Hydrogen Vehicles

[Ben@Forest]

Yes and no.

We have ground source heating from a vertical bore. It uses electricity from the grid to drive the pump and the controller that handles thermostats and the responses of the valves of the system to ambient conditions. However, we also have solar panels that generate more electricity than is used by the heating pump, water pump (another bore hole) and some of the other electric thingies of the house. Some not all.

I've read an article which, taking the author's house in New England as an example, stated that in a worst case scenario it would take 29 years to 'pay back' the fossil fuel investment in making the panels. Annoyingly he doesn't say what the best case scenario was!

Of course conventional ways of creating and delivering power are also fossil fuel dependent and he was pro solar panels, just noting they weren't a silver bullet.

[kwackers]

I've read an article which, taking the author's house in New England as an example, stated that in a worst case scenario it would take 29 years to 'pay back' the fossil fuel investment in making the panels. Annoyingly he doesn't say what the best case scenario was!

Of course conventional ways of creating and delivering power are also fossil fuel dependent and he was pro solar panels, just noting they weren't a silver bullet.

That'll be this article.

It's nonsense because his estimate assumes that the cost of the solar panel is equivalent to the energy used to make it, his calculations say that if the panel costs $150 and energy is $0.165 per kwh then the maximum energy used is 9.1MW

That's not even close.
Some obvious facts - that solar panel doesn't cost the producer $150, nor despite his best estimates are the raw materials free and wherever they come from someone is marking them up. Nor is the actual cost of energy the same as what he's paying that's also marked up.

My understanding of the process of making solar panels suggests it's a energy intensive process not dissimilar to making glass so the power used is in the order of a few KW per square meter.

The energy payback for solar panels by my overly conservative guestimate is no more than a few months. If it was a year I'd be fairly surprised and would want to see how it was worked out.

What he's really talking about is how long the payback for him personally is based on cost rather than the energy cost payback.
With no subsidies the payback typically for a 4KW installation would be about 10 years and with whatever the current subsidy is it'd somewhat less.

What's worth pointing out is that the payback drops off with installation size since most people would only use 4KW intermittently, my house with all the gadgets ticks over at about 400w so a pair of 250W panels would be in full use all the time and so would have a decently short payback period whereas any panels over that only get periodical use so I'd end up providing cheap (i.e. free) energy to the grid for most of the time.

If you have an electric car and the capability to grid-tie it then you can store that extra power and use it when you need it, payback drops then to nearer 3 or 4 years (I assume the car exists anyway so it's cost doesn't matter).

[Cugel]

But there would go the woodworking and the electric car.

A real woodworker would eschew electrical thingimajigs and use good old hand planes and saws.

If you have an electric car you don't need a house battery, simply get the car to dump power back to the house during the night.

I yam a pretend woodworker who is really a player-with-man-toys chap.

To get the car to power the house requires a charge of it's battery by running it's petrol engine. It can be done!. The next version planned by Mitsubishi for their hybrid has exactly that arrangement in mind, with the car engine serving as a UPS for the otherwise off-grid hoose, when the sun don't shine and the wind don't blow. However, I don't want to use the petrol engine, see? Just the lovely sun & wind, so the bairns don't choke, get asthma and end up stunted.

I suppose you could park the car permanently and use it only as a very expensive UPS battery. But why, then, bother with the car bits?

Cugel

[Cugel]

Yes and no.

We have ground source heating from a vertical bore. It uses electricity from the grid to drive the pump and the controller that handles thermostats and the responses of the valves of the system to ambient conditions. However, we also have solar panels that generate more electricity than is used by the heating pump, water pump (another bore hole) and some of the other electric thingies of the house. Some not all.

I've read an article which, taking the author's house in New England as an example, stated that in a worst case scenario it would take 29 years to 'pay back' the fossil fuel investment in making the panels. Annoyingly he doesn't say what the best case scenario was!

Of course conventional ways of creating and delivering power are also fossil fuel dependent and he was pro solar panels, just noting they weren't a silver bullet.

It's true that there'll be a fossil fuel bill, under the dominant factory arrangements for power usage, for making anything at all. So, two points:

* Factories too could become largely powered by renewables, along with much of the background processes such as mining and transport.

* If you use fossil-fueled power generators rather than those driven by renewable power, there's probably the same fossil-fuel "bill" for making those generators, so you still use less fossil fuel overall when using renewable-power things, in the larger equation.

Cugel

[gaz]

... an electric vehicle will be an ideal local runabout IF the owner has a drive or garage with power.

Al

In the words of Woody to Buzz Lightyear:

We’ve got AAs

[youtube]iEjTwsfqHOY[/youtube]

[PDQ Mobile]

Cugel it looks like you are the only one!
Whatever will we do when fossil reserves run scarce?

I am interested in whether your solar panels do in fact cover your total annual electric consumption?
A family member has ground source heating, an older installation, and more recently roof panels to try to offset the high leccy bills.
The ground source heating is quite high demand, 2 or 3 kwh if heating hard if memory serves (it's a decent sized house).
The point about using EV battery as a energy source for periods when the sun doesn't shine ( like winter?)
Is partially flawed I feel.
To run a heat pump such as yours for longish periods will surely result in a discharged battery and no car in the morning, at the very least?
Personally I doubt that a normal sized panel installation of 4kw output could cover those conflicting requirements. Indeed given a cloudy and dark Welsh winter of 3 or 4 months duration it looks to me as if one would need to run the car engine quite a lot.
Given the inevitable losses in such a conversion, one wonders whether a simple (seasoned!) wood fire might not be more efficient!!

[Mick F]

Doesn't stored leaded petrol go off after a period of time?

Leaded?
Unleaded doesn't go off.
Some folk reckon that you shouldn't leave fuel in your garden machinery for months coz it clogs up the carbs.
Not in my experience it doesn't.

Mower starts first or second pull after a winter lay-off. Chainsaw, hedge trimmer, leaf blower, brush cutter likewise. I never ever drian the fuel and never ever have.

[kwackers]

Modern solar panels produce a reasonable amount of lecky even on cloudy days.

My neighbour has a grid tied car and panels, they reckoned it'd had cut their lecky bill from near £1000 a year to not a lot over £100.
How true this is I can't say - they also have underfloor heating but I'm not sure what the supply for that is.

There was an online chart somewhere that someone in the NW of England had posted of their generation stats over a few years for their solar.
I used it to figure out what it meant for my personal use, I reckoned it would cut my bills by about 30% and if I had 10kw of battery storage it would cut it by 80%.

I'm personally waiting on two things. I have a room above my workshop my missus wants to use as a studio - it needs Velux fitting which means some roof work so I'm holding off on solar until after that. Then when I get a lecky car and charger it'll be grid tied.
I can't justify the cost of ground source heating - I simply won't live long enough and I reckon when my house gets sold it'll be bought by a developer and half a dozen houses rammed onto it's footprint so there's not likely to be a long term benefit for society either.

[kwackers]

I yam a pretend woodworker who is really a player-with-man-toys chap.

Me too!

To get the car to power the house requires a charge of it's battery by running it's petrol engine. It can be done!. The next version planned by Mitsubishi for their hybrid has exactly that arrangement in mind, with the car engine serving as a UPS for the otherwise off-grid hoose, when the sun don't shine and the wind don't blow. However, I don't want to use the petrol engine, see? Just the lovely sun & wind, so the bairns don't choke, get asthma and end up stunted.

I suppose you could park the car permanently and use it only as a very expensive UPS battery. But why, then, bother with the car bits?

Cugel

Ah right, I assumed full electric which with their huge batteries make a lot of sense to grid tie. Less so a hybrid.
Perhaps I could grid tie my lecky bike - 600Wh! Mind you I've tailored my commute assist to pretty much empty the battery so there's not really much spare capacity...

[bigjim]

Doesn't stored leaded petrol go off after a period of time?

Leaded?
Unleaded doesn't go off.
Some folk reckon that you shouldn't leave fuel in your garden machinery for months coz it clogs up the carbs.
Not in my experience it doesn't.

Mower starts first or second pull after a winter lay-off. Chainsaw, hedge trimmer, leaf blower, brush cutter likewise. I never ever drian the fuel and never ever have.

Apologies. I did mean unleaded. I have read about unleaded gumming up carburettors many times.

[Mick F]

Apologies. I did mean unleaded. I have read about unleaded gumming up carburettors many times.

No probs!

I've read about unleaded gumming up carburettors many times too.
Not happened to me at all ever.
Been using petrol garden equipment for 22 years here at this address. Moved to this pace in April 1997.
Dunno why other folk have problems and I don't. I don't understand at all.

Previous place just up the road was less of an issue with grass etc and no trees or banks so used lecky mowers on strimmers. Moved there in August 1985 BTW.

[Cugel]

Cugel it looks like you are the only one!
Whatever will we do when fossil reserves run scarce?

I am interested in whether your solar panels do in fact cover your total annual electric consumption?
A family member has ground source heating, an older installation, and more recently roof panels to try to offset the high leccy bills.
The ground source heating is quite high demand, 2 or 3 kwh if heating hard if memory serves (it's a decent sized house).
The point about using EV battery as a energy source for periods when the sun doesn't shine ( like winter?)
Is partially flawed I feel.
To run a heat pump such as yours for longish periods will surely result in a discharged battery and no car in the morning, at the very least?
Personally I doubt that a normal sized panel installation of 4kw output could cover those conflicting requirements. Indeed given a cloudy and dark Welsh winter of 3 or 4 months duration it looks to me as if one would need to run the car engine quite a lot.
Given the inevitable losses in such a conversion, one wonders whether a simple (seasoned!) wood fire might not be more efficient!!

We're in a strange situation, in which previous policies and associated economics of ground source, solar et al have limited, to a degree, what is economically the best thing to do now.

The extant solar panels generate a max 4Kw, which was the limit for which the then government subsidy ( 8 years ago) demanded electricity suppliers paid for the solar juice pumped into the grid. We would now like to double or triple that amount with more solar panels but to do so immediately cancels the extant contract for supplying the grid with solar juice. That contract pays us about £1400-1800 a year and will do for the next 19 years so we're now motivated not to muck it up by .... installing more solar. That's daft really.

All our solar juice is put back into the grid. We take out of the grid what we need and pay for it as anyone else does. Our yearly electricity bill looks set to be £800 at most. This is a lot less than we get for the solar juice but we get paid more per KwH than we pay for grid KwHs. Also daft, really. In terms of use, our solar panels generate perhaps 2/3rds of the amount of electricity we use, so there's a shortfall.

Personally I'd be happy to be subsidised a bit to install lots of solar but then to get nothing for any excess fed into the grid. That would encourage uptake of solar but only require a single subsidy per panel installation, not a subsidy for the next N years.

On the other hand, I hear of communal schemes where, for example, a whole village installs wind, solar and other renewable power sources then buys-sells the energy within the community. They can apparently make savings of scale (e.g. by buying and running one big village windmill and using one big village battery).

Cugel

[PDQ Mobile]

Cugel please excuse delay in reply.
Was out for supper.

Thank you for your answer.

I was interested in the simple sum
Does a solar installation cover an "eco house's" electric? Without an electric vehicle on top.?

So as I suspected a standard 4kw solar installation does not provide enough leccy to run an "eco" house in Wales plus heat pump heating over the whole of a year.
They only managed to produce "around 2/3rds".


The other figures you quote do sound as if the poor non solar installation consumer who tries to use as little leccy as possible is heavily subsidising the heavy user with panels that fail to deliver.

I suggest that given the figures and installation that you have at present, an Electric Vehicle would simply be using conventionally generated electric?
And therefore still nowhere near carbon neutral.

So I understand the conundrum for you, install double the panel size and ;that is quite a big area) which would cost around 5k (maybe?) and lose the subsidy of 1200 a year.

Unless I have overlooked something (and that is very possible?) to run even a very well insulated house with efficient geothermal domestic heating plus a small EV or even an electric bike on a reasonably sized solar installation looks impossible on a yearly basis.

[kwackers]

I suggest that given the figures and installation that you have at present, an Electric Vehicle would simply be using conventionally generated electric?
And therefore still nowhere near carbon neutral.

EV's doing average mileage need about 200Wh, call it 600Wh for 8 hours of daylight.
Easily within a solar installation's capabilities.

You can't be self sufficient without battery backup. Most of the time you simply can't use the power produced so it just ends up being dumped on the grid. And when you do need power you tend to need a lot. Most home EV chargers are 7Kw, 3Kw for an electric kettle and another Kw or so for lights, TV and any bits and pieces.

Fortunately apart from the famous soap opera tea breaks demand tends to be sporadic so you can rely on your neighbours solar installations to fill in the gaps.

Obviously as batteries become more commonplace (or grid tied EV's) then your battery/EV can be relied on to provide power during high demand and soak it up as demand falls - both for you personally and the system as a whole.

Now we no longer have the 4Kw "limit" for some people it makes more sense to put a larger array on their roof.
If I was Cugel I'd sneak a few extra panels up there anyway. His inverter may limit the power to 4Kw but more panels mean its more likely to produce 4Kw even on dull days (and obviously more power during the winter).
I believe (but it's worth checking) even in his case he can legally add more panels without issues as long as his inverter is limited to 4Kw.

Micro inverters are a good thing for scaleability. You can just keep adding panels as and when - plus they're less fussy about panels going into the shade.

[PDQ Mobile]

I know your a fan Kwackers and I am too.
I think solar is fantastic though I am less happy about old subsidy levels.
Such subsidy's credentials as fully "green" are questionable IMV.
Note Cugel's example above!

But as in most things I like to think of myself as a practical realist!

Even with a well insulated home with one of the most efficient domestic heating systems available, albeit one that uses a fair bit of leccy, there is no annual excess (in Wales) for an EV -not even a bike!