Third-party maintenance contracts and optimisation devices

Third-party maintenance contracts and optimisation devices

It has come to my attention that there is a company in Liverpool that is cold-calling owners of solar PV systems offering them so-called “upgrades” and maintenance contracts.

Firstly, I would like to give an assurance that I have never shared my customers’ telephone numbers with third parties, and never will. My advice has always been that organisations that cold-call are seldom reputable. You should steer clear of them. They will sometimes claim that they have got your number from MCS. This isn’t true either – click here for confirmation:

The company appears to be marketing a voltage optimisation (VO) device and also a monthly maintenance / breakdown insurance. Let’s deal with these one at once:

Voltage Optimisation device

According to the information on the company’s website, you’re losing up to 20% of your yield by not having one of these.

The implication is that without this device, your inverter will regularly detect an over-voltage condition and automatically shut down. This is complete nonsense.

If a healthy inverter ever shuts down due to high mains voltage, either the cable to the inverter is sized too small for its length of run, or the mains voltage exceeds statutory limits. If it’s the cable then it will need replacing with a more appropriately sized length of cable. If it’s the grid voltage then the DNO (Electricity Northwest in this area) are obliged to correct it. No gimmicky gadget required and no money to be parted with.

Solar PV maintenance or breakdown insurance

Apparently the company are offering this service at something approaching £20 per month. That’s £240 per year, or £1200 over five years. A lot of money, and considerably more than the cost of a domestic sized inverter.

Solar PV systems are inherently very reliable but do occasionally go wrong. When they do, the most common fault is a defective inverter. If yours fails and is outside its manufacturer’s warranty, you may be looking at a cost of around £700 to have it replaced (based on a typical 4kW system). This new inverter would have its own five year warranty, which can be extended to ten years for a nominal fee.


Many people have often drawn parallels with the solar panel industry and old-style double glazing. Salesman’s patter and gimmicky products are the undesirable side of the business, and there remain lots of shyster companies lining their pockets.

If your PV system is working correctly then there is no need to do anything. If, however, it develops a fault, give us a call on 01772 311016. No silly gadgets or monthly policies will be offered.