10 Things you need to know about going off the Grid
1. Convert your Lighting
If you're using old incandescent light bulbs, you're literally burning money. Even the new light bulbs have their limitations for energy saving when you have many of them.
Replace all your light bulbs with LED light bulbs. This will significantly reduce your current electricity usage and reduce the size of the solar system you require.
2. Convert your Appliances
Converting your cooking and hot water heaters to alternative power is the next big change. Electric stoves, ovens, geysers, heat pumps and heaters all use excessive amounts of power when considering a solar system.
Where possible replace these with their solar alternative and if that isn't an option replace them with gas.
3. Changing consumption patterns
Change when you're using your power. If you can change when you're using your power to position most of it during peak sunlight hours then you'll reduce the load on the batteries during the evening. This might not seem like a big deal but the less discharge you have on your batteries the longer they last.
4. Battery Store is Expensive
As mentioned in point 3, batteries have a lifespan. This lifespan is greatly reduced if you're batteries are discharged too far on a regular basis. In order to avoid having to replace your batteries often, you'll need lots of them. We're talking 20 to 30 large batteries!
5. Do you have the Space?
A full off the grid system requires a lot of space. Not only do you need space for +/- 20 panels (5kW system) on your roof or lawn, you also need the space to house the batteries mention in point 4. The 20 - 30 batteries required to have a functional off grid system need to be housed in a cool dry area. The lifespan of the batteries is also affected by the ambient temperature that they're kept.
6. Why so many panels and batteries?
If you're going off-grid, there is generally no backup (Unless you have a generator as a last resort) so in order for the system to function correctly even if you have a couple of days with bad sunshine, you need to have enough battery storage to keep you running.
Solar systems generally do not require a lot of maintenance. Ideally you should purchase maintenance free batteries to avoid the hassle of checking water levels constantly. The only other aspect that needs your attention is the panels. These should be hosed down every now and again to ensure maximum efficiency. They tend to get covered in dust etc. over time reducing their efficiency. A quick hosing down will sort out the problem.
8. Return on Investment (ROI)
At this point in time in South Africa (2015/16), the pay-off period for an off-grid solar system is prohibitively long if you're looking to convert a whole house or business. This type of system is mainly reserved for the enthusiasts with a specific non-financial gain in mind. The reduction in carbon emissions and consistent supply of power are hard to quantify in Rands and cents and therefore do not form part of the ROI calculation.
If your motivation is financial then you should consider the Hybrid and Grid-Tied systems as alternatives. These system are far less expensive and can also offer great long term savings and backup to Eskom.
9. Have a Backup
If you're intention is to completely part ways with Eskom, you should keep in mind that all technology has its limitations. If you're solar system isn't functioning for one reason or another you will not have power until the problem has been identified and fixed. Investing in a backup to your primary electrical system would be prudent. It doesn't have to be anything big or expensive especially since you've more than likely already converted all the power hungry items in your home or office to be energy efficient.
10. Source the components carefully and have a professional install them
This is your primary source of electricity. Make sure that you have good quality components with local backup and support. Are you prepared to wait weeks while the supplier is assessing the problem with your inverter and you sit in the dark? Probably not, so stick to quality brands with local support and professional installers who know what they're doing. The installation of an off-grid system can be as exciting as it is painful if you don't have it done properly.