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The only real difference between monocrystalline and polycrystalline is the method used to create the PV cell. Poly cells uses crushed up silicon to create the cell, whereas mono cells are created by growing one long ingot of silicon and slicing in to wafers.
It is true that this way of making silicon cells gives mono cells a slightly higher efficiency then poly cells, but this is a small percentage. It’s small enough that the highest efficiency poly panels do have a greater efficiency than some mono panels.
The method used to create the PV cell doesn’t change how it performs in different climates, but the quality of the silicon used will effect how it performs under different conditions.
With the UK having less irradiance then other countries in Europe the higher the efficiency, the better your panels will work, but the method used to create the silicon doesn’t factor in nearly as much as the quality of the silicon.
If you are looking at purchasing a new home that has solar panels all ready fitted you’ll need to remember a few things;
Find out if the panels are from a “free scheme”, or if they are fully owned by the current owner. If they are part of a free scheme then the purchase of the house will not include the panels. You would have to accept the panels are only giving you free/reduced electricity and not the feed in tariff, or you can negotiate buying the panels from the company that owns the PV system.
Find out which energy company the panels are registered with, you will need to call them. It doesn’t matter which energy company you get your energy from, the payments from FIT will be the same from all of them, so the simple step is to just change details with the current registered energy company and continue to receive payments from them.
Get a document confirming ownership of the panels. Each energy supplier may ask for slightly different details, but a key ingredient is confirming ownership of the panels with the sale of the house. This can be something as simple as solicitors letter confirming this, but it is best to check with the registered energy supplier first.
It is possible to have solar panels installed on a northwest facing roof, but the amount of energy that you generate will be around 1/3rd of what you would generate facing south.
The chart below will give you an idea of how the solar pv production reduces depending on your roof orientation and tilt.
The advantage of using two string inverters, or what is more commonly known as multi power point tracking inverter, is that you will be able to have to arrays on different roof faces made up of different number of panels.
With standard inverters, if you are able to split PV system in to two parts, you would have to have equal amount of panels in each sub-field. But with a multi tracker inverter you can have different amount of panels on each sub-field.
The only problem when getting a mortgage on a house with PV would only really be when the panels are not owned by the house-owner, but rather are rented to them.
You should speak more with a mortgage advisor about this.
If you believe your solar panel system is not working there are a few easy checks that you can perform.
If you system is under performing you should then contact your installer and explain that you have monitored a loss in your system and they will be able to technically assess this.