Back       Off-grid hut   Using renewable energy is an option for a variety of reasons. Practicality and cost to be connected to the electrical grid is the primary reason. The second is for people who like the idea of being independent and not relying on the grid for electricity and for environmentally conscious people.   Using alternative energy can be expensive. It is often economic to install an off-grid system for people living a distance from the grid. However when the grid is available, going off-grid is probably not economic at this stage.   The intention of this page is to broaden your knowledge of what is involved, approximate costs and existing technologies currently in use.   Solar Solar PV panels are by far the most common generation source. Solar panels are easily installed, last a very long time (upwards of 20 years), very low maintenance and can be installed anywhere with a decent northerly view (Southern hemisphere) or southerly view (northern hemisphere) including urban areas. However they do not produce a high output for the area and cost involved. They are only useful when the sun is out (cloudy conditions produce very low output).   Hydro If available this option is ideal. With a reliable water source and good head then a house can easily be powered by hydro. However few locations are suited to using hydro which limits its use.   Wind Most locations have wind at some stage. However access to a turbulent free air flow is important. Turbines are suited to hills and areas away from buildings and trees. Generally wind turbines are not installed in urban areas due to noise and visual pollution. Turbines have to be able to withstand storms. Additionally wind is not always reliable (less than the sun) so large battery storage or the grid is required. Wind speed and power output is related cubically. So low winds produce very little output compared to wind speed slightly higher. So what you find is huge amounts of power available in storms and little in daily breezes.     The following information gives a rough cost to install a system to an existing house.     The Following prices are all in NZD On Grid Alternative Energy Set Up Off Grid Alternative Energy Set Up   On Grid Alternative Energy Set up An on-grid Set up is reasonably straight forward to set up. First an energy generation method is required. This is commonly wind and/or solar and sometimes hydro. The generated electricity is passed through an inverter, an export meter or through the power meter and into the grid. Most on-grid solar panels use 26 volts. Large wind turbines and hydro set-ups can deliver 240AC so an inverter is not required. In urban areas, wind and hydro is generally not an option. In some countries the power companies will buy the electricity, otherwise the generated electricity supplements your power requirements. Generally a solar hot water system will be installed as heating water absorbs most of a household energy bill. Electricity is not generally used as a primary source to heat water due to its very high energy requirement. However often excess power (when batteries are full) is diverted to a heating element to heat water.  Economics To find the approximate income you will generate, go on to your national weather service website and find the annual sunshine hours at your location. Multiply this number of hours by the generating capacity in kilowatts (1000W = 1kW). Then divide this by the daily electricity rate in $/kWhrs.   Use this basic calculator to calculate the very rough cost of installation and pay back of a solar system Annual sunshine hrs                 Generating capacity (kW)                     kWhr rate ($/kWhr)                                   The pay off time is normally about 20 years which is 5% annual return on investment - comparable with a decent interest rate at the bank. Solar hot water heating is a viable option for sunny areas. Installation will be between $5-8,000 and will pay off faster than solar electricity installations. back to top Off Grid Setup The difference between grid and off grid is that you have to store the energy you generate, unless it is always windy or always sunny. The batteries must store electricity from the windy and sunny days for use during the dullest and calmest period you would expect in a year. The less reliable the generating source, the larger the storage capacity required. Large battery storage is key to a reliable system. A back-up generator will often be installed when power is low or when demand is higher than the system can handle for instance when using large power tools. The DC power from the battery bank is turned into 240VAC to use with conventional appliances using an inverter. Heating is generally not generated by electricity but wood or fuel is combusted. This space heats, cooks food and heats the water using a wetback and/or califont.  Deep cycle batteries are able to be discharged further and more frequently than car batteries. They are very expensive and make up a bulk of cost. Additionally they require replacing every 6-10yrs. If your site is suited to wind then this is generally cheaper per unit of generated electricity but this is often used in conjunction with solar. With a very reliable water supply then hydro can be used by itself. An energy conscious family living off grid would use 3-7 kwhrs/day. The bulk of use will be lighting and appliance use, since all heating will be from combusted fuel or solar water heating. When considering cost, it must be considered that reliance on fuels will increase. The cost will be around $30-40,000.