Solar FAQs

Want to know more about your solar system, looking at installing your own system or just plain curious? Read on below where we have provided answers to the most commonly asked questions.

Can I cook or run an electric water heater on solar?

We would recommend using gas for both cooking and water heating. Cooking on an electric element/hotplate or using an electric oven requires a lot of power that will drain your batteries quickly. The amount of power required to heat a hot water cylinder is also a high power consumption process.

If you still wish to use both electricity for cooking and water heating, you will require a larger battery bank to be able to hold enough power this is because most people cook and shower in the mornings and evenings when especially in winter the sun is not up to charge your batteries.

What size solar kit do I need?

To calculate what size solar kit you will need, start by calculating your daily power usage/consumption of all your appliances (if you have not purchased any yet, do a rough estimate) in Watt/Hours – fill out our solar consumption form here. You can then use this figure to find a kit that will produce your required amount of power. Remember to factor in all appliances, and electronic equipment that you will use or charge off your solar system on a daily or weekly basis.

The amount of energy produced by each kit will change throughout the year due to the change in daily sunlight hours. During the peak of summer most places in New Zealand will get an average of 6-8 hours daily of sunlight. In winter you will receive as little as 3-4 hours of daily sunlight. There are two options available to combat the difference between summer and winter; over winter adjust your power consumption, or get a larger kit that will keep up during the middle of winter when your power consumption will be at its greatest.

View our Solar Kits here

Is it possible to add additional solar panels into an already existing system?

This will depend on what sort of charge controller (solar regulator) you are currently using and if you are running a 12V, 24V or 48V system as well as if your solar panels are installed in parallel or series. Charge controllers will only convert a certain amount of power into storable energy, you don't want to be buying more solar panels if your system is unable to handle the additional power generation.

Can I add additional batteries to an existing kit?

Additional batteries can always be added into your solar system, however it is not always recommended. It is important to remember that any new batteries that are added must be the same voltage. When adding new batteries into an already existing battery bank, it is important that they are of similar age otherwise this will affect the health of the new batteries that are introduced to the system.

How many days will my batteries last without sun to charge them up?

This will depend on your daily energy consumption and what type of batteries you have. To calculate you will need to take 50% of your total battery capacity (based off of a Lead Acid Battery) and divide that by your daily consumption.

For example:

8.4kWh (Total battery capacity) / 2 = 4.2kWh (Available daily battery capacity)

4.2kWh / 1.5kWh (Daily energy consumption) = 2.8 Days

How much power can my solar system generate?

This can be calculated from the output of your solar panels. Multiply the output of your panels by the number of panels, then multiply by the average sunlight hours in New Zealand for your area (This will vary depending on location and time of year), we recommend always calculating using winter sunlight hours.

For example:

280W (Solar Panel Output) x 3 (Number of panels) = 840W

With six hours of sunlight in the summer you will produce 5040 Watt hours

With three hours of sunlight in the winter you will produce 2520 Watt hours

What appliances can I run from my solar system?

What appliances you can run will vary depending on the size of your solar system size. How you use your appliances and their efficiency will also play a factor. The recommended way to work out what you can run is to work out what you want to run, how much power you will need for those appliances, and then spec your solar kit to match. If you are willing to be conservative with your power usage and only run energy efficient appliances, you can make significant savings in your setup. It is always a good idea to slightly oversize your solar system for any appliances you may wish to add or buy in the future.

If we haven't answered your question, or if you are wanting to know more information, do not hesitate to contact us on 0800 33 33 44 or hello@offgridcollective.co.nz