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Top 12 Questions To Ask Before Purchasing A Solar Power System

By Kristy Hoare on in How it works

Top 12 Questions To Ask Before Purchasing A Solar Power System

Don’t be shy about asking solar companies a plethora of questions! A professional company will be prepared to handle the difficult technical questions, and inquiries from those only just learning about solar power. They are there to help.

During my 10 years of solar industry experience I have seen thousands of quotes and many different sales strategies, but no matter how much information solar experts can give you - it’s vital to ask questions.

Over the years, some customers have expressed regret at not asking more questions along the way, such as “I should have purchased a bigger system” or “I wish I had battery storage installed earlier”. There is a certain amount of due diligence required from solar power customers as each install is completely unique. Therefore I would like to offer some pre-worded questions that you can ask solar experts before signing up for a system install.  

Feel free to use these questions to help scrutinise solar power installation companies before making a purchase decision.

1. Is the company a member of SEANZ (Sustainable Energy Association New Zealand)?

Approximately 90% of solar installation companies in New Zealand are SEANZ members, others have been declined by SEANZ, and some don’t bother to join the association.

A SEANZ member must pass several rigid requirements, including background checks. Once the company is a certified SEANZ member, they must adhere to the SEANZ code of conduct.

All solar installations on New Zealand schools must be completed by a SEANZ member, this is likely to roll out to other industries too. It is also relevant to mention that some banks refuse to lend money for systems installed by non SEANZ members.

Over the last 7 years My Solar Quotes has done the hard work to curate a list of quality solar installation companies that are also SEANZ members. Click here to get quotes from reliable professionals.

2. Who will install my system?

Some solar installation companies have their own installation teams, while others subcontract this part of the job. Therefore, it is a fair question to ask who will be installing the solar power system. If the company chosen are organising contractors for the install, ask them who is liable for faults or damage. A qualified electrician is required on site, so it pays to ask who the electrician (or the electrician's company) will be.

3. Is the solar power system size recommended the best for me?

Solar power systems can be sized to meet a budget, make ample use of roof space, or to maximise return on investment (ROI). Sizing a solar power system to maximise ROI is not a simple process. Solar experts need to consider many factors; roof angle and orientation, estimated sunshine hours for unique locations, past energy consumption patterns and any expected changes to energy consumption e.g. a new spa pool.  

Receiving 3 quotes is an excellent way to figure out if the solar companies have made a good suggested system size. If there is one company that has suggested a system that is a lot bigger than the other two, something must be wrong.

4. How much will I save with solar installed?

Professional solar companies can provide estimates for annual savings. They will use NIWA data (historical weather data), calculate potential losses from shade, and a long list of other factors when establishing an estimate.  

For a grid connected system, solar professionals factor in power consumption patterns. Self-consumption is the portion of solar power used directly in the household, versus the amount exported to the grid. This percentage will be a significant factor when determining a savings figure. For most households, a realistic self consumption rate is around 50%. This number may increase if a large amount of power is used during the day, or if the installers have suggested ways in which more power can be utlised. Basically, the higher the percentage, the higher the savings.  

Make sure to quiz the solar professionals on the estimated self-consumption rate, if it’s not realistic, the results could be disappointing.

5. Has the installer checked how many phases the house is on?

Solar professionals need to find out what phase the building is on, phase 1, 2 or 3. Phases can be confusing, but most New Zealand households are on single phase power which makes the install straight forward. A lot of rural homes and commercial buildings are on 3 phase power, there are two options here; a single phase inverter can feed one of the three phases, or a 3 phase inverter can be installed to feed all three phases. It is best to discuss with the solar installer which option will maximise the solar power system.

6. Is the solar power system easily expandable?

Having the option to expand solar power system sizes in the future is a great idea, but it’s really important to let the solar professionals know this as soon as possible. String inverters can be oversized to accommodate for more solar panels to be installed at a later date. If oversized string inverters have not been installed, then purchasing a new inverter will be essential to expand. Another option to expand on a system at a later date is to use micro-inverter systems. They are modular, which means they can be easily expanded.

7. Can I add solar batteries to this system in the future?

Considering purchasing batteries after an install has been completed? Make sure all the components for the grid connected solar power system are compatible for batteries. This doesn’t make the system more expensive, it’s more about choosing the right inverter.

8. Do I need to put solar panels on the north facing roof?

If options exist for different roof faces to install solar panels on, be sure to quiz the solar designer for the ideal panel layout.

North facing solar panels will give the most solar power generation in total. However, solar panels on east and west facing roofs will allow for more solar power generation during the morning and evening hours, which may result is more solar power consumption, as opposed to exporting it to the grid.

9. Do I need to tilt the solar panels up on a flat roof?

For maximum solar gain, it is best to tilt solar panels to a 25-30 degree angle. Off-grid systems are best tilted to 45 degrees. But aesthetics are important too, panels don’t have to be tilted that much (if they are going to be obtrusive). At a minimum, solar panels need to be tilted to 10 degrees to self-clean. Don’t be bullied into placing solar panels at the optimum angle and position if they are seriously intruding on the roof. Just be sure to find out how much power the system will produce if straying away for the recommended layout.

10. How to make warranty claims years down the track?

Faults and product issues are rare in the solar industry, but they do happen. Knowing who to turn to if the original solar installation company goes out of business is important. If the solar company goes out of business, and if they’ve sourced the solar equipment directly from an overseas supplier, it will be very difficult and expensive to claim the warranty. Find out if the brands supplied have a head office in New Zealand or if they have gone through a New Zealand wholesaler. Credibility goes a long way in this industry.

11. Are the solar panels and the inverter any good?

Ask solar installers to provide 3rd party evidence that their components are high quality and have a good reputation. Ask if they have information that shows the brands they offer in real word test conditions. Choosing tier 1 solar panels are a good indicator, but they are not the be all and end all. Also, try Googling the systems brand name (along with the word review) for components that have been quoted. There are plenty of reviews out there, although not all are from New Zealand customers, the information is relevant.

12. Are there any additional costs?

The solar salesperson should provide a complete quote for the system install and all components. Some will include 3rd party costs, such as consent fees and the meter install. If not, be sure to establish the complete cost of all the services and materials to get the solar power system up and running.

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