unixman_again Posted July 23, 2014 Posted July 23, 2014 I found this UK supermarket will be the first to disconnect from the grid, use electricity generated entirely by its own rotten food on a US website today and wondered why the local press hadn't covered it. Seemed they had Express & Star and I missed it. I think this is a very cool idea and hopefully more will follow.
pcstru Posted July 23, 2014 Posted July 23, 2014 It is neat yes but it's just a shame we fly some of that food half way round the world just to throw it away.
featured_spectre Posted July 23, 2014 Posted July 23, 2014 I am of the opinion everyone should grow a large portion of their own, whether as a community with a smallholding, or allotments, or in their own gardens. This way, they grow what they need, and if they want something their neighbours have, they can barter and trade. If they need anything further from what they've grown, then they can buy from a greengrocer, but hey ho, that's just a pipedream!
abillybob Posted July 23, 2014 Posted July 23, 2014 Will it be completely capable of powering the store for the hours it's open or is it just like a small energy reserve? I can't imagine food waste would produce enough electricity to power the store and take it off the grid! It depends on how big the store is swell as the store I used to work at is fairly small and the food waste was very minimal!
Arthur Posted July 23, 2014 Posted July 23, 2014 (edited) I can't imagine food waste would produce enough electricity to power the store and take it off the grid! From Sainsbury's website... "This remaining food waste is collected from Sainsbury’s supermarkets around the UK using Sainsbury’s delivery lorries. It is returned to Biffa’s plant in Cannock". The electricity Sainsbury's currently generates from food waste is enough to power 2,500 homes, so I'm sure they could completely power the entire Cannock store. Edited July 23, 2014 by Arthur
PotNoodleTech Posted July 24, 2014 Posted July 24, 2014 I sincerely doubt that they will sever their tie to the national grid. That would be commercial suicide. What if the lorries don't arrive, or there's not enough thrown away food? You shut the store?
featured_spectre Posted July 24, 2014 Posted July 24, 2014 I sincerely doubt that they will sever their tie to the national grid. That would be commercial suicide. What if the lorries don't arrive, or there's not enough thrown away food? You shut the store? They could also shove some solar panels on their roof to get additional power, along with maybe some small wind turbines. They could then have some redundancy.
PotNoodleTech Posted July 24, 2014 Posted July 24, 2014 What if the lorries don't arrive, or there's not enough thrown away food, and it's a cloudy day with no wind? You shut the store?? No matter how many renewable technologies you bolt on - you'd still need it grid tied to cope with the what if scenario IMHO.
abillybob Posted July 24, 2014 Posted July 24, 2014 They could use human waste, a person walks into the toilet does a dump and it goes straight into a generator????? YES I HAVE INVENTED A SOLUTION TO THE WORLDS PROBLEMS!
featured_spectre Posted July 24, 2014 Posted July 24, 2014 (edited) What if the lorries don't arrive, or there's not enough thrown away food, and it's a cloudy day with no wind? You shut the store?? No matter how many renewable technologies you bolt on - you'd still need it grid tied to cope with the what if scenario IMHO. Solar will still charge with it being a cloudy day, it just wont be as efficient. My home made panel on a cloudy day will be around 25% efficient compared to a sunny day where it is around 80% efficient (its home made so I don't expect it to be perfect). Professional ones which have a better grade cell, would be far superior to mine, so will still generate electricity. Still day, well that is fair enough, but small turbines which attach to solar panels don't require massive amounts of wind to get going, a 5mph breeze would be sufficient to get it moving and generating electric (albeit slowly). *edit* Also, your what if scenarios, whilst plausible, wouldn't affect it in the long run. They'd likely have a system in place for energy storage, so if they miss a day, they use the batteries heavily compared to a day where it would trickle charge whilst in use. Edited July 24, 2014 by featured_spectre
clareq Posted July 24, 2014 Posted July 24, 2014 It's self perpetuating - they fail to produce enough waste food, the power goes off, the freezers go off - hey waste food... 1
unixman_again Posted July 24, 2014 Author Posted July 24, 2014 My mother's system (she's in Australia) works on bright moonlit nights. Over there, they have a system where-by power that you give back to the grid, is deducted from your bill. There was a bit in todays Metro, that Ben & Jerry's have a similar bio-mass generating plant at their factory in Holland. They have named it The Chunkinator
pcstru Posted July 24, 2014 Posted July 24, 2014 Solar will still charge with it being a cloudy day, it just wont be as efficient. My home made panel on a cloudy day will be around 25% efficient compared to a sunny day where it is around 80% efficient (its home made so I don't expect it to be perfect). Professional ones which have a better grade cell, would be far superior to mine, so will still generate electricity. 80% efficient?!? Efficient at what exactly??? In terms of turning incident energy (the light falling on a cell) into electricity, the best mono crystalline solar are around 30%. There are some cells with higher quoted efficiency but only when used in a concentrator (mirrors directing light from a larger area onto a smaller area of PV cells). The theoretical maximum efficiency of a PV cell is just over 80% but no one is even close to that.
pcstru Posted July 24, 2014 Posted July 24, 2014 My mother's system (she's in Australia) works on bright moonlit nights. Define "works"! I very much doubt any PV cell will show any voltage into a load under moonlight. There is only about a thousandth of a watt per m^2 with a full moon. You might be able to use one to measure how much light there is, but saying it "works" as a PV panel would be a huge stretch.
featured_spectre Posted July 24, 2014 Posted July 24, 2014 (edited) @pcstru sorry should have been clear. They're 80% efficient at creating electricity from their maximum advertised wattage range per cell. My apologies on not being clear. In a test before building my panel (max of 270wH as per cell advertised max and number of cells) 1 single 7.5w cell I can get between 1.8w and 6w depending on how good a day it is. This is me testing on hooking up a multimeter directly to the cell tabs when they've been soldered on. I'm not saying it will sustain that, but thats what I've gotten out of them on a direct connection. Edited July 24, 2014 by featured_spectre
unixman_again Posted July 24, 2014 Author Posted July 24, 2014 Define "works"! I very much doubt any PV cell will show any voltage into a load under moonlight. There is only about a thousandth of a watt per m^2 with a full moon. You might be able to use one to measure how much light there is, but saying it "works" as a PV panel would be a huge stretch.The meter says power is being returned to the grid. When you turn the lights on, it says she is drawing power from the grid.
pcstru Posted July 24, 2014 Posted July 24, 2014 @nephilim - OK, so you are getting 80% of their rated output, that makes sense. BTW you might be interested in the Open Energy monitor project. I'm in the process of building a system after a bit of a shocking bill. The meter says power is being returned to the grid. When you turn the lights on, it says she is drawing power from the grid. If the meter says she is returning power to the grid on a moonlight night, either the meter is wrong or she doesn't understand what it is telling her. It could for instance be the system allowing any battery capacity to bleed off to the grid, so that come morning, they can be topped up by the sun. She is not generating any power from the light of the moon - that is absolutely certain! 1
eyetea Posted July 25, 2014 Posted July 25, 2014 It's self perpetuating - they fail to produce enough waste food, the power goes off, the freezers go off - hey waste food... Then they could fire up the gennies again
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now