Solar panels at school

Payback from solar (that is, the time it will take to recoup the upfront costs of the solar system from savings made on your electricity bills) depends on the following factors: 

• the total upfront installation cost
• the cost per unit ($/kWh) for the generated electricity (variable charges)
• the amount of electricity which is used during daylight when the sun is shining.
• whether or not the panels are being kept clean.

• How will the solar panels reduce carbon (CO2) emissions?
• What other emissions reductions opportunities are available to the school?

• Does the proposed solar panel location have optimal sun?
• Is it in a shaded location (that is, what the number of sunshine hours where the school is located)?

Battery storage should be a good investment for the school, taking into account the ongoing costs associated with the lifecycle replacement of the battery.

Solar systems will shut down in the event of a power cut as a safety measure. The exception is if batteries are fitted – but unless a very large solar and battery system is installed, available energy services are likely to be compromised. Consider which energy services are essential for continuing the school day or in an emergency situation. Is the proposed system sufficient to meet these requirements? 

This will normally be grid electricity, although it could possibly be backup generation which is likely to be diesel. 

Has self-consumption been taken into account? Self-consumption refers to the use of solar PV energy directly at source – either immediately or delayed through the use of battery storage systems.

How can the school adapt their operational practices to maximise any energy efficiency and get the most value out of their installations? For example, how could the school move as many energy services as possible to when solar is generating, to maximise use of solar-generated electricity?

Energy efficiency at school

Will the solar installation provide sufficient electricity to meet the school’s average and maximum demands across all seasons?

• What are the maintenance costs of solar panels (including any costs associated with health and safety requirements for working on roofs)?
• What are the replacement costs of inverters and batteries if applicable if you own them and how they will be covered? Are they part of the provider’s package?
• Is there safe access to the panels for cleaning and maintenance?
• Have you considered the remaining life of the roof and any added expense and risks if solar panels need to be disconnected and re-installed if the roof requires replacement?

For your roof, consider:

• having your roof evaluated to make sure it can withstand solar panel installation
• its remaining life, including whether it is currently included in the project list on your school’s 10YPP for maintenance works 
• undertaking any required repair/maintenance/replacement before installing the solar panel. This will avoid additional costs in the long run associated with removing and reinstalling the solar panels on the roof.
• securing written confirmation from the manufacturer that the proposed installation method does not void the warranty where roofing materials are under an existing warranty. Schools or property advisors will be able to confirm if an existing roof is under warranty.  

Roofing materials for school buildings

Discuss the potential impacts on your school’s existing infrastructure with your property advisor, including:

• building age and condition: newer or refurbished buildings are more likely to support the load from solar arrays. Older buildings are more likely to be unsuitable due to their design, age or condition
• site location: ease of maintenance and cleaning to maximise energy generation capability; shade from other buildings or site features such as taller buildings or trees
• building alignment: northerly facing buildings maximise the amount of energy generation potential
• alternatives to roof mounting: ground mounted solar arrays are an option, as they can reduce the risk to Ministry assets, and are likely to be more easily cleaned and maintained.

Warranties are an important aspect of protecting a solar panel. Schools should ask their solar provider about warranties and guarantees they are offering as part of their package.

What warranties and guarantees are provided for the solar panel?

The following warranties are applicable to solar panels. Have you checked the relevant warranty with your solar provider? 

• Panel performance warranty (industry standard is 25 years): The performance warranty is to warrant the degradation of the cells over 25 years.
• Panel product warranty: The product warranty is to cover defective materials or workmanship in the manufacture of the panel. It is provided by the manufacturer of the panel, not the solar installation company. It is very important that your panels’ product warranty is at least 10 years.
• Inverter warranty: The inverter warranty is probably the most important warranty you will need. The reason for this is because this is the component of your system that is most likely to fail. They are working day in, day out at high voltage. Inverters generally will have a 5-year warranty. Upgrades to 10 years are available with some brands depending on the manufacturer.
• Installation warranty (provided by the installer): The final warranty, the installation warranty, is also very important. You need to assess what you will be charged for in case of a breakdown. It is the company’s policy that is important here. Will you have to pay for a service call if one of the components fails? Does the company take care of the entire system if there is any problem?

Are there possibilities to include an associated software package which is accessible, interesting and useful for students (with the level of analysis tailored to the students’ ages)?

Health and safety: The provider should be cognisant of the health and safety systems to be provided by the solar panel supplier. The panels will require access for maintenance and as such a safe access methodology is to be provided by the installer and/or maintenance provider. 

If entering into an agreement with a third party supplier, boards should seek independent legal advice about the Energy Services Agreement. It is a legal document that will apply for the duration of the agreement and often cannot be ended early. Boards should be confident that they are making a good decision on behalf of future boards and be fully aware of the risks and obligations that they're taking on.