Off grid polytunnel, needs power

Yurp, clever.
10 festoon or someat maybe.

ch750536

So with that system is it best to match everything, 24v DC turbine, 24v DC LED's? The battery just needs to be 24v & reasonable Ah.

Glad this is spring, I have 5 months to make this.

Thanks for all the expert help, really appreciated.

air

From your OP you want 15kWh of energy every day.
That's a colossal amount, you'll need a wind turbine of probably 6kW nameplate capacity.
Buying or building one is going to be an expensive undertaking, you'll be lucky to come out with any change from €35k.
The battery alone would cost you the guts of €10k if you want 30kWH of storage and are allowing for 50% discharge - thus 60kWh capacity.
An RE system makes even less sense than normal when you only need the energy for part of the year.
Run a mains cable.

ch750536

Yep, we moved on. It's a very windy location so eliminating storage (other than as a 'clamp'?) we will basically directly power the lights when it is windy, which is most of the time.

I'm assuming that simply adding another turbine improves things further?

Either way, this looks like a great option for a good return.

Yurp! You can add as many wind turbines as you want as long as you have more lights to load them than they can generate power for or add a few dump loads (like soil heaters).
The voltage clamp thing means the battery voltage stops the turbine alternator from runaway voltage climbing which would damage the winding insulation and end in flames. A turbine or even car alternator can reach insane voltages if you operate them without a battery or load.

Afaik you can fly the first turbine with a blade tip under 10m without planning permission as long as it's double height in lateral distance from the nearest structure and boundary. Hopefully somebody learned on the matter will correct me if I'm wrong.

Re: what voltage to go with...it's a trade off between availability of appliances and gear versus the cost of cable and equipment.
12volt doesn't transport, it's really just for motorhomes, small boats, single room cabins and control gear.
24v it's easy enough get appliances from various markets (sailing/trucking/micro off grid)
36V is about as useless as you can get
48V is interesting because you get used gear cheap because nobody wants it, industrial telecoms use it too and there's an interesting range of inverters to chose from.
110V is lots of fun but not for most people, you can run all sorts of equipment that was never really intended for it.

The higher the voltage you go with the more power you can move around on the same cables. If you double the voltage you can reduce your cable cost roughly by a factor of three because the ampacity for a given load reduces and the acceptable voltage drop increases.



For what you are trying to achieve 24v means readily available lights and easy to find gizmos then go with that.

You can make 1kW turbines for ~€1500. I've seen grid tie Provens go for not a lot used (yes you can use them off grid too but it's rather involved).

You can buy a good 600W for about €1200 or a bigger Chinese Yangzhou Shenzhou for a bit more, you can make good if you adapt the blades or furling mechanism (because they like to overspin).
Spending 10K on a battery is madness you can buy an entire working electric forklift for less.

air

air wrote: »

you'll need a wind turbine of probably 6kW nameplate capacity. Buying or building one is going to be an expensive undertaking, you'll be lucky to come out with any change from €35k.

http://www.ebay.co.uk/itm/UNUSED-10kW-WIND-TURBINE-GENERATOR-with-CONTROLLER-ROTOR-etc-Yangzhou-Shenzo-/331828772527?hash=item4d42893eaf:g:LNwAAOSwx-9Wwl19