Using Solar Energy


Solar energy systems generate electricity while the sun shines so, to make the most of your installation, you may want to look at how you can change your electricity use to coincide with this.

Maximising the benefits of your solar system

It is very unlikely you will use 100% of the solar energy you produce so, to make the most of your solar energy, you may want to consider what habits you can change to boost your solar energy use. 

For example, your solar generation peaks at midday, and if you are not home to use it, you will be exporting that energy at a buy back rate of around 8 cents per kWh.  But, when you put your washing machine on at 7am, you will be paying peak rates of 24-30c per kWh.  So, in this example, if your washing machine has a delayed start option, time it to start at 12pm.

For businesses looking to install solar it is particularly important to understand the price-plan tariffs underpinning your monthly electricity bills. For some businesses, line charges are determined in part by electricity demand during network peaks, meaning that unless solar generation coincides with these peaks, then solar may have little or no influence on reducing line charges. Similarly, some retail price-plans offer low daytime (off peak) energy pricing meaning that your solar is avoiding low cost energy purchases, saving very little.   If you would like to discuss how solar will fit with your business operation, contact us on 0800 2 UNISON.


What can I power using solar energy?

You can use solar energy to power all the appliances in your home, like dishwashers, fridges, and washing machines.  You can also use it to re-charge an electric vehicle, or to heat your hot water.

Appliances

To make the most of your solar energy, you can schedule some appliances to operate during the day time when energy is being created. For example, some washing machines allow you to delay the start of the programme.  Other ‘smart’ appliances can be connected to smart electric meters or home energy management systems which allow you to shift your electricity use to the most beneficial time of day (either during solar generation periods, or during off-peak tariff times).  Most solar installers can supply devices that optimise water heating from solar generation, meaning morning water load is deferred to coincide with rooftop generation.

Electric vehicles

Electric vehicles currently represent a very small proportion of registered vehicles in New Zealand however, as technology improves, the variety of vehicles increases, and purchase costs reduce, the ownership of electric vehicles will become more and more accessible to the masses.  The amount of time it takes to charge an electric vehicle depends on a few variables, like the charger the car comes with, your charging station, and the amount of energy your system is producing. For example, the 2013 Nissan Leaf has two charger options – a 3.3kW maximum charger, which will take eight hours to complete a full charge from empty, or a 6.6kW maximum charger, which will take four hours. To take advantage of solar generation for charging an electric vehicle, your vehicle will need to be plugged in during the times that your solar generation occurs. Various factors including the size of your solar installation, weather conditions, and other simultaneous household electricity usage will influence the ability to charge your car from your solar generation.

Solar hot water system
A solar hot water system heats and stores water in your hot water cylinder. Installing this type of solar system can be a cost efficient choice if you use more of your hot water during the day, or shortly after the hot water is created.  As the system directly heats the water, rather than powering the hot water cylinder, your electrical supply will switch in to continue heating your water once the sun goes down.