you have panels connected to grid thru inverter and that can modulate output in any way needed in few milliseconds.
same as inverter in electric car providing power to motors.
or inverter providing power to coils in your loudspeaker/ headphones.
inverter can adjust phase, voltage, frequency. it can means it is job of inverter to provide that in normal operation. that is why it is there in first place.
I stopped reading after this, sorry you totally lost me, im blocking this website:
"However, variable renewable sources, such as solar photovoltaic, do not have this capability. They generate direct current which is converted to alternating current at 50 Hertz, but they cannot react automatically to frequency variations. "
Nonsense. Go to any solar installer and ask him about this capability. or go to your roofs PV inverters manual and look up section about inputting "grid parameters".
I'm fairly knowledgeable on this topic, and I disagree that the author is ignorant or malicious. I think he was just trying to "dumb it down" for the masses.
I read quite lot about connecting Ukraine power grid to EU. Small variations in frequency and phase are quite real problem. It is quite a big problem to synchronise large international grids, and tiny PV inverter is really not build to do that!
Plus from manual, most AC inverters have parasitic power factor on AC side. Some part of power inverter sends to grid, can be out of sync junk!
Large spinning turbines with generator, are capable of absorbing out of sync junk to huge extend. But that may put turbine out of phase slightly.
Current power grid was build around huge wheels spinning at the very same frequency.
Nah. There's harmony and order in the unfolding of the universe. Mathematics can refer to both the symbols used to express that order as well as the order itself.
title says mathematics is that thing which gives form to something which does not rely on mathematics. mathematics is human construct to help us to do work in sciences or real life. mathematics is not in any shape or form innate to universe.
you are expressing it in your head, or my head or someones head. expressing in this context does not mean you are MAKING, BUILDING it in real life FROM mathematics, nor BECAUSE OF mathematics.
i mean universe as spacetime we occupy, not as marvel universe, words can have multiple meanings a lot of times even contradictory meanings between disciplines.
Thats still debateable. There is a phenomenological Mathematical description, called statistics and there are Things Like the Schrödinger ewuations or Maxwell's ewuations. These Things can capture the underlying pattern.
not like that. i do not care about math in that post.
"good" language leads to "good" and logical thinking in every area of human endeavor.
so it can also be true that "bad" language leads to "bad" thinking. you are making mistakes, making bad conclusions, which can be avoided just by using "proper" language. why make life harder.
that applies for "everything" from "marketing vs scam", to even philosophy itself,
edit: we live in complex world, stacking complexities on top of complexities, so being "20% wrong" in one layer of complexities, can lead to totally opposite result in another layer.
It's not pedantic, it's true, and it actually is deeply important because misunderstanding this can lead to very different beliefs about the world, science, and technology.
Yes ! Triple price of PV panels to buy "ceramic glass print" PV panel with eye pleasing pattern / stealthy photo on it and you can have facade or fence made from PV panels, there is drop in generated power from 10-50 % depended on pattern, color used.
Price per panel not price per install ! ! ! And subtract need to buy materials used for that purpose before.
actually this is "bad kind of article", because there is so much information in there / "everything covered". that it is almost impossible to have comments about it lol.
Literally laying them flat on minimally cleared land would win the simulation. Fewer panels, fewer acres, less mounting hardware, less labor, more power. Real world conditions not included in the analysis, such as wholesale electricity prices over a day and land not being flat, drives a lot of these choices.
but, 70% of MY! yearly households electricity consumption is literally into [PV!] hot water. Hot water tank is cheapest energy storage device on planet. and i do not have to worry to shower in noon, i can just charge my water tank during day, even when im not home. and use hot water in evening. for very little price - no need to use heat pump, resistive heater is super cheap. hot water tank can be made even DIY to lower price even more.
utility charges me so much for electricity that even tho i payed for 15 kWp roof mounted east west system literally literally ORDER OF MAGNITUDE more than prices showed in that article, AND i still save money by not buying electricity from grid !
that how much utilities are charging us, yes they need to manage all those wires, manage power plants, etc. i do understand where that cost comes from, but still, solar in residential is so cheap that installing PV on roof and directly consuming it will save you money.
So for industry/ manufacturing there will be extremely high incentive to add PV + battery even when it wont cover 100% of their loads. utility+ onsite PV+battery.
Again, back to my hot water system, 80% of year i am 100% "off-grid" for hot water [PV!]. even on days it is cloudy ! And 99%-0% of PV rest of year... And from april to October my electricity draw from grid is almost zero.
so whole residential USA can be essentially "off-grid" huge part of year with just small battery, your tv, notebooks draw almost nothing over the course of the day compared to your energy need for hot water. and less residential is on grid, easier it is to manage electricity for other sectors of economy.
this contraption from ETH Zurich can store iron/iron oxide to generate hydrogen, without storage loss! for years, without compressing hydrogen and without other cons of "standard hydrogen storage. essentially it can be thought about as hydrogen storage - it can "store" 10s of megawatts inside of a standard basement. - [https://ethz.ch/en/news-and-events/eth-news/news/2024/08/iro...]
and you do not need to make electricity from that hydrogen, you can heat your house directly with hydrogen, just by replacing 30$ burner in your existing furnace!
so you complain about "peak" power excess, and i say and i show it to you that this "peak" solar power can be used to charge that extremely cheap storage device in summer and expend that storage over winter for heating house and making hot water. when sun is not shining.
and again, calculate how much kWh is your need for heating and how much is for hot water and you can clearly see that extremely huge part of current residential energy need can be either "onsite off-grid" with this contraption + small LiFePO battery or to be on-grid and take only small loads like tv, notebooks from grid and having heating + hot water "onsite off-grid". and most importantly cheap.
ratio of kWh for your heat and for your other appliances ! ! ! !
So essentially we can charge our heating system in summer, store energy WITHOUT LOSS until winter and heat with that energy in winter. right now!
just sketch/draw for yourself timeline containing - PV + storage contraption in that link + small LiFePO battery. and you can see how huge part of energy we do not really need to draw from "grid".
small towns can even make their own shared storage, prices for SEASONAL energy storage are even lower then current prices for electricity drawn from grid....
So this physical, economical actual contemporary possibility makes me mad every time i see just another youtuber or other kind of influencer, post about just another battery technology promising who knows what, in who knows what timeframe.
we do have energy storage technologies capable of providing citizens of USA with clean energy RIGHT now, RIGHT here. for whole year, day and night. without buying one drop of oil from tyrants, dictators who literally literally kill people right at this moment.
I didn't read your entire comment (sorry), but wanted to support your water tank statement.
I live in an area with frequent, often day long power failures during winter storms. So my house is designed around that.
When I bought a new hot water tank, I spent a little extra for the super insulated one. The result?
I can take a shower during a power failure, and still another not as hot 24 hrs later! When you consider that the first shower injected cold water into the tank, that's fairly impressive.
On long power failures, on the third morning I can even take a lukewarm shower, with no cold water at the shower (I have individual hot/cold controls). This is far preferable to a shower at 5C water temp (from my well in winter)
And where did any eacaped heat go? Why... into my house! Surely not a loss.
Yeah, similarly with insulation / good building practices, my house can lose power in coldest of days and i do not have to put on hoodie for 2 days. (not heating by other means like wood, which i do not have) it is not big house tho. it is insane to me that in country where there are tornadoes, hurricanes, wildfires hundreds of times per year, we do not do this / build like this by default.
In europe, there is possibility to be on "energy spot prices", essentially utility will charge you energy market prices. today price at noon was almost zero. last Sunday, prices were negative - they literally pay you to draw from grid. but at evening, price can be quite high.
so having simple time relay / or more complex minicomputer directly reading energy market prices and switching loads can even earn you some money. it is not money making business but overall price can drop significantly. it is also an economic incentive to buy battery storage and actually got to paid it off.
Enabling citizens to do good thing is underrated.
people with "standard" contract are essentially subsidizing industry, corporations which have cheaper electricity because of bundling with residential customers. which makes weird and complicated incentive structures. essentially anti-market behavior in country which boasts itself in "capitalistic" structures... and slowing adoption of renewables, because it looks like they are more expensive than they actually are.
I read, and appreciated, your entire comment - thank you.
You describe a simple and elegant solution to some portions of these problems and what you are doing with your hot water "battery" is smart.
I am forced, however, to ask:
Where do you live and how large is your family ?
My suspicion is that you do not live in the United States and your family is relatively small ... ?
Modern, "first world" ("global north" ?) 21st century homes do not match your model in a number of different ways:
- Unlimited, temp stable hot water comes from a tankless water heater. People don't "run out" of hot water anymore.
- A family - even a relatively small family - runs a 30A dryer daily. Our family of five runs it 1-2x daily.
- Many, many people now have electric cars and some households have two of them.
- I agree that laptops and phones and personal electronics are a rounding error here but microwave ovens, toasters, coffee percolators, etc., are not - and people use them. I will note in passing that both our dishwasher and our microwave oven require 20A circuits.
I am optimistic that we (as a society) can satisfy these demands with solar power - I just want to make sure you appreciate just how much demand for electricity a modern US household has.
FWIW, we are planning on going entirely off-grid, purely solar with lifepo batteries, in the next 18-24 months.
Americans basically live like energy is unlimited, free and has no side effects, the rest of the world doesn't have that chance, last time I checked the average US household used anywhere between 3x and 4x more electricity than the average EU household
They tend to prefer huge houses with relatively complex designs (less optimal in term of area/volume ratio) / poor insulation, they make up for it by relying on tech for heating/cooling pretty much year round.
Your tankless water heater is a good example of something that is completely inadequate for solar setups, they draw insane amount of energy over very quick period of time. But I think that's the core of the issue, if you want to keep all the nice things modern American houses have you're going to need a lot of money and a lot of sun. On the other hand if you're a bit more frugal, with so called "passive house", you can get by with a much smaller setup.
> I will note in passing that both our dishwasher and our microwave oven require 20A circuits
And a tankless heater will need 5 times that, unless you're using gas but I wouldn't count that in a "modern first world 21st century home".
"Americans basically live like energy is unlimited, free and has no side effects ..."
Agreed - and guilty as charged which is why we're switching entirely to solar.
(I will also note that my household "cheats" by living in California where we need relatively little heat and do not even own an air conditioner so our path is, perhaps, a bit easier)
My main point is that whether you're a frugal EU council house or a profligate Texas McMansion, we - all of us - will continue to invent new demands for energy and continue to trend towards more energy used per person per unit time.
Therefore, if you're looking ahead to deployment of solar resources you should be realistic about that trendline.
> we - all of us - will continue to invent new demands for energy and continue to trend towards more energy used per person per unit time.
I'm personally in the process of designing my house and I'm going for maximal energy efficiency: 38cm thick brick walls + 20cm thick rock wool insulation, basic rectangular shape, 80% of the windows to the south, triple pane, heat recovery unit coupled with a air/earth heat exchanger to avoid needing a resistance to pre warm the air in winter, heat pump water heater, catalytic wood stove
Although I would agree that overall people don't give a shit and I probably am in the minority
"Ordinary European household" will change even lower :
Crisis of 2008 made EU to think about resiliency so they asked all kinds of economists, physicist, other science people what should be done to provided that and one of those things implemented was building energy efficiency directive
[https://energy.ec.europa.eu/topics/energy-efficiency/energy-...]
which progressively increased demands on building sector to provide citizens with "low energy" housing. and currently most states of EU have requirement to build houses where defacto energy need for yearly heating of a house is lower then energy yearly demand for hot water (hot ater can not be lowered significantly without heat pumps - COP3+)
> Your tankless water heater is a good example of something that is completely inadequate for solar setups, they draw insane amount of energy over very quick period
I know nothing about any of this, so please educate me for the good of us all - wouldn't this logically be a use case for a battery? IE: solar (or wind or whatever...) feeds a battery that feeds the tankless water heater. As a layperson, it would seem to me like the issue isn't generation but rather availability at the moment of demand - which would be the case in any kind of micro generation, right?
You should still probably add a hot water tank to that setup, just put it in front of the tankless heater. It is a like a battery that is 100x cheaper. You could go high tech and run the tank heater when you have solar excess, or low tech and just put it on a timer to run for a few hours around noon.
Everyone should calculate how much is consuming in kWh, recalculate gas into kWh, wood into kWh, propane into kWh.... then it starts making sense for ordinary people. Even for how much energy leaves their house. To use kW / kWh for everything.
" 1)- tankless"
more than half of USA has water tanks. both water tanks and tankless heaters have expected working life, after taht they have to be replaced either way.
Tankless heaters are more efficient if you think only about AMOUNT of energy, but water tanks are there to lower your PRICE of hot water. (or spread load over longer time for usecase as your offgrid) So yes, with tankless you are doing best in standard "old" grid situation, where price for electricity for customer was same throughout day, (some tariffs can have different price in night) (or when you ask Ask This Old House)
AND with PV! on roof and tank in basement, households are providing service for utility because A) they do not export solar at noon, they are putting that energy to water tank, B) they do not import energy during evening peak hours. so less generation / "base load" needed to exist, to operate, service, manufacture.
but there are new things like solar export which will change grid. and people have to adjust, or they can just install expensive battery paid with gov subsidies (by "utility")... residential customer can either use cheap electricity during day to heat water tank or utility can charge for "stabilising" of grid multiples of that price.
so customers incentive should be to have hot water from PV on his own roof. and when they do not have enough solar energy they can charge rest from grid. and lowering need for importing from grid by 80+% per year... for hot water energy.
"2)dryer "
how much is that kWh ? can it run during day when there is availability of PV ? Or atleast one of those cycles can run during day?
" 3) electric car "
I am one of them but unfortunately i am working from home and have nonstandard schedule (20-45 miles per day + once per week trip to buy groceries in town 130 miles ) so i can charge my car from PV, not many people can do that. but they can have water tank on PV and car on grid... or if they use one car only sporadically, then that one can maybe charge from PV ?
my electric car can be charged by 2kW from standard outlet for 10 hours to add 62 miles of range, in summer when i do not want huge loads or i can connect it to faster charger. one car takes daily roughly same amount of energy as 2 people need for hot water...
"4) appliances "
how much is that kWh ? starting current can be higher, sustain power can be lower. starting power can be lowered by using "starter circuit" - bunch of capacitors connected to motor, but lot of motor apliances already have it. coffee percolator is essentially water tank so you are already doing it ;) 20A is not much, some appliances can be connected to 240v if it is available. or adding more circuit breakers if you have slot for them, and spread loads between circuits.
"5) rest"
not waste, save, use on site first, then grid. most people live grid first... i do not mind grid
im not saying everyone should go off-grid, because high-rises can not. but everyone who can, should atleast be able to have 5-10 kWp PV on roof just for hot water, and it can be used in emergency for other things (not necessarily same lifestyle). such small pv + hot water tank as a predictable load connected to well sized PV can make PV be payed sooner. and having connection to grid, with possibility of getting payed for export of excess in future for powering highrises...
my system got payed in 6 years because i use a lot of energy directly. lifetime of inverter is presumably 10 years and panels 20 years so i have presumably next 4 years energy for free. then i have to replace inverter,... if those devices last longer, saving is even bigger.
government official had to make press conference just to tell people to stop spreading that nonsense you promote as "electrically literate" so that is that.
whole stack overflow question is bunch of nonsense, so why do we even argue about it?
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