Barn with photovoltaic panels and solar hot water panel

Our idea was to generate as much energy as possible on site and at the same time keep our energy consumption low.   

Our house is one of two at the village not connected to the national grid – we always liked the idea of being “independent” and of using renewable sources of energy where we can.  When we looked at how much electricity we need, we arrived at about 2 kilowatts per day – this is about 10% of what a typical NZ household consumes.  Our consumption is so low, because we don’t use electricity for heating water or rooms or for cooking.  This means of course that we need other sources of energy for these: Firewood and direct solar energy for cooking, baking and for hot water. We use gas for cooking when the wood fired kitchen stove is not going. 

As far as alternative systems go, our set up is very common: We are using photovoltaic panels to generate electricity which is then stored in a battery bank. We draw the electricity from there through an inverter for the freezer, lights, stereo, TV, computer and other appliances that we use.  We used to have a wind turbine as well but it broke down and instead of replacing it, we have added 4 more panels to our photovoltaic array.

As a back up we have a petrol driven generator that we use to equalize the batteries once every four to six weeks and also when we have not enough electricity in our battery bank.

It has been a steep learning curve for us – we did not know an awful lot about alternative power systems when we moved into our barn in 2000.  It was exciting to have our “own” power … and no power bills.  This does not mean that our electricity is free – to set up our system has cost a similar amount to what it would have been to connect to the national grid.  After seven years our first battery bank had to be replaced and there have been other costs for repairs to the wind turbine.  Overall I think our electricity is not cheaper than using the grid.  We are happy with our choice.

Our system:

12 Photovoltaic Panels (6 polycrystaline / 6 amorphous)
1 C40 Charge Controller / 1 Multi Powerpoint Tracker Controller
24V / 700 Ahrs Battery Bank (4 x 6V Enersun 700 in series))
Modified Sine Wave Inverter (2000W/5000W)
6 KVA Petrol Generator