Solar FAQs
Knowledge is Power
Did you know…the Sun provides the Earth with more energy in a single hour than the whole world consumes in a year. All we have to do is collect it. If every roof space in the UK had solar panels linked to battery storage, we’d have enough energy to power everything we do, everywhere we do it. We think knowledge is power, so we’ve started building a database of all the things you need to know to make good decisions about your energy future.
We’ll post the answer here.
PV stands for Photo (light) Voltaic (Electric). Solar PV panels convert light in to electricity. Note the word light, not sunlight. They continue to produce electricity on cloudy days. It’s just that their output will be higher, the brighter the light is. This is not new technology – the use of light to produce electricity dates back to the 19th Century.
Inverters change the DC current from the panels to AC current needed for your home and the grid. It’s essential the correct type of inverter is used and that they’re located in the right place. Many installers always put them in the loft, but this can be detrimental to your system. Naked Solar are meticulous about inverter choice and placement.
Our solar team have absolutely zero financial motivation to push particular products because their salaries are not commission based. Cornwall Solar Panels (renamed Naked Solar in 2017) was formed in 2010 by Tony Sampson because he had a passion for green energy and saw that there was a great opportunity to take Solar energy away from the ‘double-glazing style’ hard sell pushy sales approach and offer customers a genuinely informed choice. We’re committed to remaining 100% impartial and can install any Solar PV products on the market. And frequently do – because every home and every business is different.
Your inverter monitors grid voltage and ensures that it is putting the power from your inverter into your system at a slightly higher voltage than the grid. Voltage is best thought of as pressure, the force behind the electric. If the inverter produces a higher voltage when you switch an electrical appliance on it will naturally use the power from the panels first.
A 4kWp system in Cornwall on an unshaded south facing roof can generate over 4000 units (kWh) per year. If your roof is East or West facing you’re still likely to generate 3400 units (kWh) per year. The average household in the UK uses around 3200 units per year, so living in Cornwall is a definite benefit! Depending on when and how you use your electric depends on how much impact your PV system will have on your bills. With a bit of information about your electric usage and habits, Naked Solar can produce incredibly accurate bespoke forecasts thanks to their PV Sol modelling software.
Naked Solar use PV Sol software to accurately calculate your expected output. PV Sol accurately takes in to account panel performance, inverter performance, shading, roof pitch, roof orientation and your local weather data to calculate how much electric you will generate. We then include these figures and how much money you are likely to earn, based on your usual usage and the amount that will be returned to the grid.
You will simply draw from the grid in the normal way. But remember, it doesn’t have to be sunny to generate electricity.
The excess energy will be sold back to the grid.
Not any more. Since the end of the Feed in Tariff, there has been no need for any property with a PV installation to have an EPC. Solar PV owners can now be paid for their exported electric by their energy supplier without the need for an EPC.
Naked Solar use a Professional PV design software package called PV Sol. We can build a 3D model of your property to see which panels will fit best on your roof. There are over 400 panel manufacturers in the PV Sol database and every panel listed has details of the panel’s performance.
No, leave that to us. Naked Solar are accredited to notify all their work to Building Control.
On homes, for standard installations, the brackets used fix to the rafters of your roof which ensures the fabric is free from loadings. However, new developments in solar technology now mean you can build your roof entirely out of solar material or solar tiles that look like part of your roof.
Commercial roofs vary in construction and there are many different mounting solutions for every different scenario. At Naked Solar, we’re used to dealing with complex or unusual installations. Test us!
For the safety of linesmen who may be repairing the fault, your inverter will need to shut down. There are some battery storage systems that will allow you to have back up power in the event of a power cut. If back up is essential, we’ll be happy to put together options for you.
Naked Solar use their own fully qualified tradesmen. A domestic system team is made up of a qualified roofer, a labourer and a qualified electrician.
Home installations take up to two days to install. However, typical installations are finished in one day.
Commercial installations can take longer, depending on the size of the site and the specific requirements of your business.
FIT (Feed In Tariff) is the government-backed scheme which means your electric supplier (eg EON, N-Power, EDF, Utility Warehouse etc) will pay you for every unit that your system generates, whether you use it or if it goes back in to the grid. The Feed in Tariff scheme ran from April 2010 until March 2019 and was designed to reduce the subsidy in line with the reduced installation costs. Now that Solar PV installation prices are low enough there is no continued need for a subsidy so the Government finished the scheme in March 2019.
You’ll see savings on bills immediately. Payback of the installation cost depends on many variables including quality of panels and inverters, your local weather conditions, shading, pitch and orientation of your situation. Typically in Cornwall you can expect to pay off a home system in 8-12 years and a commercial system in 6-8 years. After that, it’s like getting free energy for the lifetime of the system (25-50 years with quality panels).
There are no government schemes since the Feed in Tariff ended in March 2019. You may see advertisements that claim there is but these are often dressed up loans so please tread carefully. You can be paid for energy that is exported to the grid and from January 2020 all energy suppliers with over 150,000 customers will be obliged to offer such a scheme. You can shop around for the best rates in the same way that you can shop around for the best imported electric deals.
You would have to check with your landlord. We’ve installed Solar PV for many landlords as they can benefit from the Feed in Tariff, increase in property value and increase in rent.
There is currently no mounting system to put Solar PV panels on thatched roofs. You may be able to have a ground mounted Solar PV system.
Yes, PV solar panels can be fitted to any roof, even if there is no access to the loft or it is used daily.
Many customers also install heat pumps. These take the small amount of heat in the air or ground and extract it to help heat homes and provide hot water. They run on electric and save huge amounts on people’s bills. They need a very specialist installer like Abode Heat. Many customers also have wood burners, sometimes with back boilers. These combined with an immersion diverter can greatly reduce or even eliminate the use of Gas or Oil for heating and hot water.
No, Solar PV panels work on light and all roofs have light shining on them. Many customers have fitted east/west facing systems and typically generate around 86% of an equivalent south-facing roof.
Solar PV panels vary greatly in efficiency so one panel may generate 250 watts while another panel of the same physical size may generate 345 watts, therefore it’s not how many panels you need but how much power you need. Domestic systems usually aim for 4kWp which is made up of 11-15 panels, depending on the quality and efficiency of the panels chose.
Feed in Tariff ended in March 2019 because the Return On Investment for Solar PV remains the same. The Government target is 8% ROI. Naked Solar are still finding domestic system can reach 16% ROI and Commercial systems can reach 30% ROI. For some people Return On Investment is important and will be affected by the amount of self-generated electric that you can use to reduce your bills.
Solar PV panels gradually degrade over time. Typically they will lose around 15% of their power over 25 years with some high quality panels only degrading around 2.5% over 25 years. This also varies depending on the quality of the panel. Naked Solar use PV Sol software which allows us to forecast very accurately the impact of any degradation.
There are advances in technology, however these are aimed more at using different materials, e.g. hiding PV technology in glass. These advances do not show any progress in efficiency so are unlikely to become mainstream. The technology we see in today’s Solar PV panels is the same technology that was used to power some satellites in the early 70s. There are some small incremental advances but these are not expected to change dramatically at the moment.
Shading will reduce the power output of solar panels and any panels directly connected to the shaded panel. Naked Solar can calculate exactly what impact your shading will have with their 3D modelling software PV Sol. Severe shading, like a chimney right in front of panels (known as Hard Shading) can also cause some long term damage. Naked Solar will be able to advise you of the best place for your panels to be installed.
Almost every panel on the market has diodes these days and they don’t completely stop the effects of shading, however they do help.
Monocrystalline panels will give more power per square meter. This might not mean that the panel is better than a high quality polycrystalline panel. There are many, many factors that affect the quality of a panel, this is just one of them and efficiency is only a critical factor if you have a limited amount of space.
Inverters are electric and electronic equipment so they’re best off being kept cooler. We usually recommend installing them in a garage, utility room or some models can be mounted outside. We advise that the loft is a poor place to install the inverter as they get very hot and in particular will get hottest on the day you want your inverter to work its hardest. This will reduce the output from the inverter and age its components quicker. We know that installing in the loft is easier and quicker and that the slightly shorter cable run may also have an impact. However, it’s a poor trade off as the extra loss in longer cables is more than offset by the extra production and life that you’ll get from your inverter. Another advantage of having the inverter where you can see it is that you can check that your system is working properly. Inverters have a display that tells you if everything is running smoothly. If this display is in the loft then you won’t know anything is wrong until you get the Christmas decorations out!
In most cases, no. Domestic solar panel installations are considered ‘permitted developments’ and don’t require planning permission unless:
- you live in a listed building
- your home’s in a conservation area or an area of outstanding natural beauty. (Panels are permitted in a conservation area as long as they’re not installed on a wall or roof that fronts a main highway)
- the panels protrude more than 200mm from the roof. We always fit within this limit.
- you are having a ground mounted array.
If you’re unsure about permitted developments, please visit the Government’s planning portal or book a call back and get free advice from us.
Yes! In the same way that Powerwall 2 works independently of your existing Solar PV system by simply monitoring when there is electric being exported to the grid, Powerwall can do the same. It will see electric being exported to the grid and charge at the same rate. When you have demand from the grid, Powerwall 3 will respond by discharging to meet your demand.
What’s better about Powerwall 3 is it will cover much higher loads up to 11kW (with Grid permission… don’t worry we do the paperwork) which is plenty for 99% of households and many small businesses.
And don’t worry if you have Feed In Tariff, it’s unaffected and Naked Solar can help navigate the process for you.
Unfortunatley not. To expand your existing Powerwall 2 installation you can add another Powerwall 2. You’ll need permission from your DNO who look after your local electric supply network. Naked Solar can take care of this application for you and Powerwall 2 is still available.
Rumour control is saying that Powerwall 3 may be able to work with existing Powerwall 2 installations in the future, however this has not been confirmed by Tesla.
The good news is both! Powerwall 3 is safe in the rain thanks to it’s IP67 rating. The innovative cell level heating system keeps the battery warm, allowing operation from -20°C up to 50°C.
Beware of outdoor installations: Studies show the most efficient temperature for Lithium Iron Phosphate batteries is highest at room temperature. For outdoor installations, bear in mind you might loose a handful of units (kWh) each year to keep the battery warm enough to perform well when the outside temperature drops below freezing.
Naked Solar’s Powerwall 3 installation price is £9489. If you’re keen, talk to our team, they’re all experts in their field with experience in helping a wide variety of customers navigate all the options on the Solar & Battery storage market. They love to help so get in touch and get your Solar Geek on.
Under the PAS 63100, Battery Energy Storage Systems should not be installed under stairs or in an area that would be considered an escape route in the event of a fire. This is because of the concern that a battery could catch fire during a house fire.
Yes, Powerwall 3 can be installed on a stud wall, our engineers will decide on the most appropriate fixings to use depending on the structure of your stud wall.
The Powerwall 3 is 1096mm high by 609mm wide and 193mm deep. It weighs in at 130kg which is why Tesla designed a ‘Dolly’ to enable safe movement of the unit.
Your first port of call is Naked Solar, our technical team have years of experience in diagnosing a wide variety of faults with Solar PV & Battery Storage systems. Tesla also have a technical team should the fault need deeper diagnosis. Naked Solar have experience of working with the Tesla Powerwall team so will be able to help, even if Naked Solar didn’t carry out your installation.
The big news is the power output increasing from 5kW to 11kW, meaning Powerwall 3 can power devices like EV chargers, Electric Showers and Heat Pumps. The addition of a Solar Inverter also reduces installation costs when compared to Powerwall 2 while also reducing the conversion losses in the system. For a full review of the differences, take a look at our Powerwall 2 v Powerwall 3 blog post.
That depends on a lot of factors, whilst 1 x Powerwall 3 will store enough electric to run the average house for more than a day, many customers want more storage to help reduce their reliance on the grid or to maximise their Solar Grid Trading. The beauty of Powerwall 3 is that you can add more storage at a later date if you want to dip your toe in to start with. Our expert team of consultants will be able to talk through your specific situation and help you make a fully informed choice.
Powerwall 3 requires an internet connection in order to commission the system. Tesla recommend installers set up both hard wired and wireless connections where possible to give the best chance of a good connection for monitoring, controlling and free software updates.
If Powerwall is not connected to the internet, it will continue to operate in the last operating mode set and provide backup power during an outage, but it will not provide remote monitoring via the Tesla app. Extended periods without an active internet connection will prevent software updates and may impact the product warranty.
The Powerwall 3 is only available with the Glossy Glass White finish. Tesla have given no indication that they intend to offer different coloured options. We know some people like to bling their things so we’re sure that some owners will add a laminate wrap and we’re looking forward to seeing the results of Powerwall 3 owners creativity.
Yes, Powerwall 3 can be installed so that you can benefit from Solar Grid Trading, so you can dip your toe and add solar later if you wish. This is also a good option for those who live in flats.
At times of heavy use, the Powerwall 3’s fans will operate to keep the cells in tip top condition. These fans will generate a similar noise to a large PC fan.
All GivEnergy products come with a 12 year warranty. You will need to have 3 x Health Checks at 5, 8 and 10 year points after installation to maintain the warranty. GivEnergy will do these remotely and may need additional information from the customer.
Choosing a GivEnergy approved installer like Naked Solar brings you peace of mind you’re in the hands of industry experts who’ve undergone detailed installation training from GivEnergy themselves.
The coveted approved installer is a symbol of trust:
- Before: Ensure you get maximium value, using in-depth knowledge to identify the most suitable GivEnergy products for your needs.
- During: Carry out an installation of the highest quality, adhering to best practices and safety standards.
- After: Provide responsive aftercare upon completion to ensure you continue to get the most out of your system.
Yes, as long as you have a cover over it. GivEnergy equipment is IP65 rated, meaning it’s OK to be sited outdoors. It must be installed out of direct sunlight and should also have a cover or canopy to keep the worst of the rain off of it. Bear in mind that Lithium batteries perform best around room temperature so you’ll also see a drop off in performance and efficiency on colder days.
No, the GivEnergy All In One is an AC coupled battery, meaning it’s designed to be installed in a property that already has Solar PV fitted. The All In One can be installed without solar if you want to power your home on off-peak electric or take advantage of Grid Trading.
You can find out the differences between AC coupled V DC coupled systems on our “6 Watts? of Solar Storage” page.
GivEnergy products can have further battery modules added to them after the initial installation. Bear in mind that things move quickly in our industry so as newer products replace existing ones, the modules to expand your system may have ceased production.
