“ Frequency Asked Questions”

Q: Is my house suitable for Solar?

A: This depends on the direction your roof faces, the amount of shading (Trees etc) and the angle of the roof.  Roof’s facing between South-east and South-west, South being the optimal position.  The roof angle does affect the performance of the installation, An angle between 30 o and 60o is best, on flat roofs we can use a mounting system to give a desirable angle. Shading from tree’s, chimneys or any similar objects will seriously affect the performance, these need to be considered during the technical assessment.


Q: I have seen free Solar installations offered, what’s the catch? 

A: Free solar panel installations are a good offer in principle however the biggest drawback is selling/leasing your roof to another company who receives the FiT benefit for 25 years.  This is the lion’s share of one of the main incentives of installing solar panels.  Although potential customers of the free solar would receive the free electricity for life, this on a 2.250 kWp installation could only amount to £123 (13% of the total benefit) a year, leaving the new leasees’ of your roof receiving over £820 a year (84% of the benefit).  We urge people to carefully consider these deals, reading the terms & conditions.  One potential issue we can see is when a Free solar installation customer comes to selling their house, they are not selling their house free of restrictions (the Installer holds a lease which is registered with the land registry), the new buyer might not want the restrictions placed, the £123a year may not seem a such good idea.  With full ownership, if a customer wishes to sell their house they are also selling an investment with a benefit of over £970 a year (using the example above).  Another problem is who really owns the lease this might potentially be repackaged and sold to an investment bank or Canadian pension fund, check the terms of ownership and rights to transfer.


Q: How long does an installation take?

A: A Typical system will take 2 days to install.  We also ensure the site is clean and free of scaffolding, before we hand over the site.  


Q: Do I need Planning?

A: Most installations do not need planning, however if you live in a conservation area or listed building planning may be needed.  Planning shouldn’t be a problem, after all, HRH Prince Charles had Solar Installed on Clarence House.


Q: What Guarantee do you offer?

A: Storm is proud of all our installations, our ethos of Right First Time ensures each installation gets the time and effort needed to get the job done.  Storm offers the whole package from survey to installation, all in-house thus ensuring our standards are consistent.  We offer a 10 year insurance backed warranty for workmanship and wiring, meaning this is underwritten by our insurers, so in the unlikely event of our business not operating in 10 years our insures will underwrite any claims.   

Solar Photovoltaic’s Explained


Q: What is photovoltaic or PV? 

A: Photovoltaic shortened to PV; these devices convert energy from light into electricity.  Just the same way our calculators have for many years.


Q: What is a Watt, a kilowatt (kW) and kilowatt hour (kWh)? 

A: Watts is a measurement of power a Kilowatt (kW) is a thousand watts.  A Kilowatt hour is the amount of energy consumed or produced in an hour. For example a 25watt lamp will consume 0.025kWh


Q:  What is a kWp, and how does it relate to kW and kWh?

A: Kilowatt Peak (kWp) is the maximum performance of a panel or solar array (multiple panels) under standard testing conditions (STC).  Every solar panel manufacturer has to test their solar panels at 1000 W/m2 irradiance with a cell temperature of 25oC this is referred to as STC.  This ensures a level playing field when comparing Solar PV performance. 


Q: What makes a solar photovoltaic (PV) system? 

A: A Solar PV system comprises of Solar panels (which convert daylight energy into electricity) and an Inverter.  The inverter converts DC (direct current) produced by the panels into AC (alternating current) which is used in our homes. 


Q: Will solar panel work on cloudy days? 

A: Yes, Solar panel manufacturers employ state-of-the-art manufacturing techniques to produce high performance and super efficient solar panels that will capture electricity even on a cloudy day.  These panels work on the intensity of light not necessarily direct sun light. 


Q: What happens in the event of a power cut? 

A: In the event of a power cut your solar PV systems automatically shut down.  This will ensure the safety of those 

working to repair the power supply.


Q: Can we store the electricity we generate in batteries? 

A: Power can only be stored if you have an off-grid system that provides all of your electricity.


Q: How much energy do I consume a year? 

A: According to DECC (Department of Energy and Climate Change), the average domestic household uses 4,700 KWh of electricity a year.  You can also check your electricity bills to see what your annual usage was. 


Q: What happens to the energy that I do not use? 

A: Electricity is like water as long as the solar panels are generating power it flows through your house, if you aren’t consuming energy then it flows to the Grid for others to use, alternatively the electricity will flow from the grid to your appliances.  One point to remember is as long as your system is installed by Storm we will ensure you receive an income from selling your electricity to the grid through your feed-in tariff (FiT)


Q: What is irradiance?

A: Solar irradiance is the amount of energy that arrives at a specific area at any given time this is measured by watts per square metre (w/m2).  Under STC the assumed irradiance is 1000w/m2 however we have recorded readings above 1000 watts (w/m2) in Essex. 


Q: What does Solar Panel/Modules efficiency mean?

A: This is a key area of a solar system, often overlooked by other Solar PV installers.  The efficiency of a Solar PV module/panel is currently 7 -18%.  This means under Standard Test Conditions (STC) with irradiance of 1000w/m2 and a temperature of 25oC only between 7% and 18% of available energy is being captured.  Therefore for every square meter a maximum of 180watts out of 1000watts of solar irradiance is captured  Please do not get confused with the efficiency of how the panels themselves work, they are 100% efficient in what they do but they only capture a maximum 18% under STC this limited by technology.  As with any technology this will improve over time, the only drawback now is that in order to generate 1000 watts of power instead you will need a solar array 5 metres squared (using an 18% efficient panel).  If they were 100% efficient they will only need a single panel of a 1 metre squared.  At storm we research to ensure we offer the very best panel on the market, however there is a cost benefit so depending on individual customer requirements different panels are applicable.  If space on a roof isn’t a issue then having twice the amount of panels will be more cost beneficial, however if you want to receive maximum yield in a limited space you will want a very efficient panel.