What should you consider when going off the grid?
Posted by Alex Barrett on 13 March 2017 at 10:45 am
Every wanted to cut your ties with the electricity grid and rely entirely on renewable power? In this article we’ll consider a few of the things to consider before setting up an off grid system.
The first thing to consider is why you want to go off grid in the first place. Off grid systems are very expensive, and aren’t necessarily any better for the environment than grid connected renewables. If your aim is to save money by no longer having an electricity bill then you might be disappointed. Living off grid is very unlikely to be cheaper than buying electricity from a supplier . The Centre for Alternative Technology advise against off grid living unless there is no other choice [2, 3]. They point out that by sharing your excess electricity you are actually reducing the total amount of fossil fuels that the electricity industry have to use.
Off grid systems make the most sense in remote rural areas, where connection to the gas or electricity grids would be prohibitively expensive. Houses in these areas often rely on diesel generators, so switching to renewable power would definitely be worthwhile. If you are convinced that an off grid system is the best option there are several things to consider. The first is your electricity demand.
How much energy do you use on a day to day basis? Having a good grasp of how much energy you need allows you to determine what generating capacity you will need, and how many batteries you will need . Look at your energy bills, and see how much power each appliance uses.
What is your peak demand? This is the most energy you ever use at one time. Your off grid system will have to be able to sustain this level of electricity generation, even if it doesn’t happen very often. Consider whether you can reduce your demand by being more energy efficient. Can you replace older appliances with more environmentally friendly versions? Are there any which you can do without? Can you shift your demand to high energy periods, such as by only using the washing machine on sunny days when you have an excess of power?
Finding an installer
Most advice on off grid systems stresses that you should hire a professional with a good track record to set up your system [5, 6]. Not all solar PV installers will be familiar with off grid set ups, so it is vital to make sure that you choose one who does. An expert will be able to verify your energy demand, and recommend the correct battery system to meet your needs. It is good to consult reviews from others who have used the installer in the past, and talk to people with similar systems.
Generating capacity and storage
Consider how you are going to generate the electricity you need. Will you use one type of generator, or multiple sources? What is your backup for times when your renewables can’t meet your demand?
If you go with solar panels you will have to ensure that you have sufficient solar access to allow your system to work year round. If you want to use wind turbines then it is vital to ensure that you live in a windy enough area for them to work.
Solar panels will have a high output in the summer months but won’t be as effective in the winter. Their winter output can be boosted by keeping them clean, and changing the angle at which they are mounted so that they always get the optimum amount of sunlight . This means that you should consider accessibility. If you have a rooftop solar array, will you be able to easily get up there to clean and reposition the panels?
An off grid system relies on battery storage, which unfortunately increases the carbon footprint of the system. The manufacture and disposal of battery technology is very carbon intensive, and they will have to be replaced every few years.
AC or DC?
Solar panels generate Direct Current or DC. This is also how energy is stored in a battery system. Systems that are hooked up to the grid require an alternator to convert this into Alternating Current or AC. AC electricity is more common, as it is easier to transmit, but this won’t be as big a concern for an off grid setup.
Many appliances actually run on DC, and their power cable contains an adaptor that coverts the AC electricity in the mains into DC. Every time this conversion takes place some energy is lost, so it can be far more energy efficient to ensure that all of your devices can be run using DC directly. This can be as simple as replacing the power cable with one designed to work with a DC system, but you may need to replace some appliances entirely .
We’ve only covered this topic in the broadest of strokes, so check out the links below for more information about the practicalities of going off grid. Making the right decisions at the start of the project, whether in selecting batteries or installers can save a lot of time and money later on.
- Visual Economics
- The Centre for Alternative Technology FAQ: Can I store electricity?
- The Centre for Alternative Technology FAQ: Can I go off grid?
- Home Power: Analyzing your electrical loads.
- Home Power: So you want to go off grid?
- Homepower: Before you go off grid.
- Low Tech Magazine: How to go off grid in your apartment.
Image Credit: Takver via flickr
If you have a question about anything in the above blog, please ask it in the comments section below.
0 comments - read them below or add one