Wookey recently quoted "McKay estimated average UK personal consumption (including 'stuff', transport, food+agriculture etc) to be 195kWh per person per day".

How much should we each use?

At home I have used on average 16kWh per day for the past year.

close to 2000W of power usage 24/7 365 days a year.

That's interesting.. A person only produces, what is it, 100W of heat output on standby? Not a very efficient conversion rate.

Our personal carbon footprint at home for my family of 4 is going to be about 250kgCO2e for the *year* for 2010 electricity and gas (ie heat and light) whereas 6 years ago for just two of us it was 6tCO2e for each year.

Our net consumption electricity is about -1.4kWh/day/person, ie we are net exporters to the grid.

http://www.earth.org.uk/saving-electricity.html#meter2010

But that is only a smallish part of the picture as pointed out above. MacKay suggested to me that the UK gov produces about 5t+ of CO2e per year per citizen on thier behalf just for a start, ie ignoring food and what MacKay calls "stuff" (eg embodied energy in all the junk that we buy).

And yes, pulling up the ladder after us on purpose would be selfish and unreasonable. We may be doing anyway by depleting reserves of oil, etc...

Rgds

Damon

Here was my page based on MacKay's "Can we live on (local) renewables" chapter. I had to invent^Wresearch some of the numbers but most of the substantive ones are his:

http://www.earth.org.uk/can-we-live-on-local-renewables.html

Rgds

Damon

Well you are mark time . any link with mark twain

Using energy isn't the problem. There's loads of it about. The problem is using the sort of energy that destroys our environment. That should be zero. Nothing more will do.

Posted By: SteamyTeawe have to be create huge carbon sinks that are permanent storage

It's great vision - put back into the ground all the hydrocarbon that we've taken out, in the form of e.g. charcoal.

About two thirds as much energy as we've released in 150yrs by oxidising (burning, eating, rotting, composting) the stuff will have to be pumped back into the chemistry, to reduce all that carbon oxide back to pure carbon. We get to keep one third of the energy we released - the bit that came from the hydrogen in the hydrocarbon - we don't need to reduce the hydrogen oxide to pure hydrogen and put it back into the ground.

Where will all that energy come from? The sun of course. Any scheme of massive carbon sequestration will require vast amounts of solar energy - no escape from that. Unless we can enlist the plants too do that job for us, e.g. trees/biomass embodies just such captured solar energy, including the hydrogen that when burnt provides not only a bit of useful energy, but also the input to chemistry that converts the rest of the tree/biomass to pure carbon/charcoal, which is fairly stable and immune to involuntary further oxidation, thus ideal to sequester 'permanently'.

Posted By: DamonHDby increasing stands of live woodland

Yes, but to be clear, increasing woodland is only a one-off contribution to carbon sequestration - carbon is certainly sequestered in the increase, but once up and running all woodland becomes (in principle) neutral i.e. neither contributing to nor detracting from sequestration.

To recap, sequestration means taken out of the carbon>CO2>carbon>CO2 cycle, which means CO2 is removed from the atmosphere and put somewhere safe 'forever'.
It must not seep out 'ever' if it's sequestered as CO2 e.g.

Posted By: DamonHDby pumping CO2 into old oil wells

If it's sequestered as reduced (i.e. de-oxidised) carbon it must also be 'forever', either as pure carbon e.g.

Posted By: DamonHDby burying biochar

'forever', or as hydrocarbon/biomass e.g. timber stored warm and dry 'forever' within building fabric.

The 'forever' bit is vital - it's no good sequestering now if it either slowly escapes, or is carelessly burnt or allowed to rot sometime in the future (when the building is demolished or decays). Particularly, sequestration must not depend upon flawless human maintenance 'forever', otherwise it becomes a political weapon/blackmail tool/magnet for madmen, just like we're creating with nuclear waste. Sequestration must continue to work 'forever' even if there's breakdown of civilisation.

Posted By: DamonHDthere is so much more oxygen that carbon in the atmosphere that pumping some of the oxygen down with the carbon, ie sequestering CO2 underground, is no problem

I agree. But I don't understand what happens to the CO2 once it's down there, long term.
Does it stay as CO2 forever? I doubt it - must surely react with something - to become what?
At depth, it must be under pressure, so does it really not escape via crevices eventually back to the surface? It's so much less viscous than the oil that was there previously, which does naturally escape to the surface.
Is the CO2 expected to eventually become inert solid, as limestone or something? Is energy-input available e.g. earth-core heat, to drive endothermic reactions?

Anyway, how come the cavity is still there to fill? As pressure drove the oil up the oil-well, why hasn't the same pressure either collapsed the emptying cavity, or filled with water? Coal mine workings soon collapse to nothing, if not constantly maintained.

Posted By: fostertomSequestration must continue to work 'forever' even if there's breakdown of civilisation.

I agree with that statement in principle but it sets the bar awfully high.

If there's a breakdown in civilization then people won't be able to use fancy wind turbines or solar panels. But in order for civilization to recover, they'll have to repeat the industrial revolution and subsequent changes (hopefully in a better-informed and less destructive way) to the point they can practically and economically make and use renewable energy sources again. So what we need to sequester is fuel. Figuratively, we need to refill the coal mines and the oil wells.

After people have thought about the practicalities and likelihood of that for a while, many find themselves strongly supportive of space development, so we don't keep all our eggs in the one basket.

"big power consumtion is fine as long as it is green power whats the harm there"

-----

If every increase in green power capacity is accompanied by increase in power use, on the basis that the "big power consumption is fine", then it really makes no serious contribution to CO2 reduction overall. In order to be green, the purpose of building renewable energy capacity must surely be to replace fossil fuel production, not to create new arenas of guilt-free 'big power consumption'. (Solar-powered garden lights spring to mind)

The power you don't use is still the greenest power of all - since there is no green power that does not involve some kind of EROI calculation.

Posted By: jolly-green-giantIf you fill uk with wind and sollar you must have a back up

Who says? why? The 'back up' power stations are more likely to break down than wind, sun and tide. The latter, collected geographically widespread and averaged together, can produce a well-predictable and reliable supply, and storage is the holy grail under development to cope with demand spikes that remain after smart metering/pricing have evened them out.

Posted By: jolly-green-giantlive life to the full

too right but that doesn't necessarily equal power consumption. There's massive scope to do the same or even more 'living' while using a fraction of present power.

Posted By: jolly-green-giantbig power consumtion is fine as long as it is green power whats the harm there

That's also true - so where does

Posted By: jolly-green-giantyou will never be able to get rid of power stations so they will never go, so live life to the full

come into it? Seems to me that if you argue to keep power stations significant in the future supply picture, that's exactly what will necessitate consumption restraint, scarcity and high prices and continued large scale CO2 emission.

Posted By: DamonHD
The cavity is something...

There aren't actually 'cavities' in the sense of great big holes. Natural gas is trapped in the pore spaces of rocks such as sandstone and sealed by overlying non-porous rock such as clay or salt. CO2 could equally be kept in such places effectively for ever.

There are two big problems with carbon capture and storage. Firstly there are only limited places where the geology is suitable and not too far from where the CO2 is being captured. Secondly, and very importantly, capturing and pumping the CO2 down uses a lot of energy, thus making the power-station less efficient. This energy cost, just at the time we are running short of energy, will be the deal-breaker for most CCS schemes. Our economies will not afford the process.

Biff: I'm not necessarily advocating, just saying why it could work given my limited understanding.

Urban PV has a more clear positive EROEI which is why I'm doing my damndest to promote that for now, after conservation.

Rgds

Damon

Cobblers that!! if you squash chalk you get limestone