsidies - eye watering sums of money for the great and the good and all their pals, all doing their bit to save the world, of course..

https://jenny4mp.wordpress.com/2016/10/27/greenwashing-drax-plenty-of-public-money-for-corporate-welfare/

[Anonymous Coward]

Don't forget that the 6 million+ tonnes of soil nutrient-depleting chomped up trees (2014 figures) need to be shipped over from the US to feed Drax alone.

The recent fall in the exchange rate will kill the economics of Drax. IIRC from their published data, they have a series of currency hedges that'll protect them for about a year to eighteen months, but after that they simply won't be paid enough for wholesale electricity to make a net profit.

In the real world they'd go bust, but because of the huge and ongoing fiasco that is UK energy policy, government will be forced to find some way of keeping Drax open. With no reserve margin to speak of, they need the capacity to stay available, and that will mean some cludge to give Drax plc more money. Or they'll hope for a jumbo sized pre-pack insolvency, where a mate of one of the senior creditors can buy the assets on the cheap, and with all the previous equity and junior debt wiped out, they'll in theory be able to run the plant profitably.

[katrinab]

Or electricity bills will increase, just like everything else. Gas powered stations have the same problem, as even if the gas comes from the North Sea, it is paid for in US$.

[Alan Brown]

Biomass/Timber burning releasing tons of CO2, 2GW

Much more tons of CO2 than you realise.

Drax is fed by clearfelling old-growth north american forests (using oil) and the clearcut land releases a shitload of CO2. It's then chipped (using oil) and transported to the power station (using oil).

The process uses more oil than would be consumed by directly generating electricity with the stuff.

The environmental effects of the clearfelling are a disaster all by themselves.

Can you say Greenwash?

[Poncey McPonceface]

This is shocking stuff. How is all this not taken into consideration when the CO2 output of this method is calculated? Even on paper (recycled, don't you worry!) it sounds stupid. Cut down trees from across an ocean?! Madness. That's literally one of the most moronic things I've heard in a long time. Not being a native Brit I just had a nice little read of https://en.wikipedia.org/wiki/Drax_power_station and boy the stats are troubling.

“The environmental effects of coal burning are well documented. Coal is considered to be "easily the most carbon-intensive and polluting form of energy generation available".[103] In 2007 the station produced 22,160,000 tonnes of CO2, making it the largest single source of CO2 in the UK.[47][104] Between 2000 and 2007, there has been a net increase in carbon dioxide CO2 of over 3,000,000 tonnes.[47] The station also has the highest estimated emissions of nitrogen oxides (NOx) in the European Union.[105]”

“Drax's annual report for 2013 reported that Drax's annual emissions were at 20,612,000 tonnes of CO2. This was a slight decrease from 2007 levels due to the burning of biomass.[107] Drax still remains the UK's largest single source of emissions.[citation needed][clarification needed]”

Both coal and biomass are largely imported! Close this thing down and build a nuke plant. If people were *really* that concerned about the environment this thing could never continue operating.

Currently 13 nuke plants are being built in China: https://en.wikipedia.org/wiki/Nuclear_power_in_China#Nuclear_power_plants_under_construction

I know China is a lot bigger energy consumption-wise, ranking 1st in the world versus 12th for the UK but still: https://www.cia.gov/library/publications/the-world-factbook/rankorder/2233rank.html

I'm no bleeding heart environmentalist and I get that the fuel of a power plant often has to be transported to it. The fuel source that Drax was built to consume is spent. The plant was started in '74, completed in '86, started co-firing biomass in 2010 -- I reckon it's had a good innings. Once you start burning trees felled an ocean-ride away you gotta rethink your existence I reckon. I honestly can't believe it, aren't we meant to be chopping trees down to pulp into paper, not to pelletize them for burning.

[John Brown (no body)]

"Nuclear (not Green energy because OMG CHERNOBYL!!! despite no CO2 emissions) = 8.4GW, (or 10.4GW, if we count the 2GW of French imports which come from their nuclear program.)"

FWIW, the other day the French issued a warning that due to some nuclear being offline for various reasons, they have to import power. Some of that is coming from the UK. The UK barely has the capacity to cover a cold day. And the French don't currently have any spare.

[Alan Brown]

"It's not possible to run an economy based solely on them, yes. "

And it's a bloody expensive distraction from investing in the technologies which can.

If all the money invested in solar/wind R&D went into LFTR, we'd have working commercial examples by now. As it is, if/when LFTR rolls out, those windmills and PVs will be expensive nuisances (unlike conventional nukes LFTR can load follow, but it's a _lot_ cheaper per Wh than conventional nukes, let alone solar or wind, as the cleanup costs are far lower than conventional nukes)

[Anonymous Coward]

> To be fair, wind and solar are gimmicks too.

Better tell that to Costa Rica.

[Pompous Git]

Better tell that to Costa Rica.

Why? They don't derive their energy from solar and wind. They derive it from hydro and geothermal.

[Lotaresco]

Pavement power

It all seemed to work so well for Michael Jackson.

[Mark 85]

In this case, I daresay PT was right about "fools" and "money" and also the one "born every minute". They must have had one hell of a sales pitch and maybe a 20 martini lunch when they pitched this.

Icon... because the city got boarded and looted.

[Pascal Monett]

Let's not complain too much : now there will be a real-life example of the tech. In a year or so, we'll be able to ask : so, how's those pads working at the generating energy part ? What are the exact figures ?

One way or another, those figures will be published, then compared to the amount of energy required.

Then we'll be able to have a hearty guffaw and that will be the end of it.

Because the only reason we're still hearing about this nonsense is that nobody is publishing actual figures, everything is just marketing. If we could harness marketing energy, we'd already be exploring the stars.

[Filippo]

We'll be able to ask for the exact figures, at which point the marketing guys will tell us the yearly energy total and word the answer in such a way that it sounds like it's daily. Or they'll say that the pads were wrongly installed. Or they'll give the total energy produced since installation in watts, so that it sounds like a big number, and fail to mention it as a percentage of total streetlight consumption. Or they'll give the numbers from the single busiest square meter and try to pass it as the average. Or a combination of the above. If you criticize them, they can lay down some astroturf claiming you're working for the great petrol conspiracy.

You and me won't be fooled, but the average guy who has trouble doing two-digits products and thinks vaccines cause autism will, easily - and then they just need to find one who's administrating a large city.

If all else fails, they'll obliquely admit it doesn't work, but then they'll say they have "Version 2.0" in the works, and that it will be 120% more efficient (and fail to mention that efficiency isn't the issue when the energy just isn't there).

Cold hard facts are not enough to defeat good marketing.

[Anonymous Coward]

Or more simple, the vendor will have the city under an NDA so the numbers can't be disclosed.

[sandman]

"You're not treading on it right".

[Anonymous Coward]

> Cold hard facts are not enough to defeat good marketing.

Just to be fair to GOOD marketers, and there are a few out there, they do not need and won't resort to lies. Yours is not an example of good marketing, it is an example of bad and aggressive marketing, which is sadly very common.

[AndyS]

> now there will be a real-life example of the tech.

I was in an airport that had this recently (I think it was Lyon or Heathrow, can't remember which). There was a short corridor with some colourful LEDs on the walls, a big sign announcing what was going on, and the floor was squishy and slightly annoying to walk on, a bit like wet sand.

Also, the normal, overhead fluorescent lights still illuminated the area.

[Linker3000]

Ditto

It's at LHR and I came here to post exactly that comment about how unnerving it was to walk on. Any energy cost savings will be wiped out by the NHS expenditure for ltreating lower-back and leg joint problems.

[Captain DaFt]

"and the floor was squishy and slightly annoying to walk on, a bit like wet sand."

And there's the big gap between marketing and reality right there.

After having to slog over an energy sapping sidewalk just once, how many are going to avoid it by taking another route, or just saying "Fuck it, it's only two blocks, but we'll drive, it's easier!"

[Anonymous Coward]

This is the US. People will drive 2 blocks to start with. I was once on holiday in Orlando and went into a restaurant to book a table for later that evening. They asked when I wanted the courtesy car to pick me up from the hotel. I pointed out that I was just over the road about 50m down and would walk.They looked at me as though I had suddenly grown an extra head.

[herman]

Man, it is Orlando! If you walk, you can get mugged or run over by a taxi. That is why they offered the courtesy car.

[Adam 1]

It's also a fundamental misunderstanding of where the said energy is coming from. It does not produce energy. It consumes some of the energy that would normally be returned to the walker. This should make walking more difficult (in the same way that walking through dry sand is more difficult than walking along the wet sand at the shoreline). If walking isn't noticeably more difficult then the power extracted is pretty laughable. Basically you are using the human body as a power generator. Putting aside for the minute that some of us really should be expending a few more KJ or moderating our intake, the efficiency question becomes about how efficient a human is at generating that energy and whether it would be more environmentally friendly to burn coal (almost certainly).

There may well be some applications where you don't need much energy, where running power specifically is a PITA where this may work (eg doorbell or keyfob that gets just enough energy from the button press to broadcast its signal) but it isn't chances are against watch batteries not coal, gas, nuke, solar, wind, hydro.

[Anonymous Coward]

> this may work (eg doorbell or keyfob that gets just enough energy from the button press to broadcast its signal)

Don't go running to the patent office with that idea.

[Ole Juul]

quantity

It's a common omission. We see it in health, be it diet or adverse radiation. Many people seem to see the world in terms of some or none, ignoring the fact that very little is of no consequence.

[David 132]

Thank you...

...for pointing out the vapidity of this idea.

To me, "energy-harvesting pavement" is the real-world equivalent of The Simpsons' Monorail, and it looks like Vegas is the latest (sadly, not the last) place to get taken in by its huckster salesmen.

[Prst. V.Jeltz]

Re: Thank you...

How the hell did vegas get taken in ? they must have a VERY good idea how much energy it takes to light a lightbulb.

[Anonymous Coward]

Re: Thank you...

"How the hell did vegas get taken in ?"

Same question I asked. Last I heard, there aren't any suckers in Vegas.

Well, maybe a lot of people that are really bad at math and critical thinking.

But that's not the same thing, really.

[find users who cut cat tail]

> each footfall can generate between 4W and 8W

Stopped reading here. A footfall can generate some energy, i.e. some Joules. Watts are units of power, i.e. energy per time, so it is meaningless to assign Watts to one footfall.

[Anonymous Coward]

Actually the article does talk about energy as well as power, but confusingly refers to "Watt seconds" rather than Joules. I suppose this is because home energy consumption is traditionally measured in kWh rather than MJ.

[Anonymous Coward]

If you'd bothered to RTFA, you would have realised that this was the entire point of said.

[find users who cut cat tail]

I did not bother. If the statement was followed with `but that is obvious bullshit' I would continue reading. But there was actually another paragraph before the article started to correct the statements (in a convoluted way). Sorry, seeing such bullshit and no correction in sight I just stop reading.

[Doctor Syntax]

"Sorry, seeing such bullshit and no correction in sight I just stop reading."

Unfortunately it didn't stop you commenting.

[Graham Dawson]

So you blame the article for your inability to pay attention for more than one or two sentences?

No wonder twitter caught on so readily...

[Tom Womack]

A competing manufacturer of annoying squishy expensive pavements says '5W continuous', so I think that particular problem is just a matter of a badly-written press release.

The problem is that a 5W generator produces £5.70 of electricity a year at retail price, and it seems wildly unlikely that the maintenance of the annoying squishy pavement, let alone the interest on a loan to cover the install price, is of that order of magnitude.

[frank ly]

This modern world

"... have access to both Microsoft Excel and Google Docs could have run the same calculation."

Some of us have access to a pencil and a scrap of paper which does the job much quicker.

[Anonymous Coward]

Re: This modern world

The 'back of an envelope' calculation is always a good place to start.

[roytrubshaw]

Re: This modern world

"The 'back of an envelope' calculation is always a good place to start."

To paraphrase Randall Munroe "any number you can write down basically rounds to zero" so pretty much all your calculations will end up that way!

[Anonymous Coward]

The Jackboots are going on

all over Europe, the US and the rest of the world.

[Phil.T.Tipp]

Re: The Jackboots are going on

@AC - WTF did that mean? The 'Jackboots' haven't gone on since early 1945.

[Will Godfrey]

Still waiting

For the first elderly person to stumble and end up with a broken hip because of one of these. As you get older your sense of balance is already less secure, so something moving underfoot (even if only a tiny amount) is a serious risk.

Hope they've got good insurance cover.

[Joe Werner]

Re: Still waiting

Have you ever heard of the piezoelectric effect? No moving parts inside (well, on the lattice scale...). I'd probably start there.

I'm not saying that the charging stuff works, nor have I looked at their spec sheet - I'll get my lab coat and do some actual work now...

[David Shaw]

Re: Still waiting

there are some in-building ideas for the future for piezo, it helps the 'fix-and-forget' sensor node models for smart-buildings/smart-components, building on DECT-ULE or 802.15.4 at around the ten-packets-per-hour rate. No more running out and buying 3700 'AAA' or was it 3700 'R-14's', to keep the HAECS (home automation, energy control and security) systems on-line.

one study thought that tidal nation land-mass tilt/deformations might even provide enough to power the soon to be ubiquitous sensor nodes . . .?

[Dave 126]

Re: Still waiting

There is a wireless doorbell button on the market that harvests all its energy from the movement of its button being pushed. Of course the receiving unit still requires batteries or wired electricity, but the latter is easier to wire up inside the house.

Small amounts of electricity can be very useful for remote sensors etc.

[Anonymous Coward]

Re: Still waiting

That's why the elderly famously have no carpets. No, wait...

[Richard Scratcher]

Re: Still waiting - @Will Godfrey

Yeah... but think of the energy released by a stumbling pensioner. Then add to that the energy of passers by rushing to help... stretcher-bearing paramedics...

[Anonymous Coward]

I never thought I'd see something dumber than solar roadways

[dervheid]

Combine the two

Think of all the traffic on the M25, squeezing down on 117 miles of roads almost constantly.

You should be able to recharge an entire fleet of electric busses for central London.

Or not.

[Gary Moore's Plectrum]

Re: Combine the two

In fact, very few people on the face of the planet know that the very shape of the M25 forms the sigil *odegra* in the language of the Black Priesthood of Ancient Mu, and means 'Hail the Great Beast, Devourer of Worlds'. The thousands of motorists who daily fume their way around its serpentine lengths have the same effect as water on a prayer wheel, grinding out an endless fog of low-grade evil to pollute the metaphysical atmosphere for scores of miles around.

[Anonymous Coward]

Re: Combine the two

My dog's the one with an inside out ear.

[Patrician]

Re: Combine the two

Bad Omens?

[Prst. V.Jeltz]

On the subject of energy harvesting I'm still waiting to see a Gym where all the little hamster wheels are connected to generators so that all the little gym rats are doing something useful with their efforts rather than just getting hot n sweaty and paying £50 per month for it.

Even if it didnt provide much energy it would provide a stark reminder of exactly how much energy we throw away in the course of normal life .

(If you measured energy in "Gym full of people on treadmills / hour" rather than kw/h )

[Chris G]

Gym rats

I like that!

[JetSetJim]

They could at least push it back into the grid on a FIT of some sorts. Perhaps the gym should sign up for a small solar array. but then accidentally connect up all the equipment to a generator that feeds the juice back to the network.

No idea how economic such a scam would be, but would be interesting to run the numbers. Obviously treadmills use power to move the belt, rather than extract power from the gym-rat, but the bikes, cross trainers and rowers could be connected up, at least. You could perhaps even do something with the machines with lumps of metal in them...

[Loyal Commenter]

Suddenly the solar panels on the roof of the sports centre opposite me make sense...

[Dave 126]

C'mon! Why have the gym rats turn their kinetic energy into electricity, only for the electricity to be turned back into kinetic energy? It is far more efficient for the gym rats to do the useful work (chop wood, carry water) directly.

Actually, I'm thinking of starting a new sort of gym, held outside on building sites. Members will pay me for a work-out regime that involves digging holes and carrying bricks.

[Mephistro]

"Members will pay me for a work-out regime that involves digging holes and carrying bricks."

That sounds like The Donald's B-plan, in case the Mexicans don't want to cough up for "Da Wall".

[Prst. V.Jeltz]

the machines with lumps of metal in them...

sure , any of the machines could be redesigned to capture energy rather than dispell it.

It annoys me seeing all that effort going to waste.

People lifting things up - and then puttting them down again! they could be doing something more usefull - like carrying the shopping home for the elderly , or digging my garden...

[DropBear]

On one of the Discovery shows a while back they did try powering an appliance (not sure if it was a laptop charger or a small CRT TV set) from a bunch of bicycle dynamos of people pedaling. If I recall correctly, a whole team of champions was practically dying right there trying to get it to work even for a short while...

[JetSetJim]

The BBC did a show, certainly. It took 30 cycle club members to run a kettle, and the 80-recruited members ran out of puff when the oven, vacuum cleaner and telly (plasma, IIRC)/wii were all turned on.

An interesting concept for the program - but currently unavailable on iPlayer :(

[Peter2]

"It took 30 cycle club members to run a kettle, and the 80-recruited members ran out of puff when the oven, vacuum cleaner and telly (plasma, IIRC)/wii were all turned on."

Obviously.

Ok. volts multiplied by amps = watts. Euro stuff is generally designed to draw ~9 amps at 220V which is ~1980W, rather than the good old fashioned british ones designed to draw 13 amps at 240W (3120W).

An oven is usually on a dedicated 30 amp circuit, and I'm going to assume electricians didn't choose to do that for entertainment. Vacuum cleaners are going to be as powerful as your allowed to get, and the plasma TV & wii are probably going to be another thousand watts. So, 9A + 9A + 4.5A = 22.5Amps on the ring main (only 7.5amps until the typical 30amp house breaker for the ring main trips) plus another 30 amps from the cooker = 52.5 amps.

This is a pretty extreme power draw. Look at the area of solar panels you'd need to actually deliver (in real world conditions) 52.5 amps at mains voltage!

If I had to generate that much power off grid, I think the easiest way of doing it would be to stick the car in the drive, stick another couple of 30 amp fuses in the car fusebox, run a set of UPS's in parallel to get the required outputs and then rev the engine to about 3k rpm to get the max rated 90 amps @ 12v out of the alternator. At about 80% efficiency you ought to be able to get ~70 amps worth of power at mains voltage and surges and spikes should get smoothed over via the UPS batteries. It'd probably last longer than cyclists as well, as long as the engine fan in the car didn't pack up while revved that high while sitting still!

[Prst. V.Jeltz]

@ peter 2 , and the car genny

I cant fault the maths, but given the original article was presumably about saving energy in some way , I'd be easier to bin the car and leave the mains plugged in .

I'm sure their generation is at least a little bit more efficient . Or do they have halls full of cars on jacks? :P

[Hunneric]

Gym Eco Mode

Actually, some of the machines in my old gym used to have some sort of Eco Mode where some of the energy you fed into the equipment went to reducing the amount of energy the treadmill itself drew from the grid (a bit).

Oh yes, those machines are so excruciatingly poorly designed that even when their whole purpose is to extract 100-200w, from the user, the machines themselves draw a great deal more from the grid. I couldn't find the spec on line but I did find a piece about a similar thing in this link (Daily Mail Warning)

http://www.dailymail.co.uk/news/article-2430771/Worlds-self-powering-gym-uses-energy-WORKOUT-lights-dont-break.html

For those who don't want to contribute towards Lord Rothermere's clickbait empire, the key sentence is this one:

"The new treadmills will also use 30 per cent less electricity and generate enough energy to power their own information screens"... but only if the user output is more than 100w.

And so they bloody should given that an ipad can run its screen, do some useful stuff and still charge it's battery from 12w

[Anonymous Coward]

http://www.dailymail.co.uk/news/article-2430771/Worlds-self-powering-gym-uses-energy-WORKOUT-lights-dont-break.html

Note the hilarious "100w per hour" error early in the article.

[Anonymous Coward]

I don't know

I would dismiss it outright as a gimmick (and a honeypot for Big Bucks Ready to Be Burnt). On the other hand, consider this: solar power is still terribly inefficient, BUT it's getting less inefficient, as technology to convert it into useable energy improves. It's still crappy, it's still around 15% that gets converted I hear but - allegedly - it's getting better. Generally things do get more efficient around us as the invisible market forces (chuckle) exert their invisible hand (remember the "Practice effect" ;). So we might get to the point in the future, where pavement power moves from a derision zone to (another) clever idea that works (every little helps, etc.).

[A K Stiles]

Re: I don't know

but the point, as was made in the article, is that the energy from footfall isn't there to be harvested in the first place, no matter how efficient your system, whilst the solar energy is already there and the panels are (apparently) becoming more efficient at converting the incident energy to usable electricity.

[AndyS]

Re: I don't know

The trouble is that comparison doesn't work.

Solar gives "free" access to a large amount of energy. Let's say about 1kW / sq m hits the ground for 10 hours per day. So, if you can harvest 15% of that, you've got 1.5 kWh of freely available energy.

"Harvesting" footfall is not free, and it is a tiny amount of energy. It is simply very, very inefficiently making people put more work into walking, so that you can get a tiny bit of energy out of them. Now, think of the numbers. A person walking probably uses something like 300 W. Let's assume we can increase that by 10% without pissing them off too much, then let's assume we can harvest that additional 10% at about 25% efficiency (hint - it will be nothing like this). So, each person is going to generate about 7 Watts, for the few minutes they are on it (so, maybe 0.01 kWh per person per day once it's installed, assuming 5 minutes of walking).

My house uses, on average, about 2 kW of electricity through the winter. My car outputs something like 30 kW average while I'm driving, which I do for about an hour a day. So between just those two I'm using something like 80 kWh of energy per day, or about 8,000 times as much energy as this pavement would generate.

[IDoNotThinkSo]

Re: I don't know

300W is a lot. If you could average that kind of output you would be winning the Tour de France (although you might need 400W to keep up on climbs).

Walking is about 50W.

Not that this makes any material difference to the result.

[Teiwaz]

Important Question

Do the paving stones light up when you step on them?

A little Billie Jean would be another tourist attraction to add to the plethora (and if it powers itself...)

Better than Hull and its fish anyway.

[Loud Speaker]

Re: Important Question

The significance of the article is: even if they were tiny LEDs under the paving stones, they would consume 100 times the energy produced.

As for the suggestion that you could increase the energy people use to walk by 25% and they not notice: I think the average person would recognise the feeling of wading through treacle or walking across a ploughed field.

[Dave 126]

Re: Important Question

>the average person would recognise the feeling of wading through treacle or walking across a ploughed field

Turn the 'bug' into a 'feature': low impact cross-training for pert buttocks.

[David Pollard]

Wading through treacle

Wikipedia, your friend and mine, tells us that "a healthy well-fed labourer over the course of an 8-hour work shift can sustain an average output of about 75 watts." If the walkway is generating "between 4W and 8W" per person then the input power will need to be something like 20 or 30W; probably about as much as is expended in a gentle stroll.

I imagine that people would soon learn to walk along the edges of the pavement where the going is likely to be somewhat easier. Even without such avoidance the projected cost per unit energy is presumably horrendous, and, crucially, the EROEI negative.

[Francis Boyle]

They're looking at the wrong limb

Just harness people's love of battering the buttons at on-demand pedestrian crossings.. Hit the button 20 times or you don't get to cross. Hit it 50 times and you actually get to cross 5 seconds sooner.

[stungebag]

Re: They're looking at the wrong limb

This is Vegas. Just harvest some of the muscle-power used for pulling slot-machine handles.

[Anonymous Coward]

Yeh. Right.

Government wants to harvest the life-energy out of me if I dare move outside of my house ?

Bring on the revolution.

[Poncey McPonceface]

Re: Yeh. Right.

Agreed. This is basically theft. Call it what it is.

[Anonymous Coward]

yeh. right.

I'm just getting my head around "mobility as a service", where some crony capitalist outfit like Crapita is going to take my disposable income and supply me with a travel service as and when it feels like it.

Now government is going to suck the life-energy out of me if I dare to walk outside of my house.

Bring on the revolution.

[Anonymous Coward]

The Register is a tech publication and we can tell you the answer is "not much”.

I think the true answer should have been 'sweet bugger all'.

[Khaptain]

Don't forget the Calories

Let's not forget that these boots would probably be heavier than normal boots and that would require the consumption of more calories..

These calories would also require energy to be used for them to be produced. a Hamburger for example would require lot's of energy before it went into said Pedestrian-Energy-Makers mouth.

If we reduce the amount of energy created by the amount of energy required to make these calories we would probably achieve a negative creation rate..

Self Defeating goal...

[Jason Bloomberg]

Re: Don't forget the Calories

On the other hand, it might mean that people lose weight, get fitter and healthier. That alone may justify a huge expenditure even if the energy generated is near zero or simply thrown away.

Just having a pavement slab flash once it has accumulated enough energy could bring about a health revolution if we could encourage people to buy into that.

People believe that walking under ladders brings bad luck so maybe we could convince them that making a slab flash has saved a life somewhere, made Jesus happy, or given an Angel some wings.

[Pompous Git]

Re: Don't forget the Calories

On the other hand, it might mean that people lose weight, get fitter and healthier.

It's odd that so many people don't notice the consequence of the lose weight/get fitter promotion means you get to die younger. Not arguing against fitness, just the Obesity Epidemic nonsense.

Association of bodyweight with total mortality and with cardiovascular events in coronary artery disease: a systematic review of cohort studies

[Olius]

But will it play "Chopsticks" when Tom Hanks walks on it?

[Mike Shepherd]

Every time

Every time a trendy green makes a crackpot suggestion (like powering a lift from the energy of users pressing the buttons or driving trains by having passengers pace the carriages), they should be invited to spend an hour cycling to generate the 100W needed for a few "energy-saving" light bulbs. 5 minutes' pedalling is probably enough for basic education; after an hour, they'll happily vote to re-open the coal mines.

[Chris Hunt]

They are trying to harvest power from Americans WALKING?

Even if they were able to get 100 KWh from every footstep, they'd only get about enough power to run a small bedside lamp.

[ecofeco]

Re: They are trying to harvest power from Americans WALKING?

Yeah, that's the problem right there.

Americans walking. Might work in a shopping mall, but that 's about it.

[inmypjs]

"you need 80 watt-hours of storage to get through eight hours of night"

And there is a show stopper before you even start. Batteries cost more that the cost of mains electricity they can charge and discharge in their lifetime.

[Anonymous Coward]

Fake news & fake solutions

Is this STILL circulating on Facebook? I haven't heard a single thing about 'pavement power' since I deleted my FB account. Then again, I don't do Twitter or Kickstarter or any of that horseshit either. I live in splendid 'social' isolation. :)

Sheesh, people. Keep your money.

Mine's the one with the big fat wallet -->

[Hunneric]

Not as stupid as energy generating speed bumps though

Which are another greenwash standby you see all the time - only worse.

https://www.theguardian.com/environment/2009/feb/08/alternative-energy-speed-bumps

Because sure, a 1.5 tonne car driving over a speed bump generates a bit more energy than a footstep but putting a speed bump in the road affects the behavior of the car and it's driver too. It probably slows down from 22mph to about 18mph before it hits the bump, slows a little more as it goes over the hump itself to 15mph and then speeds right back up.

So, assuming that the bump generates 20 times as much as the pavement -160w perhaps, for half a second or so - that's a whopping 80 joules in the bank. But that energy generation is dwarfed by the amount of energy the car uses to navigate the hump itself. If the 1.5 tonne car accelerates back from 15mph to 22mph between humps then its velocity changes by 3.1m/s. Just the change in kinetic energy is 7.35kJ. Assume a car is 40% efficient at turning dinosaurs into kinetic energy and the speed bump is the worst energy laundering system in the world.

Assuming my fag packet maths are right (and I'm assuming someone will correct me if they're not), you need 18,000 Joules of dirty energy to make 80 Joules of clean energy.

[Eddy Ito]

I'm not sure this works. Is one supposed to run in place under one light until it's bright enough for you to locate the next light whereupon you dash to the next light to charge it up and illuminate the location of the third and so on? Maybe we could get the cars to turn off their lights when the street light comes on and make it something akin to a real life game of Frogger. I'm sure all the hipsters would play. If only we can think of a way to get alligators involved.

[Tikimon]

Mechanical efficiency FTW

Walker-pressure schemes are doomed to fail for one very simple reason. Homo Sapiens has been finely tuned for efficiency in walking. We simply don't stomp every step, wasting force that we won't get back as we lift that foot again. Most of our mass vector (probably the wrong term, sorry) as we walk is directed forward, not down.

I wondered if the heavier, more deliberate step of the obese would make a notable difference. Then I realized that such folks are generally not in the habit of walking very far, so still not a good power source.

[Pompous Git]

Re: Mechanical efficiency FTW

I wondered if the heavier, more deliberate step of the obese would make a notable difference. Then I realized that such folks are generally not in the habit of walking very far, so still not a good power source.

From the ABC TV show Catalyst:

Dr Norman Swann: So can you be fat and fit? And it’s a really important question to answer because if you can be fat and fit it will make a huge difference to your health. I’ve got a photo of Pam here, Pam’s 122kg. I’m going to ask people what they think...

VOX POPS:

School Girl: She sort of looks really large around the middle.

Norman Swan: This woman is 122kg do you think she’s fit?

Young Man: No she’s not fit.

Norman Swan: Can you be fat and fit?

Young Man: Not at that weight no.

Norman Swan: Do you think you can be fat and fit?

Young Woman: No...no she’s not really fit.

Norman Swan: What if I told you she was a personal fitness trainer?

Young Woman: Oh no I wouldn’t be going to her classes.

FAT & FIT

[Tikimon]

Re: Mechanical efficiency FTW

For Fat And Fit examples, look no farther than Sumo wrestlers. However, they're the exception. Most obese people do not exercise, and are terribly unfit... which is true of a large percentage of not-overweight folks. I beat this drum all the time. Don't lose weight as a goal, get FIT!

[Glenturret Single Malt]

Foot power - the alternative

OK, so foot power is not scientifically feasible but here's an idea. What if all those millions of people sitting at desks all day had a treadle under the desk just like the old, mechanical sewing machines? How much electricity could be generated that way?

[ianmcca]

I calculate that if there is a lamp every 20 metres and every slab is generating power then there would need to be someone passing the lamp every 6 seconds to power it. So ignoring the costs of setting up and maintaiing the system it could work. But the costs of this are of course ridiculous for the power generated.

[AndyFl]

Economics of Solar in the UK

I am in the process of converting a place in the UK into residential and have been looking hard at the costs of going off grid. In this case the cost of connection to the grid is about GBP5,000. With a well insulated place and efficient equipment the worst case power consumption is around 4KWH/day. Solar panels currently cost about GBP450/kw plus cables, inverters, batteries and charge controllers. The economics of solar have changed hugely in the last 5 years and there will be sufficient power to keep all my geek obsessions happy.

My payback period works out as being about 5 years then all I need to do is change the batteries every 7 years or so along with the odd panel and charge controller. I'll probably use LIPO batteries in about 5 years from now once the safety issues have been addressed, even then I'll probably put them in the garden shed!

The real issue is December when solar daily outputs are at a minimum. The rest of the year I'll have more power than I know what to do with, in some months over 20kwh/day excess. I'll probably get PHEV or EV in a couple of years and run it for free from the excess power. Installation isn't such an issue either as in December vertical panels work surprisingly well and are easy to mount on walls etc.

The one thing which isn't practical to go off grid for is water. Utility cost is about GBP 1.50/cubic m and the cost to run a borehole for a single property ends up being higher than that. By the way, don't try to drink captured rainwater off the roof as a filtering issue can make you very ill. The building regs prohibit this for good reason.

So, yes, solar can economically power a place in the UK provided you are in a reasonable location. A microturbine can also be useful if you are limited in space for panels. The turbine won't do much for you most of the year but November-February a 1.8m turbine will provide something over 2kwh a day which makes up for the poor output of solar. You should probably dismount the turbine in summer to extend its lifetime.

Andy

[imanidiot]

Re: Economics of Solar in the UK

Just a sidenote but you won't have to wait 5 years for LIPO battery safety issues to be solved. They won't be. Ever. It's a matter of physics of that particular battery chemistry. They are great for lots of power for a low weight in a compact package but not that great for reliability and safety.

Look into LiFePo, the added iron makes thermal runaways much less likely but you still get the same amount of power out of the same compact package. They are a little heavier, but for fixed installation that should not be a problem.

For a fixed installation, if you have the space, deep cycle lead acid batteries are probably still the best option. Relatively cheap, easy to get, no/low maintenance, high recyclability.

[inmypjs]

Re: Economics of Solar in the UK

"My payback period works out as being about 5 years"

Really, 4kWh per day of mains electricity costs about £1100 for 5 years - your whole solar installation capable of providing 4kWh per day all year is going to cost less than £1100?

"So, yes, solar can economically power a place in the UK provided you are in a reasonable location"

You mean locations where they want the equivalent of 23 years worth of electricity bills to provide a mains connection?

[AndyFl]

Re: Economics of Solar in the UK

inmypjs:

you forgot it will cost GBP5,000 to connect to the grid.

[katrinab]

Re: Economics of Solar in the UK

Your forgot that when you sell the property, not having mains electricity will reduce the value by a lot more than £5000.

[Anonymous Coward]

Re: Economics of Solar in the UK

Andy, did you factor in the reduction of output of the panels when they get dirty (the usual factor is 50%)? With that in mind have you also made provision for the necessary weekly cleaning?

Another thing. Have you made provision for a, preferably diesel, standby generator? Even here in the south of France where we get more sun than the UK, friends that have a large solar installation found they need a standby generator. They have 75% more panels than calculated and use propane gas for cooking and heating and still the generator cuts in every week to keep the batteries charged.

[Emmeran]

In a battery operated world

I have to wonder how much even trickle charging from his footsteps would help a soldier keep his spare batteries charged in the modern environment. So long as the kit was ultra light weight and could be built into the body armor...

[imanidiot]

Re: In a battery operated world

Any bit of power you can extract from footsteps means extra power the walker has to put out. Not so good if you have a soldier already weighed down with lots and lots of gear that has to cross inhospitable terrain for mile after mile. You want to minimize his energy expenditure as much as possible. Not extract more from him.

[MachDiamond]

Pencil Power

The suggestion at the end of the article about using M$ Excel (shudder) or Google Docs (evil) is overkill. A scrap of paper and a pencil will do. It's not that hard, use a calculator if you want.