PV solar panels, Solar Edge inverters and voltage optimisers
“One of the joys of owning PV solar panels, is that you can sit comfortably in the knowledge that your family is protected despite an energy industry that has no outlook farther than next year’s profits.”
So you’re sitting comfortably with your newly installed photovoltaic array, then an unknown company comes along and offers you an upgrade. An upgrade to enhance your PV performance and squeeze a little more juice out of it.
Is this worth the extra expense?
Recently I was asked if it’s worth upgrading an existing PV system to a Solar Edge inverter with voltage optimisers system for £4,000 – no this is nuts!
The reality is that all good quality inverters cost around the same apart from Solar Edge and Enphase that are individual micro inverters designed to optimise each panel’s output individually.
I absolutely understand that solar companies and installers are looking at new innovative ways to complement their core business, but the concept of tempting already satisfied PV users to upgrade for thousands of pounds with juicy financial carrots is wrong.
In my humble opinion; if it isn’t broken then don’t fix it!
There is no doubt that Solar Edge products are second to none and are well-respected within time-served installer circles, but none of them would consider selling this technology on the basis of financial gain.
Anyone installing PV solar panels today should get comparison quotes with and without micro inverters, but the reality is most people don’t need this extra expense and a standard string inverter will be sufficient in most cases.
The real importance is the peak output value of the ‘actual panels’ that are far more likely to dictate performance output and should be more of a concern when choosing a PV system type.
For those who research the subject of installing PV, there is a noticeable difference in price between Solar Edge and non-Solar Edge installations, but this is within hundreds of pounds and certainly not thousands of pounds as proposed above.
In my humble opinion; Solar Edge and additionally Enphase are industry leaders and proven technologies, but expect to pay more for these system types – albeit not thousands of pounds!
The aforementioned proposal is like getting charged for installation costs twice.
These system types benefit the user and are recommended for:
- Properties who have shading issues. With un-shaded and Southerly facing installations, they probably won’t produce more electricity than a standard string inverter.
- PV solar panels with higher ‘peak output’ ratings (280 watt plus).
- Split-roofs. East and West sloping roofs are popular types of installations in the UK and micro inverters can make the most of solar technology within these constraints.
- Daily monitoring of each panels performance. This unique monitoring aspect is prized within the industry and allows the PV owner to monitor and analyse performance over the day, month, year and lifetime – an analytical and engineer’s wet dream.
Solar Edge which are today commonly sold as aftermarket additions can only be worth the extra expense when used on the right occasions at the right price and only during the original installation process. However, spending thousands of pounds to upgrade an existing already commissioned and fully operational PV system is simply not worth it!
If I was Installing today and if money isn’t a problem, I would absolutely go for the micro inverter system, simply for its ability to the monitor panels individually. However, if you’re not as nerdy as me, then a standard string inverter will do the job adequately in most cases.
The bottom line is; you don’t have to spend thousands of pounds extra to get the most out of your photovoltaic solar panels.
PV to hot water converters ‘versus’ voltage optimisers
Voltage optimisation is based on a concept that; the voltage supplied to homes by the National Grid is around 242V. The optimum rating for all electrical devices throughout the UK and Europe is 220V.
Voltage optimisation on residential sites does have its critics when sold purely on the basis of energy saving and can vary depending on what type of electrical appliances are being used.
Voltage optimisers can be purchased for around £350 as can PV to hot water converters. These hot water controllers are great devices that will effectively give you free hot water for around six to eight months of the year – provable.
What PV to hot water converters actually does is divert the spare electricity from your panels to power the immersion unit in your hot water cylinder, thus giving you free hot water when your panels are working well.
However, PV to hot water converters are not recommended with today’s ‘battery storage’ type installations because the hot water unit will be using up virtually all the ‘spare’ electricity from your panels in most cases.
If salesmen mention ‘voltage optimisers’ devices, then be very wary of the saving claims as the variables are plenty. YouGen ran tests and warned its members against selling them on the basis of any substantial savings. WHICH listed them as one of the five biggest wastes of money in saving energy.
In my humble opinion, the jury is still out on the benefits of voltage optimisers, but hot water converters is a proven technology today.
PV to hot water converters will give you plenty of hot water depending on the base load of your property and makes a better case for spending your money on higher output panels than some aftermarket products.
Realistically, hot water is a must for all families each day, so if you have an immersion heated hot water tank, then hot water provided for your family for free using your solar panels is priceless.
Charge your car with PV solar panels
If you really want to impress the neighbours and maximise its full potential, then charge your next car with PV solar panels.
Being one step ahead of the crowd is how most people create and keep hold on to their money. Many people installed PV because it was a ‘sure thing’ and they were ‘ahead of the crowd’.
Therefore, the next logical step is to trade in your old gas guzzler for an EV (electric vehicle) charged for free with your PV solar panels.
Most car manufacturers have their own EV models, so once again opportunity strikes to expand your ability to benefit from solar panels with ‘free motoring mileage’ too.
Always food for thought.
"Feel the pride."Stuart Lovatt April 26, 2016
Founder of Heat My Home.