This makes me feel that i.e. looking for bone marrow donors may become obsolete in some cases, if we know the gene sequence responsible for the disease. Instead of looking for donors, it may actually be possible to repair bone marrow cells and inject them back, fixing the problem. Am I missing something here?
Nope, not missing anything. It should also be possible to use it it to reprogram mature cells (such as skin cells) into homeopoetic stem cells in-mass, and simply introduce them into the appropriate site (eg bone marrow, for your example)
Wait, I thought that CRISPR was a matter of gene editing but that stem versus other types of cells was a matter of gene activation? Wouldn't that require different techniques?
It's even more terrifying considering the fact that it took millions of years of to accumulate such amounts of energy in fossil fuels (it's literally sun energy laying underground). Sooner or later, we'll run out of it…
BTW, it's not 10 kW/h, but 10 kWh in a litre of petrol.
I think @gravypod actually meant parallel connection, it might be quite dangerous in fact - you don't even need to draw anything from the battery to mess things up. If you connect a 100 cells in parallel and one cell dies creating a short in the circuit, the rest of cells will discharge through the shorted one. When you short a single 18650 cell, it outputs about 6-7 A of current on average. Multiplying by 100 gives you 600-700 A of current flowing through a single cell. That's why people use fuses to create parallel modules.
Yes that was mentioned in one of the maaaany EEVBlog videos iv watch that these fail closed sometimes as well as the recommendation that "you should never buy lipo cells without a built-in controller" comeing from a guy far smarter then I about electronics design. If he is afraid of it, it's for a good reason.
> Yes that was mentioned in one of the maaaany EEVBlog videos iv watch that these fail closed sometimes as well as the recommendation that "you should never buy lipo cells without a built-in controller" comeing from a guy far smarter then I about electronics design. If he is afraid of it, it's for a good reason.
If you're building a large pack you don't want cells with a built-in protection. You connect all the cells to a pack-wide BMS that keeps things safe.
The important thing is to never use unprotected cells without some protection circuit in the pack.
It doesn't make much difference whether you use Watts or Joules, since 1 Watt = 1 Joule per second, so both are just as convenient for electricity: 1 Watt = 1 Volt Amp, so 1 Joule = 1 Volt Amp Second = 1 Volt Coulomb (although amps seems to be more "normal" than coulombs).
It's a bit redundant to multiply power by time, when that's just an energy, but going between Watts and Joules is trivial (by design), so it's not too bad.
However, I can't think of a reason why hours would be easier to work with than seconds (as kiloseconds, if you want the same order of magnitude), especially regarding electricity?
It's because power needs are reported as watts, and impactful devices are typically utilized for several hours. It's much easier to do your monthly utilization napkin math in multiples of kilowatt-hours than of 3.6 megajoules.
I'm personally not a fan of the kWh, because it keeps being mistaken for kW, but I recognize that lack of need for a conversion factor help a lot of people make sense of energy.
I think the poster means the EPA test cycle for miles, they have a pre-defined "cycle" of acceleration, braking, coasting etc for Highway ratings and City driving.
just guessing, it's a standardized way to declare the driven distence, given all the variables.. such as: up hill, down hill, low/high rolling resistance surface?
I know it's not as simple as "connecting 10k batteries together". It's an interesting topic anyways, there are a few guys already doing it with promising results (check HBPowerwall on youtube for instance).
BTW: I haven't even connected these cells together yet - even that is not as simple as it may look like.
Transmission costs money, but less than many believe. The cost of high voltage DC (HVDC) transmission lines is roughly 1 cents per kwh for 500 miles, or 1.5 cents per kwh for 1,000 miles transmitted. Over 1,000 miles, an HVDC line may lose 5% or so of the electricity it transmits.
I don't consider 5% per 1000 miles an "absurd" amount.
It's a very good question. I always thought that it's because of technical difficulties when transmitting electricity over long distances, but it turns out we already do it well (HVDC). When you think about it on a continent scale: why not move all PV panels from Germany to sunnier regions of Europe like Spain or Portugal where you can generate twice more power with them (in average 200 W/m² instead of 100 W/m²). The answer is simple: we'd need to have a common grid across EU member countries, but such a thing doesn't exist and it's unlikely to happen anytime soon. It turns out the biggest issue on this planet is always politics.
The amount of copper you would need to constantly convey electricity from the sunny side of the earth to the dark side would be absolutely massive. It is not an issue of common grids, as long distance high power transmission is done at many different voltages depending on the specific route, and has nothing to do with your mains voltage and frequency.
Current long distance power transmission is most often used as a way of 'balancing' production and demand between different types of plants; it is not intended or capable of transmitting the full power needs of the recieving area.
You can use aluminium instead of copper (see HVDC Gotland).
I didn't say it's just about "connecting countries with a common grid". Switching from fossil fuels to renewable sources is much more challenging than that. However, transmitting lots of power over long distances is doable and cheaper than many people think.
I know they run large (presumably) copper lines from Utah to California to pump out electricity. That can't have been cheap, how bad can it be to pump it trans atlantic? LOL
In Spain we have ridiculous laws that make it unfeasible to a layman to have solar power installed in the houses. It would be quite ironic setting up solar panels for Germany with our current situation.
While there isn't a complete grid, the UK has connections to Ireland, the Netherlands and France, enabling a bit more balancing. You can see the UK is currently running on 60% CCGT and 25% nuclear, although the 10GW solar capacity can't be shown because there's no central real-time metering for it. That's quite an impressive amount given the total (net of solar) demand is 30GW. Two and a half "Drax" worth of power, invisibly distributed around the country!
The question was if it's possible to use someone's else electricity when the sun isn't shining in your place. While it's technically possible and in many cases economically reasonable, you probably won't see countries giving up their electricity production and importing power from overseas - the main reason is politics.
you probably won't see countries giving up their electricity production and importing power from overseas - the main reason is politics.
Importing a whole country's power consumption is probably a bit much in terms of required infrastructure (except for the microstates which already do this), but smaller links are already present and make economic sense. I don't think the politics of energy security are an obstacle if the price is right.
