Peak Oil v Alternative Sources of Energy

[eeyore]

as we are all agreed that oil is shortly going to run out - there is another impact which is largely overlooked.

no oil doesnt just mean no petrol , it also means no plastic or any of the other petroleum derivatives - take a look arround you and imagine your home without the plastic - big changes ahead (yes I know you can make plastic from vegetable sources but how are we goin to find the land area to do that and grow fuel, and grow food ??)

can you imagine a computer made soley from metal and wood for a start ??

[Rich_]

Good observation, and as you say has not really been mentioned. However, none of these oil byproducts are essential for survival by any means, our ancestors proved that. Why don't we just accept that these things will come to an end one day and we will have to learn to live as they did? I see a mad Max scenario in future though.

[Dark_One]

I suspect there is enough plastic out there which can be recycled in some way or other to sustain our plastic needs in the near future, but it will mean the more traditional materials - wood, pottery, glass and metal will come back into fashion :-)

Although metals are already starting to be in short supply.
Scrap metal merchants are raking it in - as are the metal thieves we keep hearing about !!

[eeyore]

Originally Posted by Laura J

It sickens me that WE Will inevitably go Nuclear.....The issue of where to put the waste is still frankly scary!
!

what gets me is that people group nuclear as a renewable which it isnt - theres only a finite ammount of uranium ( about 60 years after the date oil is forecast to run out) and when thats gone we really will be up the proverbial creek... sans paddle

[Sherlock]

Hello

Hot water mixings valves can sometimes be fitted to enable the hot solar water to be cooled before it reaches the tap. My system once reached 92C water temperature. That was before I added 5 more panels and 20 tubes. I later fitted a heat loss radiator on the north side of our house lo lose the heat once 65C had been reached. Good point about the blinds. Navitron have a real good forum there as you may know. I sometimes comment under the user name of OmidKnight. Some tubes are self limiting as to the heat output and other systems will drain when things get too hot.

Good points made by the the other contributors on this thread too.

[inholms]

Hello again.

Regarding my comments on Solar heating, you can read the claims made by the cowboys, if like me you get literature in the post most months from companies making the most outlandish claims. You can also see them on the internet. Companies like Rayoteck claiming “Daily hot water requirements can correspond to around 65% of your total water consumption. When spread over the whole year, this amount of water amounts to considerable energy and cost. A sensible use for solar energy is hot water supply with the help of solar collectors.” This is simply is not true. I doubt that I get 15%. I think the common misconception centres around comments made by ‘Dark one’ “In the Winter in the UK, you won't get a full tank of hot water with any solar system unless you've paid extreme amounts of money. What you will get with most systems is an increase in temperature in the tank by a several degrees - which means you burn less gas to heat the water up to full temperature”. Not true, the problem is that the Solar supply temperature has to be above 35 C to open the non return valves and that can’t happen in the winter as we are too far North. If you did not have the non return valves the hot water in the tank, heated in my case by oil, would heat the Solar panels !!!. I really wish I could say I had a system which works as my interest is simply to save money. I am sufficiently pragmatic enough not to be part of the ‘guilt brigade’ I will not be conned into having any guilt about making a personal contribution to saving CO2 emissions as clearly there is nothing of any significance that I can do.
When you consider that China and India plan to build a new coal power every month for the next 10 years, what the can hell will my contribution be to offset that? We have had our industrial revolution, they are just about to have theirs. Who’s going to tell them they can’t?

However, if someone tells me that I can save money and by the by also reduce emissions then I’m interested (not found anything yet apart from insulating my home) I’m not prepared to spend a penny or put myself out if there is no financial benefit to me.

The bottom line is there are too many humans on this planet and our mass, unhalted proliferation is going to be our down fall.

[Dark_One]

A non return valve simply allows a one way flow through the system, so that won't be based on temperature, it will be based on pressure.
The pressure will be supplied by the pump, and I suspect the pump has a built in thermostat.
If, as you say, it doesn't pump water until it has reached 35 degrees, then maybe the thermostat is set too high ?

On average, mains water is delivered at 10 degrees, so expecting a 25 degree increase in temperature in midwinter is a bit of a tall order in the UK - I agree.
I would however suggest checking the settings on your system.

See the following link for a fairly simple description of a Solar Hot Water system :

http://www.greenspec.co.uk/documents...terHeating.pdf

"The SDHW primary circuit should be controlled by a
temperature-sensitive device accurately measuring
the difference in temperature between the absorber
and the pre-heat storage or heat exchanger.
The differential is the difference between switching
points or thresholds. This is adjusted for an individual
installation according to the heat loss of the transfer
circuit and heat exchanger configuration. A long
distance between a collector and store would
require a higher differential than a short run.
The hysteresis is the difference in switching variance
around a given point: this can differ according to the
direction of movement of temperature (i.e. rising or
falling around the switching point). It can be adjusted to
avoid unnecessary short cycling or hunting of a pump.
A typical differential would be between 5ºC and 10ºC,
while the hysteresis would be between 2ºC and 5ºC."

Based on that document, I would expect your system to be pumping water that is between 15 and 20 degrees C rather than 35 ......

[Sherlock]

Well my solar water heating system comprises of a 1200 x 450mm non solar dedicated twin coil cylinder (slightly more capacity and slightly less efficient heat exchange). Panels facing due south and have a total flow and return pipe work of approximately 54 metres in 10mm copper tube

20 vacuum tubes and 17 square metres of matt black painted 28 year old flat plate panels situated on Salisbury Plain, Wiltshire

19th Decenber hazy sun 12 oclock on

Start of solar gain temperature 16C Sensor 450mm from the bottom of cylinder

0 litres water drawn approx between start of solar gain and end of solar gain

End of solar gain temperature 23C

There is an increase here of 7C plus the solar has prevented a fall in temperature of say 3C. That makes a gain of 10C approximately.

All it takes is some sunshine

Over the course of a year I estimate saving 50% of the cost of heating hot water. I try to do the washing (hot fill only) as soon as the solar system has reached a useable temperature. On the days that there is little solar gain - no machine washing is done

For further details google Navitron solar forum

[inholms]

Interesting comments.

Regarding my Solar situation, ‘the proof of the pudding is in the eating’. Having spent the time, money and effort, I end up with a system which does not deliver enough for me to want to promote it. Anyone is welcome to come and have a look and if they can suggest any cost effect improvement I’m interested.

I think the most important points to come out of this debate so far are the comments made by Sherlock, which demonstrates the fact, that if you can cobble together the components and have the skills and time, it is possible to make a cost effective system. I wonder if it would be possible to make a cheap free standing unit which could stand in the garden which did not require all the installation and was simple to plumb in. This way people could buy a unit and avoid the ‘cowboys’

The other good point is the underground heat storage idea, This is something I have considered previously. It makes great sense for new housing estates to have such a system. Not only could you store the summers heat, but you could also build an incinerator and burn domestic rubbish and put that heat in the system as well. This would also cut down land fill.

Cheers, Inholms

[Sherlock]

Yes underground storage. If only I could save all that wasted heat from the summer. Lots of good ideas on Its Not Easy Being Green Forum too. Quite a few have built their own systems.

Today temperature 17C start 23C finish