Perhaps not surprisingly there has been a last minute rush to get systems installed before the 12 December deadline to qualify for the current FIT rates. In our own immediate neighbourhood there are at least another three systems that have gone up, the installers were working on Saturday and Sunday last weekend. A neighbour of ours who had been thinking about installing a system had their system put up on Saturday. I just hope she can get her application in and accepted on time - fingers crossed for her.
Our own system has been doing nicely since the weather got a bit brighter in mid November, we just managed to achieve the predicted yield for November and seem to be doing very well so far in December. Our generation meter has just passed the 600kWh mark. I am regularly updating the information on my daily statistics page so do take a look at them if you are interested in how the system is doing.
I am still unsure how much of the energy generated we manage to use ourselves, we will probably only find out when the next quarters bill turns up and I can compare with last year. It seems likely that we are probably using most of it at the moment as it is only a few hundred watts on the cloudy days and the PC, central heating pump and fridge will probably consume that amount.
Thursday 8 December 2011
Sunday 20 November 2011
Keeping up with neighbours
The house on the left was the first to install panels in late spring and was followed by the neighbour on the right a few weeks later.
They were followed a few weeks later by their neighbour and in the last couple of weeks the next house along has installed an identical looking system, the scaffolding is still to be taken down.
A little further down the road another house had a system installed in the last two weeks.
A bit further down the road and another house had a system installed in the last week.
With the reduction in the feed in tariff rates due in the next three weeks it will be interesting to see how many more appear before the deadline.
Tuesday 15 November 2011
Changes to FIT scheme
There was a rather sudden and unexpected change to the UK FIT scheme announced on 31 October. A review of the scheme was taking place and an announcement on changes of the rates paid was expected. The big shock was both the amount that the rate was to be cut and how soon the cut would be applied. The scheme was expected to apply the new rates from April 2012 but they were applied from the 12 December. The cut was also much larger than had been predicted with the amount paid per unit falling to 21p from the current 43.1p.
This has had the effect of causing a rush to have systems installed in time to claim the current higher rate with most installers quickly having all available slots booked up. What will happen after the 12 December is the big concern, it seems these companies will see their work dry up with inevitable consequences.
One of our friends was caught out by this as she was interested in getting a system installed but had not seen the need to do anything in a rush. All of a sudden there was no time to make a considered decision, should she jump at an offer that might not be ideal or accept that she had missed out. It seems very unsatisfactory for both installers and customers.
This has had the effect of causing a rush to have systems installed in time to claim the current higher rate with most installers quickly having all available slots booked up. What will happen after the 12 December is the big concern, it seems these companies will see their work dry up with inevitable consequences.
One of our friends was caught out by this as she was interested in getting a system installed but had not seen the need to do anything in a rush. All of a sudden there was no time to make a considered decision, should she jump at an offer that might not be ideal or accept that she had missed out. It seems very unsatisfactory for both installers and customers.
Sunday 13 November 2011
How solar power works
It might sound simple enough to turn sunlight into electricity but there is a lot more to a Solar PV system than you might first think. Here is my quick not too technical guide to Solar PV.
Solar panels generate DC electricity something like a battery cell hence them being called solar cells or solar batteries. The panels will typically generate 40-50V each and are wired in series as "strings". An array of 12 to 16 panels will usually be split into two even sized strings which are then connected to an inverter. The inverter takes the DC electricity and converts to AC at the correct line voltage to feed into your house mains supply. The reason for splitting the array into strings is two fold, first it keeps the DC voltage at a suitable level for the inverter to work efficiently with, typically between 200 and 400V. Second there is also the chance that should one panel have a fault you will only lose half of your system, only the string with the faulty cell would cease to work.
In practice the inverter does quite a lot more than just do the DC to AC conversion. Most home Solar PV systems are "on-grid" which means that they are permanently connected to the grid, this is necessary for you to export electricity and earn money for it. For the system to work the inverter has to sense that the grid is up and then synchronise to the voltage and phase of the grid when it generates electricity. If the grid goes away it shuts down and stops generating. Most prospective owners dream that they can be self sufficient in electricity to some degree at least when it is sunny, sadly this is not the case.
I hope this simple description helps to shed some light on how the systems work, there are quite a few good technical articles available which go into the full details of how systems work which you can find with a bit of Googling.
Just a quick update on how our system is doing this month. We are currently well behind the predicted yield due to two weeks of almost unbroken grey cloud. Today was only the second really sunny day of the month, and we managed to generate 9.5kWh. The total for the whole month so far is only 41.6kWh, we are going to need a decent run of sunny days for the rest of the month to get anywhere near the predicted yield.
In the next post I will discuss the changes to the FIT after the 12 December.
Solar panels generate DC electricity something like a battery cell hence them being called solar cells or solar batteries. The panels will typically generate 40-50V each and are wired in series as "strings". An array of 12 to 16 panels will usually be split into two even sized strings which are then connected to an inverter. The inverter takes the DC electricity and converts to AC at the correct line voltage to feed into your house mains supply. The reason for splitting the array into strings is two fold, first it keeps the DC voltage at a suitable level for the inverter to work efficiently with, typically between 200 and 400V. Second there is also the chance that should one panel have a fault you will only lose half of your system, only the string with the faulty cell would cease to work.
In practice the inverter does quite a lot more than just do the DC to AC conversion. Most home Solar PV systems are "on-grid" which means that they are permanently connected to the grid, this is necessary for you to export electricity and earn money for it. For the system to work the inverter has to sense that the grid is up and then synchronise to the voltage and phase of the grid when it generates electricity. If the grid goes away it shuts down and stops generating. Most prospective owners dream that they can be self sufficient in electricity to some degree at least when it is sunny, sadly this is not the case.
I hope this simple description helps to shed some light on how the systems work, there are quite a few good technical articles available which go into the full details of how systems work which you can find with a bit of Googling.
Just a quick update on how our system is doing this month. We are currently well behind the predicted yield due to two weeks of almost unbroken grey cloud. Today was only the second really sunny day of the month, and we managed to generate 9.5kWh. The total for the whole month so far is only 41.6kWh, we are going to need a decent run of sunny days for the rest of the month to get anywhere near the predicted yield.
In the next post I will discuss the changes to the FIT after the 12 December.
Tuesday 8 November 2011
So how much does it earn ?
Probably the most obvious question is how much can you earn from Solar power ?
In the UK the government introduced a feed in tarrif scheme (FIT) for renewable energy generation. When we signed up for the scheme we were guaranteed a payment of 43.1p for every unit (kWh) of electricity we generate. This was paid even if we used all of the electricity ourselves. In addition our electricity supplier will pay us 3p for every unit we export to the grid. As we don't have an export meter they assume that we export 50% of the electricity generated. This means that in practice we will be given 44.6p for every unit we generate. Using this it is quite simple to calculate the revenue from our system. We had the system for the last 10 days in September and it generated 145 units which earned us around £64. In October we generated 307 units which earned us around £137.
The unknown factor is how much of the solar power generated did we use ourselves, this would gives us a direct saving on our electricity bill and so should also be counted in any calculation. We are about to be billed for electricty for the quarter ending at the beginning of November so I have used this meter reading to see how it compares with the same period last year. It showed a drop in electricity use of around 200 units, this would equate to a saving of around £28 assuming a cost of 14p/unit. We can't be sure that all of the saving is due to the use of our own solar power but a significant amount must be. We will get a better idea once we have a couple more quarters of bills to compare.
In the mean-time its just nice to be saving something on our electricity bills and also to be generating some income at the same time.
More about the feed in tarrif scheme as the goverment announced the result of a fast track review of the scheme on October 31. It was not good news for people who were still thinking about installing solar power as the tarrifs were being cut by more than 50%. This certainly changes the equations with regard to return on investment. We are hoping our system will pay pack the capital we invested in around 8 years, possibly a bit sooner if it continues to do as well as it has been. With the new tarrif rates it will take a lot longer, probably between 12 and 15 years. I do wonder how many people will want to plan that far ahead. We had doubts about making a commitment to a system that may not pay back for 8 years.
Enough ramblings for today, I will describe how solar PV systems work in my next post.
In the UK the government introduced a feed in tarrif scheme (FIT) for renewable energy generation. When we signed up for the scheme we were guaranteed a payment of 43.1p for every unit (kWh) of electricity we generate. This was paid even if we used all of the electricity ourselves. In addition our electricity supplier will pay us 3p for every unit we export to the grid. As we don't have an export meter they assume that we export 50% of the electricity generated. This means that in practice we will be given 44.6p for every unit we generate. Using this it is quite simple to calculate the revenue from our system. We had the system for the last 10 days in September and it generated 145 units which earned us around £64. In October we generated 307 units which earned us around £137.
The unknown factor is how much of the solar power generated did we use ourselves, this would gives us a direct saving on our electricity bill and so should also be counted in any calculation. We are about to be billed for electricty for the quarter ending at the beginning of November so I have used this meter reading to see how it compares with the same period last year. It showed a drop in electricity use of around 200 units, this would equate to a saving of around £28 assuming a cost of 14p/unit. We can't be sure that all of the saving is due to the use of our own solar power but a significant amount must be. We will get a better idea once we have a couple more quarters of bills to compare.
In the mean-time its just nice to be saving something on our electricity bills and also to be generating some income at the same time.
More about the feed in tarrif scheme as the goverment announced the result of a fast track review of the scheme on October 31. It was not good news for people who were still thinking about installing solar power as the tarrifs were being cut by more than 50%. This certainly changes the equations with regard to return on investment. We are hoping our system will pay pack the capital we invested in around 8 years, possibly a bit sooner if it continues to do as well as it has been. With the new tarrif rates it will take a lot longer, probably between 12 and 15 years. I do wonder how many people will want to plan that far ahead. We had doubts about making a commitment to a system that may not pay back for 8 years.
Enough ramblings for today, I will describe how solar PV systems work in my next post.
Saturday 5 November 2011
Proof of the pudding
On paper the system looked impressive but our interest was in how much power it would generate in practice. Every location is different so there is no sure way to predict just how well it is going to work. The PVGIS site has a modeller that allows you to get a prediction of what sort of power your system should generate. Comparing the power your system generates against these predictions is a good way to see how well your system is doing.
Our system was installed on the 20 September so we only had 10 days of data for September to look at. The prediction for the whole of September was 338kWh so one third of that would be 112kWh, in fact we managed to generate 145kWh which was a very encouraging start. We have just had our first full month of data for October. The prediction was that we would generate 217kWh, in practice we managed an impressive 307kWh. This was over 40% more than expected. I think that we were lucky in that the weather for the last 10 days of September and the first three weeks of October was unusually sunny, we will have to see how we get on in the coming months. The last week of October was rather cloudy and the first week of November has continued in a similar vein so we may struggle to do as well this month. I will report on how we did in early December.
Our system was installed on the 20 September so we only had 10 days of data for September to look at. The prediction for the whole of September was 338kWh so one third of that would be 112kWh, in fact we managed to generate 145kWh which was a very encouraging start. We have just had our first full month of data for October. The prediction was that we would generate 217kWh, in practice we managed an impressive 307kWh. This was over 40% more than expected. I think that we were lucky in that the weather for the last 10 days of September and the first three weeks of October was unusually sunny, we will have to see how we get on in the coming months. The last week of October was rather cloudy and the first week of November has continued in a similar vein so we may struggle to do as well this month. I will report on how we did in early December.
Thursday 3 November 2011
Our system
We had our system installed on the 20 September by EVO energy. The team from EVO energy arrived at 8am and were up on the roof working before 9am, the scaffolding had gone up a few days earlier. The work was quite noisy but progress was good. Two of the team installed the rails on the roof whilst a third one worked in the garage on the inverter and cabling. An electrician arrived to connect the system into the house mains supply which involved a power cut whilst cables were re-routed. By mid afternoon the panels were on the roof and system was ready to be commissioned. We could finally start generating our own electricity, sadly the sun had just disappeared behind a blanket of cloud so we were only generating a modest 500W, we would have to wait another day to see what the system was capable of.
Our roof faces south east and we have 16 Sanyo HIT-N240SE10 panels with a peak rating of 240W each giving a peak system output of 3.84kW.
As you can see the panels cover most of the roof area. We selected the Sanyo panels as they are some of the most efficient on the market. Each panel is signifcantly smaller than equivalent 240W panels from other manufacturers meaning that we could just fit 16 onto our roof. Had we opted for cheaper panels we could only have managed to fit 12 onto our roof. This would have left us with a system with a peak capacity of around 3kW which was less than we wanted.
Our roof faces south east and we have 16 Sanyo HIT-N240SE10 panels with a peak rating of 240W each giving a peak system output of 3.84kW.
 |
| The inverter and panels waiting to be installed |
 |
| The rails and panels being installed |
 |
| The panels immediately after the system was installed. |
Tuesday 1 November 2011
Useful Resources
Whilst doing research about solar power for our own system I found quite a few good sites for learning about solar power systems and for calculating predicted performance. Here are the most useful ones, all are worth a look -
The EU solar PV calculator - A useful resource for estimating how much energy your own system can be expected to produce.
Solar guide - Lots of useful information and a neat calculator to estimate income.
Solar Power portal - Industry news and resources
Microgeneration Certificate Scheme (MCS) - information about the MCS
Ofgem - Feed in Tarrif information
The energy saving trust - Information about the Feed In Tarrif scheme and other renewal energy information
Suppliers we got quotes from -
EVO energy
The green home company
Manufacturers websites -
Sanyo solar
Kaco
The EU solar PV calculator - A useful resource for estimating how much energy your own system can be expected to produce.
Solar guide - Lots of useful information and a neat calculator to estimate income.
Solar Power portal - Industry news and resources
Microgeneration Certificate Scheme (MCS) - information about the MCS
Ofgem - Feed in Tarrif information
The energy saving trust - Information about the Feed In Tarrif scheme and other renewal energy information
Suppliers we got quotes from -
EVO energy
The green home company
Manufacturers websites -
Sanyo solar
Kaco
Monday 31 October 2011
Taking the plunge
After much research and calculation we finally decided to take the plunge and invest in a solar PV system for our house. With very low interest available on savings and ever rising fuel bills it seemed like the perfect opportunity to invest in something that would both generate income and reduce our electricity bills at the same time.
Having made the decision to invest in solar power we next had the daunting task of deciding who to get to install the system, what size of system to install and which type of panels to select. This was much more complicated than we had imagined as there are so many companies installing solar PV systems and so many options to consider. We decided to spend some time doing research on how the systems worked and who might be reliable suppliers to get a quote from. I would recommend anyone considering installing a system to do similar research before taking the plunge, there are lots of useful resources on the Internet to help you make an informed decision. Take a look at my links section for some of the best sites that I found.
From my own research I found it very difficult to find real figures for how much electricity a system might produce in practice. All installers will supply predicted figures for the amount of electricity that might be generated but there is no way of finding out how realistic these figures are. It would be great to have a network of sites around the country reporting on how their systems were performing so you could see what someone local to you was achieving. As a result I decided to post details of how our system was performing to help others who are considering having a system installed.
I will post details about our system and regular updates about how well it performing soon.
I will post details about our system and regular updates about how well it performing soon.
Subscribe to:
Posts (Atom)