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Learn about PV (photovoltaic) solar panels in the UK's climate that benefits you for decades to come. Today, you can install an on-grid photovoltaic system, with or without a battery storage device.
PV with battery storage, water storage, and possibly car charging is perfect for this crazy 21st century.
In a nutshell:
Depending on cloud density, generation can occur passively. With denser cloud cover, not so much. Therefore, a single 1 kW Photovoltaic Monocrystalline array generates around 900 kWh/year.
Domestic PV systems range from 1-5 kW. A 3-4 kW system makes sense for most people.
Schematics are available here.
Are PV solar panels financially worth it?
The UK absorbs around 50-60% of The Sun's radiation compared to the equator. Add your annual energy/fuel costs x 30 years (panel lifespan). Add inflationary pressures = your approx future energy costs. Now compare this figure to the cost of installing a PV system.
How do PV systems work?
Photons of light strike the electrons in the p-n junction and energize them, knocking them free of their atoms. These electrons are attracted to the positive charge in the n-type silicon and repelled by the negative charge in the p-type silicon. Electrons align into the circuitry to create a current:
What happens to surplus?
If not distributed to storage devices, then it automatically feeds the National Grid, and payment comes via an export tariff. Any deficit in power generation automatically draws from your electricity supplier as per usual.
Micro-Inverter or String Inverters?
Both inverter types have positive and negative attributes.
String Inverters are the original way of altering Direct Current to a useful Alternating Current. Micro-Inverters are smaller additions to each panel.
Mico-Inverters are more complicated to install and thus typically add about 20% more to the cost of the installation. The simpler String-Inverter makes PV more affordable, and easier to access and maintain thereafter.
Micro-Inverters are typically used if shading is an issue, such as a split-roof configuration. They're often sold as giving a small increase in performance, but from a longer-term maintenance point of view, they're difficult and costly to replace if required. Any performance advantage may be negligible.
Unless there is a specific reason for doing so, then I advocate for keeping it simple by installing a traditional String Inverter and keeping the installation cost to a minimum.
Photovoltaics in cooler climates.
Photovoltaic cells work more efficiently in cooler temperatures. Panel degradation occurs much quicker in hotter climates, just like redlining a car engine will reduce lifespan and efficiency too.
Can photovoltaics heat a water tank?
PV-to-hot water converters heat traditional hot water tanks by using solar-generated electricity directed to the heating coil. This device eliminates the requirement for boiler usage most of the year.
How much roof space?
Although PV solar arrays take up a lot of roof space, most homes in the UK are suitable. Additionally, they can be ground-mounted A-frames if garden space or land allows.
Do I need planning permission?
No planning permission is required unless listed or conservation area.
What maintenance is required?
No maintenance is required. Photovoltaic is a 'solid-state' energy conversion process with no moving parts.
Do solar panels work on cloudy days?
This answer depends on the density of the cloud. Use a solar-powered calculator, and it'll work fine outside in the daylight hours. A PV system works on cloudy days, just not at peak performance.
Will the installation process have a big impact?
Once the panels are fitted, the internal components don't take up much space inside. The overall installation process is usually completed within 2-3 days.
How long does PV last?
Photovoltaics installed in the 1960s are still working today. Degradation is minimal consideration when choosing a system. Monocrystalline solar panels still have an 80% generation capacity after 20 years.
What about solar panel cleaning?
Photovoltaic solar panels are coated with a microscopic layer of titanium dioxide during manufacturing. When ultraviolet light falls on the glass, the coating reacts with organic matter to break it down. With that said, a periodic cleaning using de-ionised water will ensure the best performance.
The cost of a PV solar system depends on system size installed. Additionally, prices vary widely across different installers due to operational differences. Battery storage may be added later to bring down the cost.