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  1. pdf27

    New Solar Roof System

    It sounds like a really hard way of doing things - plenty of systems like https://www.irfts.com/easy-roof-evolution/ which are cheap (made from injection moulded plastic) and fit standard panels. Then you just fit normal tiles around them using a flashing kit, and you're sorted.
  2. pdf27

    Trimming wasted power with software defined electricity

    I work in aircraft power generation, and the problems this addresses are very relevant to us. However, there are other established ways of dealing with them that work really well - for instance, harmonics (which produce the distorted wave form - run a Fourier transform on the distorted waveform...
  3. pdf27

    Could it be true????

    It could, but you have to do so on a very, very big scale. Yes, that's a solar array the size of Portugal and storage would have to be equivalently massive (probably as natural gas in depleted gas fields). EVs are pushing at an open door with the shift to self-driving cars and on-demand...
  4. pdf27

    EPA declares biomass power carbon neutral

    The other thing is what you do with the wood instead. Using the same timber to produce a super-insulated house and burning gas in a power station to drive a heat pump for the small amount of residual heat required is always going to be vastly better than burning wood for heat in an existing...
  5. pdf27

    What's your favorite BEER?

    Just started drinking it - very dark, and the hops are maybe a little stronger than I'd like. I think if I was making it again I'd probably dilute it down a little - it's a 36 pint kit but I think I'd probably prefer it at 40 pints. I've also just got back from Germany with a carload of assorted...
  6. pdf27

    Would you like fries with that heat?

    Yeah, it's assuming that the carbon emissions are only from the fossil fuel used to grow and process the oil. That doesn't make sense to me - if not burnt directly, the oil would almost certainly be collected and processed into biodiesel, which would then displace dinodiesel itself. It's a bit...
  7. pdf27

    What's your favorite BEER?

    Started a batch of Cwtch yesterday, with my 3 year old helping out. Only a kit, but the reviews are very good so we'll have to see how it goes.
  8. pdf27

    What's your favorite BEER?

    Shame it's a pig to get in parts of Germany, let alone overseas :( The other one I really like is Kölsch, but that's even worse to get in the UK - we just bring it back by the carload whenever we're in Germany. My favourite is Schreckenskammer, but finding that is a bit hit-and-miss in Cologne...
  9. pdf27

    It's started

    Which is one of the reasons why some of the questions you're posing are inherently unanswerable - it all comes down to how much satisfaction you get from particular actions, and how you are comfortable spending the budget you have. The best the rest of us can do here is provide data to make the...
  10. pdf27

    It's started

    The thing is so far you've had a relatively straightforward route to reducing emissions: Use of wood fuel for heating, eliminating fossil fuels. Use of PV to provide electricity, with a small surplus over and above your annual consumption. Both are pretty mainstream, and for a reason - they're...
  11. pdf27

    It's started

    If correct, yes - essentially 1000g/kWh is the break-even point so gas generated electricity would have half the emissions of a petrol car. It's worth digging up the raw data if you can though - not sure if it's available in the US, but the UK has somewhere like...
  12. pdf27

    It's started

    Petrol is 2.3 kg CO2/litre and a US gallon is 3.785 litres, so a gallon releases 8.7 kg of CO2 - at 25 MPG I make that more like 350 g/mile and 220 g/km. I can't quite work out why that disagrees with your numbers - where did you get the 80 gallons/1 ton CO2 from? EIA states 20 lbs/gallon, so 80...
  13. pdf27

    It's started

    Fair enough - sounds like there is nothing more to be done here for some years. Thing is, most of that can be accomplished by a car with a reliable range of 85 miles or more - it's only the trips to the children/grandchildren which require more, and that's only ~4500 miles/year. Hence the...
  14. pdf27

    It's started

    One possible thought - what is the cheapest second-hand electric car you can get your paws on locally? For instance near me I can get a 24 kWh Leaf for as little as £4k ($5200). As a relatively cheap car you don't care very much if it's left outside, and provided you have a charging cable to it...
  15. pdf27

    It's started

    Not quite - essentially what they've announced is that any new powertrains they develop will be hybrid rather than pure internal combustion engine ones. They'll probably start offering pure electric options as well, but they're unlikely to be a big fraction of their production - in some niche...
  16. pdf27

    Fusion progress

    Amusingly enough, I used to work there including on a rather larger version of that Tokamak which has been running for a number of years. Bit hard to tell from those photos but I'm pretty sure that the magnetic coils are internal to the vacuum vessel rather than external.
  17. pdf27

    Is the reign of the ICE ending?

    Only if you're something like a UPS truck with a relatively short route which ends back at a depot every day. That's a fairly small fraction of the total market in the US as I understand it - in theory if you came up with a strict standard that everyone adheres to then you could swap them out at...
  18. pdf27

    Is the reign of the ICE ending?

    Interestingly the autonomous driving isn't necessarily where the economics is pushing you to go - there has been a lot of work on running trucks in platoons (say a dozen really closely nose to tail) in order to reduce emissions, which is both more complicated and more valuable than the...
  19. pdf27

    Is the reign of the ICE ending?

    Lets you do a number of other nice structural things too because the mass of the motors is so well distributed, and you're using distributed motors to blow air over the wing as well to improve lift at low speed. I think they're on a hiding to nothing by trying to use a pair of tiny...
  20. pdf27

    Is the reign of the ICE ending?

    Umm... some of it is out there if you know where to look, but the benefits are often quite subtle and not what or where you would expect. So far as timescales go, all I can really say is "soon" - it's all a bit flavour of the month at the moment and we're being asked to get stuff built...
  21. pdf27

    Is the reign of the ICE ending?

    This is one of those times when I wish I could tell you what I'm doing at work. All I think I can say is that this is happening, and a bunch of Tier 1 and airframer aerospace companies are putting an awful lot of money into making it happen in the very near future. Given the regulatory...
  22. pdf27

    Is the reign of the ICE ending?

    The problem Tesla have is that when it comes to making cars, technology is only a small part of the story. Making them cost-effectively is hard: Tesla haven't had to yet, because they can charge high prices and hence make a lot of profit on an expensive car to make. Problem is that they're...
  23. pdf27

    The biggest pellet furnace in the world....

    It's been consuming 5 million tonnes/year of wood since 2014, with another 2.5 million tonnes a year added to it from this year onwards. The pellets are all manufactured in dedicated plants, although they will be sucking up an awful lot of wood feedstock. As for the environmental friendliness...
  24. pdf27

    Solid state battery tech

    Yeah, I'm actually quite aware of that (my wife is originally from New York, and her parents are now on the NJ/PA border). Unfortunately I don't think personal aircraft will fit that niche - the public are far less accepting of aircraft crashing than of cars crashing, rightly or wrongly, so they...
  25. pdf27

    Solid state battery tech

    These articles may be of interest: https://www.flightglobal.com/news/articles/heli-expo-bell-unveils-fcx-concept-helicopter-434840/ https://www.nasa.gov/langley/ten-engine-electric-plane-completes-successful-flight-test
  26. pdf27

    Solid state battery tech

    With batteries as the only power source, yes. All I'm comfortable saying is that there is some serious money going into electric helicopters right now, coming from people who know what they're doing. Getting that airspace will be very painful - no way would "flying car" type aircraft be...
  27. pdf27

    Solid state battery tech

    Main one is mass - as a rough figure of merit each of these 110kW motors would have a mass of 40kg plus say 20kg for power electronics, and improving this is hard work. That's 250kg for propulsion, even before you start adding in structural mass and batteries. Ah - I assumed you were doing a...
  28. pdf27

    Solid state battery tech

    <choosing my words carefully here because I actually work in a Tier-1 aerospace supplier working on electric aircraft> A conventional helicopter-style or quadcopter drone is always going to use more energy to travel a given distance than even a huge SUV, unless the SUV is stuck in a pretty...
  29. pdf27

    The biggest pellet furnace in the world....

    I think my brother has you beaten - https://www.pellet.org/wpac-news/drax-fires-up-biomass-power 2,200,000,000 BTU/hr on pellets per unit, and three of them in parallel :)
  30. pdf27

    If you could do it over again - which stove would you choose?

    Had a Charnwood C-four in our last house - pretty good and having one air control to do everything was nice in theory but balancing it was a pain and my wife wouldn't dream of putting more wood on it. We stopped using it after our daughter was born and started trying to hug it whenever it was...