Energy Matters Forums

[Duncan]

Thanks Chris,

Those details are really helpful. I have been advised that the wood heater will be more than enough to heat the house by itself. The external walls and ceiling are SIP's and we will have an internal frame that is also insulated.
The house will be built on a concrete slab.
The house is designed to be quite air tight, there will be a circulation system so we don't run out of air while running the wood heater.
I will ask the builder about using the wood heater for extra hot water. Unfortunately it is at the other end of the house from the bathroom/kitchen/laundry so it may prove difficult in our case.

Does anyone know about the usefulness of adding a 1kw ish wind turbine to the system? Will the cost outweigh the extra capacities use?

[Cherokee Solar]

Hi Duncan,

Thanks. The hot water header tank is kind of like a normal hot water service tank with no heating element in it (although some may have a heating element). It sits in the roof space directly above the wood heater as it uses thermo-siphoning (ie. no pumps which is a good thing as it could be a real problem if they failed) to move the water from the back of the wood heater up into the header tank. The hot water for the house is taken from a long copper coil that sits immersed in this tank. The inclusion of this tank + solar hot water tubes will save you a packet of money in the long term with hot water heating. Hope that explains it better!

My house is very well sealed too and I've never felt a lack of oxygen from the wood heater, although I'd imagine plumbers and builders are pretty scared about being sued for such problems! However, if it was a very well sealed one room shack (which doesn't sound like what you're building) I'd probably have concerns about such things.

Hope you enjoy your new house!

Regards

Chris

[Gordon-Loomberah]

...Does anyone know about the usefulness of adding a 1kw ish wind turbine to the system? Will the cost outweigh the extra capacities use?

That all depends on how windy your location is (I cant find any data for the Smiths Gully area)- if it is unpleasantly windy at the potential location of the wind turbine for much of the time, then yes it will be useful, if it's just a bit breezy sometimes, then I can think of a number of "as useful as..." expressions to cover it
You could measure it yourself over a few months before deciding.

[Duncan]

Wind speed for Smiths Gully is listed here:
http://www.energymatters.com.au/index.p ... arpanel=52

Average yearly speed is 6.62 m/s
Jan 5.7m/s
Feb 8.2m/s
Mar 6.2m/s
Apr 6.2m/s
May 6.2m/s
Jun 6.7m/s
Jul 7.2m/s
Aug 7.2m/s
Sep 7.2m/s
Oct 7.2m/s
Nov 5.7m/s
Dec 5.7m/s

What do you think guys? Is it viable for a wind turbine?

[Gordon-Loomberah]

I'd say it would be viable if it's not too expensive, you have a sufficiently open site (ie not at the bottom of a deep gully named after Smith ) and use a tall enough tower, so the turbine is at least 10m above nearby obstacles, and it has a low enough rated output wind speed, so that it produces decent power in the average wind speeds.

[Duncan]

Thanks Gordon,

The site is on the top of a hill, the house will be 60m horizontally from the highest point. Smiths Gully from the name is 60m vertically below our hill.
There is a single gum tree near the top of the hill but it is otherwise cleared.

So theoretically speaking it will be ok.

[franks]

keep in mind the civil costs, depending on the turbine size you have to factor. power, tower height, cable length, its great to have a windy spot but its its 100s mts away you be paying $$$ for cable and condute to your battery.

[Gordon-Loomberah]

I would guess the prevailing winds are generally from the west there? Try to locate the tower upwind of the tree and well away from it, with the turbine well above the top of it to avoid turbulence when the wind is coming from the tree's direction. Turbulence kills output and stresses the turbine and blades, smooth air produces the best power output.

I'd be running a higher voltage from turbine to an MPP controller, to minimise cable losses/reduce cable size. Maybe a 48V WTG into a 24V system. Loss= I^2 * R, ie halve the current = quarter the loss in the cable.

[franks]

if your keen use a high voltage wind turbine, (100-250volts) and use a Midnite Classic 250 MPPT charge reg, to connect to your 48 volt battery bank ?

[70lethal]

Hi Duncan

Were in the process of finishing my standalone system 2 hours north of Adelaide.

When I started out researching a 3kw system was going to cost $30000 (may 2010) then govt change rebates starting July 2010.

If your costs of connecting to the grid is over $30000 you are eligible for 3xrecs muliplier up to 20kw till end of June 2012.

When I signed up for mine I was hoping to recieve 5x but with council and building delays i'll received 4x multiplier.

Spent heaps of time talking to guys. Talk to 20 people get 20 different answers.

I ended up taking bits of advice from eveyone and the guys from www.sunelec.com. They were extremely helpful.

I got a guy to design and install and sourced the parts myself.

I got the draftsmen to re-designed the roof of the house specifically for solar within the constraints we had.
25m frontage @ 25 degree pitch gable which is 7.1m wide facing true north. cost me $14000 to do but was worth it.
4 rows of 27 190w panels 20.5kw. a few different types of panels (ceeg, tianwei, shanpin, suntech) just in case 1 lot turned to crap. cost $27000 approx.
Council didnt like the idea of Zinc roof. dont see much of it now
2 outback 3kw inverter chargers bought at auction in adelaide (display model) $500 each biggest bargain
48 x 1080 amp batteries $11000
Railing $2000, electrical and install $8k
6 morningstar charge controllers $1500
Total cost around $51k
1680 rec approx at $30 = $50k ending up with 20kw system basically for free.

I personally believe with the recs muliplier get as many panels as you can. The muliplier works out to approx. $1.85w which should go close to cover cost of panels and install. If kids on the way get everybit u can.
so your fixed costs left is inverter $3-$4k, rails $1500, batteries $10000(you can spend $20k-30k easily if you want), charge controllers $1500 install $8000. So you can basically have a mamoth system for $25000 that you can run everything off.

We looked at energy effienct appliances, gas bottles, wood heater and decided to put everything we could into solar system instead. Problem is pretty big outlay before getting rebate.

We have gone out and bought a couple of blocks of land specifically to do the same by end of June and sell as we believe value will double with these systems. Getting a company to design, supply and install would cost $50K-70K extra. One quote was $117k.

Spent many hours of a night researching and checking out prices on ebay, solar wholesalers etc. but well worth the effort.

If interested I can put you onto some suppliers who were really helpful once I explained what I was doing.

Currently doing 7 x 3kw grid connects for family and friends and our rental.
3kw growatt inverter(not overly excited) $920
16x 190w Tianwei panels @ $1.19W $3600
Rails tile $330
electrical $350
install $1000
minus rec 124 @$29 approx $3600
total cost of 3kw system $2600 this system would cost around $6k going through a company i guess. so if you put the time in you can get rewarded well.

Have fun i remember when we first started down this track it was very nerve wrecking. All the what if's. What if we dont have power the wife is going to go ballistic? quite a few sleepless nights.
cheers
Lee