Solar Panel Guide Discussion

grahamc2003

Ron, We're in Surrey, about 10 miles NE of Gatwick. ATM the sun is really bright, but surrounded by dense clouds. Miserable weather this am, but it's been sunny for a couple of hours on and off - the clouds don't seem to be moving. It's really bright in the front of the house now the tree has gone - an amazing difference!

David, Although I'm a Fellow, unfortunately I'm not that young anymore - but still young enough (just) to get the wood for my woodburner - a hundred quids worth when dry, which helps offset the cost of having it chopped. Got all the trunk bits two of us could carry - the rest I'll have to split to get it across the road and into my garden before someone nicks it. Also there's a massive pile of beech chips which I hope to find a use for, apart from adding to the barbeque.

Martyn1981

grahamc2003 wrote: »

David, Although I'm a Fellow, unfortunately I'm not that young anymore - but still young enough (just) to get the wood for my woodburner - a hundred quids worth when dry, which helps offset the cost of having it chopped. Got all the trunk bits two of us could carry - the rest I'll have to split to get it across the road and into my garden before someone nicks it. Also there's a massive pile of beech chips which I hope to find a use for, apart from adding to the barbeque.

Glad to hear your generation has picked up. With some free logs (will they be ready for next winter?) sounds like a renewables win, win.

Mart.

ronlizpatsimon

The pleasure obtained by being able to use free wood will be offset by the guilty feeling of adding carbon to the atmosphere!

Martyn1981

ronlizpatsimon wrote: »

The pleasure obtained by being able to use free wood will be offset by the guilty feeling of adding carbon to the atmosphere!

Ah, but in turn, Graham can offset any guilty feelings, by planting a tree!

To be serious though (for a change) burning wood in a well managed way is very 'renewable'. Just need to use a PV powered chainsaw or log splitter - damn, couldn't stay serious for long!

Mart.

LittleVermin

ronlizpatsimon wrote: »

The pleasure obtained by being able to use free wood will be offset by the guilty feeling of adding carbon to the atmosphere!

No, Graham won't to have feel guilty AT ALL. In fact he can go to bed with a smile of virtue on his face!

The wood is being returned to carbon dioxide and water and it's only being transported "across the road". And maybe the tree(s) will be replaced by a new carbon store (aka tree)? Doubly virtuous!

Meanwhile your pv panels have a large carbon cost - of mining the ore (and they are pretty lean!), extracting the metals and silicon (again carbon-intensive - aluminium, rare earths - phew!), manufacture, transport, erection .... not to mention the on-going carbon cost of sorting out your FITs! So your panels need to capture quite a lot of solar energy before they are carbon-neutral ... and they have an on-going cost.

(OK, I didn't include the carbon cost of the chainsaw, splitter, wheelbarrow - but lots of carbon-cheap iron there! - and a bit of petrol).

That's not to say that denuding the countryside of trees to fuel endless woodburners is a good thing! But Graham's neighbour's trees would have just rotted gently, releasing their stored carbon, if he does not use them.

[OK, the above is slightly tongue in cheek, but the carbon calculations get complex, and there are lots of lies about, let alone all the half-truths put out by the less 'careful' in the RE business.]
..

davidanddeirdre

grahamc2003 wrote: »

David, Although I'm a Fellow, unfortunately I'm not that young anymore - but still young enough (just) to get the wood for my woodburner - a hundred quids worth when dry, which helps offset the cost of having it chopped. Got all the trunk bits two of us could carry - the rest I'll have to split to get it across the road and into my garden before someone nicks it. Also there's a massive pile of beech chips which I hope to find a use for, apart from adding to the barbeque.

We find that having a logburner, trees tend to gravitate from being a nice green asset to the landscape to becoming just a potential source of logs.... e.g., see that oak over there? That's a 1000 log tree!
NB, I keep warm not only burning the logs, but cutting them up with a bowsaw & logsplitter (worried about cutting my leg off with a chainsaw)

orrery

LittleVermin wrote: »

Meanwhile your pv panels have a large carbon cost

No, they have a carbon investment, probably about 5 years generation in a UK climate from the figures I've seen. So, assuming that the carbon investment has already been made and all our panels are now providing the carbon free power for a doubling of capacity every 5 years then:

As there were (at least) 4,000 solar installations by 2010 then we can provide more carbon free solar installations than there will be buildings to fit them on by 2080!

Oh, we look at skips in a new light since we had a wood burner. We've raided 2 this week (with permission).

LittleVermin

orrery wrote: »

No, they have a carbon investment, probably about 5 years generation in a UK climate from the figures I've seen. <snip>

Unless your panels arrived on-site* direct from an extra-terrestrial source carbon dioxide has been added to the Earth's system to get your pv generation working. It's good to know that the estimate is that it takes about 5 years of pv operation in the UK to equal this.

Maybe you'd define "carbon investment", please? Such 'definitions' as I've found do not seem applicable.


*for a self-install!

Martyn1981

LittleVermin wrote: »

Unless your panels arrived on-site* direct from an extra-terrestrial source carbon dioxide has been added to the Earth's system to get your pv generation working. It's good to know that the estimate is that it takes about 5 years of pv operation in the UK to equal this.

Maybe you'd define "carbon investment", please? Such 'definitions' as I've found do not seem applicable.


*for a self-install!

Hiya LV, all terms mean different things to different people, but I'd think carbon investment makes sense if the PV generation replaces carbon producing generation. So the 5 years expenditure of CO2 is an investment (I've heard similar figures, around 2 years for the panels, and another 2 years for all of the other bits and bobs) if the earnings exceed 5 years.

Gonna need to do some checking, but I'm not sure about the rare earths reference. These materials are used for high quality magnets in wind turbine production, and also for top quality batteries, but I'm not clear if any are used in PV production. As to the silicon and aluminium, both are extremely abundant, however I appreciate that smelting aluminium is a horrifically energy intensive process. Can I be a little cheeky and point out that the Icelanders produce a lot using geo-thermally sourced electricity.

In fact it's fair to say that the more renewable energy we produce, the less CO2 that will be consumed in the production of the renewable technology, that is used to produce more ..... well, you can see where that's going.

Lastly, I'm not clear what you mean by 'on-going cost'?

Mart.

John_Pierpoint

Grid electricity is pretty high carbon at the moment; it is partly the CO2 needed to produce the electricity but more to the point the horrendous inefficiencies in the system - only about 1/3rd of the input energy emerges at your plug.

The rest goes up the cooling tower or down the river and to heat the toes of the birds on the wire.