A possible way to keep your fridge cold in long term blackouts.

[Someone]

https://zwiftinsider.com/wp-content/uploads/2016/01/ftp-table.png

Those tables are watts per kilogram.  Not too useful.  Even in the untrained portion at the bottom, if I were untrained and 250kg of fat, believe me, I will not generate ~580 watts in 5 minutes.  I would be dead of a heart attack attempting that pace within seconds.

it is perfectly useful for people of normal weight, 250kg is so far off normal that is totally irrelevant

There is nothing "normal" about those tables, they are about athletes who choose to do the activity, a self selecting minority of people. It is not applicable to the general population.

[Cerebus]

Did you try asking if you could run an extension cord over to their house to power your fridge and run a few lights? Certainly I would oblige if one of my neighbors made the request and my generator had sufficient capacity to accommodate.

Depends where in Aus Geoff is. Neighbour could be "Just next door" or could be "We're gonna need a really long extension cable". Aussies have caught me out before by talking about their neighbours and then later it becomes clear in the conversation that you need to drive if you're going to borrow a cup of sugar from them.

[Cerebus]

  Did    YOU     try asking If   YOU   could run an extension cord over to   THEIR   house.
           ----                         ----                                                           -------

The neighbor had the generator not him, the neighbor is not here.
             

I'm with James here, you seem to not be understanding quite simple English.

James to Geoff:  "Did you [Geoff] try asking if you [Geoff] could run an extension cord over to their [the neighbours]  house ..."

What's the issue with that?

[tggzzz]

Don't use bottles with plain water, because they will only keep the freezer contents at 0C. At that temperature some of the freezer contents will already have defrosted.

Do use "eutectic plates" available from catering suppliers, e.g. https://www.frigolab.eu/gb/127-eutectic-plates

You can choose the freeze/thaw temperature, so if you want to keep something below -14C, use a -18C plate and set the freezer to -21C.

If you are a cheapskate you can make them yourself: just add the desired amount of salt to water in a plastic bottle, then test it in the freezer.

[hans]

https://zwiftinsider.com/wp-content/uploads/2016/01/ftp-table.png

Those tables are watts per kilogram.  Not too useful.  Even in the untrained portion at the bottom, if I were untrained and 250kg of fat, believe me, I will not generate ~580 watts in 5 minutes.  I would be dead of a heart attack attempting that pace within seconds.

it is perfectly useful for people of normal weight, 250kg is so far off normal that is totally irrelevant

If the table is best calibrated at normal weight, e.g. BMI=20, then the table is better expressed in terms of a person's length. But perhaps a W/m^2 is a weird figure.
Anyhow, I think those tables are more accurate at the higher end. 2 Tour-de-France athletes of similar length will have a similar power output (say a +/-10% difference + a good day will win you a race). On the lower end of the scale, the stddev is much bigger, which this table doesn't capture as well. Some people may start at 80W, others can maybe do 150W. Also depends *a lot* on age.

[Siwastaja]

https://zwiftinsider.com/wp-content/uploads/2016/01/ftp-table.png

Those tables are watts per kilogram.  Not too useful.  Even in the untrained portion at the bottom, if I were untrained and 250kg of fat, believe me, I will not generate ~580 watts in 5 minutes.  I would be dead of a heart attack attempting that pace within seconds.

Tables like this describe athlete types. Note that the lowest-tier rating on that table is "untrained (non-racer)". This means basically a self-trained non-professional person who is basically an athlete by hobby. 95% of people would fall completely outside of this table.

This is also why it works per kilogram; there's just this hidden assumption that anybody who gets on this table at all has very good muscle-to-fat ratio to begin with. If you totally exclude non-athlete types, then body mass is likely directly proportional to muscle power, even better than height is.

[Siwastaja]

I was thinking this could be done with a smaller bar fridge and a battery solar system. Which would allow the fridge to run for a while during the best power producing time, when the sun was up.
Build a processor controlled system to measure the temperature of the food and supervise it all.

PV panels are cheap; instead of buying a separate smaller fridge and juggling foodstuff between fridges, simplest is to get large enough PV system to keep your usual fridge, freezer and whatever other small loads running.

For example, my 3kWp rooftop system produces anything between 5kWh to nearly 20kWh a day, ignoring dark winter time. Some kind of worst-case super rainy day might go below 3kWh. Even this is three times the energy needed to run fridge+freezer.

A tiny (by modern standards) 1kWp PV system will be more than sufficient, and it is not much more expensive than some special "camper" installations made of small 150W panels.

But while at it, it would be a good idea to just buy decently sized PV system like 4-5kWp, then you would be part of solving the problem instead of just coping with it. But I don't know what is the current market situation with inverters that work both off-grid and grid-tied modes. Mine is grid-tie only which kind of sucks because it won't help me in case of emergency. Thankfully, grid is really fine here, and it is unlikely to radically change.

[Cerebus]

https://zwiftinsider.com/wp-content/uploads/2016/01/ftp-table.png

Those tables are watts per kilogram.  Not too useful.  Even in the untrained portion at the bottom, if I were untrained and 250kg of fat, believe me, I will not generate ~580 watts in 5 minutes.  I would be dead of a heart attack attempting that pace within seconds.

Tables like this describe athlete types. Note that the lowest-tier rating on that table is "untrained (non-racer)". This means basically a self-trained non-professional person who is basically an athlete by hobby. 95% of people would fall completely outside of this table.

This is also why it works per kilogram; there's just this hidden assumption that anybody who gets on this table at all has very good muscle-to-fat ratio to begin with. If you totally exclude non-athlete types, then body mass is likely directly proportional to muscle power, even better than height is.

That might be a false set of assumptions. There's a lot of cross-over between exercise tolerance testing for medical/physiological research/diagnosis and data published for pure cycling/active-fitness purposes. The better tabulations published for cycling and fitness purposes draw their data from published physiology papers as well as narrower studies, and so encompass a much broader range of test subjects  than "cyclists who are interested enough to have undergone exercise tolerance testing" or "healthy 70kg males aged 21-25".

[Smokey]

https://zwiftinsider.com/wp-content/uploads/2016/01/ftp-table.png

Those tables are watts per kilogram.  Not too useful.  Even in the untrained portion at the bottom, if I were untrained and 250kg of fat, believe me, I will not generate ~580 watts in 5 minutes.  I would be dead of a heart attack attempting that pace within seconds.

Tables like this describe athlete types. Note that the lowest-tier rating on that table is "untrained (non-racer)". This means basically a self-trained non-professional person who is basically an athlete by hobby. 95% of people would fall completely outside of this table.

This is also why it works per kilogram; there's just this hidden assumption that anybody who gets on this table at all has very good muscle-to-fat ratio to begin with. If you totally exclude non-athlete types, then body mass is likely directly proportional to muscle power, even better than height is.

The most important reason that cyclist compare power with watts/kg is because they ride up hills.  Every kg you have to drag up a hill  needs more power to go the same speed in a race.  That's how you can compare the effective power output of a big dude and a small dude to see who would win a race.  But realistically, there are no pro BIG dudes.
Also it's largely irrelevant that they use w/kg for this discussion.  Just use a fixed weight for everything and you can focus on the differences between watts for the various levels, which is what we are after here. 
For reference, Chris Froome weighed about 69.9 kg.
https://en.wikipedia.org/wiki/Chris_Froome

[Cerebus]

But realistically, there are no pro BIG dudes.

Not among pro road cyclists, but there are some monsters out there among the pro track cyclists.

[langwadt]

https://zwiftinsider.com/wp-content/uploads/2016/01/ftp-table.png

Those tables are watts per kilogram.  Not too useful.  Even in the untrained portion at the bottom, if I were untrained and 250kg of fat, believe me, I will not generate ~580 watts in 5 minutes.  I would be dead of a heart attack attempting that pace within seconds.

Tables like this describe athlete types. Note that the lowest-tier rating on that table is "untrained (non-racer)". This means basically a self-trained non-professional person who is basically an athlete by hobby. 95% of people would fall completely outside of this table.

This is also why it works per kilogram; there's just this hidden assumption that anybody who gets on this table at all has very good muscle-to-fat ratio to begin with. If you totally exclude non-athlete types, then body mass is likely directly proportional to muscle power, even better than height is.

The most important reason that cyclist compare power with watts/kg is because they ride up hills.  Every kg you have to drag up a hill  needs more power to go the same speed in a race.  That's how you can compare the effective power output of a big dude and a small dude to see who would win a race.  But realistically, there are no pro BIG dudes.
Also it's largely irrelevant that they use w/kg for this discussion.  Just use a fixed weight for everything and you can focus on the differences between watts for the various levels, which is what we are after here. 
For reference, Chris Froome weighed about 69.9 kg.
https://en.wikipedia.org/wiki/Chris_Froome

https://www.topendsports.com/sport/cycling/anthropometry-tourdefrance.htm

[Smokey]

But realistically, there are no pro BIG dudes.

Not among pro road cyclists, but there are some monsters out there among the pro track cyclists.

Fact.  check out the legs on that track cyclist in the toaster video.  Dude is a Beast!

[Smokey]

...
https://www.topendsports.com/sport/cycling/anthropometry-tourdefrance.htm

That's a great article.  Interesting trends.

[PlainName]

PV panels are cheap;

What's "cheap"? I look around and see they are about £1/W, which I wouldn't class as 'cheap', particularly why you need to add inverters and what not.

[Refrigerator]

PV panels are cheap;

What's "cheap"? I look around and see they are about £1/W, which I wouldn't class as 'cheap', particularly why you need to add inverters and what not.

New panels here in Lithuania are as low as 0.33€/W when on sale.
But most new panels are 0.45€/W.
Inverters and other stuff add up on top, of course.

[PlainName]

Sounds like it might even be worth buying from there and paying import duty! If I could get that price here I'd seriously think about setting up a few panels (and arguing with the rest of the household where they can go).

[BrianHG]

A quality bike setup is more expensive than panels.  Do not expect scrounging together some random parts and a bike frame to last, be efficient enough & function when you really need it.

But, if you use your bike seriously for maintaining your health, IE create proper sound hardware, this may offset those $$$ concerns.

[Siwastaja]

PV panels are cheap;

What's "cheap"? I look around and see they are about £1/W, which I wouldn't class as 'cheap', particularly why you need to add inverters and what not.

Look at the context. In the context of "install 150Wp PV system", more panels are cheap, because installation costs, inverters etc. dominate the cost. There is also this difference that a too small of a PV system is still quite expensive and cannot run the fridge. A larger system is a lot cheaper per Watt, and will actually work, so inifinitely better than too small of a system.

Price of electricity is going sharply up, faster than PV system prices, so it's actually possible to make money on PV, now. So it's a really good idea to get a larger PV system in one go, instead of spending still relatively lot of money on a tiny system supposed to only run a fridge.

For example, I'm now selling to grid for around €0.20 on average, which is +300% increase in just a year or so. And the global energy crisis is real, it won't suddenly just go away.

[PlainName]

more panels are cheap, because installation costs, inverters etc. dominate the cost.

I'm going from the price of the panels. No inverters, fixings, labour, nothing. Just the panels.

[Cerebus]

A quality bike setup is more expensive than panels.  Do not expect scrounging together some random parts and a bike frame to last, be efficient enough & function when you really need it.

But, if you use your bike seriously for maintaining your health, IE create proper sound hardware, this may offset those $$$ concerns.

One of the most amazing things about bicycles in general, when compared to other machines, is how efficient they are. Even the rattiest old bike, as long as it has intact bearings, is over 90% efficient.

In any old cobbled together pedal powered generator the mechanical 'bike' component parts of it are probably going to be the least of your worries efficiency and reliability wise.

[Siwastaja]

more panels are cheap, because installation costs, inverters etc. dominate the cost.

I'm going from the price of the panels. No inverters, fixings, labour, nothing. Just the panels.

Well... yeah. I think getting a 400W panel for 250EUR which is approximately the current situation, is a bargain. This 400W panel provides nearly 10MWh of "free" energy over its lifetime. The current value of this energy is very roughly around  2000EUR, but energy prices are only going to rise. And this is just considering the monetary value of energy for someone with reliable supply available. For those with unreliable or no grid... Having supply of electricity is definitely worth investing a few thousands. People use that kind of money shopping for throwaway clothes in a year, without blinking an eye!

And that's my point - if you need electric power, install enough PV to supply that. You will thank me later when you actually can keep the fridge running, and not only fridge but some lights, too, and also be able to post on EEVBlog forum, and even possibly use some modest amount of hot water which is hugely convenient. And having to start the gasoline genset much more rarely is definitely worth it. Of course for totally off-grid, it would be hard to completely avoid that.

[tggzzz]

Given the current energy supply problem in Europe, it is probable that there will be planned rolling electricity cuts this winter. I remember them back in "good old days" in the 70s, and India in the 90s.

This document, which is old but current, shows the effects of the cuts in the UK. I presume something similar would happen in other countries.
https://www.gov.uk/government/publications/electricity-supply-emergency-code

TL;DR: 19 levels from 0 (no cuts) to 18 (no power). Level 1 is a rotating 3 hour planned cut per day, level 17 is a rotating 3 hours of power per day. In between there planned 6 hour cuts and 9 hour cuts, progressively more of them as the level increases.

IMHO it is prudent in Europe (and that still includes the UK), to expect 3 hour cuts and think about 6 hour and 9 hour cuts.

[tggzzz]

When considering powering freezers, the normal operating power and average power consumption are only part of the story.

Just as important is the current transient as the compressor start going.

I have seen transients of 5-10 times normal operating current for around 500ms. However, that measurement was on an old compressor (containing freon!) and I wouldn't want to presume new compressors have similar values. But I wouldn't preclude it either; research and measurement is required.

[EEVblog]

I plan on doing this soon. We have two fridge/freezers and a chest freezer.
EcoFlow are sending me a 3kWh portable battery which should have enough capacity to power them all.
I plan on having a manual mains timer that charges the pack durign the day from the solar (or whatever solar is available), and then power all the fridges and freezer and night. This would eliminate them from my household consumption, they'd be on entirely seperate systems.

I also plan on upgrading my Sunnyboy inverter to a hybrid inverter that has a backup mains output and that will do the same job. Can add battery storage to that to get emergency power to the fridges and other stuff if the power goes out. Could work with an in definite blackout.

[EEVblog]

Well... yeah. I think getting a 400W panel for 250EUR which is approximately the current situation, is a bargain. This 400W panel provides nearly 10MWh of "free" energy over its lifetime. The current value of this energy is very roughly around  2000EUR, but energy prices are only going to rise. And this is just considering the monetary value of energy for someone with reliable supply available. For those with unreliable or no grid... Having supply of electricity is definitely worth investing a few thousands. People use that kind of money shopping for throwaway clothes in a year, without blinking an eye!

Agreed, seems like a no-brainer.
Ecoflow also sent me two 400W portable fold out panels.

And that's my point - if you need electric power, install enough PV to supply that. You will thank me later when you actually can keep the fridge running, and not only fridge but some lights, too, and also be able to post on EEVBlog forum, and even possibly use some modest amount of hot water which is hugely convenient. And having to start the gasoline genset much more rarely is definitely worth it. Of course for totally off-grid, it would be hard to completely avoid that.

I thought about an entire house AC backaup battery system, but it's just not practical. It would have to huge and expensive, and requires extra cost in compliant installation etc.
So I thought a hybrid inverter with a smaller battery pack would do nicely for emergency power, as well as reducing by daily usage. The hybrid inverters have an emergency main output of a few kW that can power fridges and essential gear if needed.