What should I check in a quote before I buy a solar power system?
Make sure the installer comes to your house and has a look, before you get the quote. Internet based solar companies quote you for a system over the phone can spell trouble for the install quality, as they cannot truly appreciate the individual set up of your house. Are the tiles brittle ? Where are any surrounding trees, which can cause overshadowing?What about antennas and chimney locations - which in the future through overshadowing can affect the system output significantly? How old is your switch board and does it need upgrading to handle solar? All these questions only become clear through a proper home inspection.
When internet or call centre based solar companies sell you a system they use the one size fits all approach and give you a standard price. They then negotiate with a sub-contract installer to install your system for an agreed price. So the sub-contracted installer holds all the risk should your system requires extra cabling or is a particular labor intensive installation. It is more likely in this situation for the installer to find the quickest way, not necessarily the best way to install the system. Being a sub-contractor to the company that sold you the system, the installer's relationship with your system is one of "get in and get out as quick as possible".
Should you, in years to come require support for your solar system, the internet based solar company might not be around anymore, or should they still exist are very likely to send a new sub-contractor to check out the issue. It is better, like with your car, to have the same reliable mechanic undertake the ongoing work. Someone who is familiar with your particular circumstances/system.
In general the quotation should provide solar system specifications like quantity of panels, brand and model of panels, system size and likely output per annum in kW/h, capacity and output of the inverter or if micro inverters are to be used the brand and warranty conditions.
A proper, considered quote should include also datasheets of the supplied products. In general make sure your quote includes:
- Solar PV modules - brand, model and manufacturer's warranties;
- Mounting frames - brand, warranties and which part of the roof to be installed;
- Inverter - brand, capacity and manufacturer's warranty;
- Any additional metering cost - if not included in the price, make sure this aspect is clearly outlined in the quote;
- Travel and transport requirements if not included;
- Any trench digging if solar to be installed on outbuildings e.g. farms.
Make sure the installer at hand over gives you a system user manual.
The quotation should also specify a total price, together with proposed start and completion dates. The quotation should form a basis for your contract with the designer/installer. Deposit requirements for the system should not be excessive. Usually the majority of the solar system needs to be paid for on the day of installation.