Living off-grid in New Zealand means generating your own electricity and becoming self-sufficient. This guide will cover the basics of setting up an off-grid electricity system, including the different types of renewable energy sources, essential components, and practical considerations.
1. Understanding Off-Grid Electricity
Off-Grid: Completely independent of the national grid, relying on self-generated power. The most popular option for rural areas where the cost of connecting to the grid is too high, ongoing costs and powercuts make it nonviable, or you want the freedom to move the dwelling around.
Grid-Tied with Battery Backup: Connected to the grid but with a battery system for backup during outages. This is most common in residential areas that are already connected to the grid.
2. Renewable Energy Sources
The main sources of renewable energy suitable for off-grid living in New Zealand include Solar, Wind, and Hydro. Solar is the most popular and often the core system, while wind and hydro are most often complements to it, although hydro can be suitable at the main source. Wind is not often used as a primary source due to its limited geographic suitability. Here’s a simple breakdown of the pros and cons of each:
Solar Power
- Pros: Abundant sunlight, very low maintenance.
- Cons: High initial cost, efficiency varies with weather and seasons.
- Components: Solar panels, charge controller, inverter, battery storage.
Wind Power
- Pros: Suitable for windy areas, complements solar power (produces energy during cloudy days).
- Cons: Requires a suitable location, can be noisy, more maintenance needed, may need to be taken down in high winds.
- Components: Wind turbine, charge controller, inverter, battery storage.
Micro-Hydro Power
- Pros: Reliable and consistent power if you have a suitable water source.
- Cons: High initial setup cost, specific site requirements, environmental impact considerations, maintenance required.
- Components: Water turbine, charge controller, inverter, battery storage.
3. Key Components of an Off-Grid System
- Solar Panels/Wind Turbine/Water Turbine: This is the part of the system that generates electricity.
- Charge Controller: Regulates voltage and current from the power source to the batteries, ensuring they are charged at the correct voltage and rate to maximise the longevity of the batteries, as the energy coming from the power source can vary wildly.
- Battery Bank: Stores energy for use either immediately or later. Essential to an off-grid system as the power cannot directly power anything.
- Inverter: Converts the 48V DC (direct current) from batteries to 240V AC (alternating current) for home appliances.
- Backup Generator: Provides power during prolonged periods of low renewable energy generation, highly recommended if you cannot have any system downtime.
4. Designing Your System
- Assess Your Energy Needs: The first thing to do is list all appliances, their power ratings, and estimated usage. This is a time to consider what you do and don’t really need, as the more power you need the more expensive your system becomes. Things like heating and cooking use A LOT of power, so swapping them to alternative energy such as LPG or woodburning will help you get a more affordable and efficient system.
- Site Assessment: Evaluate the potential for solar, wind, or hydro power at your location. Certain locations in NZ will have less sun than others, but this is usually easily accounted for by adding just a few more panels. You may also have to consider the placement of them, if you have obstructions such as trees or hills that will shade the panels. Hydro will require a suitably fast water source, and if it’s planned to be your primary source, it’s important to know if the water level drops drastically in summer. Wind will require suitably fast and consistent winds to produce a significant amount of power.
- System Sizing: Calculate the size of the solar array, wind turbine, or hydro system needed to meet your energy needs. You need to make sure that you can produce enough power each day to adequately recharge your batteries after your power usage, accounting for seasonal changes in energy production.
- Battery Storage: Determine the battery capacity required to store enough energy for your needs during periods without generation. This usually needs to match the generation so that the batteries can be topped up quickly enough that they aren’t left sitting partially charged for too long, as this can damage them, while also being large enough to support your usage.
5. Installation and Maintenance
- DIY: If you have technical skills, you can save money by installing most of the system yourself. Even if you only mount the solar panels and leave the rest to an electrician, you can save a fair bit of money on the installation. Ensure you follow safety guidelines and local building codes and regulations, and do not continue if you don’t feel confident in your ability to complete the installation safely and correctly.
- Professional Help: If you’re not confident in any part of the work, hiring professionals for installation ensures safety and compliance with local regulations. Regardless of whether you do the rest or not, you’ll need an electrician for any 240V work and will need a Certificate of Compliance issued by one too.
- Maintenance: Regular maintenance ensures both that you get the most out of your equipment day to day, and that you maximise the longevity of the system. This will involve things like cleaning solar panels, inspecting turbines, and checking battery health.
6. Financial Considerations
- Initial Costs: Equipment and installation can be expensive. You’ll likely be looking at several thousand dollars or more depending on your power needs, but it is usually possible to start small and upgrade later if your budget is tight.
- Long-Term Savings: Reduced or eliminated electricity bills can provide significant savings over time, though balanced against the cost of set up it is a long term pay off. Most off-gridders find the real improvement is the freedom from the monthly bills and dependence on the outside world.
7. Resources and Further Reading
- Load Calculator – Use this tool to work out how much power your intended appliances will use and how much solar you’ll need to support that.
- Jargon Guide – a list of all the common solar power terms you’ll see and what they mean
- Off Grid Solar Power Kits – Check out our full range of solar power kits for a simple and cost-effective solution to getting power off the grid.
