Saturday, 2 May 2015

Off Gridding it

Firstly, I have no practical experience of being off grid.
My food preps maybe run a month if I get creative, my pet food preps more like 6 months, my wood stores maybe a week. maybe 8 hours worth of batteries life in sex toys.

I am wildly interested in the subject, and quite well read.

So, my take.

My house is 9metres front to back and 6metres left to right and my roof is about 3metres tall, that sounds high but I'm reasonably sure.
4.5squared + 3squared = 30
square root of 30 = 5.4

So, 5x6 gets me 30sqms of useable roof space

There are two ways to go with solar panels, cheap panels that are limited by space, or expensive panels that are limited by cost.
I'll stick with space limited because I cant be bothered pricing up them all.
A 1.63515 square metre panel is rated at 235watts and costs £105

I can fit 18 panels, so for the cough low low cost of £1890 I can have a 4230w array,

But that isnt all of it.

If I dont go the Tesla route
I need a charge controller, A good one is £500, and two would be better, the controller stops the panels burning out the battery.

Either way I need an inverter.
The Tesla doesnt have one, inverters come in two flavours, cheap ones that will power the house lights for a few hundred pounds, and big ones that will power a house, a £5000

Cabling, frames, another £500

Plus batteries, the website I've been picking stuff off advises about a £4k bank,
20 batteries, 6v 350ah each
6x350ah = 2100wh
2.1kwh
42kwh

All in £11k

The biggest cost is the inverter, which converts the DC from the battery to AC for everything else
I've picked a big fat one, which can comfortably power a modern home, starter systems could use smaller ones, or you could use more DC power, stuff like heating, but you need the power first.
The second biggest cost is the battery, which is where Tesla pop up, now there battery isnt cheaper, so much as its better, significantly so.
Its only after that which we look at the panels, which is good in a way, huge arrays are available, for not much more money,

The problem is the same as the grid suffers really, peak demand.
Generating power is ok, I could, at the cost of a bit of back garden, double the size of the array above, I could sacrifice the front garden and get three or fur times the power, storing it is expensive but reasonable, but drawing it back out is hard.
If you are prepared to be a lot more conscious, you can half your inverter cost, but it means you can only power one big thing at a time, no simultaneous use of the washer, dryer, hairdryer and straighteners

The Tesla Power Wall

Pop over to here for the video

Tesla Motors claim to have solved carbon emissions (I didnt hear any actual climate change talk, beyond a muppet statement of atmospheric carbon has never been this high, which is patently untrue, because it bloody well came from somewhere)

Anyway

Gives a slide of "typical grid usage" deomstrating peak is double trough.
I personally wouldnt use a texas summer for that, because I dont believe thats representative of manywhere else.

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/295225/Seasonal_variations_in_electricity_demand.pdf

The UK sees a 37% swing in winter and only a 33% in summer

Summer trough to winter peak is 80%

Its a 10kwh battery, wall mounted, he isnt clear on what else is included, control wise.  Is it plug and play or do we need to add controllers and inverters to this?
My electricity usage is 14kwh per day
Its "only" $3,500 but thats still $7000 to cover me for a day,

You can stack 9, which is good to know, but despite what he says, 90kwh isnt a lot, I use an additional 67kwh of gas in heating, so 8 of these wouldnt get a day without power, I'd need all 9

No mains grid is of course the key here, and that is indisputable.  Out of the way locations that currently dont have grid power will be much better off with a couple of these sat between their current usage and their current supply.
We can probably expect mobile telecoms to actually be a huge customer, along with anything else that currently is backed up.


Found their website
http://www.teslamotors.com/powerwall

Now we get some truth

The 10kwh $3500 model is a "weekly cycle" unit, designed for back up
The Daily cycle model is $3000, for 7kwh

$428 instead of $350 per kwh stored, 9 of those wouldnt last me a day uncharged, but would suffer through a lot more abuse.
The output is low as well, 2kwh constant load of 3,3kwh peak
If your wife and daughter both want to blow dry their hair at the same time, one unit cant cope.
And the Inverter isnt included, youre talking $5k for a beefy inverter.

He's wittering on about a different model now, no price so far, and a requiremenr for 2billion of them.

So, big hype, with not quite the facts to back it up.
Thats not to say he's wrong, he's just blowing his load a little early.

Glide Bombs

A modern "glider" can have a glide ratio as high as 60:1, that is, for every foot it falls in unpowered flight, it travels 60 feet forwards.
A glide bomb dropped from 50,000 feet could impact 3million feet away, thats 568 miles.

Now, I know nothing about stealth or gliding, but it does seem like there is something there?
A glide package added to an optical/gps/ins guided bomb would give you fantastic reach

Shooting them down would presumably be fairly easy, if they can be seen, predictable arc of movement, but they would be significantly cheaper than the missiles thrown at them, guns could hit them eventually, but they could always jettison the glider for the impact phase?

There just arent high altitude guns anymore.

I think its an interesting topic on anti access type discussions.

Friday, 1 May 2015

Can I have £4000 from the safe?

Them: Can I have £4000 from the safe?
Me: Erm, noooo?
Them: What do you mean?
Me: Do you have authorisation, budget codes, A CASH BOX
Them: Hmph

5 minutes later

Them: Its all right abcd got it for me

5 minutes later

abcd: I gave such and such £4k



And then I lost it and went on a killing spree, on the inside of course.

Friday, 24 April 2015

A Safe is not Safe if...

A Safe is not safe if 30 people have unrestricted access to it.
A safe is not safe, no matter how thick the steel, how strong the locks, how armored the hinges, if the key is kept in a $10 key cabinet next to the safe,

Give me fucking strength

Wednesday, 15 April 2015

Invoice Numbers

TrT has gone back to a small business, no more kicking arse at a top 20 law firm or petrochem giant.
Hence his angry rants about people being stupid.

This week
Invoice numbers

The first invoice you send out, should be called 1
The second, 2
The five hundred and seventy sixth, 576
Leading zeros arent really necessary, 0000000000000001 is stupid, especially if you produce twenty invoices per month,

Invoice Numbers should not contain the date
2015/04-1 just makes you look like a twat, especially if the day before you send out 2015/03-14728

Invoice numbers should not contain some sort of code
Invoices that start with a 1 should not come come a different department than invoices that start with a 2, again, it just makes you look like a dick, I'M not learning what these 9 different departments are and sending you 9 different payments, and because you dont pay my fucking wages, you cant make me.

Combining points 1 and 3 really pisses me off.
Especially when its 16 digits and my system only copes with 12.

Lack of Purchase orders does not excuse late payment, but that you dont know who placed the order, where the order was delivered, or who signed for it does excuse not paying,

"Services Rendered" is not an acceptable description of services,

Dont reuse invoice numbers

Friday, 3 April 2015

the shit I have to deal with....

A supplier emailed me a copy of an invoice that had gone walkies (they do that a lot, seriously, scan your invoices or get fucked by a VAT audit).
Anyway, invoice comes in, I print, and notice its already signed by the budget holder and coded.
So I ring the supplier, who happily cobfeses the budget holder gave them a specimen signature that they print directly.

Yeah
Good job no one expects me to true and fair view this sack of crap.

Tuesday, 31 March 2015

the difference between the public and private sectors

Candidate 1
I oversaw a reorganisation using the prince2 methodology

Candidate 2
I oversaw a reorganisation and increased department turnover by 30%

Thursday, 26 March 2015

Ebola keeps on ticking

200 deaths per week
200 to 400 cases per week

Its not the disaster of 2000 per week predicted, 20,000 even, but its just not stopping.

Just sayin

Because *Science* bitchez

TrT has been playing with a new fangled HRM thingy for the gym and logging food.

And following on from this, goes in to calories out.

Now, there seems to be rather a lot of BroScience around what should be a pretty simple but of maths, although that said, I havent done MATHS mechanics in 12 years and PHYSICS mechanics in 13 so who knows, there will be some misuse of power and work and shit, fuck off, I'm an accountant now and dont have to deal with it.

Lets start with a treadmill, and F = MA

Force (newtons) = Mass (kg) multiplied by Acceleration (metres per second per second)

Well
My fat arse rocks in at 85kg.
A treadmill at 10kph, is accelerating a stationary object at, (10*1000/60/60), 2.7777 metres per second
85*2.777 is 236, newton metres per second(?), or handily, 236 watts

To not be thrown off the end (or run in to the bar), I need to to be providing a matching 236 watts.

Ok, thats not actual that helpful, Or is it?
Well, for all the mystery that surrounds it, a Calorie is a pretty simple thing, coming from Calor, which is greek or some shit for heat, and its the amount of energy required to heat, 1ml(?) of water by 1degree centigrade.  Helpfully, round here, its 4.1joules ish.

A Watt is a Joule per second

So, if we divide out 236 watts of sweat by our 4.1 joules of heating, we get 57 calories per second.

Hold on there science TrT, are you saying I can burn 57 calories per second at a modest jogging speed?
Why Yes, erm, questioning TrT, you can, the problem is, a calorie is not calorie.  When discussing food, we use the "Dietary Calorie", which is a kilocalorie, so lets divide that 57 by 1000, and we get 0.057, but thats per second.
If we multiply it by 60, we get a 3.5 calories per minute, and if we multiply that by 30 minutes, we get 103 calories.

Your running machine will give you a much higher number, it assumes you are an inefficient fuckwit and when you run you flail around, which is fair enough, it will also include the calories you burn just standing around making new skin cells and growing hair.

Weight Lifting
Now this is rather harder

Here, we have Mass, Height, and Gravity.

Lets say we are super beefcake, and lift a 200kg weight
And we go from ground right up to two metres
And we do this on earth.

We get 200*2*9.81 = 3924joules
Divide that by 4.1 to turn our joules to calories, and by a further 1000 to turn our calories to kcal, and we get, well just shy of 1 calorie.

A more realistic lift of 50kg, 3x8 set/rep, burns 5.7 calories

But I'm not sure.
From a potential energy point of view, I'm pretty sure I'm on the money
But if we go back to F=MA, to hold that weight off the gound and steady, requires further energy.

Anyway, I was bored at work today and played with spread sheets, feel to check my maths and shoot holes in my reasoning.