The simple answer is that there is no simple answer; However there is a though process...

Future Proof.

Whatever you can not afford now make sure that the building is easy to upgrade.

This may mean adding extra service runs; for example grey water pipes, Solar loops, Wiring for PV...

One of my favourite measures (for example) is to run piping to a fire place so that a biomas back boiler equiped stove can be added later. Cost is small future potential is very low carbon heating when cheap wood pellets (stoves and fuel) become much cheaper in the UK.

In the mean time invest the balance in renwable companies. In a few years the moeny can be used to buy cheap PV systems (You will have already made sure the roof is easy to upgrade and the wiring is in place...

Another approach (not simple is it?)

Reduce energy (and water) usage in the home (usually a better aproach than generating extra energy).

For example:

Energy meters.
Automatic night time shutters
Complete low energy light design (Use low energy daylight quality bulbs that are superior and less likely to be substituted).
A+ whiter goods, most imprtantly the fridge - get the best you can as this is usually the biggest electrical consumption in a home..

------------------------------------------
THere are other way also emerging - such as interseasonal storage (Probalby need more than 10K through)....

Posted By: PaulTnot simple is it?

..did I say it would be simple...?

J

How about one of these parked on the drive:-

http://evolution.loremo.com/content/view/13/47/lang,en/

I understand they will cost 11,000E, so you will have some change.

Perhaps use the £10K to pay the premium charged for electricity on a "green tariff". Check the small print but with the right supplier it might be possible to get ALL your electricity from a 100% green source for the next 20 years. Whereas a £10K windmill or £10K worth of PV stands no chance unless you have very small house. Main problem is it just isn't sexy.

http://www.greenelectricity.org/

http://www.greenelectricity.org/tariffdetail.php?tariff=gde1®ion=regEast

You're building to passiv haus so skip the wood chip boiler as you probably just overheat or never use it.

PV for me, but perhaps not just yet ... take the "green tariff" option above for a couple of years, keep the money burning a hole and then implement more PV when the pay-off period becomes more palatable.

Also consider rain water harvesting, at least for toilets, perhaps for washing?

James

I think a bonus relating to pressure test result is a great idea,

a lot of guy I know and work with have no interest in details when it come to insulation
you could invent some scale incentive for each percantage increase above regs.
perhaps a grand in cash per scale increase would do it , up to say 3

A greenhouse, a potting shed, a cold-frame, seed, fruit trees and bushes, hire a rotavator, build some raised beds, you get the drift.....

I wouldn't put the cash anyway near a bank, James. By the time the taxman and inflation have finished with you you'll barely be able to buy a solar power calculator never mind a PV array! Silver bullion's the place for it (real money that holds its value).

Posted By: Paul in Montreal

Posted By: Chris WardleSilver bullion's the place for it (real money that holds its value).

Chris, there is no such thing as "real money". It's all a collective agreement as to value - there is no intrinsic value.

Yes, but the collective agreement that silver and gold have persistent value has held over several thousand years, whereas no single paper currency has lasted anything like that long. In that sense, he has a point. However, I'd advise people not to take Chris' approach unless they believe that the risk that the value of their savings and paper currency will decline to zero is larger than the risk of a dramatic (and unfavourable) fluctuation in precious metal markets...

Dan

... lovely .... all very interesting I'm sure... however.....

Posted By: James Norton...what would you spend the cash on, in terms of the building, (ie women, [or men], drink, drugs and fast cars are not an option [in this context])...?

... candidates so far, (above alternative notwithstanding):

- 1.5 kWp of PV
- an urban wind turbine (3kw ish..?),
- a micro CHP unit (or at least pre order one)
- wood chip boiler for DHW and top up (in this context; as opposed to gas)....

...thinking about simple/dynamic economic / C02 payback, feasibility investment value... etc etc...

Couldn't agree more Martin.

I agree with PaulT. Future proof is an excellent idea. One of the easiest way to future proof your heating is to install a water storage 'buffer' tank.
Not too expensive, around £2500 will buy a good size >800 litre tank with proper insulation and three high effiency indirect coils.
I have a similar system fitted into my house, 1800 litre tank. It is now connected to 10sqm flat panel solar panels, an Aquafree air source heat pump and there is still one more coil waiting the pellet burner or similar. The system does take some room though so maybe it is best in new developments or if you have an outbuilding, to be placed there.
Also, the energy consumption monitoring is a good idea.

Or have a think about a DC ring main for running low power devices on. But, Is there a standard voltage? Nope

So maybe a smaller scale charging station with a high efficiency AC/DC converter, and try and locate all your things like DVD players, DECT phones and wifi boxes near to each other so they can draw their power from a central DC ring. You could then put bits of the system on a ring that shuts down at night from a master swtich to cut out all the standby use. My "rule of thumb" is that 1W on standby costs £1 a year. If you're potentially running off your free solar power in future - getting this right now would be a good investment - your buying copper cables - which will go up in price not down.

Also consider looking at the specs on everything you buy - what is the lowest power DECT phone you can buy. What about your router? Does your Freeview TV Tuner need to stay on 24x7? Do you really need a 50" plamsa - why not get a 37" LCD (with LED backlighting) and design the seating so you sit a bit nearer ;-) Is your PC low power? Like the VeryPC Green PC? http://www.very-pc.co.uk/?section=greenpcs. Don't get carried awy though - as someone ealready pointed out - buying more stuff isn't very green.

You'll soon be up to £10k. If not - get yourself a used Toyota Prius (just out of warranty) and have a conversion to LiIon cells with a home charging facility and grid connect it for supplying the house with electric. Range is 40 miles in electric only mode, or you get about 40kwh of juice in the batteries which you can pull through into the house. But you won't get all that for £10k.

Bowman raised a good point - the garden. Look up "edible landscaping"! No daffodils, hostas or bamboo - just pretty plants that also produce food. Get a professional in to start you off with a year round organic food supply, with zero carbon miles. Use you grey water for watering and "you know what" as compost. Maybe a bit far for some people - but a separate composting toilet somewhere in the house might be an option. (My wife says no way )

Simon.