Selfsufficientish.com

Hi,
Got permission from my wife to spend a couple of hundred dollars on some R&D toy. It was nice to spend it on whatever "I wanted". Doesn't happen often.

So I purchased our first solar power kit. It's a 60W, 12V system. It includes a charge regulator and an inverter (200W). I bought it for the purpose of gaining some experience with the technology...and for showing my wife how a system worked.

Now, I need to buy a battery.

Anyhow, we have a small greenhouse....so I hope to install it on top of the roof for the purpose of powering the ventilation fan.

Regards,
Chuck

If you get a 12V fan you won't need the inverter !

Excellent point! However, I've never had an 'inverter' before.

The problem now is installation. I'll be honest...I didn't really think about how to get it on top of the greenhouse. In addition, the greenhouse doesn't exactly face south...so it needs to mounted at an angle. Another though is the actual elevation angle. I'm thinking I need to make that adjustable too.

I'm going to look around for a 12V fan(s) for a greenhouse.

Thanks,
Chuck

funnily enough I have a similar project - solar greenhouse ventilation !
I got a 9" diameter 12v PC case fan (look at the litres/hour these things shift!)
next I need some 12v timers and temperature sensors.... any ideas?
I tried the simple solution of wiring the fan direct to the solar panel (so it would turn in full sun) but that failed... you'd need to very carefully match the panel to the fan I think... so it has to be battery charging plus smart electronics

last week my greenhouse hit 32C (in lousy March weather so heaven knows what it could get to in summer!)

yes I have just bought a max-min thermometer :-)


PS - beware inverters - check how much juice they draw just by being connected with nothing plugged in - this can be a HUGE overhead/waste for a small solar/battery system

dave45 wrote: PS - beware inverters - check how much juice they draw just by being connected with nothing plugged in - this can be a HUGE overhead/waste for a small solar/battery system

I agree, anything which is 12v to start with saves using precious power on converting the current. Having said that, we have been quite disappointed at the poor quality of many 12v car & camping type items. Seem to be made to break! If anyone has a GOOD supplier it would be useful!

Hi,
I'm planning on buying one of these. It's a thermostatic receptacle. It'll provide power within the right temperature range. You can use one of these to control a fan in the greenhouse. I'm certain there is a British equivalent to use 250VAC.

http://www.apelectric.com/Thermo-Cube-s ... 2godGCDTDA

Regards,
Chuck

Chuck - using that is likely to flatten your battery because of the inverter standby current. (you'll have to leave the inverter connected all the time for it to work)

I'm going for one of these to switch my 12v PC fan:

http://cgi.ebay.co.uk/12V-Temperature-C ... 1e60949f9e

The 50mA drain is probably tolerable! (Greenhouse got to 30C again today - outside was about 5C)

The 12V controller has arrived. Greenhouse up to 39C today... better get cracking on plumbing it in !

Good luck and enjoy!

Jill

Dave,
Have you got the controller setup now?

We've been using a 120VAC thermocube to control our fan. Our solar panel project is on hold...until I raise enough capital to buy a battery. =) I'm paying to replace my rotted subflooring at the moment...so that's a big hold on solar.

Regards,
Chuck

Not yet chuck - weather has been too good :-) digging instead... got a touch of sunburn today...not bad for march !

Greenhouse got above 30C again though... (I just left the door open).. 30C sounds like a good trigger temperature - what do you think?

If you've got a 60w panel and it is only there to power a 12v computer fan, I woudn't worry if it does not face in the optimum direction. You only need power on sunny days, and only a little then. If you have a use for it, there will be plenty of spare power.

Just a thought, (sorry if i'm stating the obvious) but as long as the solar panel is not shaded by anything it does not have to be high up (the suns rays have already travelled 150km so a few more feet to the ground won't matter).
Does not have to be above/on top of the greenhouse - where it will unhelpfully cast shade.