Our PV Solar installation supplied by Solar Advanced Systems consists of the following components:

  • 14 x Sungrid 215W Solar Panels
  • SMA Sunny Boy 3000HF inverter
  • Landis G 110+ Generation Meter

 

There are many questions that potential solar panel owners may want answers to. Hopefully these FAQs will cover many of the queries. The answers are based on our experience as well as generally available information on the internet. Unfortunately there are some solar installation companies that seem to peddle unsubstantiated information as facts and to use misleading statements that are untrue. Luckily the vast majority of solar panel installers are legitimate companies that do not use such tactics.

 

Some Frequently Asked Questions about Solar Power

Do solar panels generate only on sunny days?

No. PV Solar panels will generate on cloudy days and do not just need sun shining on them. However the amount of electricity generated on a cloudy day is a fraction of that generated in the sun. In the winter this can be as low as 5% of the amount for a sunny day. In the summer a cloudy day may generate as much as 10% and even on a day with mixed cloud and sunny spells you can get as much as 50% of the output of a clear sunny day.

My electricity meter is going backwards since my solar panels were fitted - what can I do?

If your electricity meter is going backwards and reading lower after installing solar panels check this video.You should inform your electricity supplier if your meter goes into reverse when solar panels generate electricity.

 

What output will my solar panels give?

The output of your solar panels will depend on a number of factors such as the direction they face, the angle of your roof, your location in the country and if they are affected by shading. The output is significantly higher during summer months and can be around 3x higher than the maximum during winter.

What is the maximum electricity my solar panels will generate?

For our panels which are virtually south facing in South East England the electricity output generated equates to around 7kWh per kWp per day. So for 3kWp of solar panels you would get a maximum of 21kWh of electricity on the best sunny day of the year. A sunny day during winter would only generate a maximum of 7kWh of solar electricity so you can see the difference that the longer days make. You can view a Month by Month comparison of UK solar panel electricity produced for 2011 onwards so you can compare how much electricity solar PV panels will produce for a south facing roof in the UK.

What direction should my solar panels face?

In the UK the best output from solar panels will be achieved if they are south facing. Directions other than due South will still generate electricity but not as much as an installation facing due South.

What is the difference in generation between sunny and cloudy days?

The amount of electricity generated on a cloudy day is a fraction of that generated on a sunny day. In the winter this can be as low as 5% of the amount for a sunny day. In the summer a cloudy day may generate as much as 10% and even on a day with mixed cloud and sunny spells you can get as much as 50% of the output of a clear sunny day.

How can I make the most of the electricity generated by my solar panels?

A member of MoneySavingExpert has created circuit diagrams for a device to monitor the output from PV Solar panels and to enable households to use the maximum output from their solar panels. You can view the information on Dave Fowler's website here

How can I check on my panels remotely?

Why does the inverter for my Solar Panels read lower than the generation meter?

Why does the inverter for my Solar Panels read higher than the generation meter?

Can I view data from my Sunny Boy inverter on my laptop?

How much will I get from the Feed in Tariff? (UK only)

What is the best position for my solar panels?

Where should my solar panel inverter be located?

A number of companies offer Free Solar Panels in the UK and understandably people wonder if this is a con or some form of scam and if the panels really are free.

The answer is that it normally is a genuine offer and the panels are free but you won't benefit from the Feed in Tariff and only get any free electricity you can use.

 

Are Free Solar Panels a Con?

 

There are also other offers where you are offered a loan to pay back, often these ones are not worth doing as they could cost you substantially.

Why does the inverter for my Solar Panels read higher than the generation meter?

Should my generation meter read the same electricity produced as the solar inverter display?

Having had solar panels installed for nearly a month now it has become clear that there is a difference between the readings from the Sunny Boy inverter and the Landis generation meter so why does my Solar PV Inverter read higher than my Generation Meter? Other people have reported the opposite - that their Solar PV Inverter reads lower than the generation meter?

The reason is that the inverter reading is an estimate based on the electricity it produces but is not an accurate reading of the output. In contrast the generation meter is a calibrated piece of equipment that has to meet certain tolerances and is tested to ensure that the meter is within these tolerances before it leaves the factory.

So the reading on the generation meter is the correct one and the inverter output reading is to give you a good idea of how the panels are performing at any given moment in time.

At present our Sunny Boy 3000HF inverter is showing a reading of 96.1kWh produced but the generation meter is showing 98.33kWh which is just over a 2% difference between them.

Solar Panel electricity generation questions and answers

Why does the inverter for my Solar Panels read lower than the generation meter?

Should my generation meter read the same as the solar inverter display?


Having had solar panels installed for nearly a month now it has become clear that there is a difference between the readings from the Sunny Boy inverter and the Landis generation meter so why does my Solar PV Inverter read lower than my Generation Meter? Other people have reported the opposite - that their Solar PV Inverter reads higher than the generation meter?

The reason is that the inverter reading is an estimate based on the electricity it produces but is not an accurate reading of the output. In contrast the generation meter is a calibrated piece of equipment that has to meet certain tolerances and is tested to ensure that the meter is within these tolerances before it leaves the factory.

So the reading on the generation meter is the correct one and the inverter output reading is to give you a good idea of how the panels are performing at any given moment in time.

At present our Sunny Boy 3000HF inverter is showing a reading of 96.1kWh produced but the generation meter is showing 98.33kWh which is just over a 2% difference between them.

Solar Panel electricity generation questions and answers

 

What is the maximum electricity my solar panels will generate?

For our panels which are virtually south facing in South East England the electricity output generated equates to around 7kWh per kWp per day. So for 3kWp of solar panels you would get a maximum of 21kWh of electricity on the best sunny days of the year and for 4kWp of solar panels you would get 28kWh.

A sunny day during winter would only generate a maximum of 7kWh of solar electricity so you can see the difference that the longer days make. Temperature has an impact and less electricity is generated from solar panels on hot days than cooler days.

The difference between the best day in winter and the best day in summer is around 3x. So in winter we would get 7kWh from our solar panels but in summer could get a maximum output of 21kWh.

Do solar panels generate only on sunny days?

No. PV Solar panels will generate on cloudy days and do not just need sun shining on them. However the amount of electricity generated on a cloudy day is a fraction of that generated in the sun. In the winter this can be as low as 5% of the amount for a sunny day. In the summer a cloudy day may generate as much as 10% and even on a day with mixed cloud and sunny spells you can get as much as 50% of the output of a clear sunny day. A day with a mix of sunshine and cloud can generate some of the biggest peaks of output as a result of the solar panels cooling down when the cloud passes over.

What output will my solar panels give?

The output of your solar panels will depend on a number of factors such as the direction they face, the angle of your roof, your location in the country and if they are affected by shading. The output is significantly higher during summer months and can be around 3x higher than the maximum obtained during winter.

What direction should my solar panels face?

In the UK the best output from solar panels will be achieved if they are south facing.

What is the difference in generation between sunny and cloudy days?

The amount of electricity generated on a cloudy day is a fraction of that generated on a sunny day. In the winter this can be as low as 5% of the amount for a sunny day. In the summer a cloudy day may generate as much as 10% and even on a day with mixed cloud and sunny spells you can get as much as 50% of the output of a clear sunny day.

How can I make the most of the electricity generated by my solar panels?

A member of MoneySavingExpert has created circuit diagrams for a device to monitor the output from PV Solar panels and to enable households to use the maximum output from their solar panels. You can view the information on Dave Fowler's website here

Solar Panel electricity generation questions and answers