Solar panels are becoming a popular option to generate some, or all of your own electricity needs. Here we provide some things you need to know when considering having solar installed at your home or business.
A solar photovoltaic (PV) panel is made up of a number of connected solar cells. These panels absorb sunlight and the silicon and conductors in the panel convert this light into DC (Direct Current) electricity. From there, the electricity flows into an inverter, which converts the DC electricity into AC (alternating current) electricity for use in your home.
Solar PV systems can be installed ‘grid-connected’, which means they will still have a connection to the local electricity network. Connection to the Northpower network will let you use power supplied through Northpower’s network and your electricity retailer when your system is not operating or producing enough energy for your electricity needs (the load). Network connected systems allow excess generation to be sold (‘exported’) back to the national grid. Off-grid systems are stand-alone and generally require battery storage so that power can be used when the solar panels are not generating.
Before you invest in solar, we recommend you do some research to make sure you get the right system for you. You need to consider things like;
A solar system should be bespoke and unique to your home or business. It needs to be designed specifically for your needs, now and into the future. Your installer should comprehensively work through all of this with you.
Check out our need to know guide for more detailed information.
If you intend to connect to the grid, you need to let Northpower know. Connecting your generated power to the grid is known as Distributed Generation. Northpower looks at new distributed generation connections on a case-by-case basis to make sure there is enough capacity in your area.
Once you have your design outlining electricity capacity, energy production and electrical system specifications, and you have contacted your energy retailer to discuss your proposal and complete any commercial arrangements they require, we advise completing the Northpower’s application form as soon as possible. This is often done by the PV provider as it requires details of the technical information of the system.
It is important to consider how you will be able to capitalise on your solar generation. If you don’t intend to invest in a battery system, then it makes sense to try and use as much of the electricity generated during the day when it is sunny, rather than export all this back to the grid and have to import electricity when the solar isn’t generating. The cost of buying/importing electricity from a retailer is much higher than what you will be paid for any energy that you export/sell.
Things such as smart load control devices, solar hot water diverters (or timers) or delayed start functions on dishwashers, washing machines and dryers mean you can set appliances to use electricity while it is being generated. It is also a good idea to invest in a monitoring device which can provide real time feedback on the solar generation and consumption, so you know exactly how much is being generated and used, or sold back to the grid.
If you connect to the grid, you will still get a power bill from your power retailer. It will include a standard daily lines charge, and charges based on the amount of power you draw from the grid.
How much you save on your electricity bill will depend on the size of the solar system installed, how you use your power while it is being generated, and whether you have batteries installed.
The export price per kWh varies per retailer. We suggest shopping around retailers to get the best price. The export price is generally less than the import price.
Yes. Anyone on a grid-connected solar system will need an import/export meter installed, as this is a requirement of the NZ Electricity Industry Code. This records electricity imported from the grid and electricity exported back to the grid. Your power retailer owns the meter.
Yes, but you will need battery storage. To have a home run completely by solar and off the grid, you will need to make sure you have the right sized system to meet your energy usage needs, and a battery to store the power to use when the solar panels are not generating, including long periods of cloudy weather.
Solar panels last approximately 25 years. It is important to understand that because solar panels degrade over time, they will produce slightly less energy each year. Under a 25-year warranty, most manufacturers will expect their solar panels to generate at 80% of their original capacity at the 25-year mark.
The inverters connected to the solar panels have different lifespans depending on the type. String inverters generally have a life expectancy of around 12-15 years, while micro-inverters and DC optimisers have an expected life of 20-25 years.
Three things influence the batteries life expectancy: how much it is used, the type of battery and its operating environment. Battery storage capacity becomes less efficient over time. Most current lithium-ion batteries will come with a 10-year performance warranty.
Solar panels can currently be recycled at the end of their life, through either re-use, mechanical recycling, or chemical recycling.
Ideally, you want your panels to be generating every time it is sunny, especially if you are using the power as it is generating. Solar panels work best with direct sunlight. For battery storage, the best-case scenario is four to five hours of direct sunlight per day to generate enough to charge the battery. Solar panels will still generate electricity when it is cloudy but not as efficiently.