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    Have your solar questions answered

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Solar FAQs

Have your solar questions answered

At Hayo, we believe that there’s no such thing as a silly question.

We install both domestic and non-domestic Solar PV systems!

Solar PV (Photovoltaics) converts photons (of light) into volts (of electricity). Solar panels are fixed to your roof (usually). These contain crystals of silicon which get ‘excited’ by daylight and produce an electric current. The panels are connected together with a cable like a ‘daisy chain’, and the cable is brought into your building where it’s connected into a box called an ‘inverter’, which makes the power from the panels compatible with your building and the electrical grid.

Another cable then takes this power from the inverter into your electrical system at the Consumer Unit or Distribution Board (often called a ‘fuse board’). And hey, presto! You have free electricity from the sun.

If you have a battery, surplus power from the panels (more than your building can use) will charge the battery until it’s full, and after this any more power will overflow out into the local electrical grid. At night, the building will use power from the batteries first and only use grid power when the batteries are exhausted. Please note that if you switch all your electrical appliances on at the same time, this will likely demand more power than the battery can supply, so some grid power will be pulled in as a result, to keep your appliances running!

It’s possible to fix solar systems to tile or slate roofs, and most kinds of commercial and agricultural roofs (standing seam, fibre cement etc). The only major exception is asbestos. If your roof contains asbestos (or might do), then we would ask you to replace the roof surface before we would install solar on it. We can also install ground mounted systems, or flat roof systems, where we construct a frame on the roof which is weighted down with concrete slabs. In all cases our installation leaves the roof as watertight as it was before the solar installation.

A pitched roof needs to face roughly East, West or South. North facing won’t work effectively enough, unless it’s a commercial system on a roof with a very shallow pitch.

When installing on old slate and tile roofs (more than 50 years old) tiles and slates can be so brittle that they break on contact during installation. If this might be an issue, please discuss solutions with our team.

We discuss specifics during the quotation process, but most residential systems cost £5-£10,000 without a battery, or £10-£15,000 with a battery. It can occasionally be higher, depending on the options you choose. Commercial and agricultural systems are typically more. This is something we can refine during the quotation process.

This depends on many variables, but the payback period on a residential system is typically 6-8 years at the moment, and for commercial systems 2-5 years. Commercial leasing options might also be available, which are cash positive from day one. Buildings which are only used occasionally, such as churches and community halls, might have longer payback periods. The best paybacks are available with the highest electricity bills, such as for manufacturing and engineering companies, for example.

A 2014 Energy Saving Trust survey found at the time that house prices were improved by 13.8% by installing renewable technologies like solar. However due to there being too many variables, our savings models do not include any property value uplift from installing solar systems.

That’s like asking what’s the best car – there are several major contenders! Solar panels typically compete with each other based on looks, warranty, price, efficiency and environmental credentials. Each of these categories has a different ‘top three’ which is constantly changing, so we recommend products which typically come very high in all these categories. If you have a particular product you wish to specify, we can usually accommodate this request.

This depends on the available space and the suitableness of the roof or ground surface. Please note that panels have tended to get larger over the years, as well as more efficient, so if your neighbour has a 16 panel system from 10 years ago, this can be out-performed by a system with 10 modern panels which are larger.

Yes in theory, but they nearly always need to be the same kind of panels, and older solar modules can be very hard to obtain. Also, if your old system qualifies for a Feed-in-Tariff payment, adding more panels nearly always disqualifies you from continuing to receive this payment.

Yes, but please be aware that this will normally attract the full rate of VAT (currently 20%), whereas adding the battery to a residential solar order means that VAT is 0% (at the moment). Also, if you add a battery onto a non-battery system this will either require a replacement of the inverter or the addition of an interface device called an ‘AC unit’.

Solar module efficiencies have been improving at about 0.5% per year for at least the last 10 years. However the losses from waiting vastly exceed the benefits, so it’s better to install now, if you can.

Batteries have 2 major benefits. Firstly, they allow you to save surplus electricity generated by the solar panels (usually during the middle of the day) for the evening, so you can use the ‘free’ solar power after dark, rather than expensive grid power.

The other major benefit of a battery is that you can charge it on low off-peak rates of electricity (e.g. during the night) and use the electricity the next day. Low off-peak rates are easier to obtain than ever thanks to smart meters. They’re often called ‘Electric Vehicle Charging Tariffs’, but you don’t always need an electric vehicle to get that rate. Moving electricity demand (or ‘load’) from expensive times to cheaper times of day is sometimes called ‘load shifting’. For residential systems this can be cost effective between late September and mid March, but from April to August it’s unlikely to be needed, as in most cases the solar system will be providing all your electrical needs.

Batteries work best if your electricity usage is high when it’s dark outside (evening or night), which is usually true for homes. Therefore you should consider a battery for a residential installation, if you have the budget. For most commercial installations, a battery is unlikely to be cost-effective because evening and night-time usage is much lower than daytime usage.

Not entirely. If you want to ‘keep the lights on’ during a short-term power outage (or ‘power cut’) then this is an option on many systems, but please be aware it isn’t a standard feature. It’s called EPS (Essential, or Emergency, Power Supply) and might be able to power some (but probably not all) of your building during short term power outages. Please ask one of our team for details. EPS is not straightforward and has a lot of ’ifs’ and ‘buts’

If you’re thinking of ‘waving goodbye’ to the national gird, you need to plan for backup winter power generation, for example with a wind turbine or diesel generator. Using a generator is likely to be more expensive than using the grid, so we recommend a grid-connected ‘hybrid’ system which gives you the best of both worlds – you can have an ‘off-grid’ feeling in the summer, but keep all your appliances running in the winter with back-up grid power.

Sometimes people ask if they can install enough batteries to store their summer electricity into the winter. If you have a budget for batteries of at least £1 million, plus a spare building for the batteries, then this might be possible! But for most people it’s far more economical to use grid power when necessary in the wintertime.

During the summer, yes it can, but during the winter you will almost certainly need some backup power (e.g. from the local grid).

Electric vehicle (EV) chargers can work with solar systems, usually independently of them. However if you want the EV charger to ‘link’ to the solar system, you need to check with the EV charger manufacturer that your chosen product has that functionality.

Hot Water diverters require a hot water tank to be present, and should only be considered if there’s no solar thermal or hot water heat pumps present, and your solar system is predicted to produce a significant surplus of power in the summer.

Most residential systems are installed within 1 day. Larger commercial systems can take several days.

Solar panels have no moving parts, so the chances of one failing is infinitesimally small. In fact the only moving part in a solar system is the cooling fan in the inverter!

Firstly, Hayo Energy provides a whole system 10-year warranty on our systems.

Panels mostly have 25 year performance warranties on them, with estimated lifespans of 50-100 years. They degrade by a tiny amount each year – typically around 0.2% – 0.4%. After 25 years they are still warrantied to produce at least 84% of day one output. For all practical purposes, solar panels should last a lifetime.

Inverters and batteries are warrantied for 10 years, with an expected lifespan of around 20 years.

Solar systems typically require no ongoing maintenance. Dust and bird muck is usually washed off by rain providing the panels are pitched by at least 13º. But once every couple of years it won’t hurt to get window cleaners with long poles to wash your panels as well.

As part of our installation, we install several isolators which allow individual components within the solar system to be replaced easily if it ever becomes necessary.

This will be discussed after your installation. A welcome pack will give you guidance on how to maximise your savings.

We typically begin with a discovery call of about 45 minutes to cover general queries and assess if your project is viable. After this, we will make a pre-survey visit of around 1 hour to cover specifics and quote.

When you’re ready to order, we ask for a £250 advance payment to initiate the process, after which we will undertake a survey. We handle liaison with the local grid and schedule the installation, typically within a few weeks. At least 1 week before installation we ask for a 25% advance payment, and once we’ve received this the scaffolding goes up, and we complete the installation. Your final payment is due at the point the system is commissioned (i.e. generating power for you), and after we’ve received it, we instruct the removal of scaffolding and handle post-installation documentation.

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