Solar Power Off Grid

Living off the power grid is often the ultimate dream of many people. Traditionally, off grid power systems have been very expensive. Technology has come along way recently. Not only has the cost of the renewable energy equipment significantly reduced over the last few years, but its durability and reliability have greatly increased. The cost of solar power panels has greatly reduced, and the advancement in battery technology has removed the single biggest financial hurdle, regular battery replacement. Modern off grid batteries now last 15-20 years.

The other factor which has made small scale renewable energy power systems more affordable is the energy efficiency of modern appliances. Years ago, an expensive system would be required just to run lights. With the advent of energy efficient LED bulbs and energy efficient appliances, the electrical load of a modern home can be much lower than in the past, meaning a much smaller system is required to service the load.

When designing an off grid system, the load sheet is the starting point. This is the list of power consuming items intended to be used along with how long they are used per 24h. Once we know the daily load, we can size the solar array, the battery bank and battery inverter. We treat all off grids the same regardless of weather its a couple of panels and a battery to run some lights in a shed, or a full high end accommodation resort, the load sheet is critical to designing a system that will operate reliably long term. 

Often, load sheets come back with high power consumption which makes the off grid power system expensive. The average New Zealand home uses about 30kw per day, a large off grid system load would be 15kw per day so it is bit of a process to work through the load sheet with clients to balance the system price with their budget and the lifestyle they want to live. Careful consideration needs to be given to home heating, water heating and cooking which are the three big areas of power consumption. 

When you are the power company, reliability and easy of use become very important. We use Victron Energy equipment in our off grid systems because they provide unmatched reliability and ease of use. Being designed for the marine market, Victron equipment is very robust and has a proven track record. Victron integrate seamlessly with Fronius solar inverters and they work in partnership with multiple brands of batteries so we have full technical support on a wide range of battery options.